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Context: The evaluation of quadriceps muscle inhibition with the interpolated twitch technique is usually performed by stimulating the femoral nerve (FN). However, there are some problems related to the use of this stimulation site, which may be partially overcome by delivering the stimulation over the motor point (MP). This study sought to compare MP to FN stimulation at different joint angles for the evaluation of quadriceps muscle inhibition, resting peak torque, and discomfort in healthy women. Design: Cross-sectional study. Methods: Sixteen healthy women (age: 28 [4] y; body mass: 60 [5] kg; height: 162 [5] cm) participated in this study. Supramaximal paired stimuli were delivered to the FN and to the rectus femoris MP before and during maximal voluntary contractions at different knee angles (15°, 30°, 45°, 60°, and 90° of knee flexion) to assess muscle inhibition and resting peak torque. Discomfort was also recorded for each stimulation site and knee angle. Results: Muscle inhibition was similar between the 2 stimulation sites (P >.05) and was higher at 45° than at 90° (P =.03). MP stimulation evoked lower resting peak torque at 30° (P =.004), 60° (P =.006), and 90° (P =.006) and higher discomfort at 30° (P =.008) and 90° (P =.027) compared to FN stimulation. Conclusions: Despite lower resting peak torque and higher discomfort at some angles, MP stimulation provided similar muscle inhibition to FN stimulation at all knee angles and is therefore a valid method to evaluate quadriceps muscle inhibition in healthy women. MP stimulation can be used as an alternative to FN stimulation for the evaluation of quadriceps muscle inhibition with no added discomfort at the angles where muscle inhibition is the highest. [ABSTRACT FROM AUTHOR]

Context: The Y-Balance Test Lower Quarter (YBT-LQ) is a widely utilized tool for evaluating dynamic postural control, requiring a combination of mobility and strength. This study aimed to investigate the combined relationship between isometric thigh muscle strength and joint kinematics on YBT-LQ performance. Design: Cross-sectional laboratory study. Methods: Isometric quadriceps and hamstrings strength were measured before the YBT-LQ in 39 healthy participants (27 females and 12 males). The test was performed under 3-dimensional markerless motion capture, where joint kinematics were extracted from the maximum reach position from each direction. Three multivariable linear regression models were then used to determine the strongest combination of predictors for YBT-LQ performance. Results: Greater hamstrings strength and increased knee flexion, ankle dorsiflexion, and trunk ipsilateral-flexion joint angles explained 56.8% (P <.001) of the variance in anterior reach. Hip flexion, knee flexion, and ankle dorsiflexion angles were the strongest predictors for posteromedial reach distance, explaining 73.0% of the variance (P <.001). Last, 43.3% (P <.001) of the variance in posterolateral reach distance was predicted by hamstring strength and knee-flexion angle. Conclusions: These results emphasize the importance of hamstring strength in YBT-LQ performance across different reach directions. Additionally, the kinematics illustrate a potential movement strategy for maximizing reach distance on the YBT-LQ in healthy individuals. Clinicians can utilize this information to guide interventions aimed at improving dynamic postural control, particularly by focusing on increasing hamstring strength and testing for impairments in specific movement patterns. [ABSTRACT FROM AUTHOR]

Context: Poor knee biomechanics contribute to knee joint injuries. Neuromuscular control over knee position is partially derived from the hip. It is unknown whether isolated activation training of the gluteal muscles improves lower-extremity frontal plane mechanics. This study examined if a home-based hip muscle activation program improves performance on the Forward Step-Down Test as well as increases surface electromyography (sEMG) activation of the gluteal muscles. Design: The study utilized a single-group repeated-measures design. Methods: Thirty-five participants (24 females, mean age = 23.17 [SD 1.36] years) completed an 8-week hip muscle activation program. The Forward Step-Down Test score and sEMG of gluteus maximus and medius were assessed preintervention and postintervention. Results: Forward Step-Down Test scores improved significantly from preintervention (Mdn = 3.5) to postintervention (Mdn = 3.0, T = 109, P =.010, r =.31.), but this result did not meet clinical significance. sEMG analysis revealed a significant increase in mean gluteus maximus activation (P =.028, d = 1.19). No significant dose–response relationship existed between compliance and the Forward Step-Down Test scores or sEMG results. Conclusions: A home-based hip activation program increases gluteus maximus activation without clinically significant changes in frontal plane movement quality. Future studies may find clinical relevance by adding motor learning to the activation training program to improve functional muscle use. [ABSTRACT FROM AUTHOR]

Context: The persistence and the recurrence of posterior medial knee pain (PKP) after anterior cruciate ligament reconstruction (ACLR) using hamstring tendon graft are often overlooked during rehabilitation. Design: Cross-sectional observational study. Methods: The study aimed (1) to evaluate the prevalence of these types of PKP before 4 months post-ACLR, (2) to measure their consequences on the knee flexors strength, and (3) to evaluate the role of the type of ACLR. From a cohort of patients operated on with hamstring tendon procedures, the persistent and the recurrent PKP were sought at 4 months post-ACLR. The evolution of isokinetic muscle strength recovery in PKP subjects was compared with those of nonpainful subjects. The functional deficit was measured at 6/7 months post-ACLR by a hop test. Results: Three hundred seventeen subjects (25.8 [6.0] y) were included. At 4 months post-ACLR, 2 populations were identified based on the recurrent onset of PKP (PKP+, n = 40) or the absence of knee pain (PKP−, n = 277). The prevalence of PKP was 8.3%. At the fourth month post-ACLR, the PKP+ group had a higher flexor strength deficit compared with the PKP− group (limb symmetry index at 60°/s: 67.2% [12.4%] vs 84.3% [12.6%]; P <.05). At 6/7 months, the loss of strength persisted (limb symmetry index at 60°/s: 82.3% [13.4%] vs 87.7% [12.8%]; P <.05). The hop test deficit was comparable, and no difference was shown according to the type of graft. Conclusions: Persistent and recurrent PKP during the rehabilitation period were not uncommon and were associated with a worsening of flexors strength loss on the ACLR side. [ABSTRACT FROM AUTHOR]

Individuals with knee osteoarthritis (KOA) and flat feet are more likely to experience increased pain and cartilage damage. This study aimed to investigate the knee kinetics, kinematics, pain, and physical function in individuals with moderate symptomatic KOA, in comparison to asymptomatic control participants. Thirty volunteers with moderate KOA (with flat feet n = 15, with normal feet n = 15) and 30 asymptomatic people (with flat feet n = 15, with normal feet n = 15) were evaluated. The knee adduction angular impulse, knee flexion moment, knee flexion angular impulse, and knee flexion angle were measured during level walking. The pain was assessed in patients with KOA. The study found that individuals with KOA had a significant increase in the knee adduction angular impulse compared with the asymptomatic people (P <.05). The KOA with flat feet group had significantly lower knee flexion moment, knee flexion angular impulse, and knee flexion angle values than the KOA with normal feet group (P <.05). Furthermore, the KOA with flat feet group had a higher pain score than the KOA with normal feet group. Individuals with osteoarthritis and flat feet had lower knee flexion moments which may indicate reduced knee force exerted through compensatory mechanisms. Despite this reduction, they reported significantly higher levels of pain compared with those without flat feet, a finding that warrants further investigation in future studies. [ABSTRACT FROM AUTHOR]

Purpose: To determine between-limbs differences in isometric rate of force development (RFD) measured during open- (OKC) and closed-kinetic-chain (CKC) strength testing and establish which method had the strongest relationship to single-leg vertical-jump performance and knee mechanics after anterior cruciate ligament (ACL) reconstruction. Methods: Subjects (n = 19) 1 to 5 years from ACL reconstruction performed isometric knee extensions (OKC), unilateral isometric midthigh pulls (CKC), and single-leg vertical jumps on the ACL-involved and -noninvolved limbs. Between-limbs differences were assessed using paired t tests, and the relationship between RFD, jump performance, and knee mechanics was assessed using correlation coefficients (r; P ≤.05). Results: There were significant between-limbs differences in OKC RFD (P =.008, d = −0.69) but not CKC RFD. OKC RFD in the ACL-involved limb had a strong association with jump height (r =.64, P =.003), knee-joint power (r =.72, P <.001), and peak knee-flexion angle (r =.72, P =.001). CKC RFD in the ACL-involved limb had a strong association with jump height (r =.65, P =.004) and knee-joint power (r =.67, P =.002) but not peak knee-flexion angle (r =.40, P =.09). Conclusions: While both OKC and CKC RFD were strongly related to jump performance and knee-joint power, OKC RFD was able to detect between-limbs RFD asymmetries and was strongly related to knee-joint kinematics. These findings indicate that isometric knee extension may be optimal for assessing RFD after ACL reconstruction. [ABSTRACT FROM AUTHOR]

Context: The purpose of this study was to compare short-term clinical outcomes between meniscus procedures performed with anterior cruciate ligament reconstruction (ACLR), ACLR (ACLR-only), ACLR with meniscectomy/resection (ACLR-resect), and ACLR with meniscal repair (ACLR-repair) for bone patellar tendon bone grafts (BPTB) and hamstring tendon grafts, separately. Design: This was a cross-sectional study conducted in a controlled laboratory setting as part of a large point-of-care collaborative research program. Methods: This study included 314 participants (168 females; mean [SD]: age, 19.7 [4.8]) with primary unilateral ACLR with a BPTB or hamstring tendon. Patients were divided into 3 groups depending on meniscal procedure (ACLR-only, ACLR-resect, and ACLR-repair). Postsurgical testing included: isokinetic assessment of knee extension and flexion, single-leg hop tests, and patient-reported outcomes. Multivariate analysis of covariance compared differences between meniscal procedures on the battery of tests, and for each statistically significant variable an analysis of covariance assessed the effect of meniscal procedure within each graft type. Chi-square analysis assessed the influence of meniscal procedure on tests' pass rates defined as 90% of limb symmetry index. Results: BPTB: ACLR-only had greater hamstring strength than ACLR-resect (P = .05) and ACLR-repair (P = .005). ACLR-only had the highest proportion of participants to pass the hamstring strength test (P=.02). amstring tendon: ACLR-only (P=.03) and ACLR-resect (P=.003) had higher International Knee Documentation Committee scale scores than ACLR-repair. There was a significant difference in the proportion of participants who scored >90% limb symmetry index on the timed hop test (P = .05). Conclusions: The influence of meniscal repair on clinical outcomes is dependent on the graft choice. Following an ACLR with BPTB and a meniscal procedure, hamstring function should be more closely monitored for optimal short-term recovery. [ABSTRACT FROM AUTHOR]

