OSTEOPATHIC MANAGEMENT OF LEG LENGTH INEQUALITY WITH HEEL LIFT THERAPY: ANALYSIS OF ALTERED GAIT KINETICS & KINEMATICS

Purpose: The overall hypothesis of this research is that leg length inequality (LLI) of 5-20 mm has deleterious effects on musculoskeletal function and gait, which can be minimized with heel lift therapy (HLT) and Osteopathic Manipulative Treatment (OMT) adjunctively to correct somatic dysfunction. Methods: Our pilot participant was asked to wear a fitted shirt, fitted shorts or pants, and comfortable walking shoes. 49 reflective markers were placed on the body. Three dimensional motion data were collected using a 12 camera system that tracked the reflective markers, allowing precise calculation of kinematics, gait parameters, and joint range of motion during movements. A dual belt instrumented treadmill with force plates mounted underneath each treadmill belt recorded ground reaction force (GRF) data. A virtual reality environment was delivered by a 180° cylindrical screen enveloping the participant's field of vision during the walking trials. Results: Analysis of the Center of Mass of the participant was measured by a center pelvis marker, before and after HLT. There was a reduction in the medio-lateral (ML) displacement, 235.89 mm before and 148.87 mm after therapy. GRFs measured at heel strike during the gait cycle were averaged for the Long and Short leg. The participant walked with a speed of 3km/h in two conditions: a "simple walk" exploring a flat path in the virtual forest and a more challenging task "complex walk" in which large arms movements were required to avoid virtual birds while walking in the forest. The shorter leg had a larger GRF at heel strike. Before HLT, there was a difference of 34 N and 30 N between the average values of GRF for the Long and Short leg, respectively, during "simple walk" and "complex walk." After HLT, the difference in GRF at heel strike between the Long and Short sides decreased to 27 N and 23 N. Symmetry was also evaluated. A perfect symmetry between the two legs would be a value of zero. In our pilot participant, the symmetry in the simple walk, prior to HLT, was -0.3 and post HLT was 0.2. Conclusions: The decrease in difference of GRF at heel strike between the Long and Short legs after HLT indicates a tendency towards symmetry. The reduction in ML sway indicates reduced energy expenditure and increased stability during walking. By including the repeat radiographs at the end of therapy to reassess sacral declination, the proposed study will help us determine the best approach for intervention.