Fig 1.
A: As the Self-Grasping Hand is flexed backward at the wrist, the fingers curl around the object. B: Self-Grasping Hand prototype. C: Self-Grasping Hand attached to the TRS simulator forearm brace with a cosmetic glove worn over the hand (Please note that the TRS simulator is designed for use with body-powered prostheses and therefore includes a cable running along the brace. This cable was not attached to the Self-Grasping Hand and was not used during this study).
Fig 2.
(Left) The included tasks from the Southampton Hand Assessment Procedure (SHAP) were grouped into 4 sections. (Right) During the 1st attempt, the researcher demonstrated the tasks in each section, the participant was then given 2 opportunities to practice before the timed and video recorded attempt. For all further attempts, no opportunities to practice were given prior to the assessed attempts. (Bottom) Analysis of the SHAP completion time was undertaken using the online SHAP analysis software. Analysis of the time spent using the contralateral hand was undertaken through manual review of the video data.
Table 1.
Tasks involved in the SHAP assessment.
Fig 3.
Box plot of SHAP IoF scores across all 10 participants.
Outliers were labelled according to 2.2*IQR [18]. Participant 7 performed the tasks slower than the other participants explaining the long whiskers for the lower bound, however the improvement trend was the same, and there were no outliers when looking at the differences in SHAP score between attempts.
Table 2.
Summary statistics relating to contralateral hand use.
Fig 4.
Mean duration of contralateral hand use during grasping/releasing for the first (1–3) and last (8–10) 3 attempts.
G 1–3 = Involvement in grasp during attempts 1–3, R 1–3 = Involvement in release during attempts 1–3, G 8–10 = Involvement in grasp during attempts 8–10, R 8–10 = Involvement in release during attempts 8–10. Error bars show the standard error.
Fig 5.
Mean duration of direct/indirect contralateral hand interactions for the first (1–3) and last (8–10) 3 attempts.
D 1–3 = Direct interaction during attempts 1–3, I 1–3 = Indirect interaction during attempts 1–3, D 8–10 = Direct interaction during attempts 8–10, I 8–10 = Indirect interaction during attempts 8–10. Error bars show the standard error.
Table 3.
Summary of grasps used for each task.