Spinal cord injuries (SCIs) can cause devastating damage including loss of mobility and sensation. Researchers have invented the Trunk-Support Trainer (TruST), a robotic device that assists and trains people with SCIs to sit more stably by improving their trunk control and thus gain an expanded active sitting workspace without falling over or using their hands to balance.
TruST was designed for people with SCIs who are typically wheelchair users. The device not only prevents patients from falling but also maximizes trunk movements beyond patients’ postural control or balance limits.
TruST is a motorized-cable-driven belt placed on the user’s torso to determine the postural control limits and sitting workspace area in people with SCIs. It delivers forces on the torso when the user performs upper body movements beyond the postural stability limits while sitting.
Test subjects with SCIs were examined with the Postural Star-Sitting Test, a customized postural test that required them to follow a ball with their head and move their trunk as far as possible without using their hands. The test was repeated in eight directions and the researchers used the results to compute the sitting workspace of each individual.
The team then tailored the TruST for each subject to apply personalized assistive force fields on the torso while the subjects performed the same movements again. With the TruST, the subjects were able to reach farther during the trunk excursions in all eight directions and significantly expand the sitting workspace around their bodies, on an average of about 25% more.
The team is exploring the use of TruST within a training paradigm to improve the trunk control of adults and children with SCI. The robotic platform will be used to train participants with SCI by challenging them to move their trunk over a larger workspace, with TruST providing assist-as-needed force fields to safely bring the subjects back to their neutral sitting posture. This force field will be adjusted to the needs of the participants over time as they improve their workspace and posture control.