A Paradigm Shift: The Foot Core System
How much time do you spend thinking about your feet? If you’re like most of us, it’s likely that you spend very little time thinking about your feet at all. But the foot is a very complex structure that has evolved over time to accommodate the great demands that we put on it every day. The arch, for example, allows the foot to manage the demands placed on the foot when a person runs.
The movement and stability of the arch in your foot is controlled by an intricate system of muscles. Some of these muscles are intrinsic – that is, they are fully contained within the foot. Other muscles are extrinsic ie. they arise outside of the foot but they act upon the foot. For example, the muscles in your calf, that act upon your foot, are extrinsic muscles.
If you have problems with your feet, you will probably start paying more attention to them, and may even need treatment or a rehabilitation plan for recovery. Clinicians have generally focused rehabilitation programs on extrinsic muscles, paying little attention to the self-contained intrinsic muscles of the foot. However, these intrinsic muscles that make up the ‘foot core system’ are starting to get more attention as crucial to proper foot function.
The foot’s stability and mobility features can be compared to the well-known lumbo-pelvic core system, or the network of muscles that make up your pelvic & abdominal core region. Consider how your core needs to be stable yet mobile to keep you upright and moving; the foot is similar. It must be stable at foot strike, yet mobile and adaptive during mid-strike, then spring-like with each push-off. From a recent article in The Journal of Sport & Exercise Medicine (2015):
The foot core system has three subsystems that inter-work to support the foot:
1. The passive subsystem of the foot core consists of the bones, ligaments and joint capsules that maintain the various arches of the foot.
2. The active subsystem consists of the muscles and tendons that attach on the foot. This includes:
- the stabilizers/plantar intrinsic muscles that both originate and insert on the foot, much like transversus abdominus /pelvic floor
- the mobilizers/extrinsic muscles that originate in the lower leg, cross the ankle and insert on the foot, much like latissimus dorsi (the broadest muscle of your back) or rectus abdominus (abdominal muscles).
3. The neural subsystem consists of the sensory receptors (a well-known, critical element to gait and balance) in the plantar fascia (thick band of tissue that runs across the bottom of your foot), ligaments, joint capsules, muscles and tendons involved in the active and passive subsystems.
Increasingly, there is a shift in treatment strategies for foot related issues. Rather than traditional use of orthotics for foot pain or injury, more emphasis should be placed on static and dynamic foot core function, with orthotics used perhaps only as a temporary solution to relieve pain.
If you’re suffering from foot injury or pain, contact us for help with a rehabilitation plan.