Loading Rate in Single-Leg Drop Landing: Associations With Risk Factors for Ankle Sprain.

UNLABELLED: Aim: The aim of this study is to investigate the association between the loading rate (LR) during single-leg drop landing (SDL) and biomechanical factors contributing to ankle sprains (AS).

METHODS

Seventeen healthy young men (mean age: 19.8 ± 0.8 years) were included in this study. A three-dimensional motion analyzer and a floor reaction force sensor were used to analyze SDLs conducted from a 20-cm-high platform onto a floor positioned 30 cm away. The change in lower limb joint angles from landing to the point of maximum vertical floor reaction force was calculated. Additionally, peroneus longus parameters, including maximum muscle tension and timing, were measured using musculoskeletal modeling software. Associations of the LR with changes in lower limb joint angles and peroneus longus parameters were analyzed using correlation analysis (p<0.05).

RESULTS

The LR was negatively correlated with the hip flexion, knee flexion, and ankle dorsiflexion angles (r = -0.781, -0.649, and -0.489; p = 0.0002, 0.005, and 0.047, respectively). In contrast, the LR was positively correlated with the timing of the peroneus longus muscle (r = 0.672, p = 0.003). No other correlations were observed.

CONCLUSIONS

A higher LR during SDL was associated with reduced sagittal plane joint motion and delayed peroneus longus activation, both of which are biomechanical factors linked to AS onset. These findings suggest that the LR may serve as a useful marker for identifying individuals at elevated risk of AS.