Eccentric Exercise Research Articles

Delayed Onset Muscle Soreness Following Acute Resistance Exercise in Untrained Females: A Comparative Study Between Vegans and Omnivores.

This study aimed to assess the levels of delayed onset muscle soreness (DOMS) markers in individuals adhering to vegan and omnivore diets after engaging in acute resistance exercise. A total of 54 untrained young, healthy, normal-body-weight women (age: 26.8±4.1 years; body mass index: 22.5±2.7 kg/m2) participated in the study. Participants were categorized into two groups: vegans (n=27) and omnivores (n=27) based on their dietary preferences, with all subjects having adhered to their respective diets for a minimum of 2 years. DOMS was induced by a single eccentric resistance exercise session, comprising four exercises (leg press, chest press, leg curls, and arm curls), each consisting of four sets of 10 repetitions. Various measurements, including dietary factors, state of wellness, body composition, muscle circumferences, muscle pressure point thresholds (PPTs), and muscle strength, were recorded both before and 48 hours after the exercise session. The results showed that wellness and muscle circumferences remained unchanged or displayed similar changes between the vegan and omnivore groups following acute resistance exercise. However, notable differences were observed in PPTs in favor of vegans, specifically for the right biceps (95% CI: 1.4 to 10.2; p=0.01), the left vastus medialis (95% CI: 0.5 to 6.4; p=0.02), and the right vastus lateralis (95% CI: 3.2 to 12.1; p=0.001). Furthermore, significant differences in right grip strength were found in favor of vegans after the exercise session (95% CI: 3.1 to 26.2; p=0.01). In conclusion, our findings suggest that vegans may experience more favorable changes in DOMS levels following acute resistance exercise in comparison to omnivores. This discrepancy in DOMS markers may indicate enhanced muscle recovery in vegans.

Muscle structure predictors of vertical jump performance in elite male volleyball players: a cross-sectional study based on ultrasonography.

The objective of this investigation is to examine the contribution of key muscle groups in the lower limbs to vertical jumping performance in elite male volleyball players. Specifically, the study focuses on the rectus femoris (RF), vastus lateralis (VL), and lateral gastrocnemius (LG), as well as exploring differences between attack jump and other vertical jump types. To achieve this, we employed B-mode ultrasound to evaluate the anatomical cross-sectional area (ACSA), muscle thickness (MT), pennation angle (PA), and fascicle length (FL) of the RF, VL, and LG in the participants. Fifteen elite male volleyball players were recruited as participants for this study. Jump heights were measured for four types of vertical jumps: attack jump (AJ), countermovement jump (CMJ), squat jump (SJ), and drop jump (DJ). We conducted regression analyses to assess whether the previously mentioned muscle structures could predict jump performance. Our findings reveal that the muscle structure of the RF does not exhibit any significant correlation with the height of any jump. However, VL-ACSA displays a significant and the most potent predictive effect on jump height for all four jump types (AJ: R 2 = 0.32, p = 0.001; CMJ: R 2 = 0.37, p = 0.005; SJ: R 2 = 0.52, p = 0.001; DJ: R 2 = 0.25, p = 0.021). Conversely, LG-FL only demonstrates a significant and stronger predictive effect on AJ jump height (R 2 = 0.18, p = 0.009). Combining VL-ACSA, LG-FL, and training age through multiple linear regression analysis resulted in a highly significant model for predicting AJ jump height (F = 13.86, R 2 = 0.73). Moreover, the model incorporating VL-ACSA and training age is also important for predicting CMJ, SJ, and DJ jump heights (F = 8.41, R 2 = 0.51; F = 13.14, R 2 = 0.63; F = 5.95, R 2 = 0.41; respectively). The muscle structure indicators in the lower limbs significantly predict jump performance among elite male volleyball players. However, different jump types are influenced by distinct indicators, particularly in the case of AJ, which is associated with LG-FL. This suggests that enhancing LG-FL may positively impact AJ ability, thereby emphasizing the importance of specificity in training. To optimize specialized jump performance in volleyball players, practitioners are advised to assess VL-ACSA and LG-FL and incorporate step-up and eccentric strength training targeting the calf muscles to yield considerable benefits.

Impact of eccentric cycling in coronary rehabilitation program: a pragmatic randomized controlled trial versus conventional rehabilitation.

