Influence of the Powers™ strap on pain and lower limb biomechanics in individuals with patellofemoral pain.

Abstract

Abnormal biomechanics, especially hip internal rotation and adduction are known to be associated with patellofemoral pain (PFP). The Powers™ strap was designed to decrease hip internal rotation and to thereby stabilise the patellofemoral joint. This study aimed to investigate whether the Powers™ strap influenced pain and lower limb biomechanics during running and squatting in individuals with PFP. Twenty-four individuals with PFP were recruited using advertisements that were placed at fitness centres. They were asked to perform a single leg squat task (SLS) and to run on an indoor track at their own selected speed during two conditions: with and without the Powers™ strap. Immediate pain was assessed with the numeric pain rating scale. Three-dimensional motion and ground reaction force data were collected with 10 Qualisys cameras and three AMTI force plates. Immediate pain was significantly reduced with the Powers™ strap (without the Powers™ strap: 4.04 ± 1.91; with the Powers™ strap: 1.93 ± 2.13). The Powers™ strap condition significantly increased hip external rotation by 4.7° during the stance phase in running and by 2.5° during the single leg squat task. Furthermore, the external knee adduction moment during the SLS and running increased significantly. This study assessed the effect of the Powers™ strap on lower limbs kinematics and kinetics in individual with PFP. The results suggest that the Powers™ strap has the potential to improve abnormal hip motion. Furthermore, the Powers™ strap demonstrated an ability to significantly reduce pain during functional tasks in patients with PFP.