Influence of Barefoot, Minimalist, and Standard Footwear Conditions on Gait and Balance in Healthy Older Adults

To the Editor: Equilibrium and gait patterns change throughout life and are influenced by various internal and external factors. In older age, internal changes include degenerative processes of the neuromuscular system and deterioration of balance,1 which are often responsible for altered stance and gait strategies, with a move to a wider stance and a gait with extended bipedal ground contact, shorter steps,2 and flatter foot support.3 An external factor that influences gait patterns and balance in older age is the choice of footwear.1, 4, 5 Several studies have investigated what kind of footwear elderly adults normally wear and which types are associated with a high fall rate,6 but little is known about the effects and feasibility of minimalist footwear in older adults. The benefits of minimalist shoe support (less cushioning and weight, greater flexibility) for maintaining and developing natural running patterns have been widely reported for younger adults.7, 8 The main purpose of this preliminary study was to investigate the effects of minimalist shoes on walking gait patterns and balance in older adults. Twenty-eight healthy, community-dwelling, physically active adults (mean age 66 ± 6.4, range 52–76) were tested under three conditions in random and counterbalanced order: barefoot, minimalist (barfuß-leguano premium, Leguano GmbH, Sankt Augustin, Germany), and standard cushioned (Asics Galaxy, Onitsuka Co., Ltd., Kobe, Japan) shoes. A balance test (Balance Error Scoring System = BESS9) and a gait analysis on an instrumented treadmill (HP Cosmos, Nußdorf, Germany) with a pressure platform under the surface (FDM-THQ, Zebris Medical GmbH, Isny im Allgäu, Germany) were completed in each condition. Mean data and variability coefficients (%) of maximum vertical impact and propulsive ground reaction forces (GRFs), step length, step time, stance phase, and cadence of all gait cycles during a 30-second treadmill walking trial were analyzed. Footwear differences in dependent variables were determined using mixed models. All models were adjusted for age, sex, and leg side. A Bonferroni corrected post hoc test was conducted to identify differences between the three footwear conditions. The results of the BESS and all gait variables (except the maximum impact GRF) were statistically significantly different (P < .001) between conditions (Table 1). Post hoc pairwise comparisons showed that balance control was significantly (P < .001) poorer during minimalist shoe and barefoot conditions than with standard shoes. Gait parameters adapted differently to changes in support. Maximum GRF at foot impact and during the propulsive phase were highest during the minimalist shoe condition and lowest during the barefoot condition. In all other gait parameters, the greatest differences were observed between barefoot and standard shoe walking. When walking barefoot, participants had a significantly (P < .001) shorter step length, step time, and stance phase and a higher cadence than with standard shoes. The minimalist shoe condition significantly reduced step time, stance phase (P < .001) and increased cadence (P = .01) but had no influence on step length. Post hoc comparisons of gait variability coefficients showed that GRF varied significantly more (P < .001) during barefoot condition than with standard shoes. Walking with minimalist shoes also significantly increased variability in step time (P < .001), cadence (P < .001), and stance phase (P = .007). One-time use of barefoot or minimalist footwear influences habitual movement patterns during gait and reduces balance control, so minimalist shoes should be used carefully when sufficient ground support during standing is needed. Changes in running biomechanics due to different footwear conditions have been widely shown in studies with young individuals,10 but the use of a different population and slower walking velocities greatly limits comparability with previous studies. The differences between all footwear conditions observed in the current study may be due to feelings of instability or tentativeness when walking without standard shoes. The lack of habituation to minimalist shoes and to barefoot walking in general could explain the greater variance in gait variables during this condition. In summary, it may not be advisable for older adults to change abruptly from standard stable shoes to minimalist shoes or barefoot in everyday life because they reduce balance control and cause acute alterations in gait patterns. Nevertheless, the regular use of minimalist shoes may also improve balance control and walking ability over time. In a protected environment, these shoes could be a cheap and easy way to exercise balance control and reduce long-term fall risk. Further studies are necessary to confirm this hypothesis. The authors thank the Leguano GmbH for providing all shoe materials used in this study. Conflict of Interest: The authors declare no conflicts of interest. None of the authors received financial support for this study.