This study aimed to compare lower extremity HHD strength and SLH distance between patients with ACLR and healthy individuals. The goal was to understand the postoperative recovery process in ACLR patients and provide insights for physical therapy evaluation.
Twenty-six females who underwent ACLR at our hospital 8 months prior and were aiming to return to sports (age: 22.5 ± 10.1 years) were compared to 26 healthy female college basketball players (age: 20.0 ± 1.3 years). Muscle strength in the ACLR group was assessed on the reconstructed limb, while the dominant leg was tested in the healthy group. Lower limb HHD (Moby-MT-100, Sakai Medical) strength was measured in knee extension/flexion and hip extension/abduction. SLH was measured as the maximum forward jump distance. Muscle strength was normalized by body weight and SLH distance by height. The differences in HHD strength and SLH distance between the ACLR and healthy groups were analyzed using unpaired t-tests or the Mann-Whitney U test. The relationship between SLH distance and strength in both groups was assessed using Pearson’s correlation coefficient or Wilcoxon’s rank correlation coefficient. Statistical significance was set at 5%.
Hip abductor strength was significantly higher in the ACLR group compared to the healthy group (0.42 ± 0.08 kgf/kg vs. 0.36 ± 0.08 kgf/kg, p0.01), while no significant differences were found in other muscle groups. SLH distance was significantly greater in the healthy group than in the ACLR group (1.00 ± 0.11 cm/cm vs. 0.77 ± 0.13 cm/cm, p0.001). In the ACLR group significant positive correlations were found between SLH distance and knee extension (rs = 0.461, p0.05) and flexion strength (r = 0.574, p0.01). No significant correlations between SLH distance and muscle strength were observed in the healthy group.
The increased hip abduction strength in the ACLR group compared to the healthy group may be attributed to physical therapy interventions initiated early in the postoperative period. Previous studies have suggested that recovery of SLH distance and knee strength following ACLR takes approximately one year. Our findings support these observations, demonstrating a correlation between knee extension and flexion strength and SLH performance in the ACLR group.
Integrating SLH performance with lower extremity HHD strength is essential for a comprehensive evaluation post-ACLR rehabilitation.
lower extremity HHD strength
single-leg hop
