Gait coordination: potential marker for mental state

Human walking involves coordinated movement between lower limbs. Locomotion is a neuromuscular activity and hence it is affected by mental tasks. Many studies on gait parameter e.g. stride length, gait speed, cadence and percentage of gait cycle in a double limb stance has been performed to determine the effect of a mental task on locomotive task. The knee being an important joint for locomotive tasks is considered here for monitoring. Spatiotemporal pattern matching in interlimb knee angle trajectories, in saggital plane, is used here to assess the effect of a mental task on locomotion. Cross correlation coefficient (CCF) is used as a mathematical tool to calculate the degree of pattern matching. The strength of peak CCF and the time shift (lag) at which this occurs is determined. Further a comparison of peak CCF of different locomotive tasks along with a mental task is compared. CCF with walking is 0.8 which decreases to 0.6 while walking with mental task. The results show that CCF between knee joint angles while walking can be used as a parameter to assess the mental task.