Flexion task

Figs. 10.7 and 10.8 plot the transition of the input pressure, the norm, and the Activity of the best performance for each task. The hngertip position reaches the desired position for each task. At the end of the control, the Activity values are 0.9824 for the flexion task and 0.9831 for the extension task, indicating that the task is almost accomplished. Values of input pressures (x = [10, 110, 10, 80] for the flexion task and x = [70, 10, 10, 60] for the extension task) are entirely different from ones in Table 10.1. Nevertheless, since the hngertip reaches the desired position, x searches for attractors that accomplish a task through interactions with various environments (eg, activity of each actuator), even if it cannot search suitable attractors, which are values of each pressure supplied each actuator to determine the desired position. Therefore, it is... 

Figure 10.7 Transition of the input pressure, the norm, and the Activity for best performance (flexion task).

Both the MVC and myoeletric data from both types of forward flexion tasks were identically processed. The EMG signals were analyzed using EMG analysis software version 3.5.1.0, (EMGWorks, Delsys, Boston, MA), then a root mean square (RMS) technique was used to smoothen the data thus producing a linear envelope of EMG activity record. The data obtained from each subject were downloaded into a personal computer (Toshiba, Japan). The values of all RMS were averaged and then normalized as % MVC. 

The estimated values for the maximum acceptable forces for female wrist flexion (power grip) me shown in Table 26. Similarily, the estimated maximum acceptable forces were developed for wrist flexion (pinch grip, see Table 27) and wrist extension (power grip, see Table 28). The torques were converted into forces by dividing by 0.081 m for the power grip and 0.123m for the pinch grip. Snook et al. (1995) note that the estimated values of the maximum acceptable wrist torque do not apply to any other tasks and wrist positions than those that were used in the study. 

Repetitive motion Does the task require flexion of the wrist ... 

One can watch for other indicators of task-related biomechanical problems. Extreme joint flexion, unusual... 

Remy et al. (1994) investigated the cerebral blood flow with positron emission tomography induced in 10 healthy subjects by two different tasks a repeated flexion-extension of all fingers and a repeated flexion-extension of the middle finger. The all-finger movement only activated the primary sensorimotor cortex (SM) and the supplementary motor area (SMA) contralateral to the movement. However the 5MA activation was only observed when the movement was triggered by an auditory cue but not when it was self-paced. 

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