Search

Purpose: Performing back squats with elastic bands has been widely used in resistance training. Although research demonstrated greater training effects obtained from adding elastic bands to the back squat, little is known regarding the optimal elastic resistance and how it affects neuromuscular performance. This study aimed to compare the force, velocity, power, and muscle activity during back squats with different contributions of elastic resistance. Methods: Thirteen basketball players performed 3 repetitions of the back squat at 85% of 1-repetition maximum across 4 conditions: (1) total load from free weight and (2) 20%, (3) 30%, and (4) 40% of the total load from elastic band and the remaining load from free weight. The eccentric and concentric phases of the back squat were divided into upper, middle, and bottom phases. Results: In the eccentric phase, mean velocity progressively increased with increasing elastic resistance, and muscle activity of the vastus medialis and rectus femoris significantly increased with the largest elastic resistance in the upper phase (P ≤.036). In the concentric phase, mean power (P ≤.021) and rate of force development (P ≤.002) significantly increased with increasing elastic resistance. Furthermore, muscle activity of the vastus lateralis and vastus medialis significantly improved with the largest elastic resistance in the upper phases (P ≤.021). Conclusion: Velocity, power, rate of force development, and selective muscle activity increased as the elastic resistance increased in different phases during the back-squat exercise. [ABSTRACT FROM AUTHOR]

Context: The incidence and recurrence rate of hamstring strain injuries remain persistently high, with recurrent injuries leading to increased time lost during play and extended recovery periods compared with initial injury. Ultrasound imaging assesses important factors such as hamstring fascicle length (FL), pennation angle (PA), cross-sectional area (CSA), muscle thickness (MT), echo intensity (EI), and shear wave elastography (SWE), all impacting athletic performance. However, its reliability must be established before employing any measurement tool in research or clinical settings. Objectives: To determine the reliability and measurement error of ultrasound for assessing hamstring FL, PA, CSA, MT, EI, and SWE among healthy adults and athletes; to synthesize the information regarding the operationalization of ultrasound. Evidence Acquisition: A systematic literature search was done from January 1990 to February 5, 2023, to identify reliability and validity studies of hamstring ultrasound assessment published in peer-reviewed journals with identifiable methodology of outcome measures. Evidence Synthesis: Intraclass correlation coefficient measurement of 14 included studies reported moderate to excellent intrarater, interrater, and test–retest reliabilities of FL, PA, and MT regardless of the site of muscle testing, probe size, and setting, state of muscle, and use of different techniques in the extrapolation of FL. Good to excellent test–retest reliability rates for all hamstring anatomic CSA along midmuscle and different percentages of thigh length using panoramic imaging. Good intrarater reliability of EI regardless of gender and orientation of the probe but with excellent intrarater reliability in transverse scan using maximum region of interest. Good intrarater, interrater, and interday repeatability on SWE with the muscle in a stretched position. Conclusion: Evidence from studies with a predominantly low risk of bias shows that ultrasound is a reliable tool to measure hamstring FL, PA, CSA, MT, EI, and SWE in healthy adults and athletes under various experimental conditions. [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]

Disruptions in gait function are common after concussion in adolescents; however, the neuromotor control deficits driving these gait disruptions are not well known. Fifteen concussed (age mean [SD]): 17.4 [0.6], 13 females, days since injury: 26.3 [9.9]) and 17 uninjured (age: 18.0 [0.7], 10 females) adolescents completed 3 trials each of single-task gait and dual-task gait (DT). During DT, participants simultaneously walked while completing a serial subtraction task. Gait metrics and variability in instantaneous mean frequency in lower extremity muscles were captured by inertial sensors and surface electromyography, respectively. A 2-way analysis of covariance was used to compare gait metrics across groups and conditions. Functional principal components analysis was used to identify regions of variability in instantaneous mean frequency curves. Functional principal component scores were compared across groups using a Welch statistic. Both groups displayed worse performance on gait metrics during DT condition compared to single-task, with no differences between groups (P <.001). Concussed adolescents displayed significantly greater instantaneous mean frequency, indicated by functional principal component 1, in the tibialis anterior, biceps femoris, and semitendinosus (P <.05) during single-task and DT compared with uninjured adolescents. Our observations suggest that concussed adolescents display inefficient motor unit recruitment lasting longer than 2 weeks following injury, regardless of the addition of a secondary task. [ABSTRACT FROM AUTHOR]

Clinical Scenario: Hamstring extensibility plays a significant role in maintaining postural alignment essential for a functional musculoskeletal system. When hamstring extensibility is lacking, individuals are placed at a higher risk for developing various lumbar spine, pelvis, knee, and foot dysfunctions. Limited hamstring extensibility is common, occurring in as much as 40% of college students and 86% of the adult population. Therefore, it is essential to maintain hamstring extensibility, which can be aided by understanding intervention effectiveness for improving flexibility. Purpose: To critically appraise the literature on the effectiveness of Active Release Technique (ART) for the treatment of hamstring extensibility deficits. Clinical Question: What is the effect of ART in a healthy population with or without hamstring extensibility deficits? Summary of Key Findings: Three studies were included for critical appraisal. Two studies concluded a single treatment session of ART that individuals possessing limited straight leg raise range of motion experienced improved active knee extension, popliteal angle, and sit-and-reach test measures. In the third study, a single session of ART was effective at improving hamstring extensibility in males without hamstring extensibility dysfunction. Clinical Bottom Line: Based on the current level 1 and level 3 evidence, ART may be an effective treatment to produce acute increases in hamstring extensibility. Future research is still needed. Strength of Recommendation: Level B evidence exists to support the use of ART to improve hamstring extensibility in the healthy population. [ABSTRACT FROM AUTHOR]

The hamstring plays an important role in reducing loads born by the anterior cruciate ligament. As anterior cruciate ligament injuries occur rapidly after ground contact, how the hamstring is activated prior to landing can influence injury risk. The purpose was to determine sex-related differences in hamstring activation immediately before landing and the effect of fatigue on "preactivation." Twenty-four participants (13 males and 11 females, age = 24.3 [6.5] y, mass = 72.2 [19.3] kg, height = 169 [9.7] cm) participated in this study. Participants completed a drop-vertical jump protocol before and after a lower body fatigue protocol. Hamstring electromyography (EMG) amplitude at 5 periods prior to landing, peak vertical ground reactions forces (in newtons/body weight), rate of loading (in body weight/second), and landing error scoring system were measured. Females had higher EMG amplitude before and after fatigue (P <.024), with decreased EMG amplitude for both sexes after fatigue (P =.025). There was no change on vertical ground reaction force, rate of loading, or landing error scoring system. Males and females demonstrated similar landing performance before and after fatigue but have different hamstring neuromuscular coordination strategies. The acute reduction in hamstring EMG amplitude following fatigue may increase loading on the anterior cruciate ligament. [ABSTRACT FROM AUTHOR]

Spasticity is a common impairment within pediatric neuromusculoskeletal disorders. How spasticity contributes to gait deviations is important for treatment selection. Our aim was to evaluate the pathophysiological mechanisms underlying gait deviations seen in children with spasticity, using predictive simulations. A cluster analysis was performed to extract distinct gait patterns from experimental gait data of 17 children with spasticity to be used as comparative validation data. A forward dynamic simulation framework was employed to predict gait with either velocity- or force-based hyperreflexia. This framework entailed a generic musculoskeletal model controlled by reflexes and supraspinal drive, governed by a multiobjective cost function. Hyperreflexia values were optimized to enable the simulated gait to best match experimental gait patterns. Three experimental gait patterns were extracted: (1) increased knee flexion, (2) increased ankle plantar flexion, and (3) increased knee flexion and ankle plantar flexion when compared with typical gait. Overall, velocity-based hyperreflexia outperformed force-based hyperreflexia. The first gait pattern could mostly be explained by rectus femoris and hamstrings velocity-based hyperreflexia, the second by gastrocnemius velocity-based hyperreflexia, and the third by gastrocnemius, soleus, and hamstrings velocity-based hyperreflexia. This study shows how velocity-based hyperreflexia from specific muscles contributes to different spastic gait patterns, which may help in providing targeted treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study implemented the Copenhagen Adductor Exercise (CAE) and Nordic Hamstring Exercise (NHE) to examine 1) whether CAE and NHE interventions are associated with adductor and hamstring strength gains in youth African male soccer players and 2) whether strength changes after a rest period and secondary intervention. STUDY DESIGN: Pre-post intervention study. METHODS: Forty-four African elite male academy players (age 14.7±1.5 [12-18] years) participated in twice weekly CAE and NHE interventions for 8- and 10-week periods separated by a 4-week rest. Long lever adductor squeeze strength and prone isometric hamstring strength were measured with mixed-effects linear regression models to observe strength changes over time. RESULTS: Ninety-six and 95% of CAE and NHE sessions were completed in each intervention, with no adverse events related to the execution of the exercises. Adductor squeeze strength increased during the first intervention (baseline 3.23 [2.99-3.47] N/kg, post-intervention 3.53 [3.30-3.76] N/kg, p=0.911) and was maintained following the rest period (3.52 [3.27-3.76] N/kg, p=0.999) and second intervention (3.60 [3.35-3.84] N/kg, p=0.002). Hamstring strength improved during the first intervention (baseline 4.95 [4.42-5.49] N/kg, post-intervention 5.48 [4.95-6.02] N/kg, p<0.001), decreased to baseline during the rest period (4.98 [4.44-5.53] N/kg, p=0.996), and did not improve during the second intervention (5.01 [4.46-5.55] N/kg, p=0.978). CONCLUSION: CAE and NHE interventions can be implemented at an elite African academy with high compliance. Adductor and hamstring strength improved in the first intervention, with no further improvements in the second intervention. Secondary interventions therefore should include higher exercise volume or load to improve longitudinal adductor and hamstring strength. Level of Evidence: Level III (Cohort Study) [ABSTRACT FROM AUTHOR]

