Lower limb movement asymmetry measurement with a depth camera

The gait movement seems simple at first glance, but in reality it is a very complex neural and biomechanical process. In particular, if a person is affected by a disease or an injury, the gait may be modified. The left-right asymmetry of this movement can be related to neurological diseases, segment length differences or joint deficiencies. This paper proposes a novel method to analyze the asymmetry of lower limb movement which aims to be usable in daily clinical practice. This is done by recording the subject walking on a treadmill with a depth camera and then assessing left-right depth differences for the lower limbs during the gait cycle using horizontal flipping and registration of the depth images half a gait cycle apart. Validation on 20 subjects for normal gait and simulated pathologies (with a 5 cm sole), showed that this system is able to distinguish the asymmetry introduced. The major interest of this method is the low cost of the material needed and its easy setup in a clinical environment.