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Introduction: Heart failure (HF) is caused by functional and structural irregularity leading to impaired ejection or filling capacity of the heart. HF leads to chronic inflammatory conditions in the heart leads to weight loss, anorexia, and muscle atrophy known as cachexia. The present study was carried out to investigate the role of Ezetimibe, an NRF2 activator, in cardiac cachexia and to develop a treatment strategy for cardiac cachexia. Method: Balb/c mice of either sex at 6–8 weeks of age were given 2 mg/kg of doxorubicin in 0.9% sodium chloride solution intraperitoneally (i.p.) for the alternate days for the first week and then once a week for the next 4 weeks. After induction of cardiac atrophy, treatment with Ezetimibe (1.5 mg/kg, p.o) was given for the next 4 weeks. Result: In the cardiac cachectic animals, a significant decrease in body weight, food, and water intake was observed. Cardiac cachectic animals showed a significant increase in serum glucose, total cholesterol, LDL, triglyceride, VLDL, CK‐MB, LDH, and CRP levels. Cardiac atrophic index, heart weight to body weight ratios (HW/BW), right ventricular weight to heart weight ratios (RV/HW), and left ventricular weight to heart weight ratios (LV/HW), were significantly decreased in cardiac cachectic animals. The weights of the skeletal muscles such as EDL, gastrocnemius, soleus, tibialis anterior, and quadriceps muscles, and the weight of adipose tissue such as subcutaneous, visceral, perirenal, and brown adipose tissue were significantly decreased in the cardiac cachectic group relative to the normal group. Treatment with ezetimibe improves body weight, food intake, and water intake. Ezetimibe decreases serum glucose, total cholesterol, LDL, triglyceride, VLDL, CK‐MB, LDH and CRP levels. Cardiac atrophic markers such as HW/BW, RV/HW, and LV/HW were improved. The weight of skeletal muscles and adipose tissue was increased after treatment with ezetimibe. Conclusion: Our data showed that the NRF2 activator, Ezetimibe produces a beneficial effect on cardiac cachexia in the doxorubicin‐induced cardiac cachexia model. Ezetimibe was successful to reduce the levels of inflammatory cytokines, ameliorate the effects on cardiac muscle wasting, lipid levels, fat tissues, and skeletal muscles. [ABSTRACT FROM AUTHOR]

The detection of a secondary inorganic phosphate (Pi) resonance, a possible marker of mitochondrial content in vivo, using phosphorus magnetic resonance spectroscopy (31P‐MRS), poses technical challenges at 3 Tesla (T). Overcoming these challenges is imperative for the integration of this biomarker into clinical research. To evaluate the repeatability and reliability of measuring resting skeletal muscle alkaline Pi (Pialk) using with 31P‐MRS at 3 T. After an initial set of experiments on five subjects to optimize the sequence, resting 31P‐MRS of the quadriceps muscles were acquired on two visits (~4 days apart) using an intra‐subjects design, from 13 sedentary to moderately active young male and female adults (22 ± 3 years old) within a whole‐body 3 T MR system. Measurement variability attributed to changes in coil position, shimming procedure, and spectral analysis were quantified. 31P‐MRS data were acquired with a 31P/‐proton (1H) dual‐tuned surface coil positioned on the quadriceps using a pulse‐acquire sequence. Test–retest absolute and relative repeatability was analyzed using the coefficient of variation (CV) and intra‐class correlation coefficients (ICC), respectively. After sequence parameter optimization, Pialk demonstrated high intra‐subject repeatability (CV: 10.6 ± 5.4%, ICC: 0.80). Proximo‐distal change in coil position along the length of the quadriceps introduced Pialk quantitation variability (CV: 28 ± 5%), due to magnetic field inhomogeneity with more distal coil locations. In contrast, Pialk measurement variability due to repeated shims from the same muscle volume (0.40 ± 0.09mM; CV: 6.6%), and automated spectral processing (0.37 ± 0.01mM; CV: 2.3%), was minor. The quantification of Pialk in skeletal muscle via surface coil 31P‐MRS at 3 T demonstrated excellent reproducibility. However, caution is advised against placing the coil at the distal part of the quadriceps to mitigate shimming inhomogeneity. [ABSTRACT FROM AUTHOR]

The aim of the present study was to determine if anodal transcutaneous spinal direct current stimulation (tsDCS) affects corticospinal excitability (CSE) and voluntary activation (VA) of the quadriceps femoris muscle (QM). This was a double‐blind, randomized study in which spine‐shoulder anodal tsDCS (active electrode centered over T11–12, 2.5 mA, 20 min) was applied in a seated position. Transcranial magnetic stimulation (TMS) was used to measure motor evoked potentials (MEP) and construct stimulus–response curves in healthy participants (eight females and five males, Experiment 1). VA was measured via the interpolated twitch technique, whereby muscle twitches were evoked using electrical femoral nerve stimulation and TMS (seven females and six males, Experiment 2). Measurements were carried out before, directly, and 30 min after sham and anodal tsDCS (with ≥4 days between sessions). There was no interaction between stimulation × time on stimulus–response curve expressed by slope, stimulus intensity corresponding to 50% of the maximal MEP, and peak‐to‐peak amplitude of the maximal MEP. Maximal voluntary isometric contraction (MVIC) torque did not change and VA was not affected regardless of the QM torque level (25, 50, or 100% of MVIC). A single, twenty‐minute session of spine‐shoulder anodal tsDCS did not increase CSE and VA of QM during submaximal and maximal contraction. This suggests that neither excitability to a known input nor responsiveness of motoneurons to submaximal and maximal cortical drive were affected by anodal tsDCS. [ABSTRACT FROM AUTHOR]

Introduction/Aims Methods Results Discussion The number of clinical trials in facioscapulohumeral muscular dystrophy (FSHD) is expected to increase in the near future. There is a need for clinical outcome assessments (COAs) that can capture disease progression over the relatively short time span of a clinical trial. In this study, we report the natural progression of FSHD and determine the feasibility of COAs for clinical trials.Genetically confirmed FSHD patients underwent various COAs at baseline and after 5 years. COAs consisted of the Motor Function Measure (MFM), manual muscle testing using the Medical Research Council score, six‐minute walk test, quantitative muscle strength assessment of the quadriceps muscle, clinical severity score, and FSHD evaluation score (FES). Statistical significance and the minimal clinically important difference (MCID) were calculated and power calculations were performed.One hundred fifty‐four symptomatic FSHD patients were included, with a mean (SD) age of 51.4 (14.6) years old. All COAs showed a minimal, yet statistically significant progression after 5 years. MCID was reached for the MFM Domain 1, MFM total score, and FES. These three COAs showed the lowest sample size requirements for clinical trials (185, 156, and 201 participants per group, respectively, for a trial duration of 2 years).The captured FSHD disease progression rate in 5 years was generally minimal. The COAs in this study are not feasible for clinical trials with a duration of 2 years. Extended trial durations or novel outcome assessments might be necessary to improve trial feasibility in FSHD. [ABSTRACT FROM AUTHOR]

To investigate the effect of moderate or heavy slow resistance training on structural and mechanical properties of patellar and Achilles tendons in older men, in vivo. Healthy older men (n = 27) undertook a 12‐week resistance training program (3 times/week) of triceps surae and quadriceps muscle‐tendon complexes. Participants were randomly assigned to either a moderate load of 55% 1RM (O55, n = 13, age: 70.0 ± 4.6 years) or a progressively heavier load from 55% up to 80% 1RM (O80, n = 14, age: 69.8 ± 4.4 years). Tendon morphology was investigated using a 1.5 T MRI scanner. Mechanical properties of the free Achilles tendon (AT) and medial gastrocnemius (MG) aponeurosis, patellar tendon (PT), and deep aponeurosis of the vastus lateralis (VL) muscle were assessed using ultrasound imaging. Both training programs led to an increase in mean CSA of the PT (O55; +2.7%, O80; +1.7%, p = 0.002) and AT (O55; +2.8%, O80; +2.5%, p < 0.001). Force and stress were increased for all the four regions investigated, while stiffness and Young's modulus assessed at a common force level were only increased for the AT and VL aponeurosis. No interaction between group and time was demonstrated for any of the outcomes. No interaction between time and the four tendon sites was observed for any of the outcomes at common force. A supervised short‐term heavy or moderate slow resistance training of equal volume yielded an increase in tendon size and altered mechanical properties of tendinous tissue. [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]

Panoramic ultrasound (US) is an extended field‐of‐view (EFOV) imaging technique that enables visualization of large‐scale skeletal muscles. This technique has previously been found to produce valid and reliable quantifications of muscle morphology in primarily young male subjects. The purpose was to investigate the intra‐rater between‐session test–retest reliability of panoramic US imaging for determining vastus lateralis (VL) and rectus femoris (RF) cross‐sectional area (mCSA) in healthy middle‐aged to elderly adults. In this cross‐sectional study, axial panoramic US images of the RF and VL muscles were captured in 23 healthy females and males aged 47 to 78. Assessed across two sessions 3–7 days apart, intra‐rater reliability was evaluated by intraclass correlation coefficients (ICC3,2), within‐subject coefficient of variation CVw−s$$ \left({\mathrm{CV}}_{\mathrm{w}-\mathrm{s}}\right) $$, standard error of measurement (SEM), and minimal detectable change (MDC). Mean mCSA for RF was mean ± SD, 7.5 ± 2.7 cm2 on both test days, with a numeric difference of 0.8%. Mean VL mCSA was 20.6 ± 6.6 cm2 and 20.5 ± 6.5 cm2 on test days 1 and 2, respectively. Test–retest ICC were: 0.997 (95% CI: 0.994–0.999) for RF and 0.995 (95% CI: 0.989–0.998) for VL. CVw−s$$ {\mathrm{CV}}_{\mathrm{w}-\mathrm{s}} $$ was 2.6% for RF and 2.4% for VL. SEM was 0.2 cm2 for RF and 0.5 cm2 for VL. MDC was 0.4 cm2 for RF and 1.3 cm2 for VL. In conclusion, panoramic EFOV US is a highly reliable imaging technique for assessing RF and VL mCSA in middle‐aged and elderly adults. These findings endorse the clinical and research utility of EFOV US and its sensitivity for detecting even minor changes in skeletal muscle size. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease, pathologically characterized by TDP‐43 aggregates. Recent evidence has been indicated that phosphorylated TDP‐43 (pTDP‐43) is present not only in motor neurons but also in muscle tissues. However, it is unclear whether testing pTDP‐43 aggregation in muscle tissue would assist in the diagnosis of ALS. We propose three key questions: (i) Is aggregation of pTDP‐43 detectable in routine biopsied muscles? (ii) Can detection of pTDP‐43 aggregation discriminate between ALS and non‐ALS patients? (iii) Can pTDP‐43 aggregation be observed in the early stages of ALS? We conducted a diagnostic study comprising 2 groups: an ALS group in which 18 cases underwent muscle biopsy screened from a registered ALS cohort consisting of 802 patients and a non‐ALS control group, in which we randomly selected 54 muscle samples from a biospecimen bank of 684 patients. Among the 18 ALS patients, 3 patients carried pathological GGGGCC repeats in the C9ORF72 gene, 2 patients carried SOD1 mutations, and 7 patients were at an early stage with only one body region clinically affected. The pTDP‐43 accumulation could be detected in routine biopsied muscles, including biceps brachii, deltoid, tibialis anterior, and quadriceps. Abnormal aggregation of pTDP‐43 was present in 94.4% of ALS patients (17/18) compared to 29.6% of non‐ALS controls (16/54; p < 0.001). The pTDP‐43 aggregates were mainly close to the sarcolemma. Using a semi‐quantified pTDP‐43 aggregates score, we applied a cut‐off value of 3 as a diagnostic biomarker, resulting in a sensitivity of 94.4% and a specificity of 83.3%. Moreover, we observed that accumulation of pTDP‐43 occurred in muscle tissues prior to clinical symptoms and electromyographic lesions. Our study provides proof‐of‐concept for the detection of pTDP‐43 accumulation via routine muscle biopsy which may serve as a novel biomarker for diagnosis of ALS. [ABSTRACT FROM AUTHOR]