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: Previous meta-analysis studies concluded that static stretching intervention cannot decrease all-cause injury in healthy active individuals. On the other hand, static stretching intervention may decrease muscle injury, but the evidence has not been integrated. The aim of this study was to systematically review the papers and analyze the preventative effects of static stretching intervention on muscle and tendon injuries in healthy active participants. Methods: A computerized search of PubMed, Web of Science, and EBSCO was performed in June 2023. Randomized controlled trials with static stretching investigations to prevent muscle and tendon injuries were included. Results: Of 5575 papers identified, 4 papers were included (three papers examined both muscle and tendon injuries, and one paper examined only tendon injuries). For muscle injuries, the result of the meta-analysis showed that the static stretching intervention group significantly decreased muscle injuries compared to the control group (odds ratio = 0.37; 95% confidence interval, 0.16–0.85; p < 0.01; I2 = 63%). For tendon injuries, it was found that there was no significant difference between the static stretching intervention group and the control group (odds ratio = 0.57; 95% confidence interval, 0.25–1.33; p = 0.194; I2 = 63%). Conclusions: These data indicated that static stretching intervention can prevent muscle injuries, but not tendon injuries, in healthy active participants. [ABSTRACT FROM AUTHOR]

Background: Hamstring flexibility significantly influences athletic performance, particularly in dynamic actions like vertical jumps and balance. This study seeks to uncover the connection between hamstring shortness and the dynamic interplay of vertical jump height and balance in these youth basketball athletes. Materials and methods: The study included 84 male youth basketball players with hamstring shortness. Participants underwent assessments including hamstring flexibility, hip flexed and knee extended (HF-KE), Sit and Reach Test, vertical jump measurement with the Optojump device, and balance measurement with the Y Balance Test. Results: The findings of our study indicate that there is a negative correlation between vertical jump test results and left HF-KE (p < 0.001). Y balance was significantly negative correlated with the right HF-KE (p = 0.011). Multiple regression analysis revealed that right HF-KE has a significant effect on jumping performance (95% CI = −0.140–0.587; p = 0.002), while left HF-KE also has a significant effect on jump performance (95% CI = −0.612–0.784; p < 0.001). Conclusion: In conclusion, our study underscores the crucial role of hamstring flexibility in vertical jump performance among youth basketball players. The significant associations found between left HF-KE with vertical jump performance highlight the importance of addressing hamstring shortness in training programs aimed at enhancing jump performance. These findings emphasize the need for targeted interventions to improve hamstring flexibility, which could ultimately contribute to better athletic performance and injury prevention in this population. [ABSTRACT FROM AUTHOR]

Spectroscopic imaging, rooted in Dixon's two‐echo spin sequence to distinguish water and fat, has evolved significantly in acquisition and processing. Yet precise fat quantification remains a persistent challenge in ongoing research. With adequate phase characterization and correction, the fat composition models will impact measurements of fatty tissue. However, the effect of the used fat model in low‐fat regions such as healthy muscle is unknown. In this study, we investigate the effect of assumed fat composition, in terms of chain length and double bond count, on fat fraction quantification in healthy muscle, while addressing phase and relaxometry confounders. For this purpose, we acquired bilateral thigh datasets from 38 healthy volunteers. Fat fractions were estimated using the IDEAL algorithm employing three different fat models fitted with and without the initial phase constrained. After data processing and model fitting, we used a convolutional neural net to automatically segment all thigh muscles and subcutaneous fat to evaluate the fitted parameters. The fat composition was compared with those reported in the literature. Overall, all the observed estimated fat composition values fall within the range of previously reported fatty acid composition based on gas chromatography measurements. All methods and models revealed different estimates of the muscle fat fractions in various evaluated muscle groups. Lateral differences changed from 0.5% to 5.3% in the hamstring muscle groups depending on the chosen method. The lowest observed left–right differences in each muscle group were all for the fat model estimating the number of double bonds with the initial phase unconstrained. With this model, the left–right differences were 0.64% ± 0.31%, 0.50% ± 0.27%, and 0.50% ± 0.40% for the quadriceps, hamstrings, and adductors muscle groups, respectively. Our findings suggest that a fat model estimating double bond numbers while allowing separate phases for each chemical species, given some assumptions, yields the best fat fraction estimate for our dataset. [ABSTRACT FROM AUTHOR]

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BackgroundObjectiveCase DescriptionOutcomesConclusionBody lateropulsion (BL) is a phenomenon in which the body involuntarily falls to one side; however, its detailed postural control characteristics remain unclear.This case report aimed to measure the surface electromyography (EMG) of the lower limbs while standing in a patient with severe BL on the affected side due to pontine infarction and to investigate the characteristics of postural control.We evaluated a patient with severe BL due to pontine infarction at two-time points, 6 and 20 days after onset, to assess static standing balance under open and closed eye conditions and measure the center of pressure (COP) and lower extremity EMG during these tasks.There were minimal changes in COP position and total locus length during the eyes closed condition compared to the eyes open condition. However, the head and trunk to the non-BL side of the tilt and bilateral medial hamstring muscle activity tended to be higher when the eyes were closed. At the final evaluation, head and trunk tilt and EMG changes were reduced during the eyes-closed condition compared to the eyes-open condition. The initial postural response was considered to reflect a compensatory postural strategy for BL, characterized by the body involuntarily tilting to one side.The change in posture over time may indicate a reduction in the compensatory postural response as the condition improves. In this case, characteristic postural findings were identified through EMG measurements, suggesting the possibility of future studies involving multiple cases. [ABSTRACT FROM AUTHOR]

Background: There have been emerging clinical trials investigating the efficacy of synthetic-graft-augmented autografts in anterior cruciate ligament reconstruction (ACLR) in recent years. Hamstring tendon and Ligament Augmentation and Reconstruction System (LARS) are both widely discussed graft choices for ACLR. Purpose: To compare the clinical efficacy of hamstring tendon grafts with LARS-augmented hamstring tendon grafts in ACLR. Study Design: Systematic review and meta-analysis. Method: A systematic literature search was performed in PubMed, Embase and the Cochrane Library to identify primary evidence related to the comparison of ACLR with a hamstring tendon (HT) versus a hamstring tendon with LARS (HT + LARS). Quality assessment of the included studies was conducted using Newcastle–Ottawa Scale for non-RCTs. Quantitative analysis was conducted with Reviewer Manager 5.4. The primary outcomes compared were the Lysholm scale, Tegnar activity scale, International Knee Documentation Committee (IKDC) evaluation, KT-1000-based laxity, complication/retear rate and rate of return-to-sports. The secondary outcomes were the Knee Injury and Osteoarthritis Outcomes Score (KOOS), Global Rating of Change (GRC) scale, hop tests, isokinetic knee strength tests and radiographic and arthroscopic evaluations. Results: Six cohort studies with 710 participants were included in this study. Compared with the HT group, the HT + LARS group had better Lysholm scores at the 1-year follow-up (P = 0.0007) and at the final follow-up (P = 0.04). HT + LARS group had better IKDC scores at the 1-year follow-up (P = 0.003). The HT + LARS group had a better return-to-sports rate in short term. No significant difference in complications or re-surgery was observed. The secondary results revealed superior or non-inferior outcomes in the HT + LARS group. Conclusions: As grafts for ACLR, the use of hamstring tendons with LARS augmentation, compared with the use of hamstring tendons alone, in the short term, has significantly superior overall functional results and better early sports participation and non-inferior results in other comparisons. In the long term, the use of hamstring tendon with LARS augmentation demonstrated non-inferior results in terms of functional scores, knee stability, knee strength, complications and re-tear rate, etc. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI) is the gold standard for measuring muscle size. However, postural conditions for thigh musculature have not been standardized across studies, with some employing supine or prone positions and the thigh either placed on the examination table or suspended to avoid contact. In either case, the thigh is compressed or sagged by gravity, potentially affecting muscle size. This study aimed to examine the effects of postural conditions on thigh muscle size. Twenty Olympic‐style weightlifters and 20 untrained controls (10 men and 10 women in each group) underwent 3‐Tesla MRI in the supine and prone positions, with the thigh in compressed and suspended conditions to determine the maximal anatomical cross‐sectional area (ACSAmax) and muscle volume of 15 thigh muscle groups/individual muscles. Postural conditions changed the ACSAmax of the quadriceps (range of postural‐related changes: 1.0%–7.9%), hamstrings (0.8%–19.1%), and adductors (2.4%–19.2%). Regardless of measurement position, the total volume of thigh muscles decreased under compressed conditions (0.6%–3.8%). Quadriceps and adductors decreased in muscle volume under compressed conditions (0.9%–4.0% and 0.8%–6.6%), while hamstrings increased (1.4%–9.3%). Male weightlifters, who possessed the largest thigh muscle volume, showed greater postural‐related changes in the muscle volume of quadriceps, hamstrings, and adductors than the other subgroups. Therefore, postural conditions during MRI substantially change thigh muscle size, and the magnitude of the change depends on muscle size. Our results provide in vivo evidence of the compressive behavior of thigh muscles and a new technical perspective for assessing thigh muscle size. [ABSTRACT FROM AUTHOR]

