Diagnostic value of the lower leg muscle stiffness in professional skiers with medial tibial stress syndrome: A retrospective shear wave elastography study

Objectives: This study aims to assess the diagnostic value of tibialis anterior (TA) and gastrocnemius muscle elasticity using shear wave elastography (SWE) in professional skiers diagnosed with medial tibial stress syndrome (MTSS). Methods: A retrospective case-control study involved 16 professional male skiers diagnosed with medial tibial stress syndrome (MTSS) and 20 healthy skiers. Shear wave elastography (SWE) assessed the stiffness of the TA and gastrocnemius muscles bilaterally. Receiver operating characteristic (ROC) analysis and logistic regression evaluated the diagnostic utility. Reliability was appraised using intraclass correlation coefficients (ICC). Results: Affected side TA stiffness was significantly higher in the MTSS group (p = 0.019, Cohen's d = 0.87). The ROC analysis revealed that TA stiffness is the most effective indicator for diagnosing MTSS (AUC = 0.72), followed by the gastrocnemius medialis at 0.60 and lateralis at 0.54. Compared to TA elasticity (AUC = 0.72), the gastrocnemius muscles do not significantly serve as biomarkers for MTSS diagnosis. Logistic regression confirmed affected side TA stiffness as a significant predictor for MTSS (p = 0.033, OR = 1.12). Conclusion: SWE-derived TA stiffness demonstrated preliminary discriminative ability for MTSS in elite skiers. SWE can improve objective musculoskeletal assessment and injury screening.