Neurology · Medical Literature
Effects of custom-made 3D-printed insoles on foot and body alignment in stroke survivors: an exploratory pilot randomized controlled trial.
Abstract
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. 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. 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. 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.
Clinical relevance
In ambulatory chronic stroke survivors who do not require ankle-foot orthosis support, do custom-made 3D-printed insoles added to standard rehabilitation improve foot alignment, postural symmetry, and dynamic balance compared with standard rehabilitation alone? __SNAPSHOT__ {"studyDesign":"Exploratory pilot randomized controlled trial","setting":"Not reported (clinical rehabilitation setting implied; country not specified)","sampleSize":"n=20 (experimental: n=10, control: n=10)","population":"Ambulatory chronic stroke survivors who did not require ankle-foot orthosis support; individuals with significant foot drop, ankle instability, or clinical indication for AFO were excluded; prior physiotherapist orthotic needs assessment required for enrollment","intervention":"Custom-made 3D-printed insoles worn during daily activities and therapy sessions, in addition to standard rehabilitation (five 30-minute sessions weekly for 6 weeks)","comparator":"Standard rehabilitation alone (five 30-minute sessions weekly for 6 weeks)","primaryOutcome":"Not formally designated as a single primary outcome in the abstract; outcomes included foot alignment measures (medial longitudinal arch angle, transverse arch angle, arch height index), body alignment measures (shoulder, pelvic, and knee tilt angles), and dynamic balance via the Timed Up and Go (TUG) test","followUp":"6 weeks (intervention duration); post-intervention assessment timepoint not separately reported beyond this period","fundingSource":"Not reported"}
Key findings
The abstract was truncated prior to reporting any numerical results; no quantitative outcome data (effect sizes, between-group differences, within-group changes, confidence intervals, p-values, or NNT/NNH) are available from the provided abstract. The study used Wilcoxon signed-rank or rank-sum tests for analysis (method truncated). No adverse events were described in the available abstract text. Specific findings regarding medial longitudinal arch angle, transverse arch angle, arch height index, shoulder/pelvic/knee tilt angles, or TUG test performance cannot be reported without access to the full publication. All outcome values are 'not reported' based on the available abstract.
Practice implications
Based solely on the available abstract, it is not possible to determine whether custom 3D-printed insoles produced a statistically significant or clinically meaningful benefit in any outcome domain for this population. The study is explicitly labeled exploratory and pilot, indicating it was not powered to confirm efficacy but rather to evaluate feasibility, estimate effect sizes, or generate hypotheses for future trials. The population is narrowly defined (ambulatory chronic stroke survivors without AFO indication), which appropriately selects a homogeneous cohort but limits generalizability to patients with more severe hemiplegia, acute-phase stroke, or AFO dependence. The small sample size (n=10 per arm) is insufficient to draw definitive conclusions about efficacy or safety. Whether practice should change cannot be assessed without full quantitative results. NOTE: This summary is based on the abstract only; the full manuscript was not available for review. __LIMITATIONS__ Critically small sample size (n=10 per arm) with very limited statistical power; typical for a pilot study but insufficient to confirm or refute efficacy,Exploratory pilot design explicitly not powered for hypothesis testing; p-values from this study, if reported in the full text, should be interpreted as hypothesis-generating only,Abstract truncated before reporting any outcome data, p-values, or effect sizes; numerical results cannot be evaluated,No single designated primary outcome is identifiable from the abstract, raising concern for multiple comparisons inflation across six or more outcome measures,No blinding of participants to intervention is feasible (open-label by nature), and assessor blinding status is not reported in the abstract,Short follow-up (6 weeks); durability of any alignment or balance changes beyond the intervention period is unknown,Funding source not reported; potential conflicts of interest cannot be assessed,Generalizability is limited to ambulatory chronic stroke survivors without AFO need; findings do not apply to acute stroke, non-ambulatory patients, or those requiring AFO,Surrogate structural outcomes (arch angles, postural tilt) used; functional, fall-related, or patient-reported outcomes are not described as endpoints,Country and institutional setting not reported, limiting assessment of external validity,Whether statistically significant differences, if found, would be clinically meaningful for the outcomes measured cannot be determined without minimal clinically important difference data for these measurement tools in stroke populations __BOTTOM_LINE_CATEGORY__ not_ready_for_clinical_application __BOTTOM_LINE__ This exploratory pilot RCT examined custom 3D-printed insoles as an adjunct to standard rehabilitation in a very small sample (n=20) of ambulatory chronic stroke survivors without AFO need, but the abstract is truncated and provides no quantitative outcome data to evaluate. The pilot and exploratory designation, combined with the small sample and lack of reportable results, means this study cannot support any change in clinical practice at this time. Clinicians should await a fully powered confirmatory trial with clearly defined primary outcomes and complete outcome reporting before considering routine adoption of this intervention.