Although the landing phases of the single-leg hop for distance (SLHD) are commonly assessed, limited work reflects how the take-off phase influences hop performance in patients with anterior cruciate ligament reconstruction (ACLR). To compare trunk and lower extremity biomechanics between individuals with ACLR and matched uninjured controls during take-off of the SLHD. Cross-sectional study design. Laboratory setting. Sixteen individuals with ACLR and 18 uninjured controls. Normalized quadriceps isokinetic torque, hop distance, and respective limb symmetry indices were collected for each participant. Sagittal and frontal kinematics and kinetics of the trunk, hip, knee, and ankle as well as vertical and horizontal ground reaction forces were recorded for loading and propulsion of the take-off phase of the SLHD. Those with ACLR had weaker quadriceps peak torque in the involved limb (P =.001) and greater strength asymmetry (P <.001) than control individuals. Normalized hop distance was not statistically different between limbs or between groups (P >.05), and hop distance symmetry was not different between groups (P >.05). During loading, the involved limb demonstrated lesser knee flexion angles (P =.030) and knee power (P =.007) than the uninvolved limb and lesser knee extension moments than the uninvolved limb (P =.001) and controls (P =.005). During propulsion, the involved limb demonstrated lesser knee extension moment (P =.027), knee power (P =.010), knee (P =.032) and ankle work (P =.032), and anterior-posterior ground reaction forces (P =.047) and greater knee (P =.016) abduction excursions than the uninvolved limb. Between-limb differences in SLHD take-off suggest a knee underloading strategy in the involved limb. These results provide further evidence that distance covered during SLHD assessment can overestimate function and fail to identify compensatory biomechanical strategies. [ABSTRACT FROM AUTHOR]

Objectives: Rupture of the anterior cruciate ligament (ACL) is a severe injury common in sports. It also has a high rate of re-injury. The aim of this work was to assess hamstring muscle fatigue in active football players after ACL reconstruction who were cleared to play and to determine symmetry between the lateral and medial hamstring muscles. Methods: In professional football players post ACL reconstruction (n = 25) and non-injured players (n = 26), the bioelectrical activity of the medial (biceps femoris—BF) and lateral (semimembranosus and semitendinosus—SEM) hamstring muscles was measured during 60 s of isometric contraction. The fatigue variables were calculated using the Continuous Wavelet Transform (CWT) tool. Results: The football players following ACL reconstruction demonstrated significant asymmetry in fatigue of the lateral and medial hamstring muscles, with greater fatigue in the SEM compared to the BF muscle. Moreover, in those after reconstruction, the changes are more pronounced, with higher muscle fatigue in both limbs (they have lower MDF than non-injured players) and more severe SEM muscle insufficiency (noted in both limbs but with greater intensity in the non-operated one). Conclusions: The higher SEM muscle fatigue observed in this study influenced the lateral-to-medial activation ratio within the hamstring muscle, which may be a probable cause of this muscle's insufficiency in laterally stabilizing the knee in the frontal and transverse plane. Furthermore, the hamstring muscles after reconstruction were more fatigued in both limbs, which may be another risk factor for ACL graft rupture. Therefore, increased fatigue in specific hamstring muscles may indicate the direction in which knee stabilization is compromised due to ACL overload. A muscle that becomes fatigued and inefficient more quickly also becomes ineffective in performing its function sooner, which can lead to increased overloading forces acting on the ACL graft. [ABSTRACT FROM AUTHOR]

This study retrospectively compared the effect of holding the 2022 FIFA World Cup™ (WC) mid-season (season 2022/23) on injury rates and patterns in French Ligue 1 soccer clubs. Epidemiological data in 17 clubs were prospectively recorded by their physicians. Time-loss injuries (injuries leading to a player being unable to fully participate in play over the following 72-hour period) were compared with those reported during a regular season (2021–22). In the WC season, an increase of approximately 23% (training + match-play) was observed for both the total number of injuries and knee, ankle and muscle injuries combined. Incidences for match-play injury overall and for the knee, ankle and muscle regions combined and the hamstrings and calf regions specifically also rose significantly (range: p < 0.05-p < 0.01). These results suggest that injury occurrence and patterns in French L1 soccer clubs were substantially affected during the 2022/23 season when a mid-season WC was held. [ABSTRACT FROM AUTHOR]

Acute effects of static stretching (SS) and proprioceptive neuromuscular facilitation (PNF) on local and non-local range of motion (ROM) were assessed in 29 participants. Three evaluations were performed one week apart: week-1 Control session (CS); weeks 2–3 either SS or PNF interventions (randomized). Dominant and non-dominant limbs, local (hamstring extensibility) and non-local ROMs (Shoulder extension-ShE) were collected at baseline (T0), immediately after (T1), and fifteen minutes post-intervention (T2). No differences were found between time-points during the CS. Local-ROM significantly increased (p=0.0002, ES=0.74 and 0.0079, 0.56, for dominant and non-dominant lower limbs, respectively) after both SS and PNF. No interaction between time and treatment was detected for ShE in both limbs. However, post-hoc analysis revealed a significant increase in dominant upper limb ShE between T0 and T1 only after SS (p=0.002; +6.5%). Acute bouts of SS and PNF can increase local-ROM, however, no clear effects were observed for non-local ROM. [ABSTRACT FROM AUTHOR]

Isokinetic knee tests mostly evaluate reciprocal concentric-concentric flexor-extensor movements in a seated position. Discrete tests generate higher moments, but time requirements impede their widespread implementation. This study examined if hip angle (flexed vs. extended) and test modality (discrete vs. reciprocal) affect camera-based data (100 fps). Sixteen healthy males performed concentric (con) and eccentric (ecc) isokinetic knee flexor (H) and extensor (Q) movements (60°/s). Peak moments and contractional work of discrete and reciprocal tests (QconQecc, HconHecc) strongly correlated for extended (Q:91%≥R2≥71%; H:95%≥R2≥87%) and flexed hip (Q:88%≥R2≥70%; H:81%≥R2≥75%) without significant differences (p>0.05) between test modalities. Discrete and "traditional" seated QconHcon-tests revealed substantially lower correlations for extended (Q:44%≥R2≥43%; H:55%≥R2≥54%) and flexed hip (Q:81%≥R2≥77%; H:48%≥R2≥47%). Although most mean values did not significantly differ, moderate correlations were predominant and the respective limits of agreement demonstrated considerable effects of hip angle and test modality. These insights assist practitioners in interpreting isokinetic data of different test procedures. If time constraints prevent discrete knee tests (gold standard), concentric-eccentric movements provide highly correlated outcomes, independent of the hip angle. [ABSTRACT FROM AUTHOR]

Objective: This study examines the correlation between MRI findings and difficult dissection during proximal primary hamstring repair and postoperative sciatica. Materials and methods: A total of 32 cases of surgically repaired hamstring tendon tears that underwent preoperative and postoperative MRI were divided into sciatica (n = 12) and control (n = 20) groups based on the presence or absence of postoperative sciatica. Cases were scored by two blinded musculoskeletal radiologists for imaging features associated with difficult surgical dissection and the development of subsequent sciatica. Intra- and interrater agreements, as well as correlation of MRI findings with symptoms (odds ratio, OR), were calculated. Results: On preoperative MRI, diffuse hamstring muscle edema pattern suggestive of active denervation (OR 9.4–13.6), and greater sciatic perineural scar circumference (OR 1.9–2) and length (OR 1.2–1.3) were significantly correlated with both difficult dissection and postoperative sciatica. Preoperatively, a greater number of tendons torn (OR 3.3), greater tear cross-sectional area (CSA, OR 1.03), and increased nerve T2-weighted signal (OR 3.2) and greater perineural scar thickness (OR 1.7) were also associated with difficult dissection, but not postoperative sciatica. On postoperative MRI, hamstring denervation, sciatic nerve tethering to the hamstring tendon, and development of perineural scar and greater perineural scar extent were all significantly correlated with postoperative sciatica. Conclusion: Preoperative hamstring MRI demonstrates findings predictive of difficult sciatic nerve dissection; careful MRI evaluation of the nerve and for the presence and extent of perineural scar is important for preoperative planning. Preoperative and postoperative MRI both depict findings that correlate with postoperative sciatica. [ABSTRACT FROM AUTHOR]