Purpose: This preregistered trial investigated how 6 weeks of unilateral flywheel leg-curl and hip-extension training impact isokinetic, isometric, and flywheel strength and power outcomes. Methods: The study involved 11 male university athletes (age 22 [2] y; body mass 77.2 [11.3] kg; height 1.74 [0.09] m) with one leg randomly allocated to flywheel training and one leg to control. Unilateral eccentric and isometric knee-flexion torque and flywheel unilateral leg-curl and hip-extension peak power were tested. Training intensity and volume (3–4 sets of 6 + 2 repetitions) were progressively increased. Results: The intervention enhanced hip-extension concentric (P <.01, d = 1.76, large) and eccentric (P <.01, d = 1.33, large) peak power more than the control (significant interaction effect). Similarly, eccentric (P =.023, d = 1.05, moderate) peak power was enhanced for the leg curl. No statistically significant differences between conditions were found for isokinetic eccentric (P =.086, d = 0.77, moderate) and isometric (P =.431, d = 0.36, small) knee-flexor strength or leg-curl concentric peak power (P =.339, d = 0.52, small). Statistical parametric mapping analysis of torque–angle curves also revealed no significant (P >.05) time–limb interaction effect at any joint angle. Conclusion: Unilateral flywheel hamstring training improved knee-flexor eccentric peak power during unilateral flywheel exercise but not flywheel concentric, isokinetic eccentric, or isometric (long-lever) knee-flexor strength. [ABSTRACT FROM AUTHOR]

Context: The long duration and high cost of anterior cruciate ligament reconstruction (ACLR) rehabilitation can pose barriers to completing rehabilitation, the latter stages of which progress to demanding sport-specific exercises critical for a safe return to sport. A staged approach shifting in-person physiotherapy sessions to later months of recovery may ensure patients undergo the sport-specific portion of ACLR rehabilitation. Design/Objective: To compare postoperative outcomes of knee function in patients participating in a staged ACLR physiotherapy program to patients participating in usual care physiotherapy through a randomized controlled trial. Methods: One hundred sixty-two patients were randomized to participate in staged (n = 80) or usual care physiotherapy (n = 82) following ACLR and assessed preoperatively and postoperatively at 2 weeks, 6 weeks, 3 months, and 6 months. The staged group completed the ACLR rehabilitation protocol at home for the first 3 months, followed by usual care in- person sessions. The usual care group completed in-person sessions for their entire rehabilitation. Outcome measures included the Lower Extremity Functional Scale, International Knee Documentation Committee Questionnaire, pain, range of motion, strength, and hop testing. Results: There were no statistically significant between-group differences in measures of knee function at 6 months postoperative. Patients in the usual care group reported significantly higher International Knee Documentation Committee scores at 3 months postoperative (mean difference = 5.8; 95% confidence interval, 1.3 to 10.4; P = .01). Conclusion: A staged approach to ACLR rehabilitation does not appear to impede knee function at 6 months postoperative but may result in worse patient reported outcomes at early follow-ups. [ABSTRACT FROM AUTHOR]

Context: To assess the reliability of a remote 2D markerless motion tracking method (Kinovea) to quantify knee and hip angles during dynamic tasks. Methods: Fourteen healthy adults performed body weight squats and lateral lunges while video recording themselves at home. Knee and hip angles were quantified in the sagittal plane for the squats and in the frontal plane for the lateral lunges. Two students each performed the video analysis procedure twice, 2 weeks apart. Intraclass correlation coefficients were used to calculate the intrarater and interrater reliability for angles at maximum depth. The intrarater and interrater agreement over the joint angle-time signals were quantified using a validation metric; an acceptable agreement threshold was set at a validation metric of 0.803 or higher. Standard error of measurement (SEM) was also calculated. Results: Reliability was good to excellent (intraclass correlation coefficients = .80-.98) for all angle comparisons at maximum depth. The agreement over the entire joint angle-time signal was acceptable for all squat variables except for the interrater hip angle comparison (validation metric = 0.797). None of the lateral lunge variables met the threshold of acceptable agreement. The mean SEM across participants for all joint angle-time signal and for maximum depth was acceptable (<5°) for all measurements (SEM = 1.2°-4.9°). Conclusions: Overall, the reliability, agreement, and SEM quantified in this study support the integration of remote methods to quantify lower-extremity kinematics into research and clinical practice. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the influence of mouth rinsing and ingesting unpleasant salty or bitter solutions on cycling sprint performance and knee extensor force characteristics. Eleven male and one female trained cyclists (age: 34 ± 9 years, maximal oxygen uptake 56.9 ± 3.9 ml·kg−1·min−1) completed a ramp test and familiarization followed by four experimental trials. In each trial, participants completed an all-out 30-s cycling sprint with knee extensor maximal voluntary contractions before and immediately after the sprint. In a randomized, counterbalanced, cross-over order, the four main trials were: a no solution control condition, water, salty (5.8%), or bitter (2 mM quinine) solutions that were mouth rinsed (10 s) and ingested immediately before the cycling sprint. There were no significant differences between conditions in mean power (mean ± SD, no solution: 822 ± 115 W, water: 818 ± 108 W, salt: 832 ± 111 W, bitter: 818 ± 105 W); peak power (no solution: 1,184 ± 205 W, water: 1,177 ± 207 W, salt: 1,195 ± 210 W, bitter: 1,184 ± 209 W); or fatigue index (no solution: 51.5% ± 5.7%, water: 50.8% ± 7.0%, salt: 51.1% ± 5.9%, bitter: 51.2% ± 7.1%) during the sprint. Maximal force and impulse declined postexercise; however, there were no significant differences between conditions in knee extensor force characteristics. The present data do not support the use of unpleasant salty or bitter solutions as an ergogenic aid to improve sprint exercise performance. [ABSTRACT FROM AUTHOR]

Background: Manipulation under anesthesia (MUA) has been recommended for refractory arthrofibrosis after anterior cruciate ligament (ACL) reconstruction. However, the effectiveness of MUA to restore normal kinematics of the arthrofibrotic knee is still unclear. The objective of this study was to evaluate tibiofemoral and patellofemoral kinematics in six degrees-of-freedom (6DOF) in patients with arthrofibrosis before and after MUA. Methods: Computed tomography and dual fluoroscopic imaging system were used to assess in vivo knee kinematics. Ten patients (6 women and 4 men; 32.6 ± 6.5y, 168.4 ± 7.8 cm, 61.8 ± 13.2 kg) were included in this study. The tibiofemoral and patellofemoral kinematics in 6DOF were collected before and one year after MUA. A simple analysis of variance was used to evaluate kinematic data of preoperative arthrofibrotic knee, postoperative arthrofibrotic knee, and the contralateral knee. Results: The patella in the postoperative arthrofibrotic knee shifted significantly more inferiorly compared to the preoperative knee at 45° (P = 0.010), 60° (P = 0.008), and 75° (P = 0.049) of flexion. The patellar flexion in the postoperative arthrofibrotic knee significantly increased at 45° (P = 0.048), 60° (P = 0.037), and 75° (P = 0.006) of flexion compared to the preoperative arthrofibrotic knee. The patellar tilt was significantly decreased at 60° (P = 0.006) and at 75° (P = 0.037) of knee flexion in the postoperative arthrofibrotic knee compared to the contralateral knee. MUA significantly increased tibial internal rotation angle in the arthrofibrotic knee at 45° (P = 0.047), at 60° (P = 0.033), and at 75° (P = 0.021) of knee flexion. Conclusions: MUA could restore normal patellar inferior shift, flexion, and tibial rotation compared to the contralateral side. However, the MUA could not restore normal patellar tilt of the arthrofibrotic knee. This indicated that improvement of patellar tilt should be emphasized in postoperative rehabilitation. Highlights: The abnormal knee kinematics has been thought to be an important factor contributing to the associated joint degeneration in patients with arthrofibrosis after ACL reconstruction. Despite the effectiveness of MUA in the ROM gains for patients with knee arthrofibrosis, the effectiveness of MUA to restore normal knee kinematics in patients with arthrofibrosis after ACL reconstruction is still unclear. The MUA could restore normal patellar inferior shift, flexion, and tibial rotation. The MUA could not restore normal patellar tilt of the arthrofibrotic knee, indicating that improvement of patellar tilt should be emphasized in postoperative rehabilitation. [ABSTRACT FROM AUTHOR]

Objectives: To compare the efficacy of the various wavelengths of low-level light therapy (LLLT) in alleviating knee pain, dysfunction, and stiffness in patients with knee osteoarthritis (KOA), and to compare the effectiveness of LLLT versus sham treatment in reducing knee pain, dysfunction, and stiffness. Methods: PubMed, Web of Science, EMBASE, and Cochrane Library were searched from inception to 12 December 2023. Randomized controlled trials that assessed the effects of different wavelengths of LLLT on alleviating pain of patients with KOA were included. A conventional meta-analysis and network meta-analysis were preformed, and standardized mean differences (SMD) with 95% confidence interval (CI) were calculated. Results: Thirteen studies involving 673 participants with KOA met inclusion criteria. Overall, LLLT was superior to sham LLLT for relieving pain (SMD = 0.96, 95% CI 0.31–1.61) but not for improving function (SMD = 0.21, 95% CI − 0.11 to 0.53) or stiffness (SMD = 0.07, 95% CI − 0.25 to 0.39). Surface under the cumulative ranking curve (SUCRA) value ranking showed the most effective wavelength of LLLT in reducing KOA pain was 904–905 nm (SUCRA, 86.90%), followed by multi-wavelengths (MWL) (SUCRA, 56.43%) and 785–850 nm (SUCRA, 54.97%). Compared to sham LLLT, L2 (SMD = 1.42, 95% CI = 0.31–2.53) and L1 (SMD = 0.82; 95% CI = 0.11–1.50) showed a significant reduction in KOA pain. However, MWL (SMD = 0.83; 95% CI = − 0.06 to 1.72) showed similar KOA pain reduction compared to sham LLLT. The certainty of evidence showed that the quality of evidence regarding the effectiveness of overall LLLT versus sham, and 904–905 nm versus sham were low, while the quality of evidence for MWL versus sham, and 785–850 nm versus sham was very low. Conclusion: While the 904–905 nm wavelength showed potential benefits in reducing KOA pain, the overall quality of the evidence was low. LLLT with 904–905 nm or 785–850 nm wavelengths yielded significantly better reduction in KOA pain compared to sham LLLT, but further high-quality research is warranted to validate these findings. [ABSTRACT FROM AUTHOR]

