RELATIONSHIP BETWEEN HIP STRENGTH AND TRUNK, HIP, AND KNEE KINEMATICS DURING A JUMP-LANDING TASK IN INDIVIDUALS WITH PATELLOFEMORAL PAIN

Background/Purpose: Decreased strength of the hip musculature and altered mechanics of the lower extremity have been identified in individuals with patellofemoral pain (PFP). The aim of this study was to determine if a relationship exists between hip muscle strength and transverse and frontal plane motion at the hip and knee, and ipsilateral trunk flexion during a jump-landing task in individuals with PFP. Methods: Fifteen individuals (10 females, 5 males) with PFP participated in this investigation. A three-dimensional motion analysis system was utilized to assess trunk, hip, and knee kinematics during a jump-landing task. An isokinetic dynamometer was utilized to assess concentric and eccentric strength of the hip musculature. Simple correlation analyses were performed to determine the relationships between hip muscle strength and peak frontal and transverse plane hip and knee kinematics and ipsilateral trunk flexion. Results: Decreased eccentric strength of the hip external rotators and abductors was significantly correlated to increased frontal plane motion at the hip and trunk, respectively (P<0.05). Conclusions: Based on these findings, eccentric strengthening exercises for the hip musculature may be an important component for clinicians to include when rehabilitating individuals with PFP who display increased frontal plane motion at the hip and trunk.