The Relationship between Femoral Nerve Tension and Hip Flexor Muscle Length

Abstract

Adverse neural tension is the inability for a nerve to glide freely in its mechanical interface. Studies demonstrate that there is relationship between muscular facilitation and adverse neural tension in the upper extremity and in the posterior thigh, but few examine a potentially similar interaction in the anterior hip. The purpose of this study was to determine the relationship between femoral nerve tension and hip flexor muscle tightness. The Prone Knee Bend test and the Thomas test were performed on a group of 20 normal subjects (40 unilateral lower extremities) without back pain or dysfunction, and on a group of 12 patients (21 unilateral lower extremities) treated with physical therapy for low back pain. The results demonstrated a significant correlation for the control and patient groups combined (r=0.530; p=0.0001); for the control group only (r=0.322; p=0.043) and the patient group only (r=0.601; p=0.002). This study indicates a correlation between the Thomas Test and the Prone Knee Bend Test suggesting a relationship between adverse neural tension of the femoral nerve and muscle length of the iliopsoas muscle. Increased femoral nerve tension may influence hip tightness in normal and patient populations. Likewise, adaptive shortening of the hip flexors may lead to adverse femoral nerve tension.