ABSTRACT
OBJECTIVE: The purpose of this study was to investigate whether grade III passive lumbar rotational mobilization on L2-3 can improve hip flexor strength and performance in the single-leg triple-hop test in asymptomatic young adults. METHODS: Twenty-four participants (12 men, 12 women) aged from 19 to 26 years who were positive in the hip flexor "break" test were recruited in this study. They were randomly allocated to the treatment group or sham group. Isometric hip flexor torque (N·m) and single-leg triple-hop distance (cm) were measured before and after a passive lumbar rotational mobilization or a sham intervention. RESULTS: After the intervention, both the treatment and sham groups exhibited a significant increase in longest hop distance (P = .040 and .044, respectively). The treatment group had a significantly higher (3.41 ± 5.44%) positive percentage change in torque than the sham group (-2.36 ± 5.81%) (P = .02). CONCLUSION: The study results indicated a potential effect of grade III passive lumbar rotational mobilization in improving hip flexor strength. However, whether the improvement in hopping performance was the result of a treatment effect or a learning effect could not be determined.