Minimalist shoes are shoes intended to closely approximate barefoot running conditions. They have reduced cushioning, thin soles, and are of lighter weight than other running shoes.
In a recent study conducted by The Hong Kong Polytechnic University and the Harvard Medical School, researchers find that running in minimalist shoes can increase leg and foot muscle volume. This means the shoes can be used in rehabilitation.
Researchers tested the shoes in 38 adult runners from local running clubs. All the runners had about 6-year running experience with traditional running shoes.
Among the 38 participants, 20 were selected to the experimental group for a 6-month training. At the beginning, each participant was given a pair of minimalist running shoes and a self-monitoring programme including transition exercise regimes such as calf strengthening exercise and balance training.
The minimalist running shoes used in this study featured an open-topped upper made of stretchy fabric, five separate toe compartments, zero heel-to-toe drop, no midsole cushioning or arch support, and a uniform 3-mm outer sole.
The other 18 runners in the control group received the same training programme running with their own TRS.
All the participants were invited to undergo a magnetic resonance imaging (MRI) scanning for measuring their right leg and foot muscles before and after six-month intervention.
The result showed that runners using minimalist shoes exhibited significantly greater leg and foot.
The mean volume of the extrinsic foot muscles attached from the leg to foot increased from around 25,100 mm 3/kg to around 27,000 mm 3/kg, an increase of 7.05%.
In addition, the intrinsic foot muscles attached from the heel to toes increased from around 4,600 mm 3/kg to near 5,000 mm 3/kg, an increase of 8.8%.
Furthermore, in runners using minimalist shoes, the forefoot muscle rather than the rearfoot muscle mainly contributed the foot muscle growth.
The mean volume of the forefoot and rearfoot was increased by 11.9% and 6.6% respectively. In contrast, the volume of leg and foot muscles in people using traditional running shoes remained unchanged.
Researchers suggest that minimalist shoes allow for more sensory contact for the foot on the ground and no mechanical support to the foot arches and muscles. Runners will experience greater demands for strength.
In addition, mid/forefoot landing imposed more stimuli to the anterior part of the foot, especially for the joint of the foot and toes. Muscles responsible for the joint motions may therefore be strengthened when running with minimalist shoes.
Citation: The Hong Kong Polytechnic University. (2016). PolyU study reveals minimalist shoes increase leg and foot muscles. Media Release.
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