A study on dynamic balance of the spatial relationship between centre of mass and centre of pressure trajectories in patients with cerebral infarction during ground-walking

Objective: To analyze the spatial relationship between centre of mass (COM) and centre of pressure (COP) trajectories in whole body three-dimensional biomechanics of patients with cerebral infarction during ground walking and to explore the characteristics of dynamic balance with hemiplegic gait to guide the safety walking and decreasing the risk factors of falling. Method: Sixteen patients after first cerebral infarction with unilateral hemiplegia were recruited. These patients were accorded with the criteria that the subjects can walk 10m independently. Twenty healthy elder matched subjects were selected as control group. Vicon system with force plate form was used in accordance with Plug In Gait Full Body software, COM and COP were analysed with C-Motion Visual 3D software. Result: Compared to the control group, there were significant differences (P<0.05) of COP-COM in medio-lateral (ML) directions and antero-posterior (AP) directions. The sway lengths of ML were larger and that of AP were less in stroke patient. Conclusion: (1) Three-dimensional motion biomechanics with full body markers located can be used for an assess- merit of dynamic balance in stroke patients. (2) Patients with cerebral infarction have larger sway in medical-lateral direction, and poorer balance in medio-lateral direction than healthy older people.