Kinematic and Kinetic Analysis of the Single-Leg Triple Hop Test in Women With and Without Patellofemoral Pain.

STUDY DESIGN: Cross-sectional study.

OBJECTIVES: To compare the biomechanical strategies of the trunk and lower extremity during the transition period between the first and second hop of a single-leg triple hop test in women with and without patellofemoral pain (PFP).

BACKGROUND: Recent literature has shown that PFP is associated with biomechanical impairments of the lower extremities. A number of studies have analyzed the position of the trunk and lower extremities for functional activities such as walking, squatting, jumping, and the step-down test. However, studies on more challenging activities, such as the single-leg triple hop test, may be more representative of sports requiring jumping movements.

METHODS: Women between 18 and 35 years of age (control group, n = 20; PFP group, n = 20) participated in the study. Three-dimensional kinematic and kinetic data were collected during the transition period between the first and second hops while participants performed the single-leg triple hop test.

RESULTS: Compared to the control group, women with PFP exhibited greater (P<.05) anterior and ipsilateral trunk lean, contralateral pelvic drop, hip internal rotation and adduction, and ankle eversion, while exhibiting less hip and knee flexion. A significant difference (P<.05) in time to peak joint angle was also found between groups for all the variables analyzed, except anterior pelvic tilt and hip flexion. In addition, women with PFP exhibited greater (P<.05) hip and knee abductor internal moments.

CONCLUSION: Compared to the control group, women with PFP exhibited altered trunk, pelvis, hip, knee, and ankle kinematics and kinetics.