Effects of custom-made 3D-printed insoles on foot and body alignment in stroke survivors: an exploratory pilot randomized controlled trial

Background Stroke survivors frequently exhibit foot deformities and postural asymmetry, contributing to gait instability and increased fall risk. This exploratory pilot randomized controlled trial examined the effects of custom-made 3D-printed insoles on foot alignment and postural symmetry in ambulatory chronic stroke survivors who did not require ankle-foot orthosis (AFO) support. Methods Twenty ambulatory chronic stroke survivors who did not require AFO support were randomly allocated to experimental ( n = 10) or control ( n = 10) groups. Prior to enrollment, a physiotherapist assessed each participant’s orthotic needs; those with significant foot drop, ankle instability, or clinical indication for AFO were excluded. Both groups participated in standard rehabilitation (five 30-minute sessions weekly for six weeks). The experimental group additionally wore custom-made 3D-printed insoles during daily activities and therapy sessions. Outcomes included foot alignment (medial longitudinal arch angle, transverse arch angle, arch height index), body alignment (shoulder, pelvic, and knee tilt angles), and dynamic balance via Timed Up and Go test (TUG). Data were analyzed using Wilcoxon signed-rank and Mann–Whitney U tests. Results The experimental group showed a significant increase in medial longitudinal arch (MLA) angle (mean difference 7.95°, p = 0.01) with a significant between-group difference at post-intervention ( p = 0.03). A between-group difference in shoulder tilt angle was observed at post-intervention (mean difference 1.2°, p = 0.03), while no significant within-group change was detected in either group. No significant within-group changes or between-group differences were observed for transverse arch angle, arch height index, pelvic tilt, knee tilt, or TUG performance. Conclusions Custom-made 3D-printed insoles improved medial arch height and were associated with a between-group difference in shoulder tilt in selected ambulatory chronic stroke survivors who did not require AFO support. These findings should be interpreted cautiously given the small sample size and exploratory pilot design. Larger definitive trials are needed to confirm these results.