Minimal shoes improve stability and mobility in persons with a history of falls

Falls are a significant problem among older adults, resulting in injury, hospitalization, and death, and placing a substantial burden on healthcare systems. Postural and walking instability are major risk factors, and plantar sensation plays a crucial role in maintaining balance. Modern conventional footwear, with features like cushioning, arch support, and restrictive toe boxes, may reduce sensory input and negatively impact gait control, potentially increasing fall risk. Previous research indicated that minimal shoes, mimicking barefoot walking, might be beneficial. However, studies comparing minimal shoes, conventional shoes, and barefoot walking in fall-prone older adults, while considering the impact of visual and cognitive factors, were lacking. This study aimed to address this gap by comparing the effects of these three footwear types on stability and mobility in older adults with a history of falls, also considering the role of visual input and dual-tasking.

Existing literature highlights the high prevalence and significant consequences of falls in older adults. Studies have established postural and gait instability as major contributing factors. The role of plantar sensation from cutaneous receptors in maintaining stability during standing and walking is well-documented. The design of modern footwear, with its cushioning and support features, can potentially interfere with the transmission of crucial sensory information to the brain, thereby affecting gait and balance. While barefoot walking is less common in modern society, the idea that footwear that replicates its neuro-mechanical properties could benefit fall prevention has been explored. Previous studies by the research team had shown the benefits of minimal shoes in middle-aged and older adults. However, this study extends this research by focusing on individuals with a history of falls and examining the impact of visual and cognitive conditions.

This cross-sectional observational study employed a within-participant repeated-measures design. Thirty participants (mean age 68.6 ± 4.4 years; 57% female) with a history of falls were recruited. Participants performed assessments in three randomized footwear conditions: conventional shoes, minimal shoes (Primus Knit, Vivobarefoot Ltd.), and barefoot. Postural stability was assessed using a pressure plate (FootWork Pro, AM CUBE) measuring center of pressure (CoP) velocity and range of motion during 30-second standing trials with eyes open and closed. Walking stability was assessed using motion capture (Qualysis AB) to calculate the margin of stability (MoS) during normal and dual-task walking. Mobility was evaluated using the Timed Up and Go (TUG) test and a modified Star Excursion Balance (SEB) test. Perceptions of the shoes were assessed using the Monitor Orthopaedic Shoes questionnaire. Linear mixed-effects models were used to analyze the data, adjusting for relevant factors such as speed and cadence. Paired-samples t-tests compared perceptions of conventional and minimal shoes.

The study revealed significant main effects of footwear on all aspects of postural and walking stability. Participants exhibited significantly better postural stability (lower CoP metrics) when wearing minimal shoes and barefoot compared to conventional shoes. This difference was consistent regardless of visual condition (eyes open/closed). In walking stability, minimal shoes resulted in significantly higher anterior-posterior MoS values compared to conventional shoes and barefoot conditions. There was no significant difference between minimal shoes and barefoot for this measure. No significant interaction effects were found between footwear type and visual or walking condition. For mobility, minimal shoes showed a significant advantage over both conventional shoes and barefoot conditions, resulting in faster TUG test completion times and greater reach distances in the SEB test. Participants perceived minimal shoes as having a better fit, being lighter, and providing greater stability compared to conventional shoes.

The findings support the hypothesis that minimal shoes are more beneficial for stability and mobility in fall-prone older adults than conventional shoes. The improved stability may be attributed to several factors: reduced heel elevation, minimizing anterior shifting of the body's center of mass; a wider sole, increasing the base of support and potentially enhancing somatosensory input; and the thinner sole, potentially increasing stimulation of plantar mechanoreceptors. The absence of significant interaction effects suggests the benefits of minimal shoes hold true regardless of visual or cognitive challenges. However, this could also be due to the relatively young age of the participants and the nature of the dual-task employed, limiting the ability to fully investigate the potential compensatory role of somatosensory input under visual and cognitive stress. The subjective perception of improved stability aligns with the objective measurements.

This study demonstrates the superior benefits of minimal shoes compared to conventional shoes and barefoot conditions for stability and mobility in older adults with a history of falls. The findings highlight the potential role of minimal shoes in fall prevention. Future research should focus on longitudinal studies to determine the long-term impact on fall risk, investigation of the effects in older populations and more challenging tasks, and examination of the effects in real-world conditions. Further investigation of footwear impact during slips and trips is also needed.

The cross-sectional design limits the ability to establish causality and to assess long-term effects. The relatively young average age of participants might not fully represent the broader population of older fallers. The study was conducted in a controlled laboratory setting, which might not fully reflect real-world conditions. Data on foot sensitivity and lower limb proprioception were not collected. The brief acclimatization period to the footwear may not fully reflect long-term adaptation.