Aim: To examine factors associated with lower urinary tract symptoms (LUTS) and lower urinary tract dysfunction (LUTD) in children with Duchenne muscular dystrophy (DMD). Methods: This cross‐sectional study included 45 individuals diagnosed with DMD between the ages of 5 and 18 years. LUTS were evaluated with the Dysfunctional Voiding and Incontinence Scoring System, functional levels with the Brooke Upper Extremity Functional Classification and the Vignos Scale, lumbar lordosis angle with a bubble inclinometer, pelvic inclination angles with a digital inclinometer, and muscle strength with a hand‐held dynamometer. Results: The mean age of the children was calculated as 9.00 ± 3.32 years, body weight as 31.10 ± 12.59 kg, and height as 125.87 ± 18.46 cm. LUTD was detected in 20 children (44.44%). There was an association between high LUTD severity and low strength of the following muscles: bilateral hip flexor (Dominant: r = −0.338, p = 0.023; nondominant: r = −0.411, p = 0.005), quadriceps femoris (Dominant: r = −0.445, p = 0.002; nondominant: r = −0.504, p < 0.001), elbow flexor (Dominant: r = −0.461, p = 0.001; nondominant: r = −0.455, p = 0.002), and elbow extensor (Dominant: r = −0.442, p = 0.002; nondominant: r = −0.450, p = 0.002). Upper extremity functionality level was significantly higher in the LUTD‐negative group (p = 0.004). There was no relationship between lumbar lordosis and pelvic inclination angles and LUTS symptoms (p > 0.05). Conclusion: To provide the adequate care for bladder health in children with DMD, it is essential to focus on parameters that will increase functionality and independence in this population. [ABSTRACT FROM AUTHOR]

We examined the effect of prolonged tennis playing on lower limb muscles' activity during the execution of first and second tennis serves. Ten male competitive tennis players executed five first and second serves before (pretest) and after (posttest) a 3‐h tennis match. Surface electromyographic (EMG) activity of four lower limb muscles (vastus lateralis, rectus femoris, gastrocnemius lateralis, and soleus muscles) on each leg was recorded along with maximum ball velocity measured by a radar gun and peak vertical forces recorded by a force platform. For the vastus lateralis, gastrocnemius lateralis, and soleus muscles of the left leg as well as the vastus lateralis muscle of the right leg, EMG amplitude decreased from pre‐ to posttests (p ≤ 0.033). These reductions in the EMG signal were generally more pronounced in the first serve (i.e., ranging from −10% to −40%) compared to the second serve (0% to −25%). Maximum ball velocity for both first (159 ± 12 vs. 154 ± 12 km/h) and second (126 ± 20 vs. 125 ± 15 km/h) serves remained unchanged from pre‐ to posttests (p = 0.638) Similarly, peak vertical forces did not differ between pretest and posttest for both first (1.78 ± 0.30 vs. 1.72 ± 0.29 body weight) and second (1.62 ± 0.25 vs. 1.75 ± 0.23 body weight) serves (p = 0.730). In conclusion, a 3‐h tennis match led to decreased activation levels in various leg muscles during serves, particularly in first serves compared to second serves. Despite consistent maximum ball velocity and peak vertical forces, these reductions in EMG signals suggest that skilled tennis players may adopt compensatory strategies after prolonged play. Highlights: A 3‐h tennis match resulted in reduced relative electromyographic (EMG) amplitudes for various knee extensor and plantar flexor muscles on both sides during the serve.Reductions in EMG signals were more prominent in the first serve (−10% to −40%) compared to the second serve (0% to −25%).Despite unchanged maximum ball velocities and peak vertical forces, muscle recruitment adjustments occurred in the vastus lateralis, gastrocnemius lateralis, and soleus muscles in the left leg and the vastus lateralis muscle in the right leg.Understanding changes in lower extremity muscle activation following prolonged play can help players and coaches develop strategies, such as targeted strength and conditioning protocols, to maintain effective serve technique. [ABSTRACT FROM AUTHOR]

It is known that microtrauma exists in the thigh muscles after long‐distance running such as the half‐marathon. Moreover, training characteristics of long‐distance runners may influence the specificity of the distribution of muscle fiber types in the thigh and affect muscle responses to lipid metabolism. However, the specific changes in microtrauma and intramuscular lipid in thigh muscles after a half‐marathon are unknown. A cohort of 20 healthy recreational marathon runners was recruited to complete a half‐marathon. MRI T2 mapping and 6‐echo q‐Dixon sequences were employed at baseline (P1), 2–3 h after running (P2), and 1 day after running (P3). Inflammatory markers (the T2 values) and intramuscular fat fraction (the proton density fat fraction, PDFF) were measured in thigh muscles to detect microtrauma and intramuscular lipid changes, respectively. One‐way analysis of variance showed significant time effects for T2 values and PDFF. Post hoc analysis of the 14 datasets collected at three time points revealed significantly higher T2 values in all thigh muscles after running (all p < 0.05). Significant differences in T2 values persisted for all thigh muscles at P3 compared to P1 (all p < 0.05). The PDFF of the vastus lateralis and vastus medialis was significantly decreased at P2 compared to P1 (p < 0.05). No significant differences in PDFF were observed for the thigh muscles at P3 compared to P1. The manifestations of inflammation edema and intramuscular lipid investigated through MRI may offer valuable insights for recreational marathon runners regarding the lower limb movement characteristics during half‐marathon running. Highlights: Magnetic resonance imaging (MRI) technology stands as a valuable noninvasive tool for the observation of musculature.Utilizing MRI T2 mapping and 6‐echo q‐Dixon sequences facilitates the examination of inflammatory edema resulting from endurance exercise along with intramuscular lipid changes.The manifestations of inflammation edema and intramuscular lipid investigated through MRI may unveil novel perspectives on the movement characteristics of lower limbs in recreational marathon runners. [ABSTRACT FROM AUTHOR]

Background: It is challenging to diagnose suspected Duchenne muscular dystrophy (DMD) patients in the very early stage of the disease. More evidence is needed to demonstrate the potential of quantitative MRI (qMRI) in precisely identifying patients before substantial physical decline occurs. Purpose: To assess the early diagnostic performance of multi‐parametric qMRI for DMD patients, and the ability to identify DMD patients with mild functional decline. Study Type: Prospective. Subjects: One hundred and forty DMD subjects (9.0 ± 2.2 years old), 24 male healthy controls (HCs) (9.2 ± 2.5 years old). Field Strength/Sequence: 3.0 T/3‐point Dixon, T1‐mapping, and T2‐mapping. Assessment: qMRI measurements (fat fraction [FF], T1, and T2) of 11 thigh muscles (rectus femoris [RF], vastus lateralis [VL], vastus intermedius, vastus medialis, gracilis, sartorius, adductor longus, adductor magnus [AM], semitendinosus, semimembranosus, biceps femoris long head [BFLH]) on the right side were conducted. NorthStar ambulatory assessment (NSAA) score used to evaluate the function of DMD patients and divided them into three subgroups: mild (76–100 score), moderate (51–75 score), and severe (0–50 score) functional decline. Statistical Tests: Independent t‐test, ANOVA analysis, and receiver operating characteristic (ROC) curves. A P‐value <0.05 was considered statistically significant. Results: Compared with HCs, FF and T2 were significantly higher in the group of all DMD patients, while T1 was significantly lower. The combination of T1 and T2 in RF, VL, AM, and BFLH achieved excellent area under curve (AUCs) (0.967–0.992) in differentiating five DMD patients without abnormal fat infiltration from HCs. Overall, T2 reached higher AUCs than FF and T1 in distinguishing DMD with mild functional decline from HCs, whereas FF achieved higher AUCs than T1 and T2 in distinguishing three DMD subgroups with functional decline. Data Conclusion: Multi‐parametric qMRI demonstrate effective diagnostic capabilities for DMD patients in the early stage of the disease, and can identify patients with mild physical decline. Level of Evidence: 2 Technical Efficacy: Stage 3 [ABSTRACT FROM AUTHOR]

