The impact of general joint hypermobility on ankle ligament stiffness in young women: a shear wave elastography investigation

General Joint Hypermobility (GJH) refers to an increased range of motion in multiple joints beyond the normal limits, often due to the laxity of ligaments. The Beighton Score (BS) is widely used to screen for GJH but does not directly assess the ankle. Whether BS corresponds to ankle-specific mechanical properties—particularly of the anterior talofibular ligament (ATFL) —remains unclear. Shear wave elastography (SWE) enables quantitative, in-vivo assessment of ligament stiffness. In this prospective cross-sectional study, 50 healthy women (aged 20–39 years) underwent SWE of the dominant-side ATFL. Participants were stratified a priori into Low-BS (≤ 3) and High-BS (≥ 6) groups; those with BS 4–5 were excluded. Three 1-mm regions of interest (proximal, middle, distal) were measured in two positions: neutral and maximal plantar-flexion–inversion. The primary outcome was shearwave velocity (SWV). Between-group differences were tested for each segment and position using independent-samples t-tests and the Mann–Whitney U test. Intra-observer reliability of SWV measurements was assessed using the intraclass correlation coefficient (ICC). Spearman correlations examined the associations between SWV and age, height, weight, BMI, foot length, and ATFL length. Low-BS participants exhibited higher SWV than High-BS participants. In the neutral position, group differences were significant at the middle segment (P < 0.0083) but not at the proximal and distal segments. Under maximal plantar-flexion–inversion, between-group differences were significant for the proximal and distal measurement points (P < 0.0083), but not at the middle segment. Intra-observer reliability for SWV measurements was good to excellent across ATFL segments and positions, with ICC values ranging from 0.82 to 0.94. Anthropometric variables showed no consistent associations with SWV (all P > 0.00069). Among healthy young women, higher BS is associated with lower ATFL stiffness on SWE, with significant group differences at rest (middle segment) and under stress (proximal and distal segments). These findings suggest that GJH may be reflected in ankle-specific mechanical properties. However, because of the cross-sectional design, no inference can be made regarding prognostic value or clinical utility. Prospective studies are needed to confirm these associations and determine their potential clinical relevance.