Table 3.
Description of select iTUG and iSway variables.
| iTUG | Total Duration (seconds) | Total duration of the ITUG trial, measured from the beginning of the detected sit-to-stand transition to the end of the turn-to-sit transition |
| Gait: Stride Length (%stature) [Mean] | Distance between two consecutive foot falls at the moments of initial contact, normalized for subject height. Mean value over all gait cycles in the trial | |
| Gait: Stride Length (%stature) [CoV] | Distance between two consecutive foot falls at the moments of initial contact, normalized for subject height. Covariance of the measure over all gait cycles in the trial | |
| Gait: Stride Velocity (%stature/s) [Mean] | Walking speed, normalized for subject height. Mean value over all gait cycles in the trial | |
| Gait: Stride Velocity (%stature/s) [CoV] | Walking speed, normalized for subject height. Covariance of the measure over all gait cycles in the trial | |
| Gait: Peak Swing Velocity R (degrees/sec) [CoV] | Peak (95%) angular right shank velocity. Covariance of the measure over all gait cycles in the trial | |
| Gait: RoM Knee (degrees) [Mean] | Angular range of knee motion. Mean value over all gait cycles in the trial | |
| Gait: RoM Knee L (degrees) [Mean] | Angular range of the left knee motion. Mean value over all gait cycles in the trial | |
| Gait: RoM Knee R (degrees) [Mean] | Angular range of the right knee motion. Mean value over all gait cycles in the trial | |
| Gait: RoM Shank (degrees) [CoV] | Angular range of shank motion. Covariance of the measure over all gait cycles in the trial | |
| Gait: RoM Shank L (degrees) [Mean] | Angular range of the left shank motion. Mean value over all gait cycles in the trial | |
| Gait: RoM Trunk horizontal (degrees) [CoV] | Angular range of trunk motion in the horizontal plane. Covariance of the measure over all gait cycles in the trial | |
| Turn: Duration (seconds) [Mean] | Duration of 180 degree turn. Mean value over all gait cycles in the trial | |
| Turn: Number of steps [Mean] | Number of steps in the 180 degree turn. Mean value over all gait cycles in the trial | |
| Turn: Peak Velocity (degrees/sec) [Mean] | Peak (95%) angular trunk velocity while turning. Mean value over all gait cycles in the trial | |
| Turn To Sit: Duration (seconds) | Duration of the turn-to-sit transition | |
| Turn To Sit: Peak Turn Velocity (degrees/sec) | Peak (95%) angular trunk velocity in the during the sit-to-stand transition | |
| Turn To Sit: RoM Trunk (degrees) | Angular range of trunk motion in the sagittal plane during the turn-to-sit transition | |
| iSway | Normalized jerk | Normalized Jerk (normalized to the range of the sway path’s excursion and duration) in the transverse plane |
| Normalized jerk (AP) | Normalized Jerk (normalized to the range of the sway path’s excursion and duration) in the anterior/posterior (forward-backward) direction | |
| Jerk (ML) (m2/s5) | Smoothness of sway from the time derivative of the sway path in the medial/lateral (side-to-side) direction | |
| Mean distance (ML) (m/s2) | Mean distance of the sway path from the center of the path in the medial/lateral (side-to-side) direction | |
| Path length (m/s2) | Total length of the sway path in the transverse plane | |
| Path length (AP) (m/s2) | Total length of the sway path in the anterior/posterior (forward-backward) direction | |
| Range of acceleration (m/s2) | Total range of the sway path in the transverse plane | |
| Mean velocity (ML) (m/s) | Mean velocity of the sway path in the medial/lateral (side-to-side) direction | |
| Total sway area (m2/s5) | Sway area, computed as the area included in the sway path in the transverse plane per unit of time | |
| Mean frequency (Hz) | Mean sway frequency in the transverse plane, calculated from the sway path’s length and duration | |
| Median frequency (AP) (Hz) | Frequency below which 50% of the sway path power in the anterior/posterior (forward-backward) direction is present | |
| Centroidal frequency (Hz) | Frequency of sway from the centroid of the sway path’s power spectrum in the transverse plane | |
| Centroidal frequency (AP) (Hz) | Frequency of sway from the centroid of the sway path’s power spectrum in the anterior/posterior (forward-backward) direction | |
| High frequency power (AP) ((m/s2)2*Hz−1) | Ratio of sway path power in the anterior/posterior (forward-backward) direction that is above 3.5Hz | |
| Frequency dispersion (ML) | Frequency dispersion in the medial/lateral (side-to-side) direction |