A question that a podiatrist will often be asked when suggesting to patients that orthotic therapy will help alleviate their musculoskeletal (MSK) pain and discomfort, is “Will the orthotics make my feet weak?”
Patients may have the perception that orthoses act as a splint or cast, which could not be further from the truth. This typically will allow a podiatrist to explain how orthoses don’t weaken the muscles in your feet, and the research supports the fact that orthotics actually make your feet stronger!
There have been 3 published studies that have looked specifically at what happens to the muscles of the foot and leg after wearing orthoses. And all 3 of them have come to the same conclusion;
The arch of the foot is supported by numerous soft tissue structures including the extrinsic & intrinsic muscles, plantar aponeurosis and other plantar ligaments. The intrinsic foot muscles are most active from early mid-stance to before heel off, helping to counter the ground reaction force as the body passes over the foot. If these muscles are weak, then one could expect a decrease in arch height at this phase of gait as has been shown in a study in which the intrinsic foot muscle function has been tested before and after administering a tibial nerve block.
Foot orthoses are prescribed for numerous musculoskeletal conditions, and for now at least, the research does not support the claim that they will cause muscle weakness of the structures responsible for maintain the integrity of the arch. One could hypothesize that the orthoses may decrease the muscle activity whilst improving their efficiency and this enables the muscles to get stronger.
Treating MSK conditions of the foot and leg will often involve the use of several treatment modalities. The use of foot orthoses in combination with appropriate strengthening or stretching exercises, manual therapies and footwear advice will help patients to resolve symptoms and increase activity levels of patients without compromising foot muscle strength.
1. Payne C & Zammit, G. Foot orthoses use does not affect muscle strength. Department of Podiatry, School of Human Biosciences, La Trobe University, Melbourne, Australia [Internet]. 2005. Available from: http://www.podiatry-arena.com/podiatry-forum/showthread.php?t=395
2. Mayer F, Hirschmüller A, Müller S, Schuberth M, & Baur, H. Effects of short‐term treatment strategies over 4 weeks in Achilles tendinopathy. British Journal of Sports Medicine, 2007; 41(7). Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2465365/
3. Jung DY, Koh EK, Kwon OY. 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):225-31. Available from: Pubmed
4. Root ML, Orien WP, and Weed JH. Normal and Abnormal Function of the Foot. Los Angeles, CA; Clinical Biomechanics Corporation; 1977
5. Fiolkowski P, Brunt D, Bishop M, Woo R, Horodyski MP. Intrinsic pedal musculature support of the medial longitudinal arch: an electromyography study. J Foot Ankle Surg. 2003