This randomized controlled trial examined the feasibility of adding eccentric exercise to a conventional cardiac rehabilitation program (CCRP) for coronary heart disease patients. Ninety-three patients were randomly assigned to either the MIX group (eccentric ergometer + CCRP) or the CON group (concentric ergometer + CCRP) for 7 weeks. Training effectiveness was assessed based on "good responders" showing improved functional capacities, such as 6-minute walk test (6MWT) distance and maximal voluntary contraction of the plantar flexors (ankle MVC). Safety was monitored with a visual analog scale for muscle soreness, perceived exertion, and heart rate during training. The proportion of good responders was similar between groups (26% in MIX, 29% in CON, P=0.744). Both groups improved in 6MWT (CON: 12.6%, MIX: 16.14%) and ankle MVC (CON: 15.5%, MIX: 11.30%), with no significant differences. Exercise tolerance did not differ significantly between the groups, but perceived effort was significantly lower in the MIX group (P<0.0001) compared to the CON group. Integrating eccentric exercise into cardiac rehabilitation is safe and well-tolerated. Nevertheless, this study did not find significant advantages over conventional programs for coronary heart disease patients. Further research should explore specific patient groups or conditions where eccentric exercise may be more beneficial, emphasizing personalized prescriptions and gradual workload progression for better cardiac rehabilitation outcomes.

Acute Inflammatory Response to Eccentric Exercise in Young and Master Resistance-trained Athletes.

This study aimed to compare the acute inflammatory response following high-intensity eccentric exercise between resistance-trained young and master athletes with similar performance levels. Resistance-trained young (n=8; 22±2 years) and master (n=8; 52±4 years) male athletes of a similar performance level performed a standardized high-intensity eccentric squat exercise protocol (10 sets of half-squats at 70% of 1-repetition maximum). The serum concentration of 20 biomarkers related to tissue damage, inflammation, remodeling, and repair was measured at baseline, immediately after exercise, and over a 72 h recovery period. Both groups experienced similar muscle damage as evidenced by a comparable increase in creatine kinase activity 24 h after exercise (p<0.001). Interleukin-6 (p=0.009) and growth hormone (p<0.001) increased immediately post-exercise in both groups. Monocyte chemoattractant protein-1 increased immediately post-exercise only in young athletes (p=0.003) and then decreased 24 h later. There were no significant differences for the remaining variables, including cell markers related to neutrophil/macrophage activation or pro/anti-inflammatory cytokines. Resistance-trained young and master athletes, matched for performance level, showed an overall similar inflammatory response to eccentric exercise, possibly reflecting regulatory mechanisms or immunological adaptations to chronic stimulation in master athletes.

Echocardiographic and Cardiopulmonary Responses to Eccentric Cycle Training in Patients with Heart Failure: A Randomised Controlled Trial

Echocardiographic and Cardiopulmonary Responses to Eccentric Cycle Training in Patients with Heart Failure: A Randomised Controlled Trial

The Preventive Efficacy of Selenium Supplements on Muscle Soreness Post Heavy Eccentric Exercise

Delayed Onset Muscle Soreness (DOMS) is the muscle pain and stiffness following unaccustomed or strenuous physical activity that initially appears 8 – 20 h after exercise, peaks at 24 – 48 h after exercise and persists for several days and affect performance. The aim of the present study was to examine the physiological effects of selenium supplementation on delayed-onset muscle soreness and muscle damage. Thirty-two recreational male students of Sports Science Department, Universitas Negeri Surabaya were randomly and double-blindly assigned to either a selenium supplementation group (n=16) or a Placebo group (n=16) and were directed to take either a selenium capsule or a placebo for a period of 3-weeks. Following the 3-weeks supplementation period, both groups underwent a 10-set x 10-rep countermovement jump (1-min recovery between sets) as an eccentric exercise protocol. Pain of DOMS and CK level were measured prior to the eccentric exercise 1-hr before, 24-hr and 48-hr after eccentric exercise. the result of this study showed that both groups experienced Delayed Onset Muscle Soreness (DOMS) and increased total CK serum within 24 to 48 hours post heavy eccentric exercise. The results indicated that the selenium-supplemented group had a significantly greater reduction in plasma DOMS and total CK serum compared to the Placebo group (p&amp;lt;0.05). In summary, selenium supplementation might lower the risk of muscle injury after heavy eccentric exercise, as it effectively reduces plasma DOMS and CK levels in the bloodstream

