biceps femoris

Background “T-Junction” or distal musculotendinous junction (DMTJ) hamstring injuries have become a true enigma for clinicians as demonstrated by the high recurrence rate. Magnetic Resonance Imaging (MRI) can sometimes fail to provide an accurate assessment of these injuries, probably because of the dynamic function that this structure provides to offer stability at the synchronous movement of the two heads of biceps femoris. The aim of the present case report was to describe a novel method for dynamic ultrasound evaluation of the DMTJ performed during functional loading exercises and to explore its potential role in return-to-play (RTP) decision-making. Study design Case Report Case description A 23-year-old male elite football player sustained a DMTJ injury. MRI revealed a complete rupture of the superficial portion (myotendinous) and the deep portion (myoaponeurotic) of the T-Junction. The injury occurred initially during high speed non-linear running action. The initial diagnosis was made using a 3T MRI scan. Subsequently, three dynamic ultrasound evaluations were performed at weeks 3, 6 and 9 during two different gym-based exercises: the single-leg barbell Romanian deadlift and the single-leg hamstrings slider with ipsilateral trunk rotation. Additional 3Tesla MRIs were conducted to assess healing and structural changes at weeks 5,8 and 14. Outcomes The player returned to competitive activity 10 weeks after the injury and experienced no re-injury during the subsequent 4-month follow-up period. Improvements in the synchronous movement between BFlh and BFsh were seen on the progressive evaluations as well as the scar healing progression. Dynamic ultrasound assessment during the SL-RDL appeared to provide clearer visualization of interhead hamstring movement than during the slider exercise. Further investigation in larger cohorts is warranted to establish the reliability, validity, and prognostic utility of this novel assessment modality for athletes with this injury. Conclusions In this single case, dynamic ultrasound of the DMTJ provided valuable information regarding interhead synchrony of the biceps femoris. This approach may complement MRI and support informed return to play decision-making following T-Junction hamstring injuries. Level of Evidence 5

matched text: “biceps femoris”

BackgroundAthletes who return to soccer after anterior cruciate ligament reconstruction (ACLR) remain at elevated risk of secondary injury despite meeting conventional discharge criteria, and neuromuscular deficits in the reconstructed limb are known to be exposed by fatigue. ObjectiveTo determine whether match-play fatigue differentially affects muscle stiffness, countermovement jump (CMJ) force symmetry, and rate of force development (RFD) asymmetry between soccer players with a history of ACLR and uninjured teammates. MethodsA prospective, cross-sectional, matched-control study enrolled 128 competitive soccer players (64 ACLR, 6-22 months post-surgery; 64 uninjured controls) across five recruitment waves (February-June 2026). Bilateral CMJ peak vertical force, jump height, RFD, and myotonometric stiffness of the rectus femoris (RF), vastus medialis (VM), and biceps femoris (BF) were recorded immediately before and after a standardized competitive match. Fatigue was quantified from second-half heart rate (percentage of age-predicted maximum) and end-match rating of perceived exertion (RPE). Within-group pre-to-post changes were evaluated with paired t-tests, between-group differences in the magnitude of change with independent-samples t-tests, and associations between fatigue indices and asymmetry changes with Pearson correlations. ResultsMatch play reduced CMJ limb symmetry index (LSI) in both groups, but the decline was more than three-fold greater in the ACLR group, 92.6% (SD 5.4%) to 85.1% (SD 7.1%), than in control group, 97.3% (SD 3.9%) to 95.0% (SD 4.2%), group-by-time difference, p < 0.001, (d = 0.64). RFD asymmetry approximately doubled in the ACLR group, 10.6% (SD 4.1%) to 17.6% (SD 6.5%), compared with a smaller rise in control group, 4.6% (SD 2.4%) to 6.3% (SD 3.7%); p < 0.001, d = 0.77). Involved-limb stiffness losses in the ACLR group exceeded those of controls for the RF (-21.2 vs. -9.2 N/m, p < 0.001), VM (-17.7 vs. -6.1 N/m, p < 0.001), and BF (-13.3 vs. -6.6 N/m, p < 0.001), whereas uninvolved-limb stiffness losses did not differ between groups (all p > 0.05). Fatigue markers (heart rate, RPE) were not significantly correlated with the magnitude of individual asymmetry change (|r| [&le;] 0.18, p > 0.15). ConclusionsIn competitive soccer players 6-22 months after ACLR, match-play fatigue selectively compromises stiffness and explosive force output of the reconstructed limb, widening inter-limb asymmetries beyond what is seen in uninjured teammates, even though global cardiovascular and perceptual fatigue were comparable between groups. These findings suggest that return-to-sport testing performed only in a rested state may underestimate residual neuromuscular deficits, and support fatigue-inclusive assessment protocols before athletes are cleared for unrestricted competition.

matched text: “biceps femoris”