Use of gait-kinematics in sensor-based gait monitoring: A feasibility study

A concept for fusing information from the kinematics describing human locomotion with body-fixed sensors for the purpose of in situ gait monitoring is studied. This is done by using an individual's gait patterns (as captured by a simplified kinematic model) with acceleration measurements made at key points on the body. The gait patterns are expressed as nominal relations between shank, thigh, and stance leg angles during normal walking. It is shown how the use of known gait patterns reduces the required number of sensors attached to the body that are required for a sensor-based monitoring of gait. The feasibility of the approach is demonstrated using a single acceleration measurement at the ankle to estimate limb angles and step size in situ. Such gait monitoring may be used for the evaluations of a subject's overall quality of gait through the determination of flexions at the knees and hip. In addition, step sizes, distance walked, and speed can be estimated. Apart from gait analysis, the method can be used for remotely monitoring the safety of individuals to the extent this can be done through consideration of the state of gait.