Review of upper extremity passive joint impedance identification in people with Duchenne Muscular Dystrophy.

Only five studies included people with DMD, so most of the reviewed evidence comes from non-disabled people or mixed groups. One reviewer searched and screened the literature, so relevant papers could have been missed. Definitions and measurement methods varied widely, so the studies cannot be combined into one clinical threshold. The authors note that their narrative focus on DMD and healthy populations may have restricted the range of experimental methods they identified. Many studies used different joints, ranges of motion and velocities, so the paper does not provide a single value for passive arm resistance.

Do not read this as evidence that measuring passive joint impedance improves arm support fitting or daily function. The paper is a methods review, and the recommendation for ramp-type testing comes from the authors' synthesis, not from a clinical trial.