Aim: Sarcopenia is reportedly associated with a poor prognosis in patients who undergo living‐donor liver transplantation (LDLT), most of whom are not able to tolerate muscle strengthening exercise training. Myostatin is one of the myokines and a negative regulator of skeletal muscle growth. The clinical feasibility of an electrical muscle stimulation (EMS) system, which exercises muscle automatically by direct electrical stimulation, has been reported. In this study, we aimed to determine the effect of perioperative application of SIXPAD, which is a type of EMS system, with reference to the serum myostatin and sarcopenia in LDLT patients. Method: Thirty patients scheduled for LDLT were divided into a SIXPAD group (n = 16) and a control group (n = 14). In the SIXPAD group, EMS was applied to the thighs twice daily. The serum myostatin was measured in samples obtained before use of SIXPAD and immediately before LDLT. The psoas muscle index (PMI) at the level of the third lumbar vertebra and the quadriceps muscle area were compared on computed tomography images before use of SIXPAD and 1 month after LDLT. Results: The preoperative serum myostatin was found to be higher in LDLT patients than in healthy volunteers and EMS significantly reduced the serum myostatin. Electrical muscle stimulation prevented a postoperative reduction not only in the area of the quadriceps muscles but also in the PMI despite direct stimulation of the thigh muscles. Conclusion: Stimulation of muscles by EMS decreases the serum myostatin and helps to maintain skeletal muscle in patients who have undergone LDLT. [ABSTRACT FROM AUTHOR]

Objective: To assess intrarater reliability of ultrasound‐determined measurements of skeletal muscle characteristics across different measurement outcomes, imaging techniques, and age groups. Methods: 2D ultrasound images (B‐mode) of the quadriceps were obtained from young (26 ± 4 year, n = 8 M, 8 F) and older (70 ± 7 year, n = 7 M, 5 F) adults on two occasions, separated by 6 ± 3 days. With participants in both standing and supine postures, images were collected from five anatomical sites along the anterior (two sites) and lateral (three sites) compartments of the thigh corresponding to 56%, 39%, and 22% (lateral only) of femur length. Images were analysed for muscle thickness, pennation angle, and echogenicity. Intraclass correlation coefficients (ICC) were used to assess reliability. Results: Muscle thickness values were higher (p < 0.05) on images collected in the stand versus supine posture only for muscles of the anterior compartment, independent of age. Echogenicity values were higher (p < 0.05) in the vastus intermedius on images collected in the supine versus stand posture only in older adults. Pennation angle values were not impacted by imaging posture (p > 0.05). ICC values for thickness, echogenicity, and pennation angle were generally higher for analyses conducted on images collected in the supine versus stand posture. Imaging posture generated a greater difference in ICC values in the lateral versus anterior muscles and in older versus younger participants. Conclusion: Our findings suggest that participant posture during imaging impacts the absolute values and intrarater reliability of ultrasound‐determined muscle characteristics in a muscle‐specific fashion, and this effect is greater in older compared to younger individuals. [ABSTRACT FROM AUTHOR]

Sarcopenia, the progressive loss of muscle mass and function, universally affects older adults and is closely associated with frailty and reduced quality of life. Despite the inevitable consequences of sarcopenia and its relevance to healthspan, no pharmacological therapies are currently available. Ghrelin is a gut‐released hormone that increases appetite and body weight through acylation. Acylated ghrelin activates its receptor, growth hormone secretagogue receptor 1a (GHSR1a), in the brain by binding to it. Studies have demonstrated that acyl and unacylated ghrelin (UnAG) both have protective effects against acute pathological conditions independent of receptor activation. Here, we investigated the long‐term effects of UnAG in age‐associated muscle atrophy and contractile dysfunction in mice. Four‐month‐old and 18‐month‐old mice were subjected to either UnAG or control treatment for 10 months. UnAG did not affect food consumption or body weight. Gastrocnemius and quadriceps muscle weights were reduced by 20%–30% with age, which was partially protected against by UnAG. Specific force, force per cross‐sectional area, measured in isolated extensor digitorum longus muscle was diminished by 30% in old mice; however, UnAG prevented the loss of specific force. UnAG also protected from decreases in mitochondrial respiration and increases in hydrogen peroxide generation of skeletal muscle of old mice. Results of bulk mRNA‐seq analysis and our contractile function data show that UnAG reversed neuromuscular junction impairment that occurs with age. Collectively, our data revealed the direct role of UnAG in mitigating sarcopenia in mice, independent of food consumption or body weight, implicating UnAG treatment as a potential therapy against sarcopenia. [ABSTRACT FROM AUTHOR]

We explored the impact of running in the severe intensity domain on running mechanics and muscle oxygenation in competitive runners by investigating the relationship between mechanical deviations from typical stride characteristics and muscle oxygen saturation (SmO2) in the quadriceps muscle. Sixteen youth competitive runners performed an 8‐min exhaustive running test on an outdoor track. Running mechanics were continuously monitored using inertial measurement units. Rectus femoris SmO2 and total hemoglobin (a measure of blood volume) were continuously monitored by near‐infrared spectroscopy. One‐class support vector machine (OCSVM) modeling was employed for subject‐specific analysis of the kinematic data. Statistical analysis included principal component analysis, ANOVA, and correlation analysis. Mechanical deviations from typical stride characteristics increased as the running test progressed. Specifically, the percentage of outliers in the OCSVM model rose gradually from 2.2 ± 0.8% at the start to 43.6 ± 28.2% at the end (p < 0.001, mean ± SD throughout). SmO2 dropped from 74.3 ± 8.4% at baseline to 10.1 ± 6.8% at the end (p < 0.001). A moderate negative correlation (r = −0.61, p = 0.013) was found between the average SmO2 and the percentage of outlier strides during the last 15% of the run. During high‐intensity running, alterations in running biomechanics may occur, linked to decreased quadriceps muscle oxygenation. These parameters highlight the potential of using running kinematics and muscle oxygenation in training to optimize performance and reduce injury risks. Our research contributes to understanding biomechanical and physiological responses to endurance running and emphasizes the importance of individualized monitoring. [ABSTRACT FROM AUTHOR]

Purpose: Abnormal adherence at functional myofascial interfaces is hypothesized as an important phenomenon in myofascial pain syndrome. This study aimed to investigate the feasibility of MR elastography (MRE)–based slip interface imaging (SII) to visualize and assess myofascial mobility in healthy volunteers. Methods: SII was used to assess local shear strain at functional myofascial interfaces in the flexor digitorum profundus (FDP) and thighs. In the FDP, MRE was performed at 90 Hz vibration to each index, middle, ring, and little finger. Two thigh MRE scans were performed at 40 Hz with knees flexed and extended. The normalized octahedral shear strain (NOSS) maps were calculated to visualize myofascial slip interfaces. The entropy of the probability distribution of the gradient NOSS was computed for the two knee positions at the intermuscular interface between vastus lateralis and vastus intermedius, around rectus femoris, and between vastus intermedius and vastus medialis. Results: NOSS map depicted distinct functional slip interfaces in the FDP for each finger. Compared to knee flexion, clearer slip interfaces and larger gradient NOSS entropy at the vastus lateralis–vastus intermedius interface were observed during knee extension, where the quadriceps are not passively stretched. This suggests the optimal position for using SII to visualize myofascial slip interface in skeletal muscles is when muscles are not subjected to any additional force. Conclusion: The study demonstrated that MRE‐based SII can visualize and assess myofascial interface mobility in extremities. The results provide a foundation for investigating the hypothesis that myofascial pain syndrome is characterized by changes in the mobility of myofascial interfaces. [ABSTRACT FROM AUTHOR]

Objectives: The orientation of the quadriceps femoris can be represented by the quadriceps angle (Q‐angle) has not yet been approved because of the high incidence of patellar instability. In this study, the correlations among components of the quadriceps femoris and the Q‐angle using the plain radiographic technique were assessed. This retrospective study aims to use the radiographic technique to clarify these doubts from anatomic viewpoints. Methods: One hundred consecutive young adult patients (50 men and 50 women; aged, 34 ± 5 and 33 ± 6 years, respectively) who sustained chronic unilateral lower extremity injuries (unilateral femoral, tibial nonunions or malunions) were enrolled. The contralateral intact lower extremity was used for the study. The full‐length standing scanogram (FLSS) was used to evaluate the rectus Q‐angle (R‐Q angle), vastus Q‐angle (V‐Q angle), and clinical Q‐angle (C‐Q angle; i.e., known as the Q‐angle). The three Q‐angles were compared statistically. The Mann–Whitney U test and the Kruskal–Wallis test were used for comparison among groups. The Spearman rank correlation coefficient was used to evaluate the degree of relationship between two groups. Results: The C‐Q angle or the V‐Q angle was statistically different from the R‐Q angle (p < 0.001). The C‐Q angle between sexes was not different (p = 0.25). High correlation occurred among the C‐Q angle, the R‐Q angle, and the V‐Q angles (correlation coefficient, 0.886–0.979). The multiple linear regression revealed of C‐Q angle = 0.72; R‐Q angle, p < 0.001 + 0.21; and V‐Q angle, (p = 0.009) + 2.61° in 100 patients. Conclusion: Orientation of the quadriceps femoris can be represented by the Q‐angle. Compared to the rectus femoris, the three vastus muscles of the quadriceps femoris are more correlated to the Q‐angle. [ABSTRACT FROM AUTHOR]

To investigate the effects of 8‐week hiking bench training on cardiorespiratory and muscular responses of highly trained sailors during hiking emulation. Twenty‐four sailors were assigned into two groups: the hiking bench training group (HTG, n = 12) and the control group (CG, n = 12). Both groups maintained their regular training with the HTG performed two additional hiking bench training sessions per week for 8 weeks, while the CG performed an equivalent duration of on‐water sailing training. Physiological responses were assessed by performing four successive 3‐min hiking bouts on a sailing emulation ergometer before and after the 8‐week training period. Comparing the pretest, both groups exhibited a significant decrease (p < 0.05) in the percentage of maximal oxygen uptake (%VO2max) and maximal heart rate (%HRmax); the HTG experienced a greater decrease in %VO2max in bouts 2 and 3. The root mean square (RMS) of rectus femoris (RF), vastus lateralis (VL), rectus abdominis (RA), and external oblique decreased significantly (p < 0.05), whereas the mean power frequency (MPF) of RF, VL, and RA exhibited an increasing trend. The RMS of RF and RA in HTG were lower than those in CG in the initial three bouts; VL and EA in HTG were lower than those in CG in bouts 1 and 2 (p < 0.05). The MPF of RA in HTG was significantly increased in bouts 2, 3, and 4 (p < 0.05). Eight‐week hiking bench training could improve hiking economy and the activation of lower limb and trunk muscles delaying the onset of fatigue in sailors. Highlights: Hiking is the most physically demanding task in dinghy sailing, eliciting highly specific cardiorespiratory, and muscular responses. Highly trained sailors attempt to improve the physiological response and performance of hiking through hiking bench training.Hiking bench training involves a series of movement exercises performed by sailors on sailing emulation ergometer that are tailored specific profiles with the objective of optimizing sailing performance.Hiking bench training can effectively enhance the economy of hiking among highly trained sailors, improve the activation of lower limb and trunk muscles, and delay the onset of fatigue in hiking. Hiking bench training can be used as an effective means of enhancing hiking performance for highly trained sailors. [ABSTRACT FROM AUTHOR]

