Relation Between Femoral Nerve Conduction Velocity and Its Mechanosensitivity Changes Among Patellofemoral Pain Syndrome

Patellofemoral pain syndrome (PFPS) is considered one of the most common condition affecting young active populations, it accounts for about 40% of individuals complaining from knee pain.PFPS is the anterior or retro patellar pain that can be precipitated by some daily activities such as ascending and descending stairs, kneeling, squatting or performing everyday tasks. Individuals with PFPS can experience a history of cracking or popping sounds when changing position or climbing stairs and also experience pain during repeated knee flexion. In a previous study conducted by Jensen et al .(2008),they observed that individuals with PFPS experienced symptoms that are related to neural compromise like patellar numbness and reduced ability to differentiate between different thermal stimulus .so PFPS may be related to neurological impairments or dysfunction. Femoral slump test can be used in examining the neurodynamic responses in individuals with anterior knee pain which has a specificity of more than 75% in testing neural mechanosensitivity In a study conducted by Lin et al (2014) that examine the hip extension range of motion (ROM) and mechanical sensitivity of femoral nerve as a neurodynamic response in individuals with PFPS , they proposed that 30% of them have decrease hip extension ROM and increased mechanosensitivity comparison with healthy individuals. The current management of the patellofemoral pain support using open- and closed-chain exercises, strengthening, stretching, aerobic exercise, patellofemoral and tibiofemoral mobilizations, patellar taping, highintensity NMES, neuromuscular training, and gait retraining as a multi modal treatment for PFPS. Despite these methods result in significant improvement, other few patients reported some residual symptoms Hung et al .,(2015) have encouraged that using the femoral nerve mobilization as a neurodynamic management for treating PFPS patients especially those with postive femoral slump test , and testing the hip extension range of motion as a reference of improvement previous studies reported the presence of neurogenic dysfunction model to PFPS but most of these scientific researches lack the presence of the gold standard and objective method for identifying the neurogenic patellofemoral pain