Effects of a 12-week home exercise therapy program on pain and neuromuscular activity in patients with patellofemoral pain syndrome

Abstract

Introduction: The aim of this study is to evaluate the effects of a 12-week home exercise therapy program on pain, function and neuromuscular activity of the vastus medialis and vastus lateralis.

Materials and methods: Fifty patients with patellofemoral pain syndrome were treated with a 12-week online home exercise program. The primary outcomes of pain and function were assessed at the 12-week follow-up using the Visual Analog Scale and Kujala Score, respectively. Secondary outcomes were the muscle onset time and the ratio of vastus medialis and vastus lateralis during different daily activities.

Results: After 12 weeks, patients showed significant (p < 0.05) improvements of 27 points on the Visual Analog Scale and 10 points on Kujala Score. Differences in pre-post comparison regarding both temporal and amplitude-related neurophysiological differences between the vastus medialis and lateralis were only found when the subjects were divided into groups of different electromyographic patterns. Then changes in the pre-post comparison were particularly evident in the patient group with a delayed vastus medialis onset and a lower activity of the vastus medialis compared to the VL.

Conclusion: Pain and function improved significantly after a home exercise therapy program in patients with patellofemoral pain syndrome. In addition, patients with a delayed onset or reduced activity of the vastus medialis compared to the vastus lateralis experienced a reduction in this imbalance.

Keywords: Anterior knee pain; Electromyography; Home exercise therapy; Patellofemoral pain; Vastus.