# Evaluation of a Myoelectrical Arm for Transradial Computation in Functional Activities
## 3 Results  
The time it takes to complete each trial of the task was normalized to 1001 timeframes between 0 and 100 in the comparison of the outcome measures such as temporal angle of trunk and shoulder, movement smoothness (Jerk), vertical ground reaction forces, and selected muscle activations. A normalized time of 0 means the start of the task, whereas 100 means the completion of the task. vGRFs were also normalized with respect to the participant's body mass. Figures 3-7 show the exemplary plots for shoulder and trunk angles, object control, movement smoothness, normalized vGRFs, and muscle activation against normalized time between baseline and post-evaluation for the box lift task, respectively. Figure 3: Trunk and left shoulder angle comparison in their three primary rotation axes. The color-shaded regions represent the mean and standard deviation of the joint angles across all trials of the box lift task at that time point. All five tasks between baseline and post-evaluation were compared. MATLAB Boxchart was used to display the data of the following outcome measures with the median, the lower and upper quartiles, any outliers, and the minimum and maximum values that are not outliers: trunk and shoulder angles (Figure 8), movement smoothness (Figure 9), vGRFs (Figure 10) and muscle activations (Figure 11). Table 1 was created to display the task completion time, task-dependent object control factor (correlation coefficient), and the COP closeness to the Right value. Only one trial was performed for the tBBT task during post-evaluation. This is because the actuator of the thumb module in the i-Limb Access did not facilitate the thumb linkage to create the proper pinch force to grasp the small box during its second trial. The participant performed two trials for the other four tasks during baseline and post-evaluation. In total, 19 trials were  
Figure 4: Myoelectric arm movement smoothness (jerk) comparison. The color-shaded regions represent the mean and standard deviation of the jerk across all trials of the box lift task at that time point. Figure 5: Hand and head movement trajectory comparison of box lift task. The color-shaded regions represent the mean and standard deviation of the head and hand trajectories across all trials of the box lift task at that time point. conducted. In addition, during the box lift task for both pre and post-evaluation sessions, the participant's left and right feet moved into the same contact area on the pressure mat at certain time points. The vGRFs on the left foot cannot thus be separated from the vGRFs on the right foot. As a result, the total force is reported for both the left side and right side and leaves the entry for closeness to the Right blank, which is called not applicable in Table 1.  
Figure 6: vGRFs of left and right feet comparison of box lift task. The color-shaded regions represent the mean and standard deviation of the vGRFs across all trials of the box lift task at that time point. Figure 7: Comparison of muscle activation of four muscle groups on left arm during box lift task. The color-shaded regions represent the mean and standard deviation of each muscle activation across all trials of the box lift task at that time point. A one-sample Kolmogorov-Smirnov test was first performed to show that the data collected were not from a standard normal distribution. The ranksum test in MATLAB (equivalent to a Mann-Whitney U-test) was thus used to compare joint angles, jerk, vGRF, and muscle activation values between baseline and post-evaluation. The trunk forward tilt angle increased significantly by 4\({}^{\circ}\) in tBBT (\(p<0.01\)) and by 2\({}^{\circ}\) in bottle pour task (\(p<0.01\)). Trunk list angle increased significantly in box lift by 3\({}^{\circ}\) (\(p<0.01\)) and pulley task by 2\({}^{\circ}\) (\(p<0.01\)). The trunk rotation angle increased significantly in tBBT by 2\({}^{\circ}\) (\(p<0.01\)), in box lift by 9\({}^{\circ}\) (\(p<0.01\)), and in bottle pour task by 3\({}^{\circ}\) (\(p<0.01\)).