Soles worn down on the inside edge, weak ankle joints, painful calf muscles?
When we talk about foot health and strength, we naturally tend to think of the intrinsic (inner) and extrinsic (outer) foot muscles, the Achilles tendon, the arches of the foot and the plantar ligaments on the soles of our feet. However, there is another key player on the inner side of the ankle that plays a vital role - the deltoid ligament.
This thick, triangular, almost indestructible connective tissue is largely responsible for controlling pronation (inward rotation) - in the ankle joint.
When we load our weight