Minimal footwear improves stability and physical function in middle-aged and older people compared to conventional shoes

Background: Effects of minimal shoes on stability and physical function in older people are under-researched. No studies have systematically explored effects of a range of minimal footwear features on these factors in older people. Methods: A within-participant repeated-measures design was used. Participants were subjected to thirteen footwear conditions: (i) barefoot, (ii) a conventional shoe, (iii) a control minimal shoe, (iv-xiii) minimal shoes differing from the control minimal shoe by one design feature. The outcomes were: (i) postural stability expressed with movement of the center of pressure (CoP) during standing (ii) dynamic stability expressed with the CoP movement during walking, (iv) physical function assessed with the Timed Up and Go test (TUG), and (iv) perceptions of footwear assessed with the Monitor Orthopaedic Shoes questionnaire. Linear Mixed Models were applied for statistical analyses. Findings: Twenty-two people participated in the study. Compared to the conventional shoe, participants: (i) were more stable during standing and walking in the majority of minimal shoes, and (ii) completed the TUG test faster when wearing the minimal shoe with wider sole. Compared to the control minimal shoe, participants: (i) completed the TUG test faster when wearing the minimal shoe with wider sole; and (ii) perceived features such as a split toe and a higher ankle collar as less fashionable and wearable. Interpretation: Wearing minimal shoes might be more beneficial for stability and physical function in older adults than wearing conventional shoes. The results will be highly valuable for the design of minimal footwear for older adults.