Figure 1.

Experimental set up and data analysis of kinematic data. Schematic outline of the motor tasks. The board (gray squares, upper row) carried a central light-emitting diode (LED) and four cubic grip objects (0.02 m × 0.045 m × 0.085 m) with response buttons and target LEDs. The central light was illuminated for 3 s as a warning cue at the start of each trial. Illumination of the target LED and dimming of the central LED was the starting cue for each movement. A successful button press was acknowledged by turning off the target LED. Patients performed the reach-to-grasp task, including a reaching phase and grip formation around the response button. The movement was analyzed with recorded kinematic data of Zebris system. Upper row: position curve of the hand wrist marker in the sagittal plane. Middle row: velocity curve of the hand wrist marker. Lower row: distance between the two markers on the thumb and index finger. Black dotted lines represent the time points in the velocity curve displaying the beginning of the movement (when velocity exceeds 0.05 m/s), maximum velocity and the end of the movement (when velocity falls below 0.05 m/s). Gray dotted lines represent the time points of the maximal peak distance between thumb and index finger (PGA) and minimal distance (MGA). Movement times (MT) were calculated from these discrete time points as demonstrated above. MT ACC: acceleration time (time from the beginning of the movement to maximal velocity). MT DEC: deceleration time (time from maximal velocity to the end of the movement). Total MT: duration of the whole movement (calculated from the velocity curve from the beginning to the end of the movement). MT PGA: time to peak grip aperture (from the beginning of the movement to the time of maximal thumb-index finger distance). MT MGA: grip closure time (time from maximal to minimal distance of thumb and index finger). Reproduced with permission from Pötter-Nerger et al. (2013).