Innovative Physiotherapy Approaches in Managing Patellar Tendinopathy (Jumper’s Knee): An Updated Literature Review

Introduction: Patellar tendinopathy (jumper's knee) is an overuse injury that usually has a gradual onset of pain. This condition is common in jumping athletes, characterized by local pain at the attachment of the proximal tendon to the bone and dysfunction of the patellar tendon during jumping and landing. Patellar tendinopathy clinically results from high loads on the tendon, such as jumping and changing direction. Patellar tendinopathy can affect health and quality of life by limiting participation in sports and activities for athletes. Objective: This study aims to summarize secondary data related to physiotherapy management of patellar tendinopathy. Methods: The research method used is a literature study using secondary data in the form of journals related to the topic of patellar tendinopathy (jumper's knee) obtained through Google Scholar, Science Direct, and PubMed. Results: From five recent journal articles obtained with various physiotherapy intervention protocols, the results were able to reduce symptoms in patients with patellar tendinopathy. Conclusion: Physiotherapeutic interventions such as progressive tendon-loading exercises (PTLE), Eccentric exercise programmes, Kinesio-tape® and isometric exercises are effective in reducing symptoms in patients with patellar tendinopathy. Keyword: patellar tendinopathy, jumper's knee, physiotherapy

The Effects of Nordic Hamstring Exercise on Performance and Injury in the Lower Extremities: An Umbrella Review.

Due to their potential positive outcomes, hamstring eccentric exercises are becoming increasingly popular in training regimens. Among the various exercises, the Nordic Hamstring Exercise (NHE) is the most common. Despite its popularity, there are still some doubts about its benefits and risks. So, the aim of this umbrella review was to summarize the effects of NHE on performance and injury prevention. Following the PRISMA guidelines, a comprehensive literature search was conducted across multiple e-databases, according to the P (injured and non-injured athletes or recreationally active or healthy individuals) I (NHE) C (no intervention, placebo, or other interventions) O (performance or injury) S (systematic reviews) model. The quality of the studies was accessed with the AMSTAR-2. From the 916 systematic reviews found, only 10 could be included. They encompassed 125 studies, enrolling 17,260 subjects. The results from the studies indicate that NHE interventions demonstrated positive effects on sprint performance, muscle activation, eccentric strength, and muscle architecture (fascicle length, muscle thickness, and pennation angle). Furthermore, NHE is effective in preventing hamstring injuries (up to 51%). In conclusion, NHE should be integrated in training (especially, in the warm-up phase) for both enhancing athletic performance and preventing hamstring injuries. For achieving more positive results, it is recommended that high-volume is followed by low-volume maintenance, targeting 48 reps/week.

Acute Effects of Combined and Distinctive Stretching, Foam Rolling, and Eccentric Exercise in Young Men with Hamstring Tightness

Acute Effects of Combined and Distinctive Stretching, Foam Rolling, and Eccentric Exercise in Young Men with Hamstring Tightness

Optimizing recovery: how PNF stretching and ice massage alleviate markers of DOMS?

Delayed onset muscle soreness (DOMS) is a common problem for both trained or untrained individuals that develop after eccentric or unaccustomed exercise. The large number of cases of DOMS and the varying results of research related to the prevention and treatment of DOMS, imply the importance of research in the effective DOMS prevention. The aim of this research was to investigate the post-exercise effects of combination Proprioceptive Neuromuscular Facilitation (PNF) stretching and ice massage on markers of exercise-induced muscle damage (DOMS). Thirty-nine subjects between the ages of 15 to 17 were randomly assigned to either the experimental or control groups. Subjects performed circuit training exercise-induced DOMS. The experimental group underwent 18 minutes of PNF stretching and 16 minutes of ice massage, which was given 2 hours after exercise. The control group did not receive any treatment. DOMS parameters (muscle soreness, creatine kinase/CK, aspartate aminotransferase/AST, neutrophil) and lower extremity functional scale (LEFS) were assessed at 0 and 24 hours after exercise-induced DOMS. The parametric and non-parametric different tests was used in data analysis. The experimental groups showed a reduction in DOMS symptoms in the form of less muscle soreness and AST, better LEFS compared to control groups (p&lt;0.05), but not for creatine kinase and neutrophils (p&gt;0.05) which is an indicator of tissue damage. In conclusion, the combination of postexercise PNF stretching and ice massage was effective in reducing the severity of DOMS, but it was not able to prevent DOMS. Keywords: PNF Stretching, Ice Massage, DOMS, Creatine Kinase, Muscle Recovery, Exercise-induced Muscle Damage

