Purpose: This study investigated the effectiveness of a relative motion flexion orthosis (RMFO) for increasing the range of motion for boutonniere deformity.
Methods: We included 28 patients aged 13-62 years with chronic boutonniere deformity who could complete 0° proximal interphalangeal (PIP) joint extension with the pencil test and were stage 1 according to the Burton classification of boutonniere deformity. At the initial hand therapy appointment, the RMFO was made.