Background: Isokinetic normative data in females' soccer players is scarce in comparison to males. Furthermore, evaluation protocols employed to obtain those data in female's studies, strongly differ from each other, using different ranges of speeds and movement patterns, thus producing different output data. Thus, it is difficult for the researcher and the clinician to choose a correct protocol for knee isokinetic test in female soccer players. Aim of this paper is to review the literature to provide updated information on how to interpret a knee isokinetic testing in healthy females. Methods: Google Scholar, PubMed, Sport Discus, and Psych info databases were queried, and 17 papers were selected. Following PRISMA methodology and PEDro scale, we classified the retrieved papers and assessed the quality. Results: In this review some common features of isokinetic testing in female soccer players of various levels of qualification are highlighted. The isokinetic performance indexes widely accepted are the hamstring/quadriceps (H/Q) ratio and dominant/non-dominant (D/ND) ratio. It also emerges that, 3 reps at the speed of 60°/sec in knee flexion/extension are preferable due to the higher reliability and that the optimal H/Q ratio in healthy female soccer players of different level of qualification and age is 50%, while the interlimb differences (D/ND) should be below 10%. Conclusions: Normative data and methodologies reviewed can be useful for the isokinetic test of female soccer players. It emerges that simplifying test procedures limiting at few testing speed and considering selected H/Q and D/ND gives all the necessary relevant informations. [ABSTRACT FROM AUTHOR]

Objective This study aimed to investigate the relationship between psychological factors and clinical outcomes of therapeutic exercise after 3 months in individuals undergoing total knee arthroplasty (TKA). Another aim of this study was to evaluate the effect of 3 months of therapeutic exercise on the psychological factors of these patients. Materials & Methods This quasi-experimental study involved 29 patients with an average age of 62.76 years who had undergone TKA for their first knees. These patients performed therapeutic exercises for three months. Pain intensity and range of motion (ROM) of flexion and extension were assessed 3 times: before surgery, at the beginning of physiotherapy and 12 weeks after therapeutic exercises. Patients' functional ability and psychological indicators were evaluated in two phases: Before surgery and at the end of the 12th week. Clinical outcomes, including pain, knee ROM, and functional ability, were assessed using the visual analog scale, goniometer and Oxford knee score, respectively. The depression index was assessed with the Beck depression inventory (BDI) second version, anxiety with the state-trait anxiety index, fear of movement with the tampa scale of kinesiophobia (TSK) questionnaire and pain catastrophizing with the pain catastrophizing scale questionnaire. Results The results showed that two psychological indices, including trait anxiety and pain catastrophizing, had a significant negative correlation with the clinical outcomes of physiotherapy after TKA. The higher the trait anxiety before surgery was, the lower the pain reduction during the activity (r=-0.574, P=0.002) and the lower the improvement in functional abilities (r=-0.402, P=0.038). Also, the higher the index of preoperative pain catastrophizing, the lower the pain reduction during activity (r=-470, P=0.013) and the lower the improvement in functional abilities (r=-0.436, P=0.023). No significant correlation was found between other psychological indicators before surgery and the clinical outcomes of physiotherapy. On the other hand, among the psychological factors, trait anxiety (P=0.01) and fear of movement (P=0.01) were significantly improved after 3-month therapeutic exercise. Conclusion Psychological factors can play an essential role in predicting the clinical outcomes of physiotherapy after TKA. In addition, the improvement of psychological factors after therapeutic exercises may indicate that these psychological problems can be improved by reducing pain and achieving better ROM during treatment, so psychological factors are not considered an obstacle to surgery. [ABSTRACT FROM AUTHOR]

Background: Osteochondral defects (OCDs) in the knee joint have significant clinical implications, particularly regarding contact pressures and pressure distribution. Understanding how these factors are influenced by defect size and location is crucial for developing effective therapeutic strategies. Purpose/Hypothesis: The purpose of this study was to investigate the impact of defect size and location on contact pressures and pressure distribution in the knee joint. It was hypothesized that an increase in defect size would result in elevated contact pressures and alterations in pressure distribution, with specific variations related to defect location. Study Design: Descriptive laboratory study. Methods: The study utilized 6 cadaveric knees, including the patella and fibula, subjected to controlled compressive loading for measuring contact pressures. Simultaneously, computed tomography-based models were created for finite-element analysis (FEA) to investigate the impact of varying defect sizes and locations on contact pressures and pressure distribution in the knee joint, excluding the patellofemoral joint. The study employed analysis of variance to assess contact pressure and defect size association. Comparison between medial and lateral femoral condyles at full extension and 30° flexion angle was performed, followed by post hoc testing. Fisher exact test analyzed peak pressure point location and defect size, categorizing them into medial and lateral. Results: An increase in defect size corresponded with heightened contact pressures on both medial and lateral femoral condyles at full extension (P =.013 for medial and P =.024 for lateral). However, this correlation did not yield significant differences at 30° of flexion (P =.674 for medial and P =.333 for lateral). During mechanical testing, the highest pressures occurred near 5 mm defect dimensions. FEAs showed a significant increase in pressure and circumferential-edge stress with 7-mm defects. Peak contact pressure points shifted laterally with more significant defects. Conclusion: Our study demonstrated the impact of defect size, location, and alignment on knee joint contact pressures. Intervening promptly with defects exceeding 3 mm is crucial, as significant stress levels manifest beyond this threshold. Significant increases in contact pressures were noted with larger defect sizes, particularly between 3 and 10 mm at full extension. Peak pressure points shifted with defect size increments, and alignment variations showed minimal stress variation at 30° compared with 0°. FEA validated increasing contact pressures up to 7 mm defect size, beyond which pressures stabilized or slightly decreased. A concentrated pressure distribution on the medial side was observed. These findings inform our understanding of the biomechanical implications of OCDs. Clinical Relevance: In the field of sports medicine, this research offers valuable insights to clinicians and researchers, elucidating key factors influencing knee joint health and the potential consequences of OCDs. [ABSTRACT FROM AUTHOR]

Background: Surgical treatment of patients with proximal hamstring avulsions provides good results; however, less is known about the outcome in patients who are offered conservative treatment. Purpose: To investigate the effect of surgical or conservative treatment (decided by a shared decision strategy) of proximal hamstring avulsions. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 24 patients with magnetic resonance imaging–verified proximal hamstring avulsion were included and had either surgical treatment (11 patients, 45% women; mean age, 50 ± 16 years) or conservative treatment (13 patients, 46% women; mean age, 50 ± 17 years). At baseline, 6 months and 12 months, all patients answered the Perth Hamstring Assessment Tool (PHAT) (0-100 scale) and Hip Sports Activity Scale (0-8 scale). Patients had their maximal hip extension strength and maximal strength at 30° and 90° of knee flexion measured in newton meters per kilogram using a handheld dynamometer. A minimal important change in PHAT was considered >7 points and a minimal important change in strength was considered >0.15 N·m/kg, respectively. Results: The surgical group had a shorter time from injury to initiation of treatment compared with the conservative group (median: 15 vs 64 days; P =.02). The surgical group had a greater amount of retraction of the tendons compared with the conservative group (3 vs 2 cm; P =.04). From baseline to 12-month follow-up, the surgical and conservative groups improved their mean PHAT scores (35 points [95 CI, 24-45 points] and 20 points [95% CI, 9-31 points], respectively) reaching a median of 79 points (interquartile range [IQR], 66-95 points) in the surgical group and 75 points (IQR, 66-85 points) in the conservative group at the 12-month follow-up. Their Hip Sports Activity Scale levels at 12 months were 3 points (95% CI, 1-4 points) and 1 point (95% CI, 0-3 points) (not significant). Furthermore, the surgical and conservative groups improved their maximal hip extension strength by 0.61 N·m/kg (IQR, 0.42-0.80 N·m/kg) and 0.62 N·m/kg (IQR, 0.13-1.10 N·m/kg), respectively. Their maximal knee flexion strength at 30° improved by 0.52 N·m/kg (IQR, 0.29-0.74 N·m/kg) and 0.32 N·m/kg (IQR, 0.12-0.52 N·m/kg) and their maximal knee flexion strength at 90° improved by 0.28 N·m/kg (IQR, 0.19-0.37 N·m/kg) and 0.22 N·m/kg (IQR, 0.02-0.41 N·m/kg). At the 12-month follow-up, the side-to-side difference in maximal muscle strength was 6% and 7%, respectively, during hip extension and 19% to 25% and 16% to 17%, respectively, during knee flexion. Conclusion: Twelve months after treatment of proximal hamstring avulsion, good clinical outcomes were seen when using a shared decision strategy regardless of whether the strategy led to surgical or conservative treatment. [ABSTRACT FROM AUTHOR]

