Comparison of Electrical Activity of Core Stability Muscles of Trunk and Knee Muscles in People With and Without Patellofemoral Pain Syndrome during Stair-Stepping
Introduction: Patellofemoral Pain Syndrome (PFPS) is known as one of the most frequent knee diseases in athletic and non-athletic people and the most frequent cause of anterior knee pain. Despite the high prevalence of PFPS, its predisposing factors are not known. Among the potential factors, neuromuscular control disorders of lumbopelvic hip complex or core have been recently focused because the stability of this complex is vital for movements of limbs and the instability of core redounds to the instability of whole movement chain. The knee is the most prevalent joint influenced by core disorders; it seems that knee is a victim of core stability disorders. Materials and Methods: This is a descriptive-analytic case-control study. Thirty-two subjects including 17 patients with PFPS (10 female, 7 male) and 15 healthy subjects (8 female, 7 male) participated in this study. Electrical activity of vastus medialis obliqus, adductor longus, gluteus maximus, external oblique abdominus (EOA), internal oblique abdominus (IOA) and transverse abdominus (TA) and multifidus was recorded during the stair-stepping activity. All statistical analyses were performed with the SPSS version 20.0 software. Results: The results showed there was a significant difference (P=0.026 for EOA, P=0.03 for IOA and TA) between the offset time of electrical activity of core abdominal muscles in patients with PFPS and healthy subjects during stair-stepping. However, there were no significant differences in other parameters. Conclusion: The end of electrical activity of abdominal muscles in patients with PFPS during stair-stepping was longer than healthy subjects. However, managing patients with PFPS is challenging because there is no consensus regarding its predisposing factors and treatment. Therefore, more accurate recognition of this syndrome is needed to develop an appropriate treatment.Keywords: Core Stability Muscles; Electromyography; Knee Muscles; Patellofemoral Pain Syndrom
