Table 1 Overview of SMSW parameters
From: Using perceptive computing in multiple sclerosis - the Short Maximum Speed Walk test
Parameter | Unit | Description | Interpretation |
|---|---|---|---|
Average walking speed | m/s | Average speed during the measurement calculated as observed distance divided by observed time | Main outcome parameter; measures a subject’s average walking speed during the test |
Speed deviation | m/frame | Standard deviation of speed between sequent frames | Measure of directional speed homogeneity |
3D direction deviation | m2 | Mean square error from the Euclidean distance between the actual position and the position from a linear model approximation over the main z-vector | Combined expression of how much directional, up/down and left/right variability a subject’s gait shows |
Left/right deviation | cm | Left/right deviation between the actual position and the position as determined by a linear model approximation over the main z-vector | Parameter describes a subject’s left/right movement during the walking test. |
Up/down deviation | cm | Up/down deviation between the actual hip center position and the position from a linear model over the main z-vector. | Parameter describes a subject’s up/down movement during the walking test. |
Observed time | s | Total time the subject was tracked | Quality parameter |
Observed distance | m | Total distance the subject was tracked | Quality parameter |
Jump count | Number of detected calibration jumps during the measurement | Quality parameter | |
Jump distance | m | Mean distance of all calibration jumps detected during the measurement | Quality parameter |
Measurement length | frames | Total number of frames collected | Quality parameter |