Posted by Steve Middleton, MS, ATC, CSCS, CES, CKTP
The medial longitudinal arch of the foot is comprised of the first three metatarsals, three cuniforms, the navicular and the rear foot (talus and calcaneus). The plantar fascia plays a vital role in the structure and function of the medial longitudinal arch. Dysfunction of the plantar fascia can lead to pes planus with subsequent tearing of the plantar fascia through overpronation of the foot. If the plantar fascia is too short, the patient will present with pes cavus and the inability to dissipate ground reaction forces.
There appears to be a direct correlation between the tension in the calcaneal (Achilles’) tendon and the planter fascia. The researchers utilized a myotonometer to measure the oscillation frequency of the plantar fascia and calcaneal tendons both relaxed and strained. Elasticity was also measured. Findings include that changes in oscillation accompany changes in elasticity of both the plantar fascia and calcaneal tendon. Researchers also found that tensioning the plantar fascia decreased the elasticity of the calcaneal tendon and vice versa.
This demonstrates a relationship between fascial lines as originally discussed by Thomas Myers (www.anatomytrains.com). Clinically, this information is relevant while evaluating any lower extremity complaint as to whether the source of pain is where the symptoms are or from a fascial tensioning elsewhere. This information is also relevant to those clinicians working with runners who are transitioning to minimalist or barefoot training > from Sakalauskaitė et al.; Journal Of Vibroengineering 14 (2012) 1751-1759. All rights reserved to Vibroengineering.