Findings of the Lower Extremity Dynamic Screen in Patients with Patellofemoral Pain Syndrome: A Pilot Study

Study Design: Case control study. Background and Purpose: Research has shown that patients with patellofemoral pain syndrome (PFPS) have altered frontal plane hip and knee kinematics. Multiple factors have been hypothesized to contribute to these altered movement patterns. The Lower Extremity Dynamic Screen (LEDS) is a previously-developed instrument used to visually assess hip and knee kinematics during dynamic activities. The purpose of this study was to compare LEDS scores between a patient population with PFPS and healthy control subjects. Methods: Ten subjects with PFPS and thirty-eight control subjects were recruited from a local outpatient clinic and the St. Catherine University Doctor of Physical Therapy program, respectively. Hip and knee kinematics were evaluated and quantified while performing the seven different components of the LEDS (including a double leg squat, double leg squat-jump, bilateral single leg squats, bilateral single leg squat-jumps, and a leaping task). The graded tasks were scored on a zero to three scale and individual task scores were summed to obtain a total possible score of 21 points. In this screen, higher numerical scores represent better lower extremity kinematics. The case subjects were matched with controls by gender. The total and component LEDS scores of the control subjects were compared to those of the case subjects using separate t-tests. Significance level was determined using p\u3c.05. Results: Results showed that subjects with pain had a lower mean score (13.9) than that of their gender-matched counterparts (16.5; p=.02). The individual task scores of Double-Leg Jump and Leap were also found to be significantly reduced in the patient population (p=.005 and p=.003, respectively). No other individual task was found to be significantly different. Conclusions: The results of this study indicate that subjects with PFPS scored significantly less overall than subjects without pain on the LEDS. Our results support that patients with patellofemoral pain demonstrate abnormal lower extremity kinematics when compared to controls. Due to the small sample size, further research is necessary to investigate whether the LEDS is a useful screening tool for patients with PFPS