There has been some debate lately on whether going barefoot actually strengthens muscles relative to the shod condition. My take is that being barefoot simply changes force application in such a way that different muscles are worked harder, so some may get stronger, and others will be worked less and may get weaker. Doing a mixture of both barefoot and shod movement may provide the best of both worlds.
Regarding this, I received the abstract below in my weekly email digest for running related scientific articles. The article indicates that muscle activation in the tibialis anterior, peroneus longus, and medial gastrocnemius all differ between barefoot and shod walking. Specific details on how things changed are difficult to ascertain from the abstract, and I hope to comment more fully over on Runblogger once I get ahold of the full text of the study. Nonetheless, it supports the contention that muscles work differently when barefoot.
Here’s a link to the abstract on PubMed.
The influence of footwear on the electromyographic activity of selected lower limb muscles during walking.
J Electromyogr Kinesiol. 2012 Jul 24. [Epub ahead of print]
Department of Podiatry, La Trobe University, Bundoora, Vic., Australia; Lower Extremity and Gait Studies Program, La Trobe University, Bundoora, Vic., Australia; Department of Podiatry, Northern Health, Bundoora, Vic., Australia.
The purpose of this study was to compare the effects of a standard flexible shoe and a stability running shoe on lower limb muscle activity during walking. Twenty-eight young asymptomatic adults with flat-arched feet were recruited. While walking, electromyographic (EMG) activity was recorded from tibialis posterior and peroneus longus via intramuscular electrodes; and from tibialis anterior and medial gastrocnemius via surface electrodes. Three experimental conditions were assessed: (i) barefoot, (ii) a standard flexible shoe, (iii) a stability running shoe. Results showed significant differences for the peak amplitude and the time of peak amplitude for tibialis anterior, peroneus longus and medial gastrocnemius when comparing the three experimental conditions (p<0.05). Significant differences were detected primarily between the barefoot and shoe conditions and with relatively small effect sizes for peroneus longus, tibialis anterior and medial gastrocnemius. Few significant differences were found between the two shoe styles. We discuss how these changes are most likely associated with the shoe upper bracing the foot, the shape of the shoe outer-sole and weight of the shoes. Further research is needed to investigate differences between these shoe styles when participants walk for longer distances (i.e. over 1000m) and following fatigue.