Background: The current standard for motion capture data collection in baseball biomechanics is marker-based optical motion capture. Recent advancement in markerless motion capture capabilities has greatly improved accessibility to in-game, high-precision motion capture data, but specific values may differ from markered systems, necessitating separate normative values. For future data comparison, reference data are needed. Purpose: To describe common kinematic variables in baseball pitching using an in-game markerless motion capture system. Study Design: Descriptive laboratory study. Methods: Kinematic data were collected in 2 collegiate stadiums in the National Collegiate Athletic Association Division I Southeastern Conference using 8 synchronized 300-Hz KinaTrax cameras placed around the playing field. The in-game biomechanics data of 51 pitchers from 5 different teams during the 2023 season were collected; only pitchers with >3 outings during the season were included. After averaging all available fastballs thrown in the first inning of a game, we analyzed triaxial trunk (rotation, flexion, and lean) and pelvic rotation angles in the global reference frame, as well as shoulder rotation, shoulder horizontal abduction, shoulder abduction, elbow flexion, stride knee flexion, and hip-shoulder separation. Results: A total of 509 fastballs were analyzed. Mean fastball velocity was 40.98 m/s (91.5 mph), with a vertical break of 42.0 ± 10.6 cm (16.5 ± 4.2 inches) and a horizontal break of 28.0 ± 11.1 cm (11.0 ± 4.4 inches). Mean stride length was 1.41 ± 0.08 m. The mean arm slot was 59.4°± 9.3°, and the mean upper arm slot was 72.9°± 9.3° at ball release. Additional normative time-series data are presented for commonly analyzed variables, and discrete metrics are provided at distinct time points in the pitching cycle. Conclusion: These data fill a need for separate norms for in-game, markerless motion capture performance metrics, and biomechanics for collegiate baseball pitchers to be used as reference values for researchers, coaches, and clinicians. Clinical Relevance: Clinicians should use these results as reference values to contextualize injury mechanisms and the injury-performance trade-off. These data will also educate clinicians on what athletes' bodies must do to perform when constructing plans of care and return-to-play timelines. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the relative muscular effort (RME) of the hip and knee extensor and ankle plantarflexor muscle groups during the back squat (BS) and split squat (SS) exercises across four external load conditions. Motion capture and force plate data were collected as participants performed the BS and SS at 0%, 25%, 50%, and 75% of their body-mass. These data were used to calculate net joint moments (NJM) at the hip, knee, and ankle of the front leg during the SS and the matched leg during the BS. A musculoskeletal model, which accounted for force-length-velocity properties of 52 muscles, was used to estimate the maximal possible NJM (NJMmax) of the hip and knee extensor and ankle plantarflexor muscle groups. RME was calculated as the ratio between NJM and NJMmax, and compared across exercises and loads. The results indicated that while hip extensor RME increased across all loads, the increases in hip extensor RME were disproportionately greater during the SS at loads of 50% and 75%. Knee extensor RME increased linearly across loads and did not differ between exercises. These results provide coaches and athletes with detailed information about how to optimise resistance training specificity. [ABSTRACT FROM AUTHOR]

The kick-start technique in competitive swimming generates a force acting on the starting platform owing to gravity, muscle contraction and resulting joint torque. To understand optimal body movement on the starting platform for maximising take-off velocity, it is necessary to investigate the joint torque in relation to the joint's rotation effects. Joint torques were calculated by inverse dynamics using kinetic and kinematic data. A one-way ANOVA showed significantly greater extensional torque for shoulders than for elbows or wrists, and for hips than for knees or ankles. The results indicated that the force of the hands was mainly influenced by extension torque at the shoulder joint. Hip joint extension torque on the front side lower limb (FSLL) was mainly used for supporting the body weight until hands off. After hands off, the front-foot force originated mainly by increases in ankle joint plantar flexion and knee joint extension torque on the FSLL. Rear side lower limb torque increases in the hip, knee and ankle joints provided the rear-foot force. This investigation clarified the magnitudes and functions of each joint torque acting on the extremities during the kick-start, providing practical information for improving starting performance. [ABSTRACT FROM AUTHOR]

Water-polo players frequently perform overhead throws that could result in shoulder imbalances. For overhead throws, execution of the 'eggbeater kick' (cyclical movement of the legs) is required to lift the body out of the water. Although a symmetrical action, inter-limb differences in task execution could lead to knee frontal plane projection (FPPA) differences. The present study examined imbalances shoulder and knee FPPA in female players. Eighteen competitive female field players (24.1 ± 5.5 years, 1.68 ± 0.06 m, 72.9 ± 13.3 kg) had their shoulder strength assessed in a shot-mimicking position with a portable dynamometer, standing and seated (isolating the shoulder contribution). Anterior: posterior and shooting: non-shooting shoulder comparison were made. Additionally, players performed a drop jump. Knee FPPA was recorded from digitising and comparing the frames just before landing and at stance phase. During standing, players exhibited higher shooting: non-shooting asymmetry (p = 0.032) in the anterior contraction direction, while during seated the shooting shoulder anterior: posterior asymmetry was higher (p = 0.032). Interlimb knee FPPA asymmetry was higher in the stance phase (p = 0.02). Despite the overhead throwing and egg-beater demands impacting differently on each limb, considerable asymmetries do not develop, suggesting the overall training requirements (e.g. swimming, resistance training) were sufficient to maintain the asymmetry within desirable limits. [ABSTRACT FROM AUTHOR]

Background: Children with developmental coordination disorder (DCD) exhibit reduced interlimb coordination compared to typically developing children (TDC) during complex tasks like running, which requires dynamic postural control. However, the extent of interlimb coordination difficulties in DCD during tasks that demand minimal dynamic balance, such as self-paced and externally auditory-paced tasks, remains unclear. This study aimed to compare interlimb coordination and auditory–motor synchronization between children with DCD and TDC during a seated antiphase coordination task of the lower limbs, which has minimal postural control requirements. Methods: Twenty-one children with DCD and 22 TDC performed an antiphase knee flexion and extension task while seated, in three conditions (baseline silence, metronome discrete, and metronome continuous), for three minutes. The interlimb coordination, synchronization, and spatiotemporal movement parameters were analyzed using a mixed model analysis; Results: Children with DCD displayed less coordinated interlimb movements compared to TDC (p = 0.0140), which was the result of the greater variability in coordinating antiphase knee flexion–extension movements (p < 0.0001). No group differences in spatiotemporal movement parameters were observed. Children with DCD, compared to TDC, had a lower synchronization consistency to metronomes (p = 0.0155). Discrete metronomes enhanced interlimb coordination compared to the baseline silence condition (p = 0.0046); Conclusions: The study highlights an inferior interlimb coordination and auditory–motor synchronization in children with DCD compared to TDC. Implementing metronomes with a discrete temporal structure improved the interlimb coordination of both groups during the used fundamental seated interlimb coordination task, supporting theorical frameworks of event-based timing. [ABSTRACT FROM AUTHOR]

Background: Musculoskeletal issues at work have an influence on daily life, productivity, and quality of life. Musculoskeletal issues that go untreated can result in severe damage and function loss, which can limit participation, cause financial loss, and add to the rising burden of illness in the world. Objective: The purpose of this study was to find the effect of occupational therapy rehabilitation program in occupational therapy students with work related musculoskeletal disorder. Study Design: Quasi-experimental, pilot study design was chosen for the research Methods: The study employed a quasi-experimental study design. Thirty occupational therapy students aged 20-25 years were recruited through convenience sampling after a prevalence check where 30 students reported 54 musculoskeletal problems. A total number of participants (n= 30) received occupational therapy rehabilitation program. Standardised Nordic musculoskeletal questionnaire (SNMQ) and Numeric pain rating scale (NPRS) were administered to Pain and work related musculoskeletal disorder for all the participants. Result: It revealed that there was a statistically significant difference in pre-test and post-test with numeric pain rating scale (t=10.625, p=0.000). There was a significant difference in percentage in 7 days component of SNMQ. There was no statistical difference with post-test of score of 12 months component of SNMQ. Conclusion: Occupational therapy rehabilitation program is effective for reducing Musculoskeletal disorder or discomfort in occupational therapy students. [ABSTRACT FROM AUTHOR]

We systematically reviewed and synthesized the evidence for the relationship between hip strength and hip and knee biomechanics during single-leg tasks in uninjured and injured populations. We searched CINAHL, EMBASE, PubMed, SportDiscus, and Web of Science from inception to July 2024. We included cross-sectional studies with uninjured and/or injured participants that reported correlations between hip strength and hip or knee kinematics during a single-leg task. We identified 41 articles that reported the correlations between hip strength and hip or knee kinematics during a single–leg task for uninjured (n = 33) and/or injured (n = 12) populations. We identified moderate–to-strong evidence for no-to-poor relationships between most hip strength and hip and knee kinematics during a single-leg task for uninjured (r = –0.33–0.45) and injured populations (r = –0.24–0.24). We observed limited-to-moderate evidence for fair-to-moderate negative relationships between concentric and eccentric hip abduction strength and hip adduction (r = –0.52) and knee abduction kinematics (r = –0.45–0.59) for uninjured populations. Isometric hip strength may not play as important of a role in controlling lower extremity motion during single-leg tasks as previously perceived, but isokinetic strength may be a better indicator of lower extremity motion during single-leg tasks. Trial Registration:PROSPERO#CRD42020153166. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate the factors affecting patient-reported outcomes after bicruciate-stabilized total knee arthroplasty (BCS TKA) in patients. Methods: We retrospectively examined 122 knees with primary varus knee osteoarthritis that underwent BCS TKA. This study analyzed preoperative, intraoperative, and postoperative predictors of patient satisfaction and persistent postsurgical pain following BCS TKA at 1 year after surgery. We evaluated persistent postsurgical pain using Knee Injury and Osteoarthritis Outcome Score (KOOS) pain subscale and patient satisfaction using a visual analog scale. Results: The univariate analysis showed a significant negative correlation between the KOOS pain subscale and three factors: the preoperative central sensitization inventory (CSI) score, medial joint laxity at 90° flexion, and acute postsurgical pain. Patient satisfaction was significantly positively correlated with lateral joint laxity at 90° flexion and postoperative extension angle. Acute postsurgical pain had a significant negative correlation with patient satisfaction. The multiple regression analysis revealed preoperative CSI score and medial joint laxity at 90° flexion influenced patients' KOOS pain subscale responses. Only lateral joint laxity at 90° flexion had an impact on patient satisfaction. Conclusions: The acquisition of adequate soft tissue balance according to the concept of BCS TKA and preoperative central sensitization syndrome affects the clinical outcomes in BCS TKA. [ABSTRACT FROM AUTHOR]

