Gait analysis of total hip arthroplasty patients based on the spectral analysis results of trunk acceleration

Abstract

The purpose of this study is to investigate the gait improvement for patients after total hip arthroplasty (THA) by using accelerometers attached to the trunk of body before and after surgery (initial gait after THA, in hospital, at discharge, 3 months after THA, 6 months after THA, 1 year after THA). Thirty patients (mean age 61.1 ± 11.1 years old) were selected. Twelve healthy subjects (mean age 24.1 ± 2.6 years old) were also selected as a control group. Dynamic load factor (DLF) corresponding to the vertical walking force and lateral displacement of the trunk are calculated using power spectrum density for time history trunk signals measured by the accelerometers. The parameter PR in the fore and posterior directions is also obtained which is defined as the power spectrum ratio of 0.5fw to fw component where 0.5fw is half frequency component of the gait cycle fw. Based on these results, it was confirmed that the parameter PR in the fore and posterior directions, DLF in the vertical direction and lateral displacement of the trunk were the useful evaluation indices in order to evaluate the gait improvement for THA postoperative patients.

Keywords

• gait analysis
• total hip arthroplasty patients
• accelerometer
• fft analysis
• rehabilitation