Knee gait kinematics : describing a normal cohort
Introduction:  The gait cycle has been studied by many disciplines. Despite multiple studies, our current understanding of the gait cycle does not allow us to model femoro-tibial kinematics in a clinically relevant manner. The primary objective of our study was to characterize femoro-tibial kinematics in healthy subjects using the KneeKGTM apparatus.   Materials and methods: Ninety-five patients, fifty-two females and forty-three males, without any known musculoskeletal or lower limb pathology, were recruited to participate in our study. Each patient underwent a KneeKGTM examination. All patients completed the knee injury and osteoarthritis outcome score (KOOS) and the 12-item Short Form Health Survey (SF-12) questionnaires and had full-length weight bearing (FLWB) x-rays. Gait cycle kinematics were generated in the sagittal motion, transverse rotation, and the frontal plane and were compared between men and women and between the right and left knees of the same patient. The results obtained were also correlated with the anatomic variations found in patients, which were estimated by angles measured on the FLWB x-rays.  Results: When comparing men and women, significant differences were found in the sagittal motion and transverse rotation planes and in the entirety of the gait cycle in the frontal plane.  In the sagittal plane, women have greater amplitude of flexion than men during the mid-swing and terminal swing phase (0.002 ≤ p ≤ 0.05).  In the transverse plabe, more internal rotation of the knee is observed in women than in men during the entire swing phase (0.005 ≤ p ≤ 0.05). In the frontal plane, more abduction occured in women compared to men throughout the entire gait cycle (0.001 ≤ p ≤ 0.002). When comparing the right and left knees, significant differences were only found in the frontal plane during which the right knees were more in adduction than the left knees during the entire swing phase (0.005 ≤ p ≤ 0.04). No meaningful correlations could be made between radiographic hip-knee-ankle (HKA) ankle and abduction-adduction angles during the gait cycle (-0.40 ≤ r ≤ -0.42, p<0.001).   Discussion-conclusion: The results of our study contribute to better understanding the kinematics of the gait cycle and foster the notion that cohorts should be divided for gender to account for gait differences in the frontal plane. Furthermore, static alignment does not appear to correlate with dynamic alignment.
knee movement KneeKG gait kinematics normal