In-Shoe Sensor Measures of Limb Loading by Foot Region During Gait in Patients Before and After Total Hip Arthroplasty

OBJECTIVES: To evaluate bilateral limb loading during gait before and after total hip arthroplasty (THA), and identify hip impairments associated with interlimb difference of loading after THA. STUDY DESIGN: Case series. METHODS: Patients with hip osteoarthritis were assessed preoperatively and at 2 weeks after THA (N = 40). Plantar force kinetics among 3 foot regions (rearfoot, midfoot, and forefoot) and the overall region in operated and contralateral limbs during gait were measured using force sensor insoles and were defined as peak force, impulse, and interlimb difference. Hip impairment measurements were hip pain, range of motion (ROM), abductor strength, and leg length discrepancy (LLD). RESULTS: Operated hip pain improved after THA. Peak force in all regions and impulse in most regions showed significant interlimb differences. The percent difference in forefoot impulse after THA was correlated with hip flexion ROM (partial correlation coefficient ρ = 0.422,), strength ( ρ = 0.404), and functional LLD ( ρ = –0.360). CONCLUSION: Asymmetrical weight-bearing patterns may not improve concurrently with pain relief after surgery. Forefoot impulse asymmetry may emerge with hip impairments after THA. JOSPT Open 2025;3(2):129-136. Epub 4 March 2025. https://doi.org/10.2519/josptopen.2025.0096