This article first appeared in the November 2019 issue of Lifelines, the Life West student magazine.
As chiropractors, we are usually concerned about the stability of the spine. We take into account the stability of the cervical spine to maintain proper head position. We stress the importance of having core and lumbopelvic stability to allow for functional movement of the extremities. However, something that often gets overlooked is stability in the feet. It makes perfect sense why we should consider it though, right? The feet act as the base of support for our entire body. You wouldn’t build a house on a foundation that was unstable. In addition to this, the fascial planes in the foot spiral up to connect many other areas of the body. Altered structures or mechanics in the foot can lead to additional problems further up in the chain. It only stands to reason, then, that we ensure a strong foundation in our feet in order to provide stability in the rest of the body.The arch in the human foot has evolved as we adapted to the need for running on two legs1. The arches are maintained not only by the many bony articulations in the foot, but also by intrinsic and extrinsic foot muscles. During the phases of gait, the foot must go through every range of motion, including dorsiflexion, plantarflexion, inversion, and eversion. It must be both flexible and rigid in order to provide the stability and mobility needed to walk.
McKeon suggests that the intrinsic foot muscles play an important role in maintaining the arch of the foot. These muscles are too small to produce large movements in the foot. They do, however, have a sensory component that maintains the posture of the foot. When these muscles fatigue, it can compromise the arch of the foot, possibly resulting in navicular drop1. Increasing strength in the intrinsic foot muscles can improve the proprioception of our feet, and help us maintain a functional arch.
Gefen’s study claims that the tibialis anterior is “critical in maintaining the foot’s stability”. Diminished function of this muscle can increase the likelihood of experiencing a fall2. He found that a decrease in force of the tibialis anterior shifts a person’s center of pressure medially on the calcaneus. This causes poor positioning at the beginning of the stance phase, resulting in collapse of the subtalar joint as the foot continues through the gait cycle. We can see that one seemingly minor fault in the system can have a cascading effect on the rest of the body.
Both of these researchers have indicated the importance of muscles with attachments in the foot and the roles they play in maintaining stability. They agree that muscles strongly impact the structure of the foot and alter our ability to maintain proper gait. As chiropractors, we should focus on achieving proper alignment in the foot so that these muscles can function adequately. We can strengthen our intrinsic foot muscles and try to increase the force capability in the tibialis anterior, however, if the bony structures are still misaligned, the strong muscles are of no use. It is important to strengthen our muscles while our bodies are in alignment, not while it is in a pathologic posture.
- McKeon PO, Hertel J, Bramble D, Davis I. The foot core system: a new paradigm for understanding intrinsic foot muscle function. Br J Sports Med. 2015; 49(290)
- Gefen A. Simulations of foot stability during gait characteristic of ankle dorsiflexor weakness in the elderly. IEEE Transactions on Neural Systems and Rehabilitation Engineering. 2011; 9(4): 333-337