Objective gait analysis using Kinect v2® for the prognosis of walking during the acute phase of rehabilitation after proximal femoral fracture surgery

Objective While factors affecting gait post-surgery for proximal femoral fracture (PFF) have been studied, the prognostic value of objective gait analysis during acute postoperative rehabilitation remains unclear. Microsoft Kinect for Windows v2® (Kinect) is a noninvasive, low-cost, and easy-to-implement posture estimation device. However, its application in analyzing gait for these patients is underreported. This study aims to analyze gait during acute postoperative rehabilitation using Kinect, identifying key gait evaluation metrics and prognostic indicators. Methods This study included 17 patients who were admitted to our hospital with PFF and underwent surgery. Rehabilitation began the day after surgery, with weekly Kinect-recorded gait videos from postoperative weeks 1 to 4. Gait parameters were analyzed thereafter. Participants were divided into two groups: those unable to walk with a walker one week after surgery were classified as having a poor prognosis ( n = 7), while those who could were classified as having a good prognosis ( n = 10). Various gait parameters were then compared between the groups to examine factors predicting gait prognosis. Furthermore, the hip joint pain/activities of daily living (ADL) index Oxford Hip Score (OHS) and the dynamic balance indicator timed up and go test (TUG) were evaluated, and the correlation with each gait parameter was examined. Key gait parameters were analyzed in both groups after equivalent rehabilitation periods. Results Increased gait velocity, decreased gait cycle time, increased swing phase, decreased stance phase, and increased maximum hip joint flexion angle were observed during the postoperative rehabilitation in both study groups. Compared with the good prognosis group, the poor gait prognosis group showed worse swing/stance phases of either healthy or affected limb, TUG, and OHS. The mean TUG value and OHS correlated with each gait parameter. Even after the same rehabilitation gait training period, the good prognosis group showed greater improvements in gait velocity, swing phase, stance phase, hip and knee joint flexion angles, and OHS compared to the poor prognosis group. Conclusion During the acute phase of rehabilitation after PFF surgery, adequate hip pain control and early weight bearing of the operated limb are important for favorable gait prognosis.