Comparative effects of myofascial release with and without eccentric resistance on pain, range of motion, and functional disability in patients with Achilles tendinopathy

BackgroundThe ankle is one of the most commonly injured areas in people with active and sedentary lives. Achilles tendinopathy (AT) is characterized by pain and stiffness that limits daily living work. Myofascial release and eccentric training are believed to improve soft tissue circulation, strength, pain, ROM, and function. ObjectiveTo compare the effects of myofascial release with and without eccentric resistance on pain, range of motion, and functional disability in patients with AT. MethodologyThis randomized clinical trial was conducted with a sample of 72 participants selected via a convenient sampling technique. Participants were divided into two groups, Group A was given myofascial release therapy, and Group B was given myofascial release with eccentric resistance. Numeric Pain Rating Scale (NPRS), Goniometer, and Foot ankle disability index (FADI) were outcome measure tools for pain, range of motion, and functional disability. The assessment was done at baseline, 2nd and 4th week. Mann-Whitney U Test and Friedman's ANOVA were applied to find between-group and within-group differences. P-value was set at ≤0.05. ResultsThere was a significant difference in pain (p = 0.03), plantarflexion ROM (p = 0.008), and functional disability (p = 0.02) between the two groups. However, no significant difference was observed in dorsiflexion (p = 0.06). Within-group differences were also significant (p < 0.05). ConclusionIt is concluded that myofascial release with eccentric resistance was more effective than myofascial release without eccentric resistance in improving pain, range of motion, and functional disability in Achilles tendinopathy.

Effects of muscle fatigue on quadriceps muscle performance in healthy amateur soccer players

IntroductionQuadriceps femoris muscle (QFM) fatigue has a detrimental impact on athlete performance. Therefore, it is crucial to evaluate various performance parameters under fatigued conditions. This study aimed to assess the performance of the QFM during both concentric and eccentric contractions before and after fatigue in the lower extremities of healthy amateur soccer players. MethodTwenty-four healthy amateur soccer players performed three consecutive knee extension and flexion movements concentrically and eccentrically at a velocity of 120°/s with maximum effort, using a Biodex dynamometer. Fatigue was induced by a protocol involving repetitive concentric knee extension and flexion movements at 120°/s, with a load of 50% of maximal voluntary isometric contraction (MVIC) of the QFM until its moment declined to 50% of MVIC. Separate 2-way analyses of variance were conducted to assess the influence of contraction and fatigue on various isokinetic parameters. ResultsNo significant interaction effect between contraction and fatigue was observed for any of the parameters. There was a significant main effect of fatigue on average power for both lower extremities. However, no significant main effect of fatigue was observed for normalized peak moment, angle of peak moment, moment at 0.2s, total work, acceleration, and deceleration times. In contrast, significant main effects of contraction were noted for normalized peak moment, moment at 0.2s, average power, acceleration, and deceleration times in both lower extremities. ConclusionAverage power appeared as the most sensitive performance parameter to fatigue. To enhance QFM performance, emphasizing eccentric exercises during training and conditioning programs could be beneficial for athletes.

Outcome of Isolated Eccentric Exercise Therapy in Sports Persons with Rotator Cuff Tendinopathy

Outcome of Isolated Eccentric Exercise Therapy in Sports Persons with Rotator Cuff Tendinopathy

Effect of Microencapsulated Cocoa Polyphenols on Macro- and Microvascular Function after Eccentric Exercise

Background: Evidence has demonstrated that non-habitual exercise, such as eccentric exercise, can increase reactive oxygen species and induce endothelial dysfunction, which plays a central role in the development of cardiovascular disease. Polyphenol-rich foods, such as cocoa, have been widely investigated in vascular function due to their antioxidant effect. Aims: The goal of this study was to evaluate the impact of microencapsulated cocoa (MC) polyphenols in the flow-mediated dilation (FMD) response and forearm muscle oxygenation (StO2) parameters after an eccentric exercise. Methods: Thirteen physically active adults were enrolled in a randomized, double-blind, and crossover study. FMD and StO2 were evaluated before and after 24 h, 48 h, and 72 h of eccentric exercise and MC or placebo supplementation. Results: No significant difference in FMD response and StO2 parameters was observed after MC and placebo (p &gt; 0.05). Conclusions: A single dose of MC did not change FMD and muscle StO2 parameters after eccentric exercise in healthy individuals.