Background/Objectives: Hamstring shortening is a significant musculoskeletal condition affecting the posture and mobility of the spine and lower extremities. This study examined the impact of incorporating neurodynamic slump stretch and suboccipital muscle inhibition into passive static stretching on hamstring flexibility in individuals with short hamstrings. Methods: 117 female participants were classified into three groups: the control group, which received passive static stretch of the hamstring muscle; the neurodynamic slump group, which received neurodynamic slump stretch with passive static stretch; and the suboccipital muscle inhibition group, which received suboccipital muscle inhibition with passive static stretch, for three sessions a week, 10 min each, for four weeks. The outcome measures were the popliteal angle test (PAT), straight leg raising (SLR) test, and forward bending test (FBT) at baseline, immediately following the first session and after four weeks. Results: Statistically significant differences were found within groups (p < 0.001) for all outcome measures. Between the groups, there was a more significant improvement in the PAT and the SLR tests, favoring the neurodynamic slump and suboccipital muscle inhibition groups in comparison with the passive static stretch group (p < 0.001) with no significant difference between the two groups after the first session and at four weeks of treatment. However, the FBT showed no significant differences immediately following the first session or at four weeks of treatment (p > 0.05). Conclusions: This study found that incorporating neurodynamic slump stretch and suboccipital muscle inhibition into passive static stretch techniques effectively treats short hamstrings in healthy individuals. [ABSTRACT FROM AUTHOR]

Background: Hamstring (HS) strength deficits and imbalances have been identified as risk factors for sustaining anterior cruciate ligament (ACL) injuries and muscular strains, with HS injuries being the most prevalent muscle injuries in soccer athletes. The aim of this study was to investigate HS eccentric strength before and after a soccer match in both male and female soccer athletes. Hypothesis: Soccer athletes have changes in eccentric HS strength after a soccer game. Study Design: Cohort observational study. Level of Evidence: Level 3. Methods: HS eccentric strength (mean and absolute peak torque and total work) was measured in 64 healthy male and female competitive football athletes (14-25 years) with an automatic device during the execution of the Nordic hamstring exercise (NHE) test before and after a 90-minute soccer match. The anterior-knee laxity (AKL) was quantified with an arthrometer. Results: Mean and absolute eccentric HS peak torque decreased by 24.5 N.m (-12.34%; P < 0.01) and 21.9 N.m (-10.08%; P < 0.01) in female athletes, whereas their male peers improved by 19.9 N.m (+9.01%; P = 0.01) and by 20.9 N.m (+8.51%; P = 0.02), respectively. HS total work in female athletes decreased by 831.1 J (P < 0.01) compared with the male athlete reduction of 235.3 J. Both the pre- versus postmatch intersex mean and absolute eccentric HS peak torque changes were significant (P < 0.01), as were the changes in HS total work (P < 0.01). The pre- versus postmatch AKL difference and the dominant versus nondominant limb comparison of the strength parameters were not significantly different. Younger female athletes (14-19 years old) presented a greater decrease in mean and absolute peak HS eccentric strength compared with those in older female athletes and men. Conclusion: HS eccentric strength and work differ based on athlete sex, as measured by the NHE test. Mean peak, absolute peak, and total work showed greater reductions in female athletes than those in their male peers. The subgroup of 14- to 19-year-old female athletes experienced the highest reduction in strength parameters. [ABSTRACT FROM AUTHOR]

This study investigated the changes in fascicle length (FL), musculotendinous unit (MTU) stiffness, muscle oxygen saturation (SmO2), and muscular performance following a single bout of a combination of static stretching (SS) or dynamic stretching (DS) with foam rolling (FR), SS only, and eccentric exercise (ECC) only in young men with hamstring tightness. Twenty-five men (20.5 ± 1.5 years) participated in a crossover randomized study of the four conditions (DS+FR, SS+FR, SS, and ECC); each session was spaced seven days apart. FL, MTU stiffness during the straight leg raise (SLR), hamstring SmO2, and isometric and eccentric torque were measured before, immediately and 30 min after exercise. Immediately after exercise, the SLR increased significantly by means of 7.4% (d = 1.07), 6% (d = 1.27), 6% (d = 1.10), and 8% (d = 1.04, all p < 0.001) for DS+FR, SS+FR, ECC, and SS, respectively. FL was longer after exercise under all four conditions (p < 0.05). MTU stiffness decreased after ECC (p = 0.038, d = 0.40). SmO2 tended to decrease for ECC (p > 0.05), but it was increased immediately after those three exercises. Hamstring isometric torque was significantly reduced by an average of 6-9%, but eccentric torque changes varied among conditions. In conclusion, substantial and similar immediate increases in hamstring flexibility, coupled with reduced isometric torque following various exercises, were accompanied by condition-specific alterations in fascicle length, MTU stiffness, or SmO2. These findings provide practical insights for acutely enhancing range of motion in individuals with tight hamstrings. [ABSTRACT FROM AUTHOR]

Background: Knee osteoarthritis (KOA) is a common musculoskeletal disorder. Therapeutic ultrasound (US) is a safe and effective treatment for KOA. It relieves knee pain and enhances function. Metformin (MF) regulates chondrocytes, hence providing chondroprotection. Furthermore, it efficiently reduces knee articular cartilage degeneration and retards the progression of osteoarthritis. However, the localized administration of MF by phonophoresis for KOA has yet to be studied. Purpose: To assess the possible effects of metformin phonophoresis (MFPH) plus exercise therapy (EX) compared to MFPH alone or the US on knee pain, function, and range of motion (ROM) in chronic KOA patients. Methods: Seventy-eight patients with unilateral mild to moderate chronic KOA were included. Patients were randomly assigned to three groups: group A (MFPH + EX), group B (MFPH alone), and group C (US). The US group used an acoustic-neutral gel, while the MFPH group used a gel containing 1.2% MF. The exercises included hamstring stretches, calf stretches, and knee strengthening exercises. Treatment in the three groups continued for four weeks (three sessions per week). The Visual Analog Scale (VAS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the goniometer were used to assess knee pain, function disability, and ROM, respectively. All measures were recorded before, 2 weeks, and 4 weeks after the intervention in all groups. Multivariate Analysis of Variance (MNOVA) was performed to compare the effects within and between groups for knee ROM and function disability. The Kruskal-Wallis test and the Friedman test analyzed the pain intensity. Results: When the baseline patient characteristics were compared, there were no significant differences in means of age, gender, body mass index (BMI), or lower limb dominance across the three groups (p > 0.05). After 4 weeks of intervention, clinical outcomes significantly improved in all three groups (p < 0.05). However, patients in the MFPH + EX group improved significantly in all outcomes compared to the MFPH and US groups (p < 0.05). Conclusion: Post-treatment results showed a statistically and clinically significant improvement in pain intensity, knee ROM, and function in the MFPH group; however, combining MFPH with exercises is more beneficial in reducing KOA symptoms. Trial registration: Clinical Trial Registry at (pactr.samrc.ac.za) database. NO: PACTR202311507335269. Date: November 9, 2023 (retrospectively registered). [ABSTRACT FROM AUTHOR]

BackgroundPurposeMethodsResultsConclusionA combination of hamstring stretching and strengthening exercises may benefit patients with knee osteoarthritis by promoting pain relief and disability improvement.The current study aimed to compare the effects of lateral hamstring strengthening and medial hamstring stretching with general hamstring stretching and general hamstring strengthening on pain, disability, and quality of life in patients with primary knee osteoarthritis and varus deformity.Forty patients with knee osteoarthritis were randomly assigned to two groups: a general hamstring strengthening group (14 women, 6 men) and a selective hamstring strengthening group (16 women, 4 men). In the general hamstring strengthening group, participants performed hamstring stretching and strengthening exercises broadly. In contrast, the selective hamstring strengthening group specifically targeted lateral hamstring strengthening and medial hamstring stretching. The treatment program was conducted three times a week for 4 weeks. Pain and disability levels were evaluated before and after treatment using the Knee Injury and Osteoarthritis Outcome Score (KOOS), quality of life was assessed using the Osteoarthritis Knee and Hip Quality of Life (OAKHQOL) questionnaire, and physical activity levels were determined using the Tegner activity scale.Both groups demonstrated significant improvement in all outcomes except for the quality of life subscale of the KOOS questionnaire (p = .98) in the general hamstring strengthening group. However, the selective hamstring strengthening group exhibited greater improvements in symptoms (p = .02, effect size (d) = 0.92) and pain subscales (p = .01, d = 0.80) according to the KOOS questionnaire. Additionally, the pain subscale (p = .02, d = 0.79) of the OAKHQOL questionnaire exhibited greater improvements in the selective hamstring strengthening group. Tegner activity scale scores significantly improved in both groups.Strengthening the lateral hamstring and stretching the medial hamstring muscles seem to be beneficial for reducing pain in patients with primary knee osteoarthritis and varus deformity. Attention to stabilization in frontal and horizontal planes in the knee joint might be better than simply evaluating the joint in the sagittal plane. [ABSTRACT FROM AUTHOR]

