A high prevalence of manual wheelchair rear-wheel misalignment could be leading to increased risk of repetitive strain injuries.
Joseph Ott, Travis Henderson, Holly Wilson-Jene and 2 others
PMID 33710939WHAT IT FOUND
Most manual wheelchairs in this community sample had rear-wheel misalignment, with 61% showing toe angles over 0.5 degrees.
Combined with underinflated tires, this creates resistance equivalent to carrying extra weight, which may increase propulsion effort and injury risk.
Key findings
0161% of measured wheelchairs had rear-wheel misalignment greater than 0.5 degrees when loaded.
02Tire pressure was on average only 40% of the maximum recommended level, adding resistance equivalent to carrying a nine-kilogram weight.
03No specific wheelchair factors predicted toe angle, but tire manufacturer and wheel diameter were significant predictors of slop.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTsWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The sample was recruited from adaptive sporting events, so it may not represent the general wheelchair-using population. Tire pressure was only measured for the final 50 participants, not the whole group. The study used a novel test rig and static measurements, which may not fully capture dynamic propulsion conditions. The link between misalignment and injury risk is inferred from resistance calculations, not directly measured injury outcomes.
Declared interests
The authors declared no conflicts of interest. The study was supported by the National Institutes of Health and the U.S. Government.
The easy way to misread this
Do not assume that checking toe angle will solve propulsion difficulties. The study found that no factors predicted toe angle, and the primary driver of increased resistance in this sample was likely tire underinflation, which was measured in only a quarter of the participants.