Abstract
Abstract
Background:
Light volleyball (LVB) is a popular recreational sport with increasing participation. Hamstring strain (HS) is common among LVB players and leads to significant time loss and reinjury risk. Clinical flexibility tests such as passive knee extension (KE), straight leg raise (SLR), and forward flexion distance (FFD) are widely used for HS screening, but prospective evidence of their predictive value is limited and conflicting. Shear-wave elastography (SWE) can quantify muscle mechanical properties, yet its role in predicting future HS remains unclear. This study aimed to compare the predictive value of a dynamic SWE parameter—the change in shear-wave velocity (ΔSWV) of the distal biceps femoris long head (BFlh) from relaxed to maximally stretched position—against KE, SLR, and FFD for 3‑month HS risk in LVB enthusiasts.
Methods:
In this prospective cohort study, 75 healthy LVB players (42 males, 33 females, age 25.7±6.2 years) underwent baseline measurements of SWV at distal/proximal BFlh and semitendinosus in relaxed and stretched positions (ΔSWV calculated), along with KE, SLR, and FFD. Participants were followed for 3 months to record HS occurrence. Predictive performance was assessed using receiver operating characteristic (ROC) curves, and comparisons between tests were made with the DeLong test.
Results:
Nine participants (12.0%) sustained HS. Only distal BFlh ΔSWV was significantly higher in the HS group (median 8.17 vs. 4.40 m/s, PConclusions:
Distal BFlh ΔSWV accurately predicts 3‑month HS risk in LVB players, far outperforming KE, SLR, and FFD alone or combined. These findings suggest that dynamic SWE measurement could serve as a valuable screening tool for HS risk, although further validation in larger populations is warranted.
Clinical trial number:
Not applicable.