Background/Objective: Short hamstring syndrome is common in the general population and can lead to impaired balance, function, and posture, and increased risk of injuries. Local treatments have obtained controversial results, so it is necessary to evaluate the effectiveness of other types of therapy such as osteopathic treatment. To evaluate the efficacy of osteopathic techniques in increasing the elasticity of the hamstring musculature in short hamstring syndrome. Methods: A systematic review of randomised controlled trials was conducted in PubMed, Medline, Cinhal, Scopus, WOS, SPORTDiscuss, and PEDro. The PEDro scale was used to evaluate the methodological quality and the RoB2 for the evaluation of biases. Results: A total of eight articles were selected. Most of the participants were assessed with the Active Knee Extension or Straight Leg Raise tests. The osteopathic techniques used were the muscle energy technique, suboccipital inhibition, and vertebral mobilisations. As for the control interventions, they mainly included passive stretching and placebo. Conclusions: The results suggest that osteopathic techniques are more effective than placebo or other interventions in increasing flexibility in adult patients with short hamstring syndrome. This effect can be explained by neurophysiological (Golgi apparatus, neuromuscular spindle activity, and Hoffmann reflex) and structural factors (dura mater, posture, and myofascial chains). Nevertheless, the evidence suggests that it would be beneficial to incorporate this type of treatment into flexibility improvement programmes. [ABSTRACT FROM AUTHOR]

Purpose: Hamstring spasticity is prevalent following neurological injury. The standardized assessment involves passive knee extension, in a position of 90° hip flexion. This creates passive insufficiency of the muscle and lacks ecological validity for walking, whereby the hip typically flexes to a maximum of 40° during swing phase, while the knee extends. This study compared assessment outcomes when completed in 40° and 90° hip flexion. Methods: The Modified Ashworth Scale and Modified Tardieu Scale, were performed on 35 adults with a neurological condition. Each participant was assessed by three assessors, resulting in 105 trials at 40° and 90°. Results: There was a significant increase in the proportion of trials rated as spastic using the Modified Ashworth Scale (p=.012, phi=.27), and Modified Tardieu Scale (p<.001, phi=.36), and the severity of spasticity using the Modified Ashworth Scale (p<.001, effect size (ES)=.50), and Modified Tardieu Scale (p<.001 ES=.47), at 90° hip flexion. The angle of reaction occurred 32° earlier at 90° hip flexion (p<.001, ES = 1.61). Conclusions: Completing hamstring assessments in 40° hip flexion may reduce the passive insufficiency and improve the ecological validity of assessment, for walking. This may assist in the selection of patients requiring intervention, when their goal relates to walking. IMPLICATIONS FOR REHABILITATION: The position of the hip joint impacts hamstring spasticity assessment outcomes, regardless of the clinical outcome measure chosen The application of bedside assessment methods in a manner reflective of functional tasks may assist in selecting individuals who require active spasticity intervention As per international guidelines, the use of validated outcome measures in a goal directed and patient centered manner is required to maximize patient care [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]

Purpose: Previous evidence indicated that the tibiofemoral bone configuration might elevate the risk of an anterior cruciate ligament (ACL) injury. Furthermore, a low hamstring‐to‐quadriceps muscle ratio predisposes especially females to unfavourable knee kinematics. The primary objective of the present study was to investigate sex‐specific associations between tibiofemoral bone geometry and isokinetic knee flexion torque in patients with primary ACL injury followed by ACL reconstruction. Methods: N = 100 patients (72 = male, 28 = female, age = 31.3 ± 10.2, body mass index = 25.3 ± 3.6) with primary ACL rupture with isokinetic knee flexion torque assessments before and 6 months after ACL reconstruction surgery were analysed. Magnetic resonance imaging scans were analysed for medial posterior tibial slope (MPTS) and lateral posterior tibial slope, notch width index (NWI) and lateral femoral condyle index (LFCI). Additionally, isokinetic knee flexion torque (60°/s) and hamstring–quadriceps ratios were evaluated. Subsequently, functional parameters were correlated with imaging data for gender subgroups. Results: The findings showed that presurgical isokinetic knee flexion torque was not associated with any marker of femoral or tibial bone geometry. Further, while significant differences were observed between female (0.883 ± 0.31 Nm/kg) and male (1.18 ± 0.35 Nm/kg) patients regarding preoperative normalized knee flexion torque (p < 0.001), no significant sex differences were found for percentage increases in normalized knee flexion torque from presurgery to postsurgery. Generally, female patients demonstrated significantly higher MPTS magnitudes (p < 0.05) and lower LFCI values (p < 0.05) compared to men. Conclusion: The present results demonstrated no association between tibial or femoral bone geometry and muscle strength of the hamstrings in patients with ACL reconstruction, indicating an important mismatch of muscular compensation to deviations in bone geometry. There were no sex‐specific differences in tibiofemoral bone parameters. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Background: Anterior instability of the sternoclavicular joint (SCJ) is a rare but potentially devastating pathological condition, particularly when it occurs in young or active patients. SCJ reconstruction using hamstring tendon autograft is a commonly used treatment option, yet to date results are limited to small case series. Studies on baseline, preoperative factors and their association with postoperative outcome are limited. Purpose: To assess the midterm clinical outcomes and survivorship after SCJ reconstruction using hamstring tendon autograft in patients experiencing anterior SCJ instability and to determine whether baseline patient or causative factors are associated with postoperative outcomes or patient satisfaction. Study Design: Case series; Level of evidence, 4. Methods: Patients who underwent SCJ reconstruction with a hamstring tendon autograft for anterior SCJ instability between October 2005 and October 2020 were included in this retrospective single-center study. At a minimum of 2 years postoperatively, clinical outcomes were collected, including the following patient-reported outcomes (PROs): the 12-Item Short Form Survey (SF-12) score; American Shoulder and Elbow Surgeons (ASES) score; Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score; Single Assessment Numeric Evaluation (SANE) score; and visual analog scale (VAS) pain score. Subjective postoperative satisfaction with the procedure was quantified on a scale from 0 (very unsatisfied) to 10 (very satisfied). The predictive role of patient factors, including age, sex, and injury in dominant arm, on postoperative PROs and satisfaction at short-term follow-up was evaluated using multiple linear regression. Results: A total of 49 patients (mean age, 29.6 ± 16.2 years; range 13.8-67.1 years; 27 females) were included in the final analysis. At a mean follow-up of 3.9 ± 2.1 years, all PROs had significantly improved, including the mean SF-12 Physical Component Summary score (40.4 ± 6.8 to 52.6 ± 6.9; P <.001), ASES score (54.9 ± 20.4 to 91.0 ± 11.3; P <.001), QuickDASH score (41.2 ± 18.5 to 10.2 ± 9.1; P <.001); SANE score (50.2 ± 21.1 to 88.3 ± 8.8; P <.001), VAS pain score (4.4 ± 2.6 to 0.8 ± 1.4; P <.001), and VAS pain score at its worst (7.4 ± 2.5 to 3.3 ± 2.6; P <.001). The median postoperative satisfaction score was 9 (range, 1-10). Revision-free survivorship was 95.9%. Male patients had a significantly lower VAS pain score at its worst compared with female patients (2.6 ± 2.6 vs 4.1 ± 2.4; P =.045); higher age was significantly correlated with a worse QuickDASH score (correlation coefficient, 0.314; P =.036). Overhead athletes had a significantly lower propensity to return to sport compared with nonoverhead athletes (P =.043), with only 45% of the overhead athletes returning to a level similar to their preinjury level, whereas 81% of the nonoverhead athletes were able to do so. Conclusion: The significant improvements in clinical and sport-specific outcomes and high patient satisfaction after SCJ reconstruction with a hamstring tendon autograft demonstrate the success of this procedure in treating anterior SCJ instability. Male sex and younger patient age are associated with superior outcomes, while overhead athletes have to be counseled about difficulties of returning to preinjury level of sport postoperatively. [ABSTRACT FROM AUTHOR]