Bioimpedance analysis for identifying new indicators of exercise-induced muscle damage

A noninvasive, immediate, and convenient method for assessing muscle tissue status during exercise-induced muscle damage (EIMD) has not been established. This study was designed to assess and determine parameters suitable for measuring EIMD after eccentric exercise, using multi-frequency bioimpedance analysis (BIA). Thirty-five young male participants performed dumbbell exercises with their left arm, and their BIA parameters were measured at various time points up to 168 h post exercise using a multi-frequency BIA device. At all-time points, intra and extracellular water content was greater in the left arm than in the right arm, whereas the impedance, reactance, resistance, and phase angle were lower in the left arm than in the right arm. Established EIMD indices, such as maximal isometric voluntary contraction, were measured and used in correlational analyses. Only reactance was correlated with biomarkers, indicating muscle damage (r = − 0.56 to − 0.49). Furthermore, reactance was found to correlate well with indirect indicators of EIMD, suggesting that it may be a suitable marker for evaluating EIMD. However, the relationship with the limited evaluation indices employed in this study is constrained. Future studies should investigate the correlation between reactance and direct damage indicators, such as structural damage, observed in biopsies.

The relationship between sustained hamstring pain and reorganisation of somatosensory representations: a randomised, controlled study.

Recurrent hamstring injuries are highly prevalent amongst sporting populations. It has been hypothesised that pain from an initial hamstring injury may induce reorganisation of somatosensory representations that could contribute to reinjury. However, because of the cross-sectional nature of existing research, it remains unknown whether somatosensory changes are a cause or effect of pain or if they are driven by other potentially confounding factors. Here, we explored the effect of experimentally induced sustained hamstring pain on tasks that interrogate somatosensory and spatial representations. Fifty healthy participants were randomly allocated to an experimental group that performed an eccentric exercise protocol on the right hamstring to induce delayed onset muscle soreness or a control group performing a repetition-matched concentric exercise protocol. The tactile cortical representation was assessed using two-point discrimination and tactile localisation, whereas the proprioceptive representation was assessed using a left-right judgement task. Peripersonal spatial representations were assessed using an auditory localisation task. Assessments were performed at baseline and day 2. No between-group differences in tactile acuity were observed. However, improvements in left-right judgments and worsening of auditory localisation occurred in the experimental group compared with the control group. This study provides preliminary evidence showing that somatosensory changes occur in response to sustained hamstring pain. Experimentally induced, sustained hamstring pain elicited enhancements in proprioceptive processing and deficits in peripersonal spatial processing, suggesting a shift in the allocation of attentional resources from the external (peripersonal) to internal (body) environment. These findings may hold important implications for reinjury risk and rehabilitation following hamstring pain.

A Comparison of Force Production in Eccentric Hamstring Exercises

A Comparison of Force Production in Eccentric Hamstring Exercises

Impact of Eccentric versus Concentric Cycling Exercise on Neuromuscular Fatigue and Muscle Damage in Breast Cancer Patients.

This study investigated the magnitude and etiology of neuromuscular fatigue and muscle damage induced by eccentric cycling compared with conventional concentric cycling in patients with breast cancer. After a gradual familiarization protocol for eccentric cycling, nine patients with early-stage breast cancer performed three cycling sessions in eccentric or concentric mode. The eccentric cycling session (ECC) was compared with concentric cycling sessions matched for power output (CON power ; 80% of concentric peak power output, 95 ± 23 W) or oxygen uptake ( ; 10 ± 2 mL·min·kg -1 ). Preexercise to postexercise changes (30-s through 10-min recovery) in knee extensor maximal voluntary contraction force (MVC), voluntary activation, and quadriceps potentiated twitch force ( Qtw ) were quantified to determine global, central, and peripheral fatigue, respectively. Creatine kinase and lactate dehydrogenase activities were measured in the plasma before and 24 h after exercise as markers of muscle damage. Compared with CON power (-11% ± 9%) and (-5% ± 5%), the ECC session resulted in a greater decrease in MVC (-25% ± 12%) postexercise ( P < 0.001). Voluntary activation decreased only in ECC (-9% ± 6% postexercise, P < 0.001). The decrease in Qtw was similar postexercise between ECC and CON power (-39% ± 21% and -40% ± 16%, P > 0.99) but lower in ( P < 0.001). The CON power session resulted in twofold greater compared with the ECC and sessions ( P < 0.001). No change in creatine kinase or lactate dehydrogenase activity was reported from preexercise to 24 h postexercise. The ECC session induced greater neuromuscular fatigue compared with the concentric cycling sessions without generating severe muscle damage. ECC is a promising exercise modality for counteracting neuromuscular maladaptation in patients with breast cancer.

