Due to the high heterogeneity in outcome measures after total hip arthroplasty (THA), the prospective observational study investigated the relationships between symmetry-based (SBMs), performance-based (PBMs), and functional outcome measures in THA patients to determine necessary or redundant categories of tests. The study material consisted of 24 patients with end-stage hip osteoarthritis scheduled for THA. The patients were examined one day before surgery and consecutively on the 4th day, 9th day, and 10th week postoperatively using the SBMs (weight-bearing chair-rising test, measurements of the maximal isometric torque of the quadriceps muscle); the PBMs (10-m walk, timed up-and-go, and stair-climbing tests); and the functional outcome measure (Harris Hip Score). The results obtained in a given category of tests at different time points were compared, and the correlations between the tests were determined. The reliability of the outcome measures was determined. The results of tests in the studied categories statistically significantly (p < 0.05) improved at the 10th week postoperatively compared to preoperative results. No strong correlations were revealed between the three studied types of outcome measures in THA patients. Therefore, none of them can be considered redundant. It also means that the relevance of symmetry for a core measurement set to describe the domain function in THA patients must be further clarified.

Background/Objectives. Despite growing interest in capacitive-resistive electric transfer TECAR) and Vibration therapy (VT), their comparative effectiveness in sports recovery remains unclear. This study aimed to evaluate and contrast the short-term effects of TECAR and VT on neuromuscular recovery following eccentric muscle fatigue, relative to passive rest, in active young adults. We hypothesized that both interventions would accelerate recovery and potentially reduce injury risk. Methods. Forty-one participants were randomized into two groups: TECAR therapy (Group 1) and VT (Group 2). Neuromuscular function was assessed at baseline, post-exercise, and post-intervention using tensiomyography (TMG) and electromyography (EMG). Results. Both groups showed a significant increase in EMG MDF intercept after exercise. Post-intervention, VT induced a further rise in this parameter, whereas TECAR stabilized values without significant change. In the contralateral resting limb, increases persisted after exercise and passive recovery. Between-limb differences were significant only in the TECAR group. TMG analysis revealed a non-significant but large-effect increase in contraction delay (Td) post-exercise, followed by significant reductions after both interventions. In the left limb, Td changes were not significant. For maximal displacement (Dm), both VMO and VLO muscles demonstrated a significant decrease post-exercise and a marked recovery after both therapies. Other TMG parameters (Ts, Tc, Tr) showed no significant changes. Conclusions. Both TECAR and VT effectively enhanced neuromuscular recovery after eccentric exercise. TECAR demonstrated a modest but consistent advantage, particularly in normalizing muscle recruitment and restoring mechanical properties, making it suitable in contexts requiring rapid recovery. VT, however, remains a more accessible and cost-effective modality. These findings support the application of both techniques in sports recovery, while highlighting the need for further research in professional athletes and diverse exercise settings to optimize regeneration strategies and reduce injury risk.

This study aimed to develop and evaluate the reliability of a surface electromyography-based (sEMG) index to quantify knee muscle coactivation in healthy recreational athletes during the Lower Quarter Y-Balance Test (YBT-LQ). A prospective observational repeated measures design was used to assess both intra- and inter-rater reliability. Forty males completed three trials, with two raters independently conducting assessments. sEMG signals from the vastus medialis, vastus lateralis, biceps femoris, and semitendinosus muscles were collected to calculate four coactivation indices (CoAIs) for different muscle pairs. The reliability evaluation of these CoAIs was based on intraclass correlation coefficients. The results revealed that the reliability of the CoAIs varied depending on the muscle pair, direction, and limb examined. The highest intra- and inter-rater reliability was noted for the left lower limb in the posterolateral direction. The lowest reliability was found for the right lower limb in the anterior direction. Statistical analyses indicated significant differences in specific CoAIs across different YBT-LQ directions. These findings highlight the potential of sEMG-based CoAIs for assessing knee muscle activity during the YBT-LQ in healthy male recreational athletes. However, choosing CoAIs is critical for reliable clinical and research assessments of knee stability and neuromuscular control.