Objective: To compare the effects of the Muscle Energy Technique (MET) and the Bowen Technique on hamstring muscle tightness in chronic low back pain (CLBP) patients. Method: A randomized clinical trial (RCT) designed study in which 62 participants were recruited through the purposive sampling technique were divided into two groups by the lottery method. Subjects who had pain for more than six months in the back and hamstring tightness were included. The duration of the study was four months from February to May 2023 conducted at Madinah Teaching Hospital Faisalabad. Subjects in Group-A were given the Bowen technique, whereas subjects in Group-B were given the MET. Numeric pain rating scale (NPRS), Oswestry disability index (ODI), and active knee extension (AKE) tests were used for measurements of outcomes. Results: Intra-group comparison by using Friedman test revealed that both Group-A & B subject’s pain were reduced (P<0.000), their tightness in back thigh muscles were significantly reduced (P<0.000) and functional activities of subjects were also improved (P<0.000). Mann Whitney test was used to determine the between group comparison. P-value ≤ 0.05 was considered as significant. Inter Group-Analysis revealed that there was no statistically significant difference between effects of Bowen technique & MET on pain, hamstring tightness and disability as both techniques improved pain, flexibility & disability. Conclusion: This study revealed that both groups treated by MET and Bowen Technique had significantly reduced pain, improved flexibility of back thigh muscle and reduced functional disability. [ABSTRACT FROM AUTHOR]

Background/Objectives: Hamstring muscle (HM) flexibility is frequently compromised in people with chronic low back pain (CLBP), contributing to disability and leading to a less favorable recovery. In a previous article, we presented the results of a study on the immediate effect of passive HM stretching on flexibility in 90 people with CLBP. There was considerable variability in the changes after stretching. The objective of this supplementary analysis was to compare the clinical characteristics of individuals who experienced a significant improvement in flexibility with those who did not. Methods: We fixed a threshold of 7° to indicate an improvement in passive Straight Leg Raise (SLR) angle and differentiate between 'Responders' and 'Non-responders' regarding passive HM stretching. Results: Only body mass index differed between groups; it was significantly smaller in Responders (p = 0.007). The majority of Non-responders experienced workplace accidents, but this was of marginal difference compared to Responders (p = 0.056). Conclusions: Further studies should consider a broader clinical analysis with a larger sample size to understand which factors influence the HM stretching response in CLBP patients. [ABSTRACT FROM AUTHOR]

Background: Strength and power represent two crucial physical qualities for the attainment of a high level of performance considering the frequency and the importance of explosive actions occurring during elite soccer match-play. Evaluation of strength and power is a multifaceted concept involving a vast array of tests and outcome variables. Nevertheless, a comprehensive and systematic search of strength and power assessment procedures in elite soccer has yet to be undertaken. Objectives: The aims of this systematic review were to: (1) identify the tests and outcome variables used to assess strength and power of elite male soccer players; (2) provide normative values for the most common tests of strength and power across different playing levels; and (3) report the reliability values of these strength and power tests. Methods: A systematic review of the academic databases MEDLINE, CINAHL, SPORTDiscus, Web of Science and OVID for studies published until August 2023 was conducted, following the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were eligible for inclusion if they: (1) were original research studies, published in a peer-reviewed journal, and written in English language; (2) had the primary aim to assess strength and/or power; (3) players were male and older than 17 years of age (i.e., mean age of the group); and (4) their playing level was defined as "professional", "international" or "elite". Results: Regarding strength testing, 115 studies and 29 different tests were identified. The three most frequent strength tests were the knee extensor isokinetic strength test (58 studies), the knee flexor isokinetic strength test (55 studies) and the Nordic hamstring strength test (13 studies). In terms of power testing, 127 studies with 31 different tests were included. The three most frequent power tests were the countermovement jump with hands fixed on hips (99 studies), the squat jump (48 studies) and the vertical jump with arm swing (29 studies). Conclusions: The wide range of different tests and outcome variables identified in this systematic review highlights the large diversity in the employed testing procedures. The establishment of a hybrid testing approach, combining standardised and widely accepted tests for establishing normative standards and enabling comparisons across different contexts, with flexible context-specific testing batteries, has the potential to maximise the impact of testing information for practitioners. In addition, the limited reporting of reliability data across studies highlights the need for practitioners to establish their own reliability measure within their specific contexts, informing the selection of certain tests and outcome variables. [ABSTRACT FROM AUTHOR]

This study compared lower extremity (LE) muscular strength by 3 groups of female athletes using chronological age and consideration of age of peak height velocity (PHV). Isometric quadriceps, hamstrings, and hip abductors strength were assessed from physically active, pediatric females. The body mass normalized isometric strength (N m/kg) was compared by the 3 age groups. There were 388 young female athletes (<10 years [14.2%], 11-14 years [48.7%], and 15-18 years [37.1%]). The body mass normalized LE strength was lower in 11-14 years compared with <10 years (quadriceps [ P =.001], hamstrings [ P =.001], and hip abductors [ P =.037]) as well as in 15-18 years relative to <10 years in quadriceps (P =.001) and hamstrings (P =.001). The analysis results were consistent with both chronological age alone and incorporating effects of age of PHV. In short, body mass normalized LE strength (quadriceps, hamstrings, and hip abductors) of 11-14 years females was lower than <10 years females. [ABSTRACT FROM AUTHOR]

Purpose: Proprioceptive neuromuscular facilitation (PNF) stretching is considered a clinically effective way to enhance muscle properties; however, rare information exists about its effect on muscle flexibility and strength of the patients with stroke. To investigate the efficacy of PNF exercise on lower extremity muscle flexibility and strength after stroke. Methods: Twenty-four... [ABSTRACT FROM AUTHOR]

Background: Biocomposite screws reportedly provide equivalent graft fixation in anterior cruciate ligament reconstruction (ACLR) to metallic screws while simplifying subsequent imaging and surgery. One purported complication of biocomposite screws is paradoxical tunnel widening. Previous studies on beta-tricalcium phosphate screws have only reported outcomes at short- and midterm follow-up. Purpose: To radiographically assess the tibial tunnel 10 years after ACLR using hamstring tendon autografts and biocomposite interference screws in anatomic single-bundle (SB) and double-bundle (DB) methods. Study Design: Case series; Level of evidence, 4. Methods: Of the 105 initially recruited patients, 61 (58%) completed all follow-up evaluations for inclusion in this long-term study. A total of 26 patients received anatomic SB ACLR and 35 patients received DB ACLR with biocomposite interference screws containing beta-tricalcium phosphate in the tibia. Weightbearing anteroposterior and lateral radiographs of the index knee were taken in the early postoperative period and at 2, 5, and 10 years postoperatively; computed tomography (CT) imaging was performed at 10-year follow-up. Subjective and objective clinical assessments were recorded preoperatively and at 10-year follow-up. Results: The mean follow-up period was 122 months. In 76% of radiographs in the SB group, the width of the tibial tunnel had not increased at 10 years compared with the early postoperative period. The mean tibial tunnel volume on CT in the SB group was 2.04 cm3 (± 0.85 cm3). In the DB group, the posterolateral tunnel width had not increased in 69% of radiographs; the same was found in 63% of radiographs for the anteromedial tunnel at 10-year follow-up. The mean posterolateral tunnel volume on CT was 2.04 cm3 (±1.92 cm3) and the mean anteromedial tunnel volume was 1.38 cm3 (±0.54 cm3). There was no correlation between tunnel widths and KT-1000 arthrometer assessments. There was a moderate but statistically significant correlation between SB tibial tunnel volume on CT imaging and KT-1000 arthrometer anterior 134 N side-to-side difference (r = 0.45; P =.039). Conclusion: Most patients' tibial tunnels had not increased on 1 or both radiographic views at 10-year follow-up compared with the early postoperative period after ACLR using biocomposite interference screws, with no obvious negative effect on outcomes. However, the tunnels were still visible in most patients at 10 years on standard radiographs and CT imaging. [ABSTRACT FROM AUTHOR]

Context: The assessment of strength is one of the most usual practices among professionals involved in health care or sport. Quadriceps and hamstrings are the most commonly assessed muscle groups. Generally, the methods used to assess muscle strength are active and, therefore, alternative passive methods could be useful. Myoton provides measures on 3 mechanical properties of the muscle: tone, elasticity, and stiffness. Objective: This study aimed to analyze the association of Myoton, an easy-to-use tool not requiring voluntary stimulus from the subject, with strength values in quadriceps and hamstrings. Study Design: Experimental. Setting: University kinesiology laboratory. Participants: Thirty-eight recreational athletes were evaluated. Main Outcome Measures: Anthropometric and demographic data, Myoton-based measures of vastus lateralis, rectus femoris, vastus medialis, biceps femoris, and semitendinosus, and the maximum voluntary isometric contraction of quadriceps and hamstrings. Procedures: The association was examined using multiple regression models to estimate strength through Myoton-based parameters and different patient characteristics. The models encompassed either 2 or 3 independent variables. Results: The adjusted R2 values for predicting quadriceps strength were.666 for rectus femoris,.726 for vastus lateralis, and.667 for vastus medialis, while in regard to hamstrings, they were.617 for biceps femoris and.604 for semitendinosus. Conclusions: The main finding was that acceptable relationships were found between muscle strength and Myoton-based parameters when variables such as gender and/or age are considered. Our study reveals a new tool for estimating strength with outstanding advantages: it is easy, time-efficient, adaptable, and highly manageable through the feasible equations provided. [ABSTRACT FROM AUTHOR]

