A gait analysis using wearable devices on activities of daily life in patients with knee osteoarthritis

Purpose: Gait analysis is widely used to assess the kinematics and kinetics of the lower limb during gait. However, gait analysis system is too expensive and needs a wide space for the analysis. In the recent years, a wearable device has been used approach to as simple approach to evaluate the gait valuables. The purpose of the present study was to develop a handy device to assess the gait parameters, and to show possibility for practical measurement of the parameters in patients with knee osteoarthritis (OA) using the device. Methods: Ten patients with medial knee OA (mean age 70.9, mean BMI 22.7 kg/m2) participated in the present study. After a written informed consent, conventional gait analysis was performed using three-dimensional motion analysis system which consisted of 8 cameras (200 frames/s; Oqus, Qualisys, Sweden) and 2 force plates (frequency 2000 Hz; AM6110, Bertec, Columbus, OH, USA). A total of 46 retroreflective markers (14 mm in diameter) were placed on standardized bony landmarks. The force plate collected ground reaction force (GRF) data at 2000 Hz and were synchronized to the camera sampling rate (200 Hz). The subjects performed level walking at a self-selected speed. The motion of markers was recorded by Qualisys Track Manager Software (version 2.7). To calculate knee kinematics and kinetics, Visual 3D (C-motion Company) was utilized. At the same time, tri-axial inertial sensors (TSND151, ATR-Promotions, Kyoto, Japan) were attached to six body segments (sternum, pelvis, both thighs and both shanks) (Figures 1 and 2), and similar gait parameters were calculated using our original software. The correlation between the data obtained from conventional gait analysis and those from inertial sensors. Furthermore, the same inertial sensors were mounted on three patients with knee OA for about 3 to 6 h, and the collected data was examined. Results: Gait pattern obtained from the conventional gait analysis system showed the same tendency as the pattern obtained from the inertial sensors especially with the lateral movement of the knee. Although some errors occurred with respect to the maximum and the minimum values, it was confirmed that data could be accumulated for approximately 3–6 h in daily life. Conclusions: In 2013, Maly et al. reported that easy monitoring of knee adduction moment in activities of daily life. Thereafter, several reports on gait analysis using wearable devices have shown the possibility to analyze the joint kinematics using the device. However, there were few reports concerning the gait parameters of daily activities. The wearable devices in the present study can be a useful tool to evaluate the lateral thrust in daily activities in patients with knee OA.Figure 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)