We previously observed lifelong endurance exercise (LLE) influenced quadriceps whole‐muscle and myofiber size in a fiber‐type and sex‐specific manner. The current follow‐up exploratory investigation examined myofiber size regulators and myofiber size distribution in vastus lateralis biopsies from these same LLE men (n = 21, 74 ± 1 years) and women (n = 7, 72 ± 2 years) as well as old, healthy nonexercisers (OH; men: n = 10, 75 ± 1 years; women: n = 10, 75 ± 1 years) and young exercisers (YE; men: n = 10, 25 ± 1 years; women: n = 10, 25 ± 1 years). LLE exercised ~5 days/week, ~7 h/week for the previous 52 ± 1 years. Slow (myosin heavy chain (MHC) I) and fast (MHC IIa) myofiber nuclei/fiber, myonuclear domain, satellite cells/fiber, and satellite cell density were not influenced (p > 0.05) by LLE in men and women. The aging groups had ~50%–60% higher proportion of large (>7000 μm2) and small (<3000 μm2) myofibers (OH; men: 44%, women: 48%, LLE; men: 42%, women: 42%, YE; men: 27%, women: 29%). LLE men had triple the proportion of large slow fibers (LLE: 21%, YE: 7%, OH: 7%), while LLE women had more small slow fibers (LLE: 15%, YE: 8%, OH: 9%). LLE reduced by ~50% the proportion of small fast (MHC II containing) fibers in the aging men (OH: 14%, LLE: 7%) and women (OH: 35%, LLE: 18%). These data, coupled with previous findings, suggest that myonuclei and satellite cell content are uninfluenced by lifelong endurance exercise in men ~60–90 years, and this now also extends to septuagenarian lifelong endurance exercise women. Additionally, lifelong endurance exercise appears to influence the relative abundance of small and large myofibers (fast and slow) differently between men and women. [ABSTRACT FROM AUTHOR]

Limb immobilization causes rapid declines in muscle strength and mass. Given the role of the nervous system in immobilization‐induced weakness, targeted interventions may be able to preserve muscle strength, but not mass, and vice versa. The purpose of this study was to assess the effects of two distinct interventions during 1 week of knee joint immobilization on muscle strength (isometric and concentric isokinetic peak torque), mass (bioimpedance spectroscopy and ultrasonography), and neuromuscular function (transcranial magnetic stimulation and interpolated twitch technique). Thirty‐nine healthy, college‐aged adults (21 males, 18 females) were randomized into one of four groups: immobilization only (n = 9), immobilization + action observation/mental imagery (AOMI) (n = 10), immobilization + neuromuscular electrical stimulation (NMES) (n = 12), or control group (n = 8). The AOMI group performed daily video observation and mental imagery of knee extensions. The NMES group performed twice daily stimulation of the quadriceps femoris. Based on observed effect sizes, it appears that AOMI shows promise as a means of preserving voluntary strength, which may be modulated by neural adaptations. Strength increased from PRE to POST in the AOMI group, with +7.2% (Cohen's d = 1.018) increase in concentric isokinetic peak torque at 30°/s. However, NMES did not preserve muscle mass. Though preliminary, our findings highlight the specific nature of clinical interventions and suggest that muscle strength can be independently targeted during rehabilitation. This study was prospectively registered: ClinicalTrials.gov NCT05072652. What is the central question of this study?Action observation and mental imagery (AOMI) may be a possible and potentially promising rehabilitation strategy via facilitation of neural adaptations, whereas neuromuscular electrical stimulation (NMES) may augment muscle strength and mass via peripheral mechanisms. We compared the ability of these interventions to distinctly preserve strength versus mass during one week of knee joint immobilization.What is the main finding and its importance?Effect sizes suggested that AOMI preserved voluntary strength, and may be used therapeutically to target neural adaptations during immobilization. [ABSTRACT FROM AUTHOR]

Knee osteoarthritis is among the most prevalent chronic diseases. Total knee arthroplasty is a common solution that effectively addresses the continued structural degeneration of the articular cartilage. However, effective physical therapy is critical for recovery. Despite participating in physical therapy, many patients fail to recover. This study investigated the potential efficacy of a behaviorally informed approach to surface electromyographic biofeedback following total knee arthroplasty relative to the clinical standard, neuromuscular electrical stimulation. The surface electromyographic biofeedback procedure incorporated improved techniques for establishing a baseline and individualized and adjusting criteria for feedback. The findings suggest some advantages for surface electromyographic biofeedback over neuromuscular electrical stimulation in quadriceps strength, range of motion, functional recovery, and quality of life. Behaviorally informed surface electromyographic biofeedback holds promise for total knee arthroplasty recovery and these data suggest considerable room for collaboration between behavior analysts and physical therapists. [ABSTRACT FROM AUTHOR]

Background: Survival from pediatric critical illness in high‐income countries is high, and the focus now must be on optimizing the recovery of survivors. Muscle mass wasting during critical illness is problematic, so identifying factors that may reduce this is important. Therefore, the aim of this study was to examine the relationship between quadricep muscle mass wasting (assessed by ultrasound), with protein and energy intake during and after pediatric critical illness. Methods: A prospective cohort study in a mixed cardiac and general pediatric intensive care unit in England, United Kingdom. Serial ultrasound measurements were undertaken at day 1, 3, 5, 7, and 10. Results: Thirty‐four children (median age 6.65 [0.47–57.5] months) were included, and all showed a reduction in quadricep muscle thickness during critical care admission, with a mean muscle wasting of 7.75%. The 11 children followed‐up had all recovered their baseline muscle thickness by 3 months after intensive care discharge. This muscle mass wasting was not related to protein (P = 0.53, ρ = 0.019) (95% CI: −0.011 to 0.049) or energy intake (P = 0.138, ρ = 0.375 95% CI: −0.144 to 0.732) by 72 h after admission, nor with severity of illness, highest C‐reactive protein, or exposure to intravenous steroids. Children exposed to neuromuscular blocking drugs exhibited 7.2% (95% CI: −0.13% to 14.54%) worse muscle mass wasting, but this was not statistically significant (P = 0.063). Conclusion: Our study did not find any association between protein or energy intake at 72 h and quadricep muscle mass wasting. [ABSTRACT FROM AUTHOR]

Dynamic resistance exercise may produce reductions in pain locally at the exercising muscle and systemically at non‐exercising sites. However, limited research has examined these changes with multiple noxious stimuli. This study examined changes in heat pain threshold (HPT) and pressure pain threshold (PPT) on different musculature after an upper and lower body exercise to compare local and systemic effects. A crossover design with 28 participants (mean age: 21 ± 4 years, 21 female) completed three sessions. Visit one included baseline quantitative sensory testing and 5‐repetition maximum (RM) testing for upper (shoulder press) and lower (leg extension) body. In subsequent sessions, participants performed upper or lower body exercises using an estimated 75% 1‐RM with pre/post assessment of HPT and PPT at three sites: deltoid, quadriceps, and low back. A significant three‐way interaction was observed for HPT (F (1.71, 3.80) = 2.19, p = 0.036, η2p = 0.12) with significant increases in HPT over the quadriceps (p = 0.043) after leg extension and over the deltoid (p = 0.02) after shoulder press. Significant systemic changes were not observed for HPT or PPT. Local but not systemic effects were demonstrated after an acute bout of exercise. Peripheral pain sensitivity may be more responsive to heat stimuli after resistance exercise. [ABSTRACT FROM AUTHOR]

Multiple intramuscular variables have been proposed to explain the high variability in resistance training induced muscle hypertrophy across humans. This study investigated if muscular androgen receptor (AR), estrogen receptor α (ERα) and β (ERβ) content and fiber capillarization are associated with fiber and whole‐muscle hypertrophy after chronic resistance training. Male (n = 11) and female (n = 10) resistance training novices (22.1 ± 2.2 years) trained their knee extensors 3×/week for 10 weeks. Vastus lateralis biopsies were taken at baseline and post the training period to determine changes in fiber type specific cross‐sectional area (CSA) and fiber capillarization by immunohistochemistry and, intramuscular AR, ERα and ERβ content by Western blotting. Vastus lateralis volume was quantified by MRI‐based 3D segmentation. Vastus lateralis muscle volume significantly increased over the training period (+7.22%; range: −1.82 to +18.8%, p < 0.0001) but no changes occurred in all fiber (+1.64%; range: −21 to +34%, p = 0.869), type I fiber (+1.33%; range: −24 to +41%, p = 0.952) and type II fiber CSA (+2.19%; range: −23 to +29%, p = 0.838). However, wide inter‐individual ranges were found. Resistance training increased the protein expression of ERα but not ERβ and AR, and the increase in ERα content was positively related to changes in fiber CSA. Only for the type II fibers, the baseline capillary‐to‐fiber‐perimeter index was positively related to type II fiber hypertrophy but not to whole muscle responsiveness. In conclusion, an upregulation of ERα content and an adequate initial fiber capillarization may be contributing factors implicated in muscle fiber hypertrophy responsiveness after chronic resistance training. [ABSTRACT FROM AUTHOR]

