Gait Kinematics of Patients with Lateral Collateral Ligament Injuries of Ankle

Abstract Background Lateral collateral ligament (LCL) injuries of ankle are a common problem in sports medicine. The purpose of this study is to evaluate the walking kinematics in patients with LCL injuries of ankle for examining how ankle ligament injuries affect foot and ankle motion. The results will serve in precision assessment and computer-aided diagnosis. Methods Kinematics of walking were assessed by the Heidelberg Foot Measurement Model (HFMM) in 6 adults (3 patients, 3 control subjects). We hypothesized that patients with ligament injury will: present a shorter stance phase, but longer swing phase; be observed with an increasing number of shank and foot adjustments during the stance phase; reduce velocity of foot during the early swing phase with an increasing variation. Velocity profiles and micro-adjustment of knee, ankle, and foot were calculated during different gait phases and compared between two different subject groups by independent-sample t-test with 95% confidence intervals and standard error of measurements. Results In the gait cycle, 1 st rocker phase was 2.09% shorter (p < 0.001) and 2 nd rocker phase was 1.54% longer (p = 0.009) in patients than in controls. Compared to control subjects, the patients showed 89.1 mm shorter stride length (p<0.001), 0.10s slower stride (p<0.001) and 1.57 more complex micro-adjustments in 2 nd rocker phase than in other rocker/swing phases during natural walking (p=0.017). The mean velocity of knee (6.05 mm/10 -2 s vs. 4.74 mm/10 -2 s), ankle (0.85 mm/10 -2 s vs. 0.52 mm/10 -2 s), midfoot (0.79 mm/10 -2 s vs. 0.48 mm/10 -2 s) and forefoot (1.72 mm/10 -2 s vs. 0.97 mm/10 -2 s) in 2 nd rocker was significantly higher in patients (p<0.001). Conclusion Our findings revealed the human motion compensatory mechanism. Patients with ligament injuries need more musculoskeletal adjustments to keeping body balance than control subjects. Precise descriptions of the kinematics are crucial for clinical assessment before and after surgical management. These results will also provide a foundation for computer-aided diagnosis in the future. Key Terms ankle ligaments, gait analysis, Heidelberg Foot Measurement Model, foot and ankle kinematics, phase/rocker, physical therapy/rehabilitation.