Eccentric exercise before a 90min exposure at 24,000ft increases decompression strain depending on body region but not total muscle mass recruited.

Eccentric upper-body exercise performed 24h prior to high-altitude decompression has previously been shown to aggravate venous gas emboli (VGE) load. Yet, it is unclear whether increasing the muscle mass recruited (i.e., upper vs. whole-body) during eccentric exercise would exacerbate the decompression strain. Accordingly, this study aimed to investigate whether the total muscle mass recruited during eccentric exercise influences the decompression strain. Eleven male participants were exposed to a simulated altitude of 24,000ft for 90min on three separate occasions. Twenty-four hours before each exposure, participants performed one of the following protocols: (i) eccentric whole-body exercise (ECCw; squats and arm-cycling exercise), (ii) eccentric upper-body exercise (ECCu; arm-cycling), or (iii) no exercise (control). Delayed onset muscle soreness (DOMS) and isometric strength were evaluated before and after each exercise intervention. VGE load was evaluated at rest and after knee- and arm-flex provocations using the 6-graded Eftedal-Brubakk scale. Knee extensor (-20±14%, P=0.001) but not elbow flexor (-12±18%, P=0.152) isometric strength was reduced 24h after ECCw. ECCu reduced elbow flexor isometric strength at 24h post-exercise (-18±10%, P<0.001). Elbow flexor DOMS was higher in the ECCu (median 6) compared with ECCw (5, P=0.035). VGE scores were higher following arm-flex provocations in the ECCu (median (range), 3 (0-4)) compared with ECCw (2 (0-3), P=0.039) and control (0 (0-2), P=0.011), and in ECCw compared with control (P=0.023). VGE were detected earlier in ECCu (13±20min) compared with control (60±38min, P=0.021), while no differences were noted between ECCw (18±30min) and control or ECCu. Eccentric exercise increased the decompression strain compared with control. The VGE load varied depending on the body region but not the total muscle mass recruited. HIGHLIGHTS: What is the central question of this study? Does exercise-induced muscle damage (EIMD) resulting from eccentric exercise influence the presence of venous gas emboli (VGE) during a 90min continuous exposure at 24,000ft? What is the main finding and its importance? EIMD led to an earlier manifestation and greater VGE load compared with control. However, the decompression strain was dependent on the body region but not the total muscle mass recruited.

Combined regenerative rehabilitation improves recovery following volumetric muscle loss injury in a rat model.

Volumetric muscle loss (VML) injury causes irreversible deficits in muscle mass and function, often resulting in permanent disability. The current standard of care is physical therapy, but it is limited in mitigating functional deficits. We have previously optimized a rehabilitation technique using electrically stimulated eccentric contraction training (EST) that improved muscle mass, strength, and size in VML-injured rats. A biosponge scaffold composed of extracellular matrix proteins has previously enhanced muscle function postVML. This study aimed to determine whether combining a regenerative therapy (i.e., biosponge) with a novel rehabilitation technique (i.e., EST) could enhance recovery in a rat model of VML. A VML defect was created by removing ~20% of muscle mass from the tibialis anterior muscle in adult male Lewis rats. Experimental groups included VML-injured rats treated with biosponge with EST or biosponge alone (n = 6/group). EST was implemented 2 weeks postinjury at 150 Hz and was continued for 4 weeks. A linear increase in eccentric torque over 4 weeks showed the adaptability of the VML-injured muscle to EST. Combining biosponge with EST improved peak isometric torque by ~52% compared with biosponge treatment alone at 6 weeks postinjury. Application of EST increased MyoD gene expression and the percentage of large (>2000 μm2) type 2B myofibers but reduced fibrotic tissue deposition in VML-injured muscles. Together, these changes may provide the basis for improved torque production. This study demonstrates the potential for combined regenerative and rehabilitative therapy to improve muscle recovery following VML.