Background: Allogeneic hematopoietic stem cell transplantation (allo‐HSCT) is a potentially curative treatment for hematological malignancies. Several complications following allo‐HSCT, such as graft‐versus‐host disease, infection, and malnutrition, often cause physical dysfunction, and the assessment of physical function and evaluation of muscle mass are incompletely performed. Use of ultrasound (US) allows muscle mass measurement in patients with poor general conditions. In allo‐HSCT recipients, the correlation between physical function and muscle thickness, as measured by US, remains unclear. Objective: To clarify whether muscle thickness measured by US correlated with physical function in allo‐HSCT recipients. Design: A single‐center prospective cohort study. Setting: Hospital. Patients: Ninety‐two patients underwent allo‐HSCT at our hospital from April 2017 to March 2019. Interventions: Not applicable. Main Outcome Measure(s): Biceps and quadriceps muscle thickness measured by US, grip strength, isometric muscle strength (elbow flexion and knee extension), and 6‐minute walking test (6MWT) before allo‐HSCT and on days 30, 90, 180, 1 year, and 2 years after allo‐HSCT. The implementation rates of these assessments were also investigated. Results: Correlations were observed between biceps thickness and elbow flexion muscle strength/grip strength before allo‐HSCT, on days 30, 90, 180, 1 year, and 2 years after allo‐HSCT (r = 0.71/0.74, 0.73/0.72, 0.70/0.79, 0.67/0.75, 0.72/0.75, and 0.85/0.79, respectively, all p <.001). At the same time points, quadriceps thickness moderately correlated with knee extensor strength (r = 0.49, 0.50, 0.45, 0.64, 0.61, and 0.58, all p <.001). However, biceps and quadriceps thicknesses did not correlate with the 6MWT. The percentages of patients measured with US and 6MWT were 93.4% and 82.4% (p =.01) on day 30 and 97.5% and 87.8% (p =.02) on day 90, respectively. Conclusions: US assessment may be a useful alternative method for estimating muscle strength in fragile allo‐HSCT recipients, particularly when physical function assessment is difficult to quantify. [ABSTRACT FROM AUTHOR]

Background: Associations between muscle architecture and rate of force development (RFD) have been largely studied during fixed‐end (isometric) contractions. Fixed‐end contractions may, however, limit muscle shape changes and thus alter the relationship between muscle architecture an RFD. Aim: We compared the correlation between muscle architecture and architectural gearing and knee extensor RFD when assessed during dynamic versus fixed‐end contractions. Methods: Twenty‐two recreationally active male runners performed dynamic knee extensions at constant acceleration (2000°s−2) and isometric contractions at a fixed knee joint angle (fixed‐end contractions). Torque, RFD, vastus lateralis muscle thickness, and fascicle dynamics were compared during 0–75 and 75–150 ms after contraction onset. Results: Resting fascicle angle was moderately and positively correlated with RFD during fixed‐end contractions (r = 0.42 and 0.46 from 0–75 and 75–150 ms, respectively; p < 0.05), while more strongly (p < 0.05) correlated with RFD during dynamic contractions (r = 0.69 and 0.73 at 0–75 and 75–150 ms, respectively; p < 0.05). Resting fascicle angle was (very) strongly correlated with architectural gearing (r = 0.51 and 0.73 at 0–75 ms and 0.50 and 0.70 at 75–150 ms; p < 0.05), with gearing in turn also being moderately to strongly correlated with RFD in both contraction conditions (r = 0.38–0.68). Conclusion: Resting fascicle angle was positively correlated with RFD, with a stronger relationship observed in dynamic than isometric contraction conditions. The stronger relationships observed during dynamic muscle actions likely result from different restrictions on the acute changes in muscle shape and architectural gearing imposed by isometric versus dynamic muscle contractions. [ABSTRACT FROM AUTHOR]

Background: Athletic taping has long been a physiotherapeutic application in individuals with patellofemoral pain (PFP). However, the therapeutic effects of local and proximal taping have not been fully determined. Objective: To evaluate the effects of two different taping techniques applied in addition to exercise on patellofemoral alignment, pain, and function in individuals with PFP. Design: Randomized controlled trial. Setting: An outpatient hospital clinic. Participants: Individuals with PFP aged 18–50 years (n = 36). Interventions: Group 1 underwent only the exercise program. Group 2 underwent the exercise plus McConnell patellar taping (MPT), and Group 3 underwent the exercise plus femoral rotational taping (FRT) (6 weeks). Main Outcome Measures: Bisect offset index (BOI) and patellar tilt angle (PTA) were measured in relaxed and maximum voluntary contractions of the quadriceps muscle (MVCq) using magnetic resonance imaging. Pain intensity was assessed by the Visual Analog Scale for three conditions: at daytime rest, during activity, and at nighttime. Functional level was assessed by the Kujala Patellofemoral Scoring System. Results: Significant improvements in the BOI of Group 2 at rest (p =.015; r = 0.593) and in PTA of Group 3 at MVCq (p =.010; r = 0.613) were found. Improvements in pain under all three conditions were significant within groups (all, p values <.050 and r > 0.5). The change in pain was similar between groups (all, p values >.05). All groups showed significant improvement in functional level (all, p values <.010 and r > 0.5). However, the increase in Group 3 was higher than that in Group 1 (p =.019). Conclusion: This study shows that MPT and FRT applications increase functionality and can affect patellofemoral alignment in different ways. In the treatment of PFP, more successful results can be obtained with appropriate taping techniques for the local and proximal region. [ABSTRACT FROM AUTHOR]

Diabetic foot ulcers (DFUs) present significant challenges due to their associated amputation rates, mortality, treatment complexity and excessive costs. Our earlier work introduced a wound surgical integrated treatment (WSIT) for DFUs, yielding promising outcomes. This study focuses on a specific WSIT protocol employing antibiotic‐loaded bone cement (ALBC) in the first Stage, and free vastus lateralis muscle‐sparing (VLMS) flaps and split‐thickness skin grafts (STSGs) in the second stage to repair non‐weight‐bearing DFUs. From July 2021 to July 2023, seven DFU patients (aged 47–71 years) underwent this treatment. Demographic data, hospital stay and repair surgery times were collected. Histological and immunohistochemical analyses assessed angiogenesis, collagen deposition and inflammation. SF‐36 questionnaire measured pre‐ and postoperative quality of life. Preoperative ultrasound Doppler showed that the peak blood flow velocity of the recipient area artery was significantly >30 cm/s (38.6 ± 6.8 cm/s) in all patients. Muscle flap sizes varied from 8 × 3.5 × 1 to 18 × 6 × 2 cm. The operation time of the repair surgery was 156.9 ± 15.08 minutes, and the hospital stay was 18.9 ± 3.3 days. Histological analysis proved that covering DFUs with ALBC induced membrane formation and increased collagen, neovascularization and M2 macrophages fraction while reducing M1 macrophages one. All grafts survived without amputation during a 7‐ to 24‐month follow‐up, during which SF‐36 scores significantly improved. A combination of ALBC with free VLMS flaps and STSGs proved to be safe and effective for reconstructing non‐weight‐bearing DFUs. It rapidly controlled infection, enhanced life quality and foot function, and reduced hospitalization time. We advocate integrating this strategy into DFU treatment plans. [ABSTRACT FROM AUTHOR]

Backgrounds: The lack of systematic classification and standard treatment principles for knee ankylosis prevents optimal treatments. This study explored treatments for type I (mild) knee joint ankylosis. Method: This retrospective study analysed patients with knee joint ankylosis admitted from March 2013 to January 2018 who underwent sequential arthroscopic release. Result: The 62 patients had 12–36 (average, 18) months of follow‐up. Thirty‐eight patients were released; of these, 18 were assisted by limited incision with partial quadriceps femoris expansion myotomy and released according to arthroscopy. Six patients underwent lengthening and release of the quadriceps femoris. All surgeries combined with full‐course rehabilitation resulted in improved joint mobility. The range of motion (ROM) of the knee joint recovered to a range of 0° to 85°‐140° (mean: 118.32 ± 9.42°) from the preoperative range of 30°–70° (mean: 45° ± 15.50°). The clinical effect was evaluated according to the Judet criteria at the final follow‐up. The outcomes at the last follow‐up (at least for 1 year) were excellent in 55 cases, good in six cases, and fair in one case. Conclusion: Sequential arthroscopic release, minimal selective invasion of limited incision of partial quadriceps femoris expansion myotomy, assisted by pie‐crusting technique to release, or quadriceps femoris lengthening, and release surgery for type I knee joint ankylosis, accompanied by early rehabilitation training provided satisfactory results without significant complications. [ABSTRACT FROM AUTHOR]

Anterior cruciate ligament (ACL) ruptures result in lasting quadriceps dysfunction that contributes to secondary injury risk and development of osteoarthritis. There is evidence of persistent reduced nervous system drive (corticospinal excitability [CSE]) to the quadriceps and sex differences in both quadriceps performance and CSE post‐ACL reconstruction (ACLR). The purposes of this study were to investigate the differences in CSE and quadriceps dysfunction after ACLR between sexes and relative to controls. Twenty subjects 4–9 months post‐ACLR and 20 age, sex, and activity matched controls participated in this study. Quadriceps performance (peak torque, PT; rate of torque development from onset to 100 ms, RTD100; and RTD from 100 to 200ms, RTD200) and CSE (active motor threshold; slope of the stimulus response (SR) curve, SR curve slope) were measured using an isokinetic dynamometer (HUMAC NORM) and transcranial magnetic stimulation respectively. Significant group differences were found for SR curve slope, PT, RTD100, and RTD200 on the surgical limb. Males after ACLR had higher slopes (higher CSE) than females. Females after ACLR had worse surgical limb quadriceps PT than control males and slower RTD100 and RTD200 than control males and control females. Higher CSE in males after ACLR may point to a potentially adaptive neurological change in males post‐ACLR and indicate greater need for novel interventions to address cortical drive in females after ACLR. [ABSTRACT FROM AUTHOR]

While physical performance has long been thought to be limited only by physiological factors, many experiments denote that psychological ones can also influence it. Specifically, the deception paradigm investigates the effect of psychological factors on performance by manipulating a psychological variable unbeknownst to the subjects. For example, during a physical exercise performed to failure, previous results revealed an improvement in performance (i.e., holding time) when the clock shown to the subjects was deceptively slowed down. However, the underlying neurophysiological changes supporting this performance improvement due to deceptive time manipulation remain unknown. Here, we addressed this issue by investigating from a neuromuscular perspective the effect of a deceptive clock manipulation on a single‐joint isometric task conducted to failure in 24 healthy participants (11 females). Neuromuscular fatigue was assessed by pre‐ to post‐exercise changes in quadriceps maximal voluntary torque (Tmax), voluntary activation level (VAL), and potentiated twitch (TTW). Our main results indicated a significant performance improvement when the clock was slowed down (Biased: 356 ± 118 s vs. Normal: 332 ± 112 s, p =.036) but, surprisingly, without any difference in the associated neuromuscular fatigue (p >.05 and BF < 0.3 for Tmax, VAL, and TTW between both sessions). Computational modeling showed that, when observed, the holding time improvement was explained by a neuromuscular fatigue accumulation based on subjective rather than actual time. These results support a psychological influence on neuromuscular processes and contribute significantly to the literature on the mind–body influence, by challenging our understanding of fatigue. Limits of physical performance can be extended by psychological manipulation. However, the fundamental mechanisms underlying this phenomenon remain unclear. Here we explore the underlying neurophysiological changes that support performance improvement due to deceptive clock manipulation. Our results showed that fatigue accumulation followed subjective rather than real time for participants who improved their performance, thus allowing to overcome physical performance limits without increasing the generated neuromuscular fatigue. [ABSTRACT FROM AUTHOR]

