Feasibility of optimizing muscle activation of individuals with spinal cord injuries to reduce caregiver effort in assisted transfers.

Only two SCI participants and one caregiver were tested, so the results cannot be generalized. The paper does not name a primary outcome, and the statistical test of ground reaction force did not show a significant difference between conditions (p=0.1250). The model was sagittal-plane only, so it did not include transverse and coronal movements that occur in real transfers. Only the lifting portion of transfer was studied, not pivoting or lowering, which also can injure caregivers. Caregiver joint reaction forces were estimated by a model and simplified assumptions, not measured directly at the joints. The two participants used different stimulation systems and muscles, so differences may reflect setup rather than one FNS strategy. The SCI model had fixed head, neck, and trunk and welded feet, and the caregiver model had doubled joint limits and doubled muscle strength, which are simplifications. Seating height was 7.0 cm higher for S2, which may account for observed caregiver joint angle deviations.

The study was funded by the U.S. Department of Defense and the NIH. The supplied text does not report author conflicts of interest.

Do not conclude that functional electrical stimulation reliably reduces caregiver ground-force load or injury risk. The ground-force difference was not significant (p=0.1250), only two SCI participants and one caregiver were tested, and joint-force reductions are model estimates rather than direct measurements.