Abstract
Walking in minimalist shoes has been shown to strengthen and increase the size of plantar intrinsic foot muscles (PIM). While previous research has examined the effects of an 8-week minimalist shoe walking protocol in runners, this protocol has not been observed in non-runners. PURPOSE: Examine the effects of an 8-week minimalist shoe training intervention on muscle size and strength in healthy non-runners. METHODS: Ten healthy young adults were recruited for this study and randomized equally to either the control group (age: 21±0.89 yr; BMI: 24.1±3.4 kg/m2) or minimalist shoe group (age: 21.4±2.1 yr; BMI: 23.1±3.4 kg/m2). Participants were included if they had not experienced a lower extremity injury or previously worn minimalist shoes within the past three months and had an average step count of 5,000 steps/day. Participants in the minimalist shoe group were provided with minimalist footwear and instructed to wear them during a progressive 8-week intervention, five days a week, while gradually increasing their daily step count in the shoes. Muscle strength was measured by performing paper grip tests on AMTI force platforms in the anterior-posterior (Fy) and vertical forces (Fz). Averages for peak force were obtained across three trials for the greater toe and lesser toes individually. Images of abductor hallucis (ABDH), flexor digitorum brevis (FDB), and flexor hallucis brevis (FHB) were obtained using an ultrasound. All test measures were performed at baseline, week 4, and week 8. The distributions for the dependent variables were examined for normality. Separate 2x3 repeated measures ANOVAs were used to determine the effects of minimalist shoe walking on increasing muscle strength and size. Alpha was set to ≤0.05 for significance. RESULTS: For greater toes strength there were no significant time (p=.12), group (p=.256), or time*group (p=.339) effects for peak Fz force. Similar results in group (p=.759) and time*group (p=.388) were observed in peak force strength in Fy. However, there was a significant time effect in Fy (p=.031). Likewise, Fz and Fy had no significant time (Fy: p=.28); Fz: p=.13), group (Fy: p=.393; Fz: p=.56) and time*group (Fy: p=.067; Fz: p=.618). Moreover, ABDH, FDB, and FHB, found no significance in time (ABDH: p=069; FDB: p=.153; FHB: p=.67), group (ABDH: p=.19; FDB: p=.26; FHB: p=.831), or time*group (ABDH: p=.270; FDB: p=.433; FHB: p=.714) effects. CONCLUSION: These preliminary findings of an 8-week minimalist shoe walking intervention in healthy non-runners showed no significant effects in either plantar intrinsic muscle strength or size. While not statistically significant, the minimalist shoe group did show some increases in strength and size. Limitations for this study, including unsupervised training may affect the present outcome in addition to the sample size.
Recommended Citation
Saenz, Andrea; Gil, Alfredo; Gant, Alexis C.; Hwang, Chueh-Lung; and Ricard, Mark D.
(2025)
"Effects of Minimalist Shoe Walking on Plantar Intrinsic Foot Muscle Strength and Size in Normal Healthy Adults: Preliminary Findings,"
International Journal of Exercise Science: Conference Proceedings: Vol. 2:
Iss.
17, Article 96.
Available at:
https://digitalcommons.wku.edu/ijesab/vol2/iss17/96