The downward slope during the near‐infrared spectroscopy (NIRS)‐vascular occlusion test (NIRS‐VOT) is purported as a simplified estimate of metabolism. Whether or not the NIRS‐VOT exhibits sex‐ or limb‐specificity or may be acutely altered remains to be elucidated. Thus, we investigated if there is limb‐ or sex specificity in tissue desaturation rates (DeO2) during a NIRS‐VOT, and if acute dietary capsaicin may alter this estimate of muscle metabolism. Young healthy men (n = 25, 21 ± 4 years) and women (n = 20, 20 ± 1 years) ingested either placebo or capsaicin, in a counterbalanced, single‐blind, crossover design after which a simplified NIRS‐VOT was conducted to determine the DeO2 (%/s), as an estimate of oxidative muscle metabolism, in both the forearm (flexors) and thigh (vastus lateralis). There was a significant limb effect with the quadriceps having a greater DeO2 than the forearm (−2.31 ± 1.34 vs. −1.78 ± 1.22%/s, p = 0.007, ηp2 = 0.19). There was a significant effect of sex on DeO2 (p = 0.005, ηp2 = 0.203) with men exhibiting a lesser DeO2 than women (−1.73 ± 1.03 vs. −2.36 ± 1.32%/s, respectively). This manifested in significant interactions of limb*capsaicin (p = 0.001, ηp2 = 0.26) as well as limb*capsaicin*sex on DeO2 (p = 0.013, ηp2 = 0.16) being observed. Capsaicin does not clearly alter O2‐dependent muscle metabolism, but there was apparent limb and sex specificity, interacting with capsaicin in this NIRS‐derived assessment. [ABSTRACT FROM AUTHOR]

This article presents a case report of an 11-year-old girl with progressive limitation of movement in her left knee. The patient was diagnosed with a fibrotic band of the vastus lateralis muscle, which caused restricted knee flexion. The article discusses the rarity of this condition and emphasizes the importance of careful assessment and necessary imaging procedures to identify and manage such cases. The authors highlight the potential permanent alterations in the joint and related structures if the condition is not promptly addressed. [Extracted from the article]

Introduction: In patients with haemophilia A, chronic arthropathy develops over time as a result of recurrent joint bleeds, which leads to restricted mobility and disability in the affected joints. There are limited studies in the literature evaluating sarcopenia in patients with haemophilia. The present study aims to determine the prevalence of sarcopenia in severe haemophilia‐A patients and to evaluate musculoskeletal health and functional performance. Methods: Thirty haemophilia‐A patients and 26 adult male volunteers were enrolled in the study. For detection of sarcopenia, the appendicular skeletal muscle mass (ASM) obtained by bioelectrical impedance analysis (BIA) was divided by height squared (m2) to obtain the appendicular skeletal muscle mass index (ASMI) value. The thighs of both lower extremities were measured using the Modified Sonographic Tight Adjustment Ratio (STAR) method, which was obtained by adding the bilateral rectus femoris and vastus intermedius muscle thicknesses measured by ultrasound. Hand and quadriceps muscle strength (MS) were measured with a dynamometer. Physical performance was determined using the walking speed (WS), timed up‐and‐go test (TUGT), 5‐repetition sit‐to‐stand test (5RSTS), and 6‐min walk test (6MWT). Haemophilia Joint Health Score (HJHS) and Haemophilia Early Arthropathy Detection‐Ultrasonography (HEAD‐US) were also used to assess the musculoskeletal system. Results: According to the modified STAR values calculated based on body mass index, sarcopenia was present in 15 (50%) of 30 patients. However, based on the ASMI‐BIA values, sarcopenia was present in only two (6.6%) patients. A weak correlation was found between ASMI and HJHS, HEAD‐US, WS, TUGT, and hand MS (left), while a moderate correlation was found with knee MS (right), knee MS (left), and 5RSTS. A strong correlation was found between the modified STAR score and HEAD‐US, HJHS, knee MS (left), 5RSTS, TUGT, and WS, while a moderate correlation was found with hand MS (left), hand MS (right), and knee MS (right). Conclusion: This study showed muscle loss, joint mobility restrictions, and decreased functional capacity in haemophilia patients and demonstrated the presence of sarcopenia in these patients. The STAR measurement method showed stronger relationships with MS and functional performance values than ASMI measurements in terms of evaluating sarcopenia. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the muscle activation of the vastus medialis, vastus lateralis, and gluteus medius during different strength and stability exercises with a water tank compared with a sandbag. A cross‐sectional study was conducted in the Functional Anatomy Laboratory, and the sample consisted of 28 athletes. The main outcome measures were surface electromyography (dependent variable), water tank and sandbag, and exercise type (independent variables): Isometric Single Leg Stance (ISLS), One Leg Deadlift (OLDL), Front Rack Forward Lunge (FRFL), and Lateral Lunge (LL). Repeated measures analysis of variance (ANOVA) revealed a significant Group × Time interaction in gluteus medius root mean square (RMS) (F = 14.198, p < 0.001, ŋ2 = 0.35), vastus lateralis RMS (F = 24.374, p < 0.001, ŋ2 = 0.47), and vastus medialis RMS (F = 27.261, p < 0.001, ŋ2 = 0.50). In the between‐group analysis, statistically significant differences were observed in gluteus medius RMS in the ISLS: 28.5 ± 15.8 water tank and 20.8 ± 12.6 sandbag (p < 0.001, ŋ2 = 0.08) and OLDL: 29.7 ± 13.3 water tank and 26.5 ± 13.1 sandbag (p < 0.001, ŋ2 = 0.01). In vastus lateralis in ISLS: 30.4 ± 37.6 water tank and 19.0 ± 26.7 sandbag (p < 0.001, ŋ2 = 0.03). In vastus medialis in ISLS: 14.2 ± 13.0 water tank and 7.0 ± 5.6 sandbag (p < 0.001, ŋ2 = 0.12), OLDL: 21.5 ± 16.9 water tank and 15.5 ± 10.7 sandbag (p = 0.002, ŋ2 = 0.04), and LL: 51.8 ± 29.6 water tank and 54.3 ± 29.3 sandbag (p = 0.017, ŋ2 = 0.00). These results confirm significantly greater activation of the gluteus medius and vastus medialis in the ISLS and OLDL exercises, and of the vastus lateralis in the water tank ISLS exercise. However, the vastus medialis shows greater activation in the LL exercise. [ABSTRACT FROM AUTHOR]

The first aim of this study was to compare the medial patellofemoral length between contracted and relaxed quadriceps muscle and second to assess the importance of the intermeshed vastus medialis oblique fibers. After a priori power analysis (α = 0.05, power [1−β] = 0.95), 35 healthy males aged 18–30 were prospectively examined with a 3.0‐T magnetic resonance imaging (MRI) scanner in 10–15° of knee flexion. Two axial MRI sequences (25 s each) were made with relaxed and contracted quadriceps. Two blinded, independent raters measured twice medial patellofemoral ligament length (curved line) and attachment‐to‐attachment length (straight line). Mean medial patellofemoral ligament length and attachment‐to‐attachment length with relaxed quadriceps was: 65.5 mm (SD = 3.7), 59.7 mm (SD = 3.6), and after contraction, it increased to 68.7 mm (SD = 5.3), 61.2 mm (SD = 4.7); p < 0.01 and <0.001, respectively. Intraclass correlation coefficients for intra‐ and inter‐rater reliabilities ranged from 0.55 (moderate) to 0.97 (excellent). Mean medial patellofemoral ligament length elongation after quadriceps contraction was significantly greater (3.2 mm, SD = 3.9) than mean attachment‐to‐attachment length elongation (1.6 mm, SD = 2.8); p < 0.001. Contraction of quadriceps muscle causes elongation of the medial patellofemoral ligament to the extent greater than the elongation of distance between its attachments. This confirms that medial patellofemoral ligament elongation after quadriceps contraction results not only from movement of its patellar attachment but also directly from intermeshed vastus medialis oblique fibers pulling medial patellofemoral ligament in a different direction creating a bow‐like construct in agreement with the "pull‐and‐guide mechanism" proposed in the literature. [ABSTRACT FROM AUTHOR]

Objectives: Cardiorespiratory fitness (CRF) declines with advancing and has also, independent of age, been shown to be predictive of all‐cause mortality, morbidity, and poor clinical outcomes. In relation to the older patient, there is a particular wealth of evidence highlighting the relationship between low CRF and poor surgical outcomes. Cardiopulmonary exercise testing (CPET) is accepted as the gold‐standard measure of CRF. However, this form of assessment has significant personnel and equipment demands and is not feasible for those with certain age‐associated physical limitations, including joint and cardiovascular comorbidities. As such, alternative ways to assess the CRF of older patients are very much needed. Methods: Sixty‐four participants (45% female) with a median age of 74 (65–90) years were recruited to this study via community‐based advertisements. All participants completed three tests of physical function: (1) a step‐box test; (2) handgrip strength dynamometry; and (3) a CPET on a cycle ergometer; and also had their muscle architecture (vastus lateralis) assessed by B‐mode ultrasonography to provide measures of muscle thickness, pennation angle, and fascicle length. Multivariate linear regression was then used to ascertain bedside predictors of CPET parameters from the alternative measures of physical function and demographic (age, gender, body mass index (BMI)) data. Results: There was no significant association between ultrasound‐assessed parameters of muscle architecture and measures of CRF. VO2peak was predicted to some extent from fast step time during the step‐box test, gender, and BMI, leading to a model that achieved an R2 of 0.40 (p < 0.001). Further, in aiming to develop a model with minimal assessment demands (i.e., using handgrip dynamometry rather than the step‐box test), replacing fast step time with non‐dominant HGS led to a model which achieved an R2 of 0.36 (p < 0.001). Non‐dominant handgrip strength combined with the step‐box test parameter of fast step time and BMI delivered the most predictive model for VO2peak with an R2 of 0.45 (p < 0.001). Conclusions: Our findings show that simple‐to‐ascertain patient characteristics and bedside assessments of physical function are able to predict CPET‐derived CRF. Combined with gender and BMI, both handgrip strength and fast step time during a step‐box test were predictive for VO2peak. Future work should apply this model to a clinical population to determine its utility in this setting and to explore if simple bedside tests are predictive of important clinical outcomes in older adults (i.e., post‐surgical complications). [ABSTRACT FROM AUTHOR]