Context: Exercise-induced muscle damage (EIMD) is prevalent especially in sports and rehabilitation. It causes loss in skeletal muscle function and soreness. As there are no firm preventive strategies, we aimed to evaluate the preventive efficacy of nonthermal 448-kHz capacitive resistive monopolar radiofrequency (CRMRF) therapy after eccentric bouts of EIMD response in knee flexors. Design: Twenty-nine healthy males (age: 25.2 [4.6] y) were randomized in control group (CG; n = 15) and experimental group (EG; n = 14) where EG followed 5 daily 448-kHz CRMRF therapies. All assessments were performed at baseline and post EIMD (EIMD + 1, EIMD + 2, EIMD + 5, and EIMD + 9 d). We measured tensiomyography of biceps femoris and semitendinosus to calculate contraction time, the maximal displacement and the radial velocity of contraction, unilateral isometric knee flexors maximal voluntary contraction torque, and rate of torque development in first 100 milliseconds. Results: Maximal voluntary contraction torque and rate of torque development in first 100 milliseconds decreased more in CG than in EG and recovered only in EG. Biceps femoris contraction time increased only in CG (without recovery), whereas in semitendinosus contraction time increased in EG (only at EIMD + 1) and in CG (without recovery). In both muscles, tensiomyographic maximal displacement decreased in EG (in EIMD + 1 and EIMD + 2) and in CG (without recovery). Furthermore, in both muscles, radial velocity of contraction decreased in EG (from EIMD + 1 until EIMD + 5) and in CG (without recovery). Conclusion: The study shows beneficial effect of CRMRF therapy after inducing EIMD in skeletal muscle strength and contractile parameters in knee flexors. [ABSTRACT FROM AUTHOR]

Context: Anatomy trains theory states that performing techniques in any part of the superficial myofascial backline can remotely treat other parts of this pathway. Due to the connections of different parts of the superficial backline, it is possible to influence the hamstring by performing the technique in the lumbar area. As chronic nonspecific low back pain (LBP) may lead to or be caused by hamstring tightness, remote myofascial release (MFR) techniques using the superficial backline can help improve hamstring tightness. Objective: This study aimed to evaluate the effect of remote MFR on hamstring tightness for those with chronic nonspecific LBP. Design: Single-blind, parallel design. Setting: The present study was performed at the clinical setting of Tarbiat Modares University in Iran. Methods: This study included 40 participants (20 males and 20 females) who were 40.5 (5.3) years old with chronic nonspecific LBP and hamstring tightness. Interventions: Participants were randomly divided into the lumbar MFR (remote area) and hamstring MFR groups. Participants underwent 4 sessions of MFR for 2 weeks. Main Outcome Measures: A passive knee-extension (PKE) test was used for muscle tightness evaluation 3 times. Results: Repeated-measure analysis of variance test showed that after the lumbar and hamstring MFR, the PKE was significantly reduced in both legs: lumbar MFR (right knee: from 61.04° [2.17°] to 51.01° [4.11°], P ≤.003 and left knee: from 63.02° [3.12°] to 52.09° [2.48°], P ≤.004) and hamstring MFR (right knee: from 62.01° [4.32°] to 50.50° [7.18°], P ≤.001 and left knee: from 63.11° [2.56°] to 51.32° [5.31°], P ≤.002). Least Significant Difference (LSD) post hoc test results showed that the 2 groups were not significantly different after the MFR (P ≥.05). Also, the intraclass correlation coefficient index showed that the PKE test has excellent reliability (intraclass correlation coefficient,.910 for the right limb and.915 for the left limb). The minimal detectable change at the 95% confidence interval indicated that a change greater than or equal to 6° is required to exceed the threshold of the error PKE test, respectively. Conclusion: The present study showed that the remote MFR technique to the lumbar region demonstrated the same significant results in decreasing hamstring tightness as was noted in hamstring MFR to both limbs in patients with chronic nonspecific LBP. [ABSTRACT FROM AUTHOR]

BACKGROUND: Impaired hamstring muscle strength, anterior patellar pain, high incidence of osteoarthritis, and loss of proprioception after anterior cruciate ligament reconstruction lead to poor functional recovery due to a higher incidence of osteoarthritis and loss of proprioception. Arthroscopic repair of the anterior cruciate ligament combined with dynamic or static internal brace repair preserves the original ligament structure and results in favorable short-term outcomes. OBJECTIVE: To prospectively observe the efficacy and imaging findings of modified double-bundle arthroscopic repair of the anterior cruciate ligament after Sherman type I injury METHODS: From January 2020 to September 2022, a total of 60 patients with anterior cruciate ligament injury admitted at the Department of Sports Medicine, Foshan Hospital of Traditional Chinese Medicine were included and divided into two groups (n=30 per group) according to the treatment protocols. The functional repair group was treated with double bundle repair combined with internal brace fixation, and the reconstruction group was treated with single bundle anatomical reconstruction of autologous hamstring muscle. All cases were followed up for 12 months after surgery, and International Knee Documentation Committee score, Lysholm score and KT-1000 difference between the affected and healthy sides of the two groups were evaluated at 3, 6 and 12 months after surgery. RESULTS AND CONCLUSION: Three months after surgery, International Knee Documentation Committee scores, Lysholm scores and KT-1000 difference between the affected and healthy sides were significantly different between the two groups (P < 0.05), and the functional repair group was better than the reconstruction group. At 6 and 12 months after surgery, there was no significant difference in International Knee Documentation Committee score, Lysholm score and KT-1000 difference between the two groups (P > 0.05). To conclude, anterior cruciate ligament repair preserves the original ligament structure, avoids drilling larger marrow tracts and removing autologous tendons for reconstruction, reduces the damage to the original normal structure, and has fewer complications. Early postoperative efficacy is better than that of anterior cruciate ligament reconstruction with stumps, but there is no significant difference in the efficacy of the two groups 6 months after surgery. [ABSTRACT FROM AUTHOR]

Purpose: Muscle architecture is associated with motor performance and muscle injury. While muscle architecture and knee-flexor eccentric strength change with growth, the influence of anthropometric measures on these properties is rarely considered. This study aimed to investigate the relationship between hamstring muscle architecture and knee-flexor eccentric strength with anthropometric measurements. Methods: Sixty male footballers (16.6 [1.05] y) from the U16, U17, and U19 teams of an elite soccer club were included in this study. Fascicle length, pennation angle, and muscle thickness of the biceps femoris long head (BFlh) and semimembranosus muscles were measured in both legs using ultrasound. Knee-flexor eccentric strength, height, body mass, leg length, femur length, and peak height velocity (PHV) were measured within 1 week of the ultrasound images. A stepwise regression and 1-way analysis of variance tests were used to evaluate the effects of age, maturity, and anthropometric measurements on muscle properties. Results: Variance within BFlh and semimembranosus muscle thickness (r <.61), semimembranosus pennation angle (r <.58), and knee-flexor eccentric strength (r =.50) were highly related to body mass. We observed no significant correlations between muscle architecture and age (P >.29). However, moderately greater BFlh muscle thickness was shown for the post-PHV compared with the PHV group (effect size ± 90% CI: 0.72 ± 0.49). Conclusions: In conclusion, weak correlations between muscle architecture and anthropometric measurements suggest that other factors (ie, genetics, training regimen) influence muscle architecture. The moderate effect of maturity on BFlh muscle thickness strongly suggests post-PHV hypertrophy of the BFlh muscle. Our results confirmed previous findings that eccentric knee-flexor strength is influenced by body mass. [ABSTRACT FROM AUTHOR]

Anterior cruciate ligament injury prevention should focus primarily on reduction of the knee abduction moment (KAM) in landing tasks. Gluteus medius and hamstring forces are considered to decrease KAM during landing. The effects of different muscle stimulations on KAM reduction were compared using 2 electrode sizes (standard 38 cm2 and half size 19 cm2) during a landing task. Twelve young healthy female adults (22.3 [3.6] y, 1.62 [0.02] m, 50.2 [4.7] kg) were recruited. KAM was calculated under 3 conditions of muscle stimulation (gluteus medius, biceps femoris, and both gluteus medius, and biceps femoris) using 2 electrode sizes, respectively versus no stimulation during a landing task. A repeated-measures analysis of variance determined that KAM differed significantly among stimulation conditions and post hoc analysis revealed that KAM was significantly decreased in conditions of stimulating either the gluteus medius (P <.001) or the biceps femoris (P <.001) with the standard electrode size, and condition of stimulating both gluteus medius and biceps femoris with half-size electrode (P =.012) when compared with the control condition. Therefore, stimulation on the gluteus medius, the biceps femoris, or both muscles could be implemented for the examination of anterior cruciate ligament injury potential. [ABSTRACT FROM AUTHOR]