Background/Objectives: Despite the growing popularity of training with a controlled form of vascular occlusion, known as blood flow restriction (BFR) training, in the rehabilitation of orthopedic patients and sports medicine, there remains ample space for understanding the basis of its mechanism. The pilot study assessed the effect of BFR during a low-load resistance training unit on knee flexor muscle fatigue, intending to decide whether a larger trial is needed and feasible. Methods: The study used a prospective, randomized, parallel, double-blind, placebo-controlled design. Fifteen male healthy recreational athletes were randomly assigned to three equal groups: BFR Group, Placebo Group, and Control Group. The primary outcome was the change in the surface electromyography-based (sEMG-based) muscle fatigue index, which was determined by comparing the results obtained before and after the intervention. The intervention was the application of BFR during low-load resistance training for knee flexors. The occurrence of any adverse events was documented. Results: In all groups, the sEMG-based fatigue index for semitendinosus and biceps femoris muscles decreased after low-load resistance training, with the largest decrease in the BFR group. Although not statistically significant, BFR showed moderate and large effect sizes for the fatigue index of semitendinosus and biceps femoris, respectively. No adverse events were noted. Conclusions: The pilot study suggested that BFR during a low-load resistance training unit might affect knee flexor muscle fatigue, supporting the development of a larger randomized clinical trial.

Purpose: To systematically evaluate the morphology, temporal evolution and musculoskeletal adaptations associated with semitendinosus tendon (ST) and muscle (SM) regeneration after isolated ST autograft harvest for primary anterior cruciate ligament reconstruction (ACLR). Methods: A systematic review was conducted according to PRISMA 2020 guidelines. PubMed, Embase, Scopus and Web of Science were searched from inception to 20 December 2025. Eligible studies included primary ACLR with isolated ST autografts and objective post‐operative assessment of ST or SM regeneration using imaging (ultrasound, magnetic resonance imaging and computed tomography) or histology. Methodological quality was evaluated using the JBI checklist for randomized controlled trials and the Methodological Index for Non‐Randomized Studies instrument for non‐randomized studies. Due to heterogeneity in surgical techniques, imaging protocols, follow‐up intervals and regeneration definitions, results were synthesized narratively according to synthesis without meta‐analysis principles, with regeneration frequencies reported by modality and predefined time windows. Results: Sixteen studies comprising 376 patients (mean age 25.5 years) were included. Across studies, tendon‐like continuity was frequently detected between 6 and 12 months post‐operatively, although reported regeneration rates varied depending on imaging modality and definitional criteria. The regenerated neotendon (NT) typically demonstrated non‐anatomical distal attachment or fusion patterns, accompanied by proximal migration of the musculotendinous junction, permanent shortening and atrophy of the SM. Conclusion: The ST and SM exhibit robust biological potential for regeneration after isolated harvest, typically forming a viable NT within the first post‐operative year. However, regeneration does not restore native anatomy; significant muscle shortening, atrophy and proximal insertion shifts are consistent findings. Despite these morphological deficits, the high rate of tissue continuity supports the isolated ST graft as a low‐morbidity option that preserves overall hamstring complex integrity. Level of Evidence: Level IV.

Background: A comprehensive rehabilitation program is recommended following anterior cruciate ligament reconstruction (ACLR) to restore function, strength and lower limb stability. Despite advancements in surgical techniques, high reinjury rates highlight the need to refine rehabilitation strategies. This study investigates performance across various physically demanding tasks and compares outcomes between the injured and uninjured leg, using a modified Back in Action (BIA) test battery. It is hypothesized that due to test learning effects patients exhibit faster improvement in coordinatively demanding tasks compared to strength-related tasks. Methods: Thirty-two patients (aged 18–40) following primary unilateral ACLR participated in a prospective cross-sectional study within the context of a larger trial. Participants completed a modified BIA test battery, including stability, countermovement jump (CMJ), drop landing, speedy jumps, and quick-feet test (QFT). Each test was conducted in three sets, with three immediate repetitions. Self-reported outcomes were also collected. Results: Patients showed significant within-session improvements in coordinative tasks, with 32% in the injured and 26% in the uninjured limb during the speedy jumps [p < 0.05]. No significant learning effects were observed in strength-related tasks (drop landing, stability test, CMJ). Patients with lower baseline performance exhibited greater improvement than patients with higher performance level from baseline. Furthermore, a correlation between self-assessed abilities and actual performance was identified. Conclusions: This study showed that improvement of coordinative tasks after Return to Sport (RTS) testing of ACLR patients are rather affected by test learning effects. In contrast, this phenomenon is not seen in strength-related tasks. Rehabilitation programs should integrate both types of exercises while considering individual baseline abilities. Tailoring rehabilitation to individual needs, establishing sport-specific rehabilitation programs and incorporating self-assessment tools can enhance patient-centered care and reduce reinjury risks.