Objective: To describe the epidemiology of quadriceps muscle strain injury (QMSI) in elite Australian Football League (AFL) players, explore recovery milestones and determine whether recovery is impacted by factors such as injury type (index vs. re‐injury), the primary muscle injured and the mechanism of injury. Measures: All QMSI data reported to the Soft Tissue Injury Registry of the AFL from the 2014 to 2020 seasons were evaluated. Player demographic data, circumstances of injury, MRI reports and recovery outcomes following injury were extracted. Descriptive statistics and frequency distributions are presented. Recovery outcomes for injury type, primary muscle injured and the mechanism of injury were compared using univariate analyses. Results: There were 164 QMSIs from 122 players reported (134 index; 30 re‐injuries). Almost all (91.3%) QMSIs involved the rectus femoris. Half (48.4%) of the QMSIs occurred during kicking and most commonly affected the dominant kicking leg (72%). The majority occurred at training (64.6%). All re‐injuries involved the rectus femoris, most occurred from kicking (63.0%) and within 6 months of the preceding injury (70%). The mean return to play (RTP) time was 25.4 days (95%CI = 22.6–28.2) and rectus femoris injuries took around 14 days longer to RTP than vastii injuries (p = 0.001). QMSIs with a kicking mechanism took the longest to RTP of all injury mechanisms. Conclusion: In AFL players, QMSIs occur mostly in the dominant leg from a kicking mechanism. Rectus femoris injuries are more prevalent and result in longer RTP time frames. Re‐injuries exclusively involved the rectus femoris, primarily from kicking. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to examine whether 10‐20‐30 training (consecutive 1‐min intervals consisting of 30 s at low‐speed, 20 s at moderate‐speed, and 10 s at high‐speed), performed with submaximal effort during the 10‐s high‐speed runs, would lead to improved performance as well as increased maximum oxygen uptake (VO2‐max) and muscle oxidative phosphorylation (OXPHOS). In addition, to examine to what extent the effects would compare to 10‐20‐30 running conducted with maximal effort. Design: Nineteen males were randomly assigned to 10‐20‐30 running performed with either submaximal (SUBMAX; n = 11) or maximal (MAX; n = 8) effort, which was conducted three times/week for 6 weeks (intervention; INT). Before and after INT, subjects completed a 5‐km running test and a VO2‐max test, and a biopsy was obtained from m. vastus lateralis. Results: After compared to before INT, SUBMAX and MAX improved (p < 0.05) 5‐km performance by 3.0% (20.8 ± 0.4 (means±SE) vs. 21.5 ± 0.4 min) and 2.3% (21.2 ± 0.4 vs. 21.6 ± 0.4 min), respectively, and VO2‐max was ~7% higher (p < 0.01) in both SUBMAX (57.0 ± 1.3 vs. 53.5 ± 1.1 mL/min/kg) and MAX (57.8 ± 1.2 vs. 53.7 ± 0.9 mL/min/kg), with no difference in the changes between groups. In SUBMAX, muscle OXPHOS was unchanged, whereas in MAX, muscle OXPHOS subunits (I‐IV) and total OXPHOS (5.5 ± 0.3 vs 4.7 ± 0.3 A.U.) were 9%–29% higher (p < 0.05) after compared to before INT. Conclusion: Conducting 10‐20‐30 training with a non‐maximal effort during the 10‐s high‐speed runs is as efficient in improving 5‐km performance and VO2‐max as maximal effort exercise, whereas increase in muscle OXPHOS occur only when the 10‐s high‐speed runs are performed with maximal effort. [ABSTRACT FROM AUTHOR]

Resistance exercise training is effective to counteract the adverse effects of androgen deprivation therapy (ADT) on body composition, muscle mass and leg strength in prostate cancer patients (PCa). However, it is unknown whether these effects can be autonomously maintained after cessation of the supervised program. Sixty‐eight PCa patients on ADT were included. The exercise intervention group (EX, n = 37) performed 20 weeks of supervised resistance exercise training. Thereafter, patients were advised to autonomously continue exercise training. The control group (CON, n = 31) only received usual care. Outcome measures were compared between baseline and after 1 year. Changes during the intervention (baseline vs. 20 weeks) and follow‐up period (20 weeks vs. 1 year) were descriptively explored. In EX, 83% reported to have continued exercise training themselves. After 1 year, fat mass gains were attenuated in EX compared to CON (1.2 ± 2.6 and 2.8 ± 1.9 kg, respectively; time × treatment effect p = 0.032). The fat percentage increased, and lean mass and quadriceps muscle cross‐sectional area decreased over time, with no differences between groups (overall 1.6 ± 2.1%, −0.7 ± 2.3 kg and −2.2 ± 2.9 cm2, respectively; time effects, all p < 0.05). For muscle strength, an increase of ∼5% in EX was observed, significantly different from the ∼10% decrease in CON (p < 0.001). Subsequent analyses showed that the initial exercise training‐obtained gains in lean mass, muscle mass and strength in EX compared to CON, declined during the follow‐up period. In conclusion, PCa patients on ADT are not capable to autonomously maintain the exercise‐obtained gains of a 20‐week supervised training program over a subsequent 1‐year period. Highlights: ADT for prostate cancer results in many side effects, including muscle mass lossA supervised resistance exercise training program can counteract many side effectsAfter cessation of the supervised program, exercise benefits are not effectively preservedMore focus on sustainability of exercise programs during ADT is required [ABSTRACT FROM AUTHOR]

Studies examining the effect of protein (PRO) feeding on post resistance exercise (RE) muscle protein synthesis (MPS) have primarily been performed in men, and little evidence is available regarding the quantity of PRO required to maximally stimulate MPS in trained women following repeated bouts of RE. We therefore quantified acute (4 h and 8 h) and extended (24 h) effects of two bouts of resistance exercise, alongside protein‐feeding, in women, and the PRO requirement to maximize MPS. Twenty‐four RE trained women (26.6 ± 0.7 years, mean ± SEM) performed two bouts of whole‐body RE (3 × 8 repetitions/maneuver at 75% 1‐repetition maximum) 4 h apart, with post‐exercise ingestion of 15 g, 30 g, or 60 g whey PRO (n = 8/group). Saliva, venous blood, and a vastus lateralis muscle biopsy were taken at 0 h, 4 h, 8 h, and 24 h post‐exercise. Plasma leucine and branched chain amino acids were quantified using gas chromatography mass spectrometry (GC–MS) after ingestion of D2O. Fifteen grams PRO did not alter plasma leucine concentration or myofibrillar synthetic rate (MyoFSR). Thirty and sixty grams PRO increased plasma leucine concentration above baseline (105.5 ± 5.3 μM; 120.2 ± 7.4 μM, respectively) at 4 h (151.5 ± 8.2 μM, p < 0.01; 224.8 ± 16.0 μM, p < 0.001, respectively) and 8 h (176.0 ± 7.3 μM, p < 0.001; 281.7 ± 21.6 μM, p < 0.001, respectively). Ingestion of 30 g PRO increased MyoFSR above baseline (0.068 ± 0.005%/h) from 0 to 4 h (0.140 ± 0.021%/h, p < 0.05), 0 to 8 h (0.121 ± 0.012%/h, p < 0.001), and 0 to 24 h (0.099 ± 0.011%/h, p < 0.01). Ingestion of 60 g PRO increased MyoFSR above baseline (0.063 ± 0.003%/h) from 0 to 4 h (0.109 ± 0.011%/h, p < 0.01), 0 to 8 h (0.093 ± 0.008%/h, p < 0.01), and 0 to 24 h (0.086 ± 0.006%/h, p < 0.01). Post‐exercise ingestion of 30 g or 60 g PRO, but not 15 g, acutely increased MyoFSR following two consecutive bouts of RE and extended the anabolic window over 24 h. There was no difference between the 30 g and 60 g responses. [ABSTRACT FROM AUTHOR]

Imbalances between muscle strength and tendon stiffness may cause high‐level tendon strain during maximum effort muscle contractions and lead to tendon structural impairments and an increased risk for tendinopathy in adolescent athletes. However, it remains unclear whether the development of musculotendinous imbalances is influenced by sex. At four measurement time points during a competitive season, we measured quadriceps femoris muscle strength and patellar tendon mechanical properties in 15 female (14.3 ± 0.7 years) and 13 male (16.0 ± 0.6 years) elite handball players of similar maturity using dynamometry and ultrasonography. To estimate the tendon's structural integrity, the peak spatial frequency (PSF) of proximal tendon ultrasound scans was determined. Females demonstrated significantly lower muscle strength (p < 0.001) and patellar tendon stiffness (p < 0.001) than males with no significant changes over time (p > 0.05). Tendon strain during isometric maximum voluntary contractions and PSF neither differed between sexes nor changed significantly over time (p > 0.05). We found lower fluctuations in muscle strength (p < 0.001) in females during the season but no differences in the fluctuations of tendon strain, stiffness, and PSF (p > 0.05). Descriptively, there was a similar frequency (~40%) of athletes with high‐level tendon strain (>9%) in both sexes. These findings suggest that the lower strength capacity of female athletes is paralleled by lower tendon stiffness. Thereby, muscle–tendon imbalances occur to a similar extent in both sexes leading to increased strain levels during the season, which indicates the need for specific tendon training. [ABSTRACT FROM AUTHOR]

