Table 2.

Spatiotemporal and kinematic gait parameters computed over the 3-D body joint data.

Gait Parameter	Definition
Stride duration	Duration of the gait cycle or stride
Step duration	Duration of the left/right step, when considering a left/right gait cycle
Stance duration	Duration of the stance phase
Swing duration	Duration of the swing phase
Single support duration	Duration of the single-limb support phase
Double support duration	Duration of the double-limb support phase
Stride length	Distance (in the xz-plane) between the position of the left/right ankle at the beginning and end of the left/right gait cycle
Step length	Distance (in the xz-plane) between the position of the left/right ankle at the instant during the swing phase when the ankle distance is minimum, and at the instant corresponding to the end of the left/right gait cycle
Step width	Minimum value of the distance between ankles (in the xz-plane) during the swing phase
Gait speed	Mean value of the trunk velocity (mean of velocity of the head, neck, spine shoulder, spine middle, and spine base joints)
Gait speed variability	Standard deviation of the trunk velocity
Foot swing velocity	Maximum value of the left/right ankle joint velocity during the swing phase, when considering a left/right gait cycle
Arm swing velocity	Maximum value of the left/right hand velocity (mean of velocity of the left/right wrist and hand joints) during the stance phase, when considering a left/right gait cycle
TBCM sway x/y-component	Measure of the body sway computed as the mean distance (in the x/y-axis) of the total body center of mass (TBCM), in relation to the RGB-D sensor’s coordinate system, for all gait cycle frames. For each frame, TBCM’s position is the mean position of all body segments’ CM, which was obtained according to [28] using the parameters indicated by Dempster in [29].
Spine shoulder angle	Mean value of the angle at spine shoulder (defined by head, spine shoulder, and spine base joints), considering the whole gait cycle
Spine middle angle	Mean value of the angle at spine middle (defined by head, spine middle, and spine base joints), considering the whole gait cycle
Maximum elbow angle	Maximum value of angle at the left/right elbow (defined by left/right shoulder, elbow and wrist joints) during the stance phase, when considering a left/right gait cycle
Minimum elbow angle	Minimum value of angle at the left/right elbow during the stance phase, when considering a left/right gait cycle
Maximum knee angle	Maximum value of angle at the left/right knee (defined by left/right hip, knee, and ankle joints) during the stance phase, when considering a left/right gait cycle
Minimum knee angle	Minimum value of angle at the left/right knee during the swing phase, when considering a left/right gait cycle
Hip angle range	Difference between the maximum and minimum value for the left/right hip angle (defined by left/right knee joint, hip joint, and point with knee y-coordinate and hip x- and z-coordinates) during the stance and swing phases respectively, when considering a left/right gait cycle
Ankle angle range	Difference between the maximum and minimum value for left/right ankle (defined by left/right knee, ankle, and foot joints) during the swing and stance phases respectively, when considering a left/right gait cycle