Plantar Fasciitis and Disorders of the Lower Kinetic Chain: Are you Getting Off On the Right Foot?”
Posted by Dr. Chris Taylor, DC
Chiropractor, Clinic director
As a chiropractor in downtown Toronto, I see an incredibly wide assortment of injuries and conditions – low back, neck pain and headaches, sprains, strains, tears, fractures, acute injuries, chronic conditions, postural issues and everything in between. Of all the weird and wonderful things I see, one particular intersection of personal and professional interest lies in mechanical issues of the foot and it’s effect on the rest of the “lower kinetic chain” – that is, the muscles, bones and joints of the foot, ankle, shin/calf, knee, thigh and hip. In an ideal biomechanical world, the foot contacts the ground (whether standing/walking or running) and experiences “reaction forces” that are dissipated by or distributed over the appropriate structures in the foot, ankle and leg.
If everything works as designed, these reaction forces are appropriately managed (the shock effectively absorbed) because each link of the chain is pulling its own weight. BUT – what if there is a weak link, and that link is the one that starts a chain reaction?
Consider this: the human foot and ankle contains 26 bones, 33 joints and more than 100 muscles, tendons and ligaments. For a comprehensive review of foot anatomy click here. When walking, the foot experiences 1-2x one’s bodyweight in reaction force during each step.
Quicken the cadence to running and the force jumps to 3-7 x bodyweight. Check out this link for more insights.. Given the immense volume of force that a foot typically experiences each day, it’s vitally important that the foot functions ideally in order to avoid overuse and injury to the rest the joints and muscles in the kinetic chain.
One of the primary underlying issues, in my humble opinion, that results in lower body overuse injuries is a chronic “deconditioning” of the dynamic stability of the foot over time. The vast array of intrinsic muscles that help to maintain and support the structure of the foot often become “lazy” over time due to persistent use of footwear – preventing the foot from being naturally stimulated during interaction with the ground (i.e. during a step) and often putting it in an artificially supported position.
This deconditioning response causes foot musculature to become weak, inactive and/or inhibited, thereby negatively affecting the function of the foot’s natural support mechanism. Think about what might happen to your other muscles if they were keep in an immobilized state – ever worn a cast for ~6 weeks?
One of the more common foot conditions is called “plantar fasciitis” – a very painful irritation on the sole (bottom, or “plantar” side) of the foot, near the inner aspect of the heel. It occurs when the plantar fascia (or “plantar aponeurosis”), a thick band of connective tissue, tugs on its attachment to the underside of the heel bone, causing tissue damage, pain and inflammation. Check out: https://www.health.harvard.edu/pain/plantar-fasciitis. The fascia becomes stressed (and stretched) during over-pronation – or excessive collapsing of the medial longitudinal arch – of the foot.
Over-pronation also causes abnormal stress on the tibialis posterior muscle, whose tendon runs under the inside of the foot, supporting the arch like a stirrup. Excessive stress and strain on this muscle can lead to a painful condition on the inside of the shin (tibia) called medial tibial stress syndrome (MTSS). Check out this link.
MTSS is the precursor for postero-medial shin splints and, if severe enough, can develop into stress fractures of the tibia. Over-pronation also commonly has a role in the formation of bunions, stress fractures in the foot, arthritis at the base of the big toe (or “hallux”), patello-femoral pain syndrome (pain at the knee cap), iliotibial band syndrome, hip and low back pain and a host of other issues up the kinetic chain.
So how does one stop over-pronation from occurring? There may be a simple, straight forward answer to this question and it lies in addressing the root cause of the problem: a deconditioned foot with poor dynamic stability. Since the foot is the “gatekeeper” – the first line of defence against the constant onslaught of reaction forces – if we can “recondition” it’s intrinsic capabilities, we can improve function and allow it to direct force into the appropriate tissues. This can be achieved in a few simple steps:
1. Consult a qualified health professional (chiropractor, physiotherapist, etc) to have your feet properly assessed.
2. Wear bare feet as often as (realistically) possible. This will help your foot function improve through providing better tactile feedback and by stimulating support muscles naturally.
3. Perform a series of exercises on a daily basis aimed at working the intrinsic muscles. For an example of an intrinsic foot exercise program, click HERE.
Foot issues and other problems of the lower kinetic chain are exceptionally common in the general population. If you live or work in the downtown core of Toronto and these problems sound familiar to you, or if you’d like more information, our team at Wellington Healthcare would be happy to help!