Many previous studies have investigated the relationship between kinematics of the lower limbs and gait speed7, 12, 13).
In addition, gait speed has been shown to have a significant effect on gait kinematics and clinicians can provide normative
kinematic data as goals for patients who walk slowly at their normal gait speed.
Recent research has proposed the use of self-selected gait speeds to specify walking speed, because it offers the advantages of allowing comparisons between speeds, while concurrently allowing the subjects to act as their own control to normalize gait parameters10, 11).
Thus, self-selected gait speeds are recognized as valid and sensitive measures of gait performance, and identifying
kinematic profiles that relate to gait speed could provide guidance for intervention strategies aimed at improving
normal gait.
Recent studies have addressed gait movement patterns using three-dimensional (3D) motion analysis systems,
but these have been limited to the sagittal plane and have neglected the frontal and transverse planes7, 14).
Both the frontal and transverse planes are important because gait performance occurs in three-dimensional space.
Therefore, we investigated the individual kinematic gait profiles of normal subjects in all three planes and identified frontal and transverse profiles in addition to the sagittal profile at self- selected gait speeds.