Introduction: Total knee arthroplasty (TKA) is accompanied by severe postoperative pain, which is reported to be an important cause of chronic pain. Ultrasound-guided adductor canal block (ACB) combined with infiltration between the popliteal artery and posterior capsular of the knee (IPACK) has been proven to have a better effect on relieving acute pain after TKA. However, whether it has a significant effect on the incidence of chronic pain after TKA has not been reported. This trial was designed to investigate the effect of ultrasound-guided ACB combined with IPACK on the incidence and intensity of chronic pain after TKA. Methods: In this prospective, randomized, double-blind, placebo-controlled study, 100 subjects scheduled for TKA were randomly (1:1) divided into two groups: the ropivacaine group and the placebo group. Patients in each group received ultrasound-guided ACB + IPACK procedures with 0.25% ropivacaine or equal volume normal saline. All patients received multimodal analgesia. Pain intensity was assessed using the Numerical Rating Scale (NRS). The primary outcome was the incidence of chronic pain at 3 months after TKA by telephone follow-up. In addition, pain intensity in early resting and mobilized states, chronic pain intensity, the time to first rescue analgesia; opioid consumption; CRP and IL-6 after the operation; length of postoperative hospital stay; and cost of hospitalization and postoperative complications; as well as the function of the knee in the early stage after the operation, were recorded. Results: Ninety-one participants were included in the final analysis. At 3 months, the incidence of chronic pain was 30.4% in the ropivacaine group, significantly lower than 51.1% in the placebo group. Compared with the placebo group, the ACB + IPACK with ropivacaine group had significantly lower pain scores at 4 hours, 8 hours, 16 hours, and 24 hours after the operation; increased the knee range of motion at 8 hours and 24 hours after the operation; and a significantly decreased incidence of chronic pain at 3 months after the operation. During the follow-up period, there were no nerve block-related complications in either group. Conclusion: In the context of multimodal analgesia protocols, ACB combined with IPACK before surgery decreases the incidence and intensity of chronic pain 3 months after TKA compared with placebo injection. In addition, it reduces the NRS scores, whether at rest or during mobilization, and improves knee function within 24 hours after TKA. Trial registration: This trial was registered in the China Clinical Trial Center (registration number ChiCTR2200065300) on November 1, 2022. [ABSTRACT FROM AUTHOR]

Background: Chondrocyte viability is associated with the clinical success of osteochondral allograft (OCA) transplantation. Purpose: To investigate the effect of distal femoral OCA plug harvest and recipient site preparation on regional cell viability using traditional handheld saline irrigation versus saline submersion. Study Design: Controlled laboratory study. Methods: For each of 13 femoral hemicondyles, 4 cartilage samples were harvested: (1) 5-mm control cartilage, (2) 15-mm OCA donor plug harvested with a powered coring reamer and concurrent handheld saline irrigation ("traditional"), (3) 15-mm OCA donor plug harvested while submerged under normal saline ("submerged"), and (4) 5-mm cartilage from the peripheral rim of a recipient socket created with a 15-mm cannulated counterbore reamer to a total depth of 7 mm with concurrent handheld saline irrigation ("recipient"). The 15 mm–diameter plugs were divided into the central 5 mm and the peripheral 5 mm (2 edges) for comparisons. Samples were stained using calcein and ethidium, and live/dead cell percentages were calculated and compared across groups. Results: Compared with the submerged group, the traditional group had significantly lower percentages of live cells across the whole plug (71.54% ± 4.82% vs 61.42% ± 4.98%, respectively; P =.003), at the center of the plug (72.76% ± 5.87% vs 62.30% ± 6.11%, respectively; P =.005), and at the periphery of the plug (70.93% ± 4.51% vs 60.91% ± 4.75%, respectively; P =.003). The traditional group had significantly fewer live cells in all plug regions compared with the control group (77.51% ± 9.23%; P <.0001). There were no significant differences in cell viability between the control and submerged groups (whole: P =.590; center: P =.713; periphery: P =.799). There were no differences between the central and peripheral 5-mm plug regions for the traditional (62.30% ± 6.11% vs 60.91% ± 4.75%, respectively; P =.108) and submerged (72.76% ± 5.87% vs 70.93% ± 4.51%, respectively; P =.061) groups. The recipient group (61.10% ± 5.02%) had significantly lower cell viability compared with the control group (P <.0001) and the periphery of the submerged group (P =.009) but was equivalent to the periphery of the traditional group (P =.990). Conclusion: There was a significant amount of chondrocyte death induced by OCA donor plug harvesting using a powered coring reamer with traditional handheld saline irrigation, which was mitigated by harvesting the plug while the allograft was submerged under saline. Clinical Relevance: Mitigating this thermally induced damage by harvesting the OCA plug while the allograft was submerged in saline maintained chondrocyte viability throughout the plug and may help to improve the integration and survival of OCAs. [ABSTRACT FROM AUTHOR]

Background: Data are lacking as to when a meniscal allograft transplant (MAT) may be biomechanically superior to a partially resected lateral meniscus. Hypothesis: Lateral MAT using a bone bridge technique would restore load distribution and contact pressures in the tibiofemoral joint to levels superior to those of a partial lateral meniscectomy. Study Design: Controlled laboratory study. Methods: Eleven fresh-frozen human cadaveric knees were evaluated in 5 lateral meniscal testing conditions (native, one-third posterior horn meniscectomy, two-thirds posterior horn meniscectomy, total meniscectomy, MAT) at 3 flexion angles (0°, 30°, and 60°) under a 1600-N axial load. Pressure sensors were used to acquire contact pressure, contact area, and peak contact pressure within the tibiofemoral joint. Results: Limited (one-third and two-thirds) partial lateral posterior horn meniscectomy showed no significant increase in mean and peak contact pressures as well as no significant decrease in contact area compared with the intact state. Total meniscectomy significantly increased mean contact pressure at 0° and 30° (P =.008 and P <.001, respectively), increased peak contact pressure at 30° (P =.04), and decreased mean contact area in all flexion angles compared with the native condition (P <.01). Lateral MAT significantly improved mean contact pressure compared with total meniscectomy at 0° and 30° (P =.002 and P =.003, respectively) and increased contact area at 30° and 60° (P =.003 and P =.009, respectively), although contact area was still significantly smaller (24.1%) after MAT relative to the native meniscus (P = 0.015). However, allograft transplant did not result in better tibiofemoral contact biomechanics compared with limited partial meniscectomy (P >.05). Conclusion: The peripheral portion of the lateral meniscus provided the most important contribution to the distribution of contact pressure across the tibiofemoral joint in the cadaveric model. Total meniscectomy significantly increased mean and peak contact pressure in the cadaveric model and decreased contact area. Lateral MAT restored contact biomechanics close to normal but was not superior to the partially meniscectomized status. Clinical Relevance: Surgeons should attempt to preserve a peripheral rim of the posterior lateral meniscus. Meniscal allograft transplant appears to improve but not normalize mean contact pressure and contact area relative to total lateral meniscectomy. [ABSTRACT FROM AUTHOR]

This study was aimed to compare the knee kinematic parameters between dominant and non-dominant legs of adolescent female athletes during change of direction (CoD) in fatigued and unpredictable settings. Knee kinematic parameters on 49 athletes (mean± SD; age = 14.69 ± 0.14 years; mass = 49.05 ± 1.22 kg; height = 1.61 ± 0.08 m) during CoD before and after performing the Bruce protocol and also in predictable and unpredictable setting situations were collected. Kinematic data were recorded at a sampling rate of 200 Hz. The results showed that the dominant leg had significantly 18.7% more flexion (p = 0.001, η = 0.95), 7.1% less valgus (p = 0.001, η = 0.95) and 0.32% lower tibia rotation (p = 0.003, η = 0.16) compared to the non-dominant leg in predictable and pre-fatigue (p < 0.05) conditions. With unpredictable and post-fatigue conditions the dominant limb again demonstrated 17.4% (p = 0.001, η = 0.67), greater knee flexion, 6.8% (0.003,η = 0.97) lower knee valgus and 1.4% (p = 0.001, η = 0.71) less tibiarotation. In conclusion, there may be an increased risk of injury withthe non-dominant leg due to changes in kinematic parameters caused by fatigue and unpredictable CoD manoeuvres. [ABSTRACT FROM AUTHOR]

Background: Changes in the trunk and lower limbs' sagittal movements may cause patellofemoral pain (PFP) because they influence the forces acting on this joint. Objectives: To compare trunk and lower limb sagittal kinematics between women with and without PFP during functional tests and to verify whether sagittal trunk kinematics are correlated with those of the knees and ankles. Methods: A total of 30 women with PFP and 30 asymptomatic women performed single-leg squat (SLS) and step-down (SD) tests and were filmed by a camera in the sagittal plane. The trunk inclination angle, forward knee displacement, and ankle angle were calculated. Results: The PFP group exhibited less trunk flexion (SLS, p =.006; SD, p =.016) and greater forward knee displacement (SLS, p =.001; SD, p =.004) than the asymptomatic group; there was no significant difference in ankle angle (SLS, p =.074; SD, p =.278). Correlation analysis revealed that decreased trunk flexion was associated with increased forward knee displacement (SLS, r = −0.439, p =.000; SD, r = −0.365, p =.004) and ankle dorsiflexion (SLS, r = −0.339, p =.008; SD, r = −0.356, p =.005). Conclusion: Women with PFP present kinematic alterations of the trunk and knee in the sagittal plane during unipodal activities. Furthermore, the trunk and lower limb sagittal movements were interdependent. [ABSTRACT FROM AUTHOR]

BACKGROUND: A potential relationship may exist between the vastus medialis (VM) and the contractile efficiency of the vastus intermedius (VI) due to their anatomical connection and common innervation by the same branches of the femoral nerve. However, this relationship has not been explored using physiological experiments. OBJECTIVE: This study aimed to use electromyography (EMG) to investigate the functional significance of the VI and VM muscles during isometric contraction. METHODS: Twenty-six healthy male volunteers underwent EMG recordings from the VI, VM, and vastus lateralis (VL) at 90∘ or 30∘ of knee flexion. The EMG pre-motor time (PMT) was measured during rapid knee extension in response to an auditory stimulus. Additionally, the M-wave latency was determined by femoral nerve stimulation and subtracted from the PMT to calculate the descending conduction time (DCT). RESULTS: DCT was shortest at VM, followed by VL and VI. The DCT difference of VI-VM was significantly greater than that of VI-VL during maximal effort at 90∘ of knee flexion. CONCLUSIONS: VM is neurally driven to act as a pre-activator that primes the VI muscle; this tendency is particularly pronounced when explosive high-moment knee extension is required. [ABSTRACT FROM AUTHOR]