We aimed to investigate the impact of pistachio nut consumption on muscle soreness and function following exercise-induced muscle damage. Using a randomised cross-over design, male teamsport players (n = 18) performed a 40-minute downhill treadmill run to induce muscle damage, which was conducted after 2-wks of consuming either control (CON, water), a standard dose of daily pistachios (STD, 42.5 g/d) or a higher dose of daily pistachios (HIGH, 85 g/d). Lower limb muscle soreness (visual analogue scale), muscle function (maximal voluntary isokinetic torque and vertical jump), and blood markers of muscle damage/inflammation (creatine kinase, Creactive protein, myoglobin, superoxide dismutase) were measured pre (baseline) and post (24, 48, and 72 h) exercise. No trial order effects were observed for any outcome measurement across trials. Mean quadriceps soreness (non-dominant leg) during exercise recovery was reduced (p < 0.05) in HIGH vs. CON (mean difference (95%CI): 13(1-25) mm). Change in soreness in the dominant quadriceps was not different between HIGH vs. CON (p = 0.06; mean difference (95%CI): 13(-1 to 26 mm)). No main effects of time or trial were observed for mean soreness of hamstrings, or on isokinetic torque of knee extensors or knee flexors, during recovery. Serum creatine kinase concentration peaked at 24 h post-damage (mean(SEM): 763(158)µg/L) from baseline (300(87)µg/L), but had returned to baseline by 72 h post (398(80)µg/L) exercise in all trials, with no trial or trial × time interaction evident. These data suggest that high dose pistachio nut ingestion may provide some alleviation of muscle soreness, but no effect on muscle function, following modest muscle damage. [ABSTRACT FROM AUTHOR]

The rectus femoris and its covering, the fascia lata (i.e., fascia profundis), are two anatomical structures involved in anterior thigh stretching. This study aimed to identify the role of strain changes in the fascia lata in limiting stretch tolerance. The reaction force intensity of 11 men and 5 women was assessed during passive stretching of the anterior thigh at 130, 110, 90, and 70° of knee flexion. Recent data suggest that the fascia lata strain field is modified with knee flexion. Therefore, the relationship between knee flexion angle and stretch tolerance was assessed. We found that the reaction force of the anterior thigh increased almost linearly with the degree of knee extension between 130° and 70°. The fascia lata stretched surface proprioceptive information seems responsible for stretch tolerance. Fascia profundis strain field must be considered during stretching experiments. [ABSTRACT FROM AUTHOR]

A 1‐year‐old, female, domestic shorthair cat was referred for orthopaedic evaluation of acute‐onset, non‐progressive left pelvic limb lameness of 2.5‐week duration. Orthopaedic examination revealed an abnormal gait with impaired ability to support weight on the left pelvic limb. There was marked atrophy of the quadriceps muscles. Neurological examination revealed an absent patellar reflex and decreased sensation in the cutaneous zone of the saphenous nerve of the left pelvic limb. Magnetic resonance imaging showed T2‐weighted/short‐tau inversion recovery hyperintensity and contrast enhancement in the area of the femoral nerve and within muscles innervated by this nerve. Findings were deemed consistent with traumatic nerve injury and denervation/traumatic myopathy or myositis/neuritis. Electromyography of the quadriceps muscles revealed fibrillation potentials and positive sharp waves. Follow‐up over the next 9 months revealed no changes in the neurological deficits. This was deemed to be consistent with either partial axonotmesis or partial neurotmesis of the left femoral nerve. [ABSTRACT FROM AUTHOR]

Purpose: Although total hip arthroplasty (THA) is expected to result in a postoperative loss of muscular strength, no study investigated the benefit of an enhanced-recovery-after-surgery (ERAS) concept on the hip muscles in detail. We evaluated if (1) an ERAS-concept for primary THA results in reduced loss of muscular strength five days and four weeks postoperative. We (2) compared the two groups regarding Patient-Related-Outcome-Measures (PROMs), WOMAC-index (Western-Ontario-and-McMaster-Universities-Osteoarthritis-Index), HHS (Harris-Hip-Score) and EQ-5d-3L-score. Methods: In a prospective, single-blinded, randomized controlled trial, we compared isokinetic muscular strength of 24 patients receiving primary THA with an enhanced recovery concept with early mobilization (n = 12, ERAS-group) and such receiving conventional THA (n = 12, non-ERAS). Isokinetic muscular strength was measured with a Biodex-Dynamometer before, as well as five days and four weeks after surgery (peak-torque, total-work, power). Furthermore, WOMAC, HHS, PROMs and EQ-5d-3L were imposed. Results: The ERAS group revealed significant higher isokinetic strength (peak-torque, total-work, power) at both time points. Both groups showed a significant pain decrease at both time points meeting very high rates of patient satisfaction resembled by good results in PROMs, WOMAC, HHS, EQ-5d. There was no significant difference in any of the scores between both groups. Conclusion: We proved a significant reduced loss of muscular strength five days and four weeks after primary THA in combination with an ERAS concept. However, the reduced loss of muscular strength is not reflected by patient's functional outcome and quality of life, showing no significant differences in WOMAC, HHS, EQ-5d-3L, PROMs and NRS. Therefore, this study supports the implementation of an ERAS concept for primary THA in terms of isokinetic strength. Further studies are needed to evaluate the development of muscular strength over a long period. [ABSTRACT FROM AUTHOR]

Background: Beta‐hydroxy‐beta‐methylbutyrate (HMB) is a nutrition supplement that may attenuate muscle wasting from critical illness. This trial aimed to determine feasibility of administering a blinded nutrition supplement in the intensive care unit (ICU) and continuing it after ICU discharge. Methods: Single‐center, parallel‐group, blinded, placebo‐controlled, randomized feasibility trial. After traumatic injury necessitating admission to ICU, participants were randomized to receive an enteral study supplement of 3 g of HMB (intervention) or placebo daily for 28 days or until hospital discharge. Primary outcome was feasibility of administering the study supplement, quantified as protocol adherence. Secondary outcomes included change in quadriceps muscle thickness, measured weekly until day 28 or hospital discharge by using ultrasound and analyzed by using a linear mixed model. Results: Fifty randomized participants (intervention, n = 26; placebo, n = 24) showed comparable baseline characteristics. Participants received 862 (84.3%) of the 1022 prescribed supplements during hospitalization with 543 (62.8%) delivered via an enteral feeding tube. The median (IQR) number of study supplements successfully administered per participant was 19.5 (13.0–24.0) in the intervention group and 16.5 (8.5–23.5) in the placebo group. Marked loss of quadriceps muscle thickness occurred in both groups, with the point estimate favoring attenuated muscle loss with the intervention, albeit with wide CIs (mean intervention difference after 28 days, 0.26 cm [95% CI, −0.13 to 0.64]). Conclusion: A blinded, placebo‐controlled, randomized clinical trial of daily enteral HMB supplementation for up to 28 days in hospital is feasible. Any effect of HMB supplementation to attenuate muscle wasting after traumatic injury remains uncertain. [ABSTRACT FROM AUTHOR]

Objective: Most paraplegic patients with complicated trochanter sores or ischial sores present with lower limb muscle atrophy. Therefore, in patients who have undergone Girdlestone arthroplasty, filling the dead space and replacing the volume defect through an appropriate surgical technique is extremely challenging. This study presents a case series of vastus lateralis and vastus intermedius myocutaneous flap reconstruction after extended proximal femoral osteotomy in paraplegic patients. The aim of study is to investigate (i) whether sufficient volume replacement was achieved, (ii) whether muscle volume was maintained during long‐term follow‐up, and (iii) the presence of donor site morbidity. Method: A retrospective review was conducted with eight patients who underwent this method from March 2017 to December 2021. A total of nine flaps was elevated, and the defect was successfully reconstructed without dead space. Computed tomography was performed to identify the changes in thickness and volume of the muscle portion. The Wilcoxon signed‐rank test was performed to assess the significance of the differences in muscle thickness between pre‐ and post‐measurements. Results: After surgery, all patients healed within 1 month; three patients experienced minor complications. The average follow‐up period was 14.5 months, during which only one patient with an ischial pressure ulcer developed wound disruption and recurrence. The average thickness of the rotated muscle was 51.95 mm at 2 to 4 weeks postoperatively and 53.07 mm at 6 months postoperatively (푝 = 0.071). Conclusion: All nine cases healed well without major complications. When comparing the volume of the rotated muscle on radiological examinations before and after surgery, no significant differences were observed. Our modified Girdlestone resection technique provides a simple and reliable method for reconstructing complex trochanteric or ischial sores in paraplegic patients. It ensures anatomical consistency, ample volume, and structural stability by leaving the rectus femoris (RF) in place. Careful tension management is required when using this flap in the ischial area. [ABSTRACT FROM AUTHOR]

This study examined whether muscle typology (muscle fibre type composition) is related to maximal strength and whether it can explain the high inter-individual variability in number of repetitions to failure during resistance training. Ninety-five resistance training novices (57 males) were assessed for their maximal isometric knee extension strength and muscle typology. Muscle typology was estimated by measuring carnosine in the soleus, gastrocnemius and/or vastus lateralis using proton magnetic resonance spectroscopy. Forty-four subjects (22 males) performed dynamic strength tests (1RM) and 3 sets of leg extensions and curls to failure (60%1RM) to determine the association between muscle typology and (total) number of repetitions. Twenty-one subjects performed additional biceps curls and triceps extensions (60%1RM) to assess influence of exercise, 23 subjects performed additional leg extensions and curls at 80% and 40%1RM to evaluate influence of training load. There was a weak but significant relationship between muscle typology and maximal isometric strength (r = 0.22, p = 0.03) favouring the fast typology individuals. Slow and fast typology individuals did not differ in upper arm and upper leg 1RM. Total number of repetitions was related to muscle typology at 80% (r = −0.42; p = 0.04) and 60% (p = −0.44; p = 0.003) but not at 40%1RM. Slow typology individuals performed more repetitions to failure at 60%1RM in the leg extension (p = 0.03), leg curl (p = 0.01) and biceps curl (p = 0.02). In conclusion, muscle typology has a small contribution to maximal isometric strength but not dynamic strength and partly determines the number of repetitions to failure during resistance training. This insight can help individualizing resistance training prescriptions. Having a fast muscle typology is positively associated with maximal isometric strength delivery in resistance training novices. The muscle typology seems to be a determining characteristic in the number of repetitions that can be performed during resistance training as slow typology individuals perform significantly more repetitions to failure compared to fast typology individuals. This study indicates the importance for coaches to shift from using traditional load-repetition tables and 1RM prediction equations to individualized 1RM testing and training volume prescriptions. [ABSTRACT FROM AUTHOR]