Effects of Somatic Dysfunction on Leg Length and Weight Bearing

Abstract

Context — Somatic dysfunction of the pelvis, sacrum and lumbar spine are common and have been associated with leg length discrepancies; however, it is unclear which specific pelvic, sacral and lumbar spine somatic dysfunctions lead to mild changes in leg lengths or weight bearing differences in asymptomatic individuals. Objective(s) — To determine which specific somatic dysfunctions of the pelvic, sacral and lumbar spine lead to minor leg length and weight bearing differences. Additionally, to determine which somatic dysfunctions are most common in the asymptomatic population. Methods — 98 asymptomatic participants between the ages of 18 to 40 were enrolled in the study absent of a recent history of trauma. Each participant had their leg lengths measured, followed by their weight through each lower extremity measured on a quadruped scale. Participants were then evaluated for pelvic, sacral and lower lumbar spine somatic dysfunctions. Results — The most common somatic dysfunctions found were superior shears of the innominate, left on left sacral torsions and right rotated lower lumbar spine segments. Several significant associations were found. Participants with right anterior innominate dysfunctions mostly exhibited an ipsilateral long leg and contralateral short leg when measured in supine, p=.05. Participants with a left superior shear tended to exhibit a shorter left leg in supine p=.05. For sacral somatic dysfunctions, participants with a left on left sacral torsion tended to exhibit a shorter left leg in standing, p=.02. In addition, a significant association was found between right anterior innominate rotation dysfunctions and weight bearing, p=.02. A higher percentage of patients with a right anterior innominate dysfunction bore more weight through their left lower extremity (45%). Conclusion — Specific pelvic and sacral somatic dysfunctions have the potential to influence leg lengths in turn leading to mild disparities. Specific pelvic somatic dysfunctions can also influence the way individuals distribute weight through their lower extremities. It is recommended to practitioners who diagnose and treat somatic dysfunctions to include a routine assessment for leg length discrepancies in their osteopathic structural examination regardless of severity since they may impact the extent and response to treatment and weight bearing if the somatic dysfunctions are long lasting