Elective surgeries were postponed during the COVID-19 pandemic to alleviate healthcare strains, affecting majority of elective orthopaedic surgeries such as total knee arthroplasties (TKAs). The aim of this study is to evaluate the impact on knee function and quality of life of patients who had their planned TKA postponed due to the pandemic. This is a retrospective analysis of data collected in a tertiary hospital. Patients included were diagnosed with primary knee osteoarthritis and they were initially scheduled for primary TKA between January to April 2020 but surgery was postponed by at least 6 months from the initial operative date. 160 patients were included in this study (53 males and 107 females, mean age 68.0 ± 8.1). Patients were assessed prior to initial surgery date and assessed again, prior to the postponed surgery date. Clinical scores included Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee scores (OKS) and Short-Form 36 Physical and Mental Component Scores. (SF36 PCS and MCS). Paired T-test was performed for parametric data whereas Wilcoxon signed-rank analysis was performed for non-parametric data. Comparing initial preoperative versus postponement preoperative scores, the cohort had significantly poorer KSKS (38.4 ± 15.4 and 36.5 ± 15.4, p = 0.034), SF36 PCS (34.3 ± 9.2 and 32.7 ± 8.6, p = 0.02) and OKS (34.9 ± 0.77 and 35.8 ± 8.6, p = 0.02) scores respectively. The postponement of elective TKAs has resulted in a significant deterioration of knee scores and physical quality of live scores of patients in a short span of 6 months. Further studies can evaluate if there are repercussions on long term TKAs outcomes. Retrospective study, Level III. [ABSTRACT FROM AUTHOR]

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To investigate the effect of dual-task training on balance and knee proprioception in both weight-bearing and non-weight-bearing conditions in older adults with significant imbalance and high risk of falling. This pre-posttest experimental design included 83 older adults (43 males, 40 females), selected based on age criteria (65–75 years) and specific inclusion and exclusion criteria. Participants underwent dual-task training consisting of 30-minute sessions, three times per week, for four weeks (totaling 12-sessions). Measures included Berg Balance Scale and knee proprioception deficit before and after dual-task training. The study showed statistically significant effect of dual-task training on balance (p < 0.001) and knee proprioception in both weight-bearing (p < 0.001) and non-weight-bearing (p < 0.001) in older adults. Pre-and post-measurements of independent variables between male and female older adults showed no significant difference. Dual-task training improves balance and knee proprioception in both weight-bearing and non-weight-bearing conditions in older individuals, thereby enhancing stability and reducing the risk of falls. [ABSTRACT FROM AUTHOR]

Context: Contralateral training in the early stages after surgery can improve the balance of the reconstructed knee, which is impaired following anterior cruciate ligament reconstruction (ACLR). However, little is known about the neuromuscular cross exercise after ACLR. Objective: To investigate the effects of an 8-week cross exercise on balance and function of the reconstructed knee following ACLR. Design: A single-blind randomized clinical trial. Participants: Thirty athletic males who underwent ACLR were randomly divided into intervention (n = 15) and control groups (n = 15). Intervention: The intervention and control groups received a routine physiotherapy program. In addition, the intervention group performed neuromuscular exercises on the nonoperated limb. Outcome Measures: Before and 9 weeks after ACLR, dynamic and static balance, function, and pain in the reconstructed knee were measured by Star Excursion Balance Test (SEBT), stork balance stand test, balance error scoring system (BESS), Lysholm questionnaire, and visual analog scale. Data were analyzed by SPSS using 2-independent sample t test, paired t test, and analysis of covariance. Results: Between-group comparison showed that, contralateral knee neuromuscular exercises significantly increased in the reaching distance in SEBT in the anterior (P <.001), posterior (P <.001), posteromedial (P =.010), and posterolateral directions (P =.007), decreased the number of errors in 4 stance positions of BESS including single stance on the firm (P ≤.001) and foam surface (P ≤.001), and tandem stance on the firm (P =.028) and foam surface (P ≤.001). It also increased the time of standing of the stork stand test (P =.044) and decreased the pain intensity (P =.014). Conclusion: Neuromuscular exercise of the nonsurgical knee could improve the dynamic and static balance, and pain in the early stages following ACLR in the surgical leg. These findings may be potentially valuable for current rehabilitation protocols. [ABSTRACT FROM AUTHOR]

Context: Among numerous knee-related patient-reported outcome measures, the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) has been used across a wide variety of knee pathologies. However, traditional validation procedures (classical test theory) and existing studies (estimating item parameters) have limitations in establishing the measurement properties of the IKDC-SKF. Rasch analysis reveals a strong validation approach to improve IKDC-SKF clinical interpretation with larger samples. Objective: To assess psychometric properties, including differential item functioning, of the IKDC-SKF as a patient-reported measure of knee function. Design: Cross-sectional study. Setting: Secondary data. Data were extracted from the cloud-based orthopedic and sports medicine global registry Surgical Outcome System (Arthrex). Patients: A total of 1725 individuals who underwent an arthroscopic knee procedure and completed all items on the IKDC-SKF. Main Outcome Measure(s): Rasch analysis including model-data fit, rating scale's function, item-person map (distribution of item difficulty and person ability), and differential item functioning (sex and age groups) was used to evaluate the psychometric properties of the IKDC-SKF. Results: Ten misfit items were found and removed. The 5-point Likert scale of the 9-item IKDC-SKF worked well. Item difficulty ranged from 0.58 to 0.81 logits, and person's knee function had ranged from –5.56 to 4.86 logits, with a wide distribution. The IKDC-SKF was found to function similarly for sex (male vs female) and age. Conclusions: Rasch analysis identified a unidimensional structure retaining 9 of the original IKDC-SKF items; however, a more comprehensive inventory is necessary to assess a wider range of knee function and improve measurement validity. [ABSTRACT FROM AUTHOR]

Background: Increased Posterior Tibial Slope (PTS) angle has been reported to be a risk factor for primary anterior cruciate ligament (ACL) tears. However, it is unknown whether increased PTS has an associated increased risk for non-contact versus contact ACL injury. Purpose: The purpose of this study is to determine whether patients with non-contact ACL injury have a higher PTS angle than those with contact ACL injury. Methods: A total of 1700 patients who underwent primary ACL reconstruction between January 2011 and June 2023 at a single academic institution were initially included. Electronic medical records were reviewed for demographic information as well as evidence that the patient sustained a contact or non-contact ACL injury. Patients in the contact cohort were propensity score matched to patients in the non-contact cohort by age, sex and BMI. Additionally, patients in the contact cohort were then propensity score matched to a control group of patients with intact ACLs also by age, sex and BMI. Results: One hundred and two patients with contact injury were initially identified and 1598 patients with non-contact injuries were identified. Of the 102, 67 had knee X-rays that were suitable for measurement. These 67 contact injury patients were propensity score matched to 67 noncontact patient and 67 patients with intact ACLs based on age, sex and BMI. There were no significant differences between contact and non-contact cohorts in age (28.7±6.3 vs. 27.1±6.5, p = 0.147), sex (Female: 36.0% vs. 34.3%, p = 0.858), or BMI (26.7±5.6 vs 26.1±3.4, p = 0.475). There was no significant difference in PTS angle between contact versus non-contact ACL injury patients (11.6±3.0 vs.11.6±2.8, p = 0.894). There was a significant difference in PTS between the contact ACL injury and the intact cohort (11.6±3.0 vs. 10.0±3.9, p = 0.010) and the non-contact ACL injury and the intact cohort (11.6±2.8 vs. 10.0±3.9, p = 0.010). Conclusion: There was no significant difference in the degree of PTS between patients who sustained contact versus non-contact ACL injuries. Additionally, there was a significantly increased PTS in both the contact and non-contact ACL injury cohorts compared to patients with intact ACLs. [ABSTRACT FROM AUTHOR]

Individuals with neuromuscular pathologies are often prescribed an ankle-foot orthosis (AFO) to improve their gait mechanics by decreasing pathological movements of the ankle and lower limb. AFOs can resist or assist excessive or absent muscular forces that lead to tripping, instability, and slow inefficient gait. However, selecting the appropriate AFO with mechanical characteristics, which limit pathological ankle motion in certain phases of the gait cycle while facilitating effective ankle movement during other phases, requires careful clinical decision-making. The aim of this study is to propose an explicit methodology for the adjustment of multi-function articulated AFOs in clinical settings. A secondary aim is to outline the evidence supporting this methodology and to identify gaps in the literature as potential areas for future research. An emerging class of AFO, the multi-function articulated AFO, offers features that permit more comprehensive, iterative, and reversible adjustments of AFO ankle alignment and resistance to ankle motion. However, no standard method exists for the application and optimization of these therapeutic devices in the clinical setting. Here we propose an evidence-guided methodology applicable to the adjustment of multi-function articulated AFOs in the clinical setting. Characteristic load-deflection curves are given to illustrate the idealized yet complex resistance-angle behavior of multi-function articulated AFOs. Research is cited to demonstrate how these mechanical characteristics can help mitigate specific pathologic ankle and knee kinematics and kinetics. Evidence is presented to support the effects of systematic adjustment of high resistance, alignable, articulated AFOs to address many typical pathomechanical patterns observed in individuals with neuromuscular disorders. The published evidence supporting most decision points of the algorithm is presented with identified gaps in the evidence. In addition, two hypothetical case examples are given to illustrate the application of the method in optimizing multi-function articulated AFOs for treating specific gait pathomechanics. This method is proposed as an evidence-guided systematic approach for the adjustment of multi-function articulated AFOs. It utilizes observed gait deviations mapped to specific changes in AFO alignment and resistance settings as a clinical tool in orthotic treatment for individuals with complex neuromuscular gait disorders. [ABSTRACT FROM AUTHOR]

