Orthotics support or weaken the foot?
Most people with foot orthotics mistakenly believe that they will weaken the structures and muscles in the ankle and foot. It is not uncommon to hear healthcare professionals believe the same. Indeed, it may seem logical that foot orthotics weaken the muscles of the foot and ankle since they seem to support the foot.
However, two studies have been done on this subject in recent years and show that orthotics do not weaken the foot. Indeed, they would even have the opposite effect! That is, to strengthen the foot [1, 2].
What explains these results?
The theory explaining this phenomenon would be that plantar orthotics would not inactivate the muscles of the foot. They would rather come to strengthen them by activating the nerve receptors in the skin. Indeed, the effect on nerve receptors in the skin has been measured in the elderly as well as in people with diabetes. Plantar orthotics improved the feeling in their feet. This allowed them to improve their reflexes [3]. Also, another reason that may explain the effect of plantar orthotics may be that the foot muscles are not active at the same time as the plantar orthosis during the support phase of walking.
The plantar orthosis is most effective from the moment we put our heel on the ground until the moment before our toes leave the ground. However, the muscles in our foot would start to be active when our heel leaves the ground and this continues until our toes leave the ground [4]. There would therefore be a kind of relay between the plantar orthosis and the muscles of our foot.
Caution and nuance
However, we must remain cautious, because it is not very obvious that orthotics strengthen the foot or do not weaken it. However, it is also wrong to say and claim that foot orthotics weaken the foot, as scientific studies on the subject diverge. If in doubt, it is always possible to do exercises to strengthen the muscles in your foot. All these exercises are available on the podformance site.
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Future direction
It is essential to stay on top of the latest news in this area. Just because we find explanations for the things we observe don't necessarily mean they are true. Future studies will allow us to shed light on this subject which, for the moment, seems rather nebulous.
- Jung, D.Y., E.K. Koh, and O.Y. Kwon, Effect of foot orthoses and short-foot exercise on the cross-sectional area of the abductor hallucis muscle in subjects with pes planus: a randomized controlled trial. J Back Musculoskelet Rehabil, 2011. 24(4): p. 225-31.
- Mayer, F., et al., Effects of short-term treatment strategies over 4 weeks in Achilles tendinopathy. British Journal of Sports Medicine, 2007. 41(7): p. e6.
- Bagherzadeh Cham, M., et al., The clinical and biomechanical effects of subthreshold random noise on the plantar surface of the foot in diabetic patients and elder people: A systematic review. Prosthetics and Orthotics International, 2016. 40(6): p. 658-667.
- Farris, D.J., et al., The functional importance of human foot muscles for bipedal locomotion. 2019: p. 201812820.