Chronic lumbopelvic pain (CLPP) and its associated disabilities significantly affect women's social, professional, and personal lives. However, the specific factors contributing to CLPP in women remain unclear. To address this gap, this prospective cross-sectional study aims to identify the risk factors predicting CLPP in women and develop a prediction model that can predict CLPP in women. The study was conducted across Delhi, India, where free health camps were held, and 2400 women were assessed. Among the assessed individuals, the study revealed a high prevalence rate of CLPP among Indian women, standing at 70.4%. Seven risk factors namely, hamstring muscle tightness (> 20° on passive knee extension test), increased lumbar lordosis (> 11.5 cm of the lumbar lordotic index), reduced hip flexibility (> 15 cm on bent knee fallout test), altered foot posture (≥ 20 on foot posture index score), increased perception of psychological stress (> 25 on cohen's perceived stress scale-10 score), reduced physical activity level (< 475 metabolic/minute on international physical activity questionnaire) and reduced performance of transversus abdominis muscle (≤ 5 on deep muscle contraction scale score) strongly predict the risks of CLPP in women. Identifying these risk factors is crucial for effectively preventing and managing CLPP symptoms, especially considering its high prevalence among Indian women. Health professionals should prioritize raising awareness about CLPP and its causative factors, as well as implementing strategies for early detection and intervention. [ABSTRACT FROM AUTHOR]

Background/Objective: This study aimed to compare the functional outcomes, such as knee muscle strength, dynamic postural stability, pain scores, and physical activity, in patients with knee osteoarthritis (OA) on stair climbing training with and without interferential electrotherapy (IFE) for 12 weeks. Methods: A total of 40 knee OA patients with Kellgren–Lawrence (K–L) grade ≤ 2 were enrolled (20 stair-climbing training with IFE vs. 20 stair-climbing training without IFE). The knee quadriceps and hamstring muscle strengths were measured using an isokinetic device. The dynamic postural stability was assessed using postural stabilometry. The pain score was evaluated using the visual analog scale (VAS). Physical activity was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results: The WOMAC score was significantly different (p < 0.019) between stair-climbing training with and without IFE in patients with knee OA, while knee muscle strength, dynamic postural stability, or pain score were not (all p > 0.05). Conclusion: Stair-climbing training with IFE was more beneficial for physical activity recovery than stair-climbing training without IFE. Therefore, clinicians and therapists should be aware that stair climbing, which can be practiced in daily life for the management of patients with knee OA, and the addition of IFE may improve physical activity. [ABSTRACT FROM AUTHOR]

A reprint of the article "Palpating the Anterior Hip" which originally appeared in the January/February 2024 issue of "The Associated Bodywork & Massage Professionals" is presented. It discusses the methods for examining the anterior part of the hip, which is important for diagnosing and treating hip-related issues in traditional medicine. Also mentioned are the palpation of the hip flexors and application of the hill and valley approach to palpation of the hip flexor musculature.

Given the posterior chain configuration, it is anticipated that tibial positioning influences hamstring recruitment; medial hamstrings should be more activated during medial rotation, while lateral hamstrings should be more activated during lateral rotation. However, most studies showing this pattern have focused on concentric or isometric strength, leaving the influence on eccentric strength fairly unknown. Therefore, the aim of this study was to investigate the electromyographic response of the hamstring muscles during Nordic hamstring exercises in three leg positions: internal rotation, external rotation, and neutral. This study encompassed a randomized crossover study and used surface electromyography to analyze the activity of the biceps femoris and semitendinosus muscles during the Nordic hamstring exercise, in the three positions. Results indicated no statistically significant differences in muscle activation between positions or sides (p > 0.05), though small effect sizes were observed for the biceps femoris in different positions (η2 = 0.01–0.03). Furthermore, the internal rotation position generally elicited the highest muscle activations. Notably, biceps femoris muscles exhibited higher activations compared to semitendinosus muscles, with the greatest differences seen in the internal rotation position. This suggests that tibial rotation influences hamstring recruitment patterns; however, it was lower than expected. [ABSTRACT FROM AUTHOR]

Background: Bone–patellar tendon–bone (BPTB) and double-looped semitendinosus and gracilis (hamstring) grafts are commonly used for anterior cruciate ligament (ACL) reconstruction. Short-term and midterm studies show little or no differences between the 2 grafts; however, there are only a few long-term studies to compare results between the 2 grafts. Purpose: To compare the results after using either BPTB grafts or hamstring tendon grafts 18 years after ACL reconstruction. Study Design: Randomized controlled trial; Level of evidence 2. Methods: A total of 114 patients with ACL rupture between 2001 and 2004 were randomized to reconstruction with either a BPTB graft or a hamstring tendon graft. Patients were operated on at 4 major hospitals. The 18-year follow-up evaluation included anterior knee laxity measured with a KT-1000 arthrometer, defined as the primary outcome, while clinical examination (Lachman and pivot-shift tests), isokinetic testing of muscle strength, patient-reported outcome measures, and an assessment of radiographic osteoarthritis using the Kellgren-Lawrence classification were defined as secondary outcomes. Results: A total of 96 patients (84%, 47 BPTB and 49 hamstring grafts) were available for follow-up, 71 of these for clinical examination. Seven of 96 patients were excluded for ACL revision (n = 5) or knee replacement (n = 2) surgery. In total, 25 patients (10 BPTB and 15 hamstring grafts) had undergone additional surgery other than ACL revision or total knee arthroplasty. There were no significant differences between the groups in terms of anterior laxity test with KT-1000 arthrometer (primary outcome). In secondary outcomes, no significant differences between groups were reported regarding clinical examination, patient-reported outcome scores, or radiographic osteoarthritis (Kellgren-Lawrence grade 2-4 for patellofemoral joint [18 hamstring and 14 BPTB] or tibiofemoral joint [20 hamstring and 19 BPTB]), while isokinetic testing revealed that the hamstring group had a 10.7% reduction in mean peak flexion torque compared with the BPTB group at 60 deg/s (df = 59; P =.011). At 60 deg/s the mean total flexion work in the hamstring group was reduced by 17.2% compared with the BPTB group (df = 59; P =.002). Conclusion: The flexion strength in the hamstring group was significantly reduced in the operated knee after 18 years. There were no significant differences between the groups regarding subjective outcomes, patient-reported outcomes, range of motion, clinical and instrumented knee laxity, and the development of osteoarthritis. Registration: NCT05876013 (ClinicalTrials.gov identifier). [ABSTRACT FROM AUTHOR]

Existing patellofemoral pain (PFP) literature has primarily been focused on quadriceps muscle volume, with limited attention given to the deep and superficial muscle volume of the lower limbs in individuals with unilateral and bilateral PFP. In this paper, we aim to fill this gap. To explore superficial and deep lower extremity muscle volume in women with unilateral or bilateral PFP compared with a normative database of pain-free women. Cross-sectional study. University imaging research center. Twenty women with PFP (10 unilateral and 10 bilateral) and 8 pain-free women from a normative database. We quantified lower extremity muscle volume via 3.0-T magnetic resonance imaging. Two separate 1-way analyses of variance were performed: (1) unilateral PFP (painful versus nonpainful limb) versus pain-free control groups and (2) bilateral PFP (more painful versus less painful limb) versus pain-free control groups. We observed no differences in age and body mass index across groups (P >.05). Compared with the pain-free group, the unilateral and bilateral PFP groups had bilaterally smaller volumes of the anterior (iliacus: P ≤.0004; d range, 2.12–2.65), medial (adductor brevis, adductor longus, gracilis, and pectineus: P ≤.02; d range, 1.25–2.48), posterior (obturator externus, obturator internus, and quadratus femoris: P <.05; d range, 1.17–4.82), and lateral (gluteus minimus: P ≤.03; d range, 1.16–2.09) hip muscles and knee extensors (rectus femoris: P ≤.003; d range, 1.67–2.16) and flexors (long and short head of the biceps femoris: P ≤.01, d range, 1.56–1.93). Women with unilateral and those with bilateral PFP displayed less volume of multiple superficial and deep muscles of the bilateral hips and knees than pain-free women. Interventions should bilaterally target lower limb muscles when treating PFP, and hypertrophy exercises for specific muscles should be explored to increase choices for intervention. [ABSTRACT FROM AUTHOR]