Patellar tendinopathy is more prevalent in males versus female athletes and commonly presents in the medial region of the tendon. Separate measures of patellar tendon strain in the medial, central, and lateral regions of the tendon, however, have not been quantified. The purpose was to investigate the differences in tendon strain between the medial, lateral, and central regions of the patellar tendon in healthy men and women. Strain in the medial and lateral regions of the patellar tendon in healthy participants (10 males, 10 females) was evaluated using ultrasound during isometric quadriceps contractions at 20%, 40%, 60%, 80%, and 100% of maximum voluntary contraction (MVIC) in 60° and 90° of knee flexion. Central strain was also measured at 60% MVIC in 90° of knee flexion. Mixed models were used to determine strain between tendon regions and sex at 60% MVIC in 90° of knee flexion. Sequential modeling was used to fit region, sex, %MVIC, and angle to predict strain. The central region had less strain compared with both medial and lateral regions. The lateral region had higher strain compared with the medial region regardless of sex. Females had higher strain compared with males, regardless of region. Knee position did not influence tendon strain. Patellar tendon strain differs by region and sex. The varying prevalence between sex and in location of patellar tendinopathy may in part be explained by the unbalanced strains. Differential assessment of regional patellar tendon strain may be of importance for understanding injury risk and recovery with exercise. [ABSTRACT FROM AUTHOR]

Background: In elderly tibial plateau fractures (TPFs), the lateral condyles are involved frequently. This study aimed to compare the outcomes of open reduction and internal fixation (ORIF) and double reverse traction repositor (DRTR) assisted closed reduction and internal fixation (CRIF) in elderly patients with lateral TPFs. Methods: From January 2015 to July 2020, we retrospectively reviewed 68 patients treated surgically at our trauma center for lateral TPFs (Schatzker type I-III). 31 patients were eventually assigned to the DRTR assisted CRIF group, whereas 37 patients were assigned to the ORIF group. The primary outcomes included surgical details, radiological assessment, follow-up knee function, and complications. Results: The DRTR assisted CRIF group experienced a 43.6 mL decrease in intraoperative blood loss (161.3 ml vs 204.9 ml, p = 0.033), and the operation duration was 32.1 min shorter than the ORIF group (83.8 min vs 115.9 min, p < 0.001). There was no statistically significant difference in terms of widening of the tibia plateau (WTP), depth of articular depression (DAD), medial proximal tibial angle (MPTA) and posterior tibial slope angle (PTSA) immediately after surgery and at the last follow-up. No differences in malreduction (p = 0.566) or reduction loss (p = 0.623) were observed between the groups, and Lysholm and HSS scores were similar between the two groups (83.6 ± 15.8 vs 83.4 ± 5.1, p = 0.934; 89.3 ± 7.8 vs 86.9 ± 6.2, p = 0.172; respectively). However, ORIF was associated with a greater increase in postoperative complications than DRTR assisted CRIF (3.2% vs 27%, p = 0.008). Conclusion: Both types of internal fixation provide good radiological outcomes and knee function in the treatment of lateral TPFs in the elderly. However, DRTR assisted CRIF has the advantage of a shorter duration of surgery, less blood loss, and fewer postoperative complications, and appears to be a better treatment option for elderly patients with lateral TPFs. [ABSTRACT FROM AUTHOR]

Objective Total knee replacement (TKR) is a common solution for patients with advanced knee osteoarthritis (OA). Still, fall rates remain relatively high after surgery. TKR may alter pain and knee function, balance control, and proprioception. However, given the role of complex (dual-task) walking in fall prediction for older adults, it is unknown how TKR alters the attentional demand of walking in older adults. The goal of this study was to examine the effect of TKR on dual-task walking among older adults. Methods Participants were evaluated 1 month before surgery and 4.5 months after surgery. Participants walked along an instrumented 7-meter path for 1 minute with and without a cognitive task (serial-3 subtraction). Pain and knee function, knee proprioception, dynamic balance, and balance confidence, as well as dual-task costs (DTC) were compared before and after the surgery and factors associated with change in gait DTCs were assessed. Results Thirty-eight participants completed the study (age 72.6 years, SD = 4.9; 11 men). A significant decrease in pain was found following TKR, with no change in balance, balance confidence, or proprioception. There were no differences in gait DTCs before and after the surgery. However, change in dynamic balance, specifically reactive postural control and dynamic gait, predicted changes in gait speed and stride time DTCs. Conclusion The absence of an effect of TKR on gait DTCs can potentially underlie increased fall risk after TKR. Results from this study emphasize the significance of balance as a measure and focal point for rehabilitation after TKR. Impact This study contributes to our understanding of the attentional cost of walking in people before and after TKR, as well as to factors associated with it. Results from this work can assist formulation of rehabilitation programs for people with knee OA. [ABSTRACT FROM AUTHOR]

This study investigated the effects of plyometric training on lower‐limb muscle strength and knee biomechanical characteristics during the landing phase. Twenty‐four male subjects were recruited for this study with a randomised controlled design. They were randomly divided into a plyometric training group and a traditional training group and underwent training for 16 weeks. Each subject was evaluated every 8 weeks for knee and hip isokinetic muscle strength as well as knee kinematics and kinetics during landing. The results indicated significant group and time interaction effects for knee extension strength (F = 74.942 and p = 0.001), hip extension strength (F = 99.763 and p = 0.000) and hip flexion strength (F = 182.922 and p = 0.000). For landing kinematics, there were significant group main effects for knee flexion angle range (F = 4.429 and p = 0.047), significant time main effects for valgus angle (F = 6.502 and p = 0.011) and significant group and time interaction effects for internal rotation angle range (F = 5.475 and p = 0.008). The group main effect for maximum knee flexion angle was significant (F = 7.534 and p = 0.012), and the group and time interaction effect for maximum internal rotation angle was significant (F = 15.737 and p = 0.001). For landing kinetics, the group main effect of the loading rate was significant (F = 4.576 and p = 0.044). Significant group and time interaction effects were observed for knee extension moment at the moment of maximum vertical ground reaction force (F = 5.095 and p = 0.010) and for abduction moment (F = 8.250 and p = 0.001). These findings suggest that plyometric training leads to greater improvements in hip and knee muscle strength and beneficial changes in knee biomechanics during landing compared to traditional training. Highlights: Plyometric training changes landing biomechanics.Changes help to reduce the risk of ACL injury.Changes from long‐term training are more noticeable. [ABSTRACT FROM AUTHOR]

Early rehabilitation after total knee arthroplasty (TKA) is crucial in functional outcomes. However, considering improvements in the first six months, there may be benefits to continuing rehabilitation beyond three months postoperatively to achieve maximum functionality and strength. The aim was to compare: (a) effectiveness of late-phase clinic-based and home-based progressive resistance training (PRT) in female patients with TKA; and (b) crude cost of both interventions and explore feasibility. Thirty-two patients were assigned to clinic-based PRT (n = 16) and home-based PRT (n = 16) groups. A training program was performed at the clinic or at home for eight weeks. Pain, quadriceps and hip abductor strength, patient-reported and performance-based outcomes, knee range of motion (ROM), joint awareness, quality of life (QoL) were assessed at baseline (three months postoperatively) and after 8-week intervention (five months postoperatively). Feasibility and crude cost were examined. Exercise adherence was 100% in clinic-based PRT and 90.6% in the home-based PRT group. Both interventions improved quadriceps and hip abductor muscle strength, performance-based and patient-reported outcomes, knee ROM, and joint awareness without side effects (p <.05). Clinic-based PRT showed better results in: activity pain (p =.004, ES = −0.888); knee flexion (p =.002, ES = 0.875) and extension ROM (p =.004, ES = −1.081); chair sit-to-stand test (p =.013, ES = 0.935); joint awareness (p =.008, ES = 0.927); and QoL than home-based PRT (p <.05). Late-phase clinical-based and home-based PRT interventions may be beneficial in improving muscle strength and functionality in patients with TKA. Late-phase PRT is feasible, cost-effective, and recommended for rehabilitation after TKA. [ABSTRACT FROM AUTHOR]

We evaluated whether the clinical outcomes, including postoperative knee range of motion (ROM), after unicompartmental knee arthroplasty (UKA) were associated with the sagittal spinopelvic parameters and coronal alignment of the full lower extremity. Forty-two patients (50 knees: six men, seven knees; 36 women, 43 knees) who underwent medial UKA between April 2015 and December 2022 were included. Preoperative radiographic examinations of the index for sagittal spinopelvic alignment included the sagittal vertical axis (SVA), lumbar lordosis, sacral slope (SS), pelvic tilt (PT), and pelvic incidence. The anteroposterior hip-knee-ankle angle (HKAA) was calculated. The relationship of clinical outcomes and the risk of knee flexion angle ≤125° and knee flexion contracture ≥10° 1-year post-UKA with radiographic parameters were evaluated. Preoperative HKA angle affected postoperative knee flexion angle ≤125° (p = 0.017, 95% confidence interval [CI]: 0.473–0.930) in logistic regression analysis. Patients with a knee flexion angle ≤125° had a higher preoperative HKAA (9.8 ± 3.0°), higher SVA (83.8 ± 37.0 mm), and lower SS (23.7 ± 9.0°) than those with a flexion angle >125° (preoperative HKAA: 6.6 ± 4.0°, SVA: 40.3 ± 46.5 mm, SS: 32.0 ± 6.3°) (p = 0.029, 0.012, and 0.004, respectively). PT related to postoperative knee flexion contracture ≥10° (p = 0.010, 95% CI: 0.770–0.965) in the logistic regression analysis. Patients with flexion contracture ≥10° had higher PT (35.0 ± 6.6°) and SVA (82.2 ± 40.5 mm) than those with flexion contracture <10° (PT, 19.3 ± 9.0°; SVA, 42.4 ± 46.5 mm) (p = 0.001 and 0.028, respectively). The postoperative clinical outcome was correlated with the postoperative knee flexion angle and SVA (p = 0.036 and 0.020, respectively). The preoperative HKAA affected postoperative knee flexion angle, and the knee flexion contracture and clinical outcomes post-UKA were associated with PT and SVA, respectively. To predict outcomes for knee ROM and clinical scores after UKA, radiographic examination, including the sagittal spinopelvic parameters and the coronal view of the full lower extremity, is essential. [ABSTRACT FROM AUTHOR]

