# Evaluation of a Myoelectrical Arm for Transradial Computation in Functional Activities
## 4 Discussion  
On average, the time for the tBBT, box lifting, bottle pouring, and pulley task tasks decreased by 24.0, 1.6, 9.0, and 8.4 s, respectively, while the time for the bottle cap task did not change. The increased average shoulder angle in all three axes in most tasks during post-evaluation may indicate that the left shoulder joint became more engaged in performing these tasks. However, the increased average trunk angle in all three axes in some of these tasks may also indicate that the trunk compensation was not reduced to some extent. In addition, the post-evaluation angle changes also appear smoother than the angle changes in the baseline evaluation, which may indicate that the participant had greater control of movement. When comparing these angle data, one caveat is that these joint angle differences for both the trunk and shoulder may not be clinically meaningful enough to conclude whether the training procedure was effective or ineffective. There does appear to be larger spikes in the baseline evaluation, meaning there may have been larger jerk movements, although no significant change was shown in the averaged jerk value. In the comparison of the baseline evaluation to the post-evaluation, the vGRFs results of tBBT and pulley tasks show that the average vGRFs on the left foot tend to increase, whereas the average vGRFs on the right foot tend to decrease. The data from closeness to the Right may indicate that the participant was overcompensating by leaning more on the right foot while performing functional tasks during the baseline evaluation and that the training program may have contributed to the participant more effectively keeping the center of mass towards the midline of the body by more evenly distributing weight between the left foot and the right foot. The vGRFs results of box lift and bottle cap tasks show that the average vGRFs on the right foot tend to increase. The data from closeness to the Right may indicate that the participant was overcompensating by leaning more on the left foot while performing the bimanual tasks during the baseline evaluation. They also indicate that the training program may have contributed to the participant more effectively keeping the center of mass towards the midline of the body by more evenly distributing weight between the left foot and the right foot. Muscle activation is expected to decrease as the participant becomes more adaptive to performing bimanual and unimanual tasks after the first two weeks of training [24]. However, the participant showed increased muscle activations across all muscles in all tasks during the post-evaluation when compared to baseline. The prosthetic hand opens and closes when the extensor carpi radialis and flexor digitorum profundus muscles activate, respectively. We suspect that the participant may have become more cognitively attuned to \begin{table}
\begin{tabular}{c c c c c} \hline
**Outcome Measures** & **Time Point** & **Task Completion Time (s)** & **Correlation Coefficient** & **Closeness to the Right (Percentage)** \\ \hline tbbt & Pre & 58.5 (5.7) & 0.63 (0.18) & 83.1 (3.3) \\  & Post & 34.5 & 0.79 & 69.3 \\  & Pre & 18.9 (0.0) & 0.98 (0.01) & Not applicable \\ box lift & Post & 17.4 (2.2) & 0.98 (0.00) & Not applicable \\  & Pre & 20.0 (5.8) & 0.39 (0.02) & 56.3 (2.7) \\ bottle pour & Post & 11.1 (0.5) & 0.29 (0.06) & 71.1 (0.6) \\ bottle cap & Pre & 13.8 (1.0) & 0.76 (0.18) & 34.4 (6.3) \\  & Post & 13.8 (2.1) & 0.49 (0.31) & 57.1 (7.6) \\ pulley & Pre & 17.3 (0.1) & 0.67 (0.13) & 46.9 (5.2) \\  & Post & 8.9 (2.8) & 0.21 (0.47) & 41.4 (5.5) \\ \hline \end{tabular} Note: Values are mean (SD) except for task completion time and correlation coefficient of tbbt, as only one trial was conducted for tbbt post-evaluation.  
\end{table} 
Table 1: Outcome measures related to task performance. flexion as the muscle activation that opens the hand and may have translated that to more activation in all four muscles during the post-evaluation.