Gait analysis has become a useful tool for clinicians in evaluating the progression of pathologies through functional analysis. The high cost and dedicated laboratories associated with the traditional camera-based motion analysis systems present the need for an alternative system. Direct measurement of kinetic parameters using inertial sensors (gyroscopes and accelerometers), in place of indirect calculations from position data obtained using cameras, has been shown effective in resolving important gait parameters.

In order to directly compare gait parameters obtained using inertial sensors and a camera system, data was simultaneously collected from both systems for seven test subjects during normal gait. Three uni-axial gyroscopes and one tri-axial accelerometer were mounted on each subject's right leg, as well as the reflective markers needed for the camera-based system. Knee flexion angle, angular velocities, and linear and angular accelerations were compared between the two systems.

The similarities between the two methods validate the accuracy of the inertial sensor system with respect to the currently accepted camera-based method for some parameters. The errors found when comparing the two systems can be minimized by altering the number of sensitive axes of the sensors, as well as improving the accuracy of their placement. Such an inertial sensor system may provide an alternative that is suitable for use in a clinical setting.