Introduction: Anti-inflammatory and anti-fibrotic properties maximize the therapeutic potential of bone marrow aspiration concentrate (BMAC) in osteoarthritis (OA) knee. There is a lack of studies to standardize the treatment procedure to make the studies done across various centers comparable to understand the lacunae better and develop further the deficiency in our understanding of BMAC for OA knee. We aimed to assess the degree of pain relief, functional outcome, and cartilage thickness with different doses of BMAC in primary OA knee. Materials and Methods: A single-centered prospective observational study was conducted with 80 patients of OA knee who were divided into 4 groups where group A (n = 20), group B (n = 20), group C (n = 20), and group D (n = 20) received intra-articular 1, 2, 5 million BMAC cells per kg body weight, and intra-articular saline, respectively. All patients were followed up with Visual Analog Scale (VAS), knee Injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and International Knee Documentation Committee (IKDC) scores both pre and post-procedurally at 1, 3, 6, and 12 months follow-up. Results: The study found no significant differences in demographics or co-morbidities across four participant groups (A, B, C, D). However, clinical outcomes varied markedly: Groups B and C showed significant improvements in pain perception (VAS scores), knee function, and quality of life (KOOS and WOMAC scores), while Group A showed marginal or non-significant changes, and Group D exhibited no significant improvements. These findings suggest that treatments in Groups B and C reached the Minimal Clinically Important Difference, significantly enhancing patient-reported outcomes. Conclusion: A dose of 2 million BMAC cells per kg body weight for knee OA serves as the better regenerative modality of choice in cartilage regeneration. With our dose-escalation study, we would be able to standardize the treatment procedure and enable global comparison of the treatment method across various regions of the world. [ABSTRACT FROM AUTHOR]

Background: Step width is a spatial variable in the frontal plane, defined as the mediolateral distance between the heel (forefoot during sprinting) of bilateral feet at initial contact. Variations in step width may impact the lower limb biomechanics. This systematic review aimed to synthesize the published findings to determine the influence of acute changes in step width on locomotion biomechanics and provide implications for injury prevention and enhanced sports performance. Methods: Literature was identified, selected, and appraised in accordance with the methods of a systematic review. Four electronic databases (Web of Science, MEDLINE via PubMed, Scopus, and ScienceDirect) were searched up until May 2023 with the development of inclusion criteria based on the PICO model. Study quality was assessed using the Downs and Black checklist and the measured parameters were summarized. Results: Twenty-three articles and 399 participants were included in the systematic review. The average quality score of the 23 studies included was 9.39 (out of 14). Step width changed the kinematics and kinetics in the sagittal, frontal, and transverse planes of the lower limb, such as peak rearfoot eversion angle and moment, peak hip adduction angle and moment, knee flexion moment, peak knee internal rotation angle, as well as knee external rotation moment. Alteration of step width has the potential to change the stability and posture during locomotion, and evidence exists for the immediate biomechanical effects of variations in step width to alter proximal kinematics and cues to impact loading variables. Conclusion: Short-term changes in step width during walking, running, and sprinting influenced multiple lower extremity biomechanics. Narrower step width may result in poor balance and higher impact loading on the lower extremities during walking and running and may limit an athlete's sprint performance. Increasing step width may be beneficial for injury rehabilitation, i.e., for patients with patellofemoral pain syndrome, iliotibial band syndrome or tibial bone stress injury. Wider steps increase the supporting base and typically enhance balance control, which in turn could reduce the risks of falling during daily activities. Altering the step width is thus proposed as a simple and non-invasive treatment method in clinical practice. Key Points: Short-term changes in step width during gait could influence multiple lower extremity biomechanics. Increasing step width may be beneficial for specific injury rehabilitation. Wider steps increase the supporting base and typically enhance balance control to reduce the falling risks. [ABSTRACT FROM AUTHOR]

Background: The outcomes of medial meniscal allograft transplantation (MMAT) combined with high tibial osteotomy (HTO) compared with isolated MMAT remain unclear. Purpose: To compare the clinical and radiological results of MMAT combined with HTO and isolated MMAT. Study Design: Cohort study; Level of evidence, 3. Methods: This retrospective study included 42 consecutive patients, who were divided into group M (isolated MMAT; n = 22) and group H (MMAT combined with HTO with a varus angle >3°; n = 20). Group differences in subjective knee scores, isokinetic muscle strength test, and radiological outcomes (Kellgren-Lawrence grade, mechanical axis, graft extrusion, graft status, and articular cartilage loss) were compared. Results: The mean follow-up period was 29.2 ± 4.9 months and 27.4 ± 5.3 months for groups M and H, respectively. The Lysholm score improved from 55.4 ± 9.5 to 81.3 ± 9.7 and from 52.6 ± 8.9 to 84.2 ± 10.2 in groups M and H, respectively (both P <.001). The International Knee Documentation Committee subjective score improved from 51.4 ± 10.3 to 79.6 ± 9.4 and from 49.3 ± 11.4 to 81.4 ± 8.3 in groups M and H, respectively (both P <.001). Both groups showed no significant differences in subjective knee scores and isokinetic extensor strength at the final follow-up. The rate of preoperative and postoperative high International Cartilage Regeneration & Joint Preservation Society grade (≥3) did not differ between the 2 groups. Group M showed greater coronal graft extrusion than did group H (3.3 ± 0.7 mm vs 2.7 ± 0.8 mm; P =.014); the rate of pathologic graft extrusion (≥3 mm) was not higher in group M (40.9%) than in group H (20%) with the number of patients available (P =.143). Both groups showed no significant difference in the graft status. Graft tears were observed in 2 patients (9%) in group M and 1 patient (5%) in group H (P =.607). Conclusion: Clinical scores significantly improved after isolated MMAT and MMAT combined with HTO compared with preoperative values, and their short-term outcomes were similar. Postoperative graft extrusion was greater in patients who underwent isolated MMAT, implying that active correction of varus alignment during MMAT may help in intra-articular biomechanics. [ABSTRACT FROM AUTHOR]

Background: Both kinematically-aligned (KA) total knee arthroplasty (TKA) and bicruciate stabilized (BCS) TKA aim to reproduce the physiological knee kinematics. In this study, we compared the femoro-tibial component rotational mismatch between patients who underwent modified KA-TKA and those who received guided-motion BCS-TKA, and its influence on the clinical outcomes. Methods: In this retrospective study, 77 consecutive patients were included and divided into two groups: subjects who underwent modified KA-TKA with Persona (KA Group; n = 42) and those who received BCS-TKA with JOURNEY II (BCS group; n = 35). Range of motion, the 2011 Knee Society Score (KSS), the rotational alignment of the femoral and tibial components, and the correlations between the rotational mismatch and the 2011 KSS subscales were examined. Results: The postoperative objective knee indicators (P = 0.0157), patient satisfaction (P = 0.0039) and functional activity scores (P = 0.0013) in the KA group were significantly superior to those in the BCS group 1 year postoperatively. There was no significant difference between the two groups observed in the rotational mismatch. In the BCS group, significant negative correlations were identified between the rotational mismatch and objective indicators, patient satisfaction, and functional activity scores but not in the KA group. Conclusions: The short-term clinical results following KA-TKA showed superior objective knee indicators, patient satisfaction and functional activity scores. A negative correlation was observed between component rotational mismatch and the 2011 KSS subscales in the BCS group, compared to no relationship found between the two in the KA group. These findings suggested that KA-TKA has a relatively higher tolerance for rotational mismatch than BCS-TKA. [ABSTRACT FROM AUTHOR]

As a complex movement, Tai Chi (TC) could be challenging for knee control, and the compensatory changes in TC biomechanics of knee pain patients are unknown. The Brush Knee and Twist Step (BKTS) is a typical TC movement that involves basic leg motion repeated in the whole TC. This pilot study examined electromyography and retro-reflective marker trajectory data to investigate neuromuscular control strategies of the lower extremity during BKTS in TC practitioners with and without knee pain. Twelve experienced TC practitioners with (n = 6) and without knee pain (n = 6) participated. Our results revealed that knee pain practitioners presented muscle imbalance in the vastus medialis-vastus lateralis and vastus lateralis-biceps femoris, and poor alignment of the knee with the toes in TC lunge. Additionally, they adaptively developed rigid coordination strategies, showing higher levels of lower limb muscle co-contraction and activity compared to controls. Training programs for TC practitioners with knee pain should be designed to modify both abnormal muscle synergy patterns and incorrect lunge during TC, which may improve exercise safety. [ABSTRACT FROM AUTHOR]

Few studies have explored the kinetics of performance and perceived fatigability during high‐intensity interval training, despite its popularity. We aimed to characterize the kinetics of fatigability and recovery during an 8 × 4‐min HIIT protocol, hypothesizing that most muscle function impairment would occur during the initial four intervals. Fifteen healthy males and females (mean ± standard deviation; age = 26 ± 5 years, V̇O2max = 46.8 ± 6.1 mL·kg−1·min−1) completed eight, 4‐min intervals at 105% of critical power with 3 min of rest. Maximal voluntary knee extension contractions (MVCs) coupled with electrical nerve stimulation were performed at baseline and after the first, fourth, and eighth intervals. MVC, potentiated twitch force (Pt), and Db10:100 ratio all declined throughout HIIT (p < 0.05). MVC sharply declined after interval 1 (−15 ± 9% relative to baseline; p < 0.05) and had only further declined after interval 8 (−26 ± 11%; p < 0.05), but not interval 4 (−19 ± 13%; p > 0.05). Pt and Db10:100 also sharply declined after interval 1 (Pt: −18 ± 13%, Db10:100: −14 ± 20%; p < 0.05) and further declined after interval 4 (Pt: −35 ± 19%, Db10:100: −30 ± 20%; p < 0.05) but not interval 8 (Pt: −41 ± 19%; Db10:100: −32 ± 18%; p > 0.05). Voluntary activation did not significantly change across the HIIT protocol (p > 0.05). Evoked force recovery was significantly blunted as more intervals were completed: after interval 1, Pt recovered by 7 ± 11% compared to −6 ± 7% recovery after interval 8 (p < 0.05). Ratings of perceived effort, fatigue, and leg pain rose throughout the session (p < 0.05 for each) and were greater (effort and fatigue) for females (p < 0.05). Otherwise, males and females exhibited similar performance fatigability kinetics, with contractile function declines blunted in response to additional intervals. [ABSTRACT FROM AUTHOR]