The trunk segmental motion complexity and balance performance in challenging seated perturbation among individuals with spinal cord injury.

This was a laboratory group comparison, not a randomised trial, so it cannot show that a treatment changes trunk motion complexity or seated balance. The study enrolled 17 individuals with SCI and 18 controls, and the paper reports a required sample size of 26 participants; the text does not state how this planned number maps onto the two groups. Participants had to sit upright for more than 10 min without back support and could use their upper limbs for protection, so results may not apply to people with SCI who are less able to sit upright. The table reports 13 participants with AISA grade A and 12 with injury level T10-T12, so the sample may not represent cervical, lumbar, or incomplete injuries. The perturbation intensity was set at 70% of maximal acceptable strength and participants held the armrests, so the task may not match everyday wheelchair perturbations. Outcomes were research measures of segmental motion complexity and centre-of-pressure balance, not clinical fall rates, patient-reported outcomes, or activity participation. The paper suggests future FES strategies, but no FES intervention was tested.

The work was supported by Shanghai Rehabilitation Medical Research Center (Top Priority Research Center of shanghai) and National Natural Science Foundation of China. The supplied text does not report author conflicts of interest.

Do not conclude that increasing trunk motion complexity will improve seated balance, because no treatment was tested. Do not read the lower final balance error as better overall balance, because the SCI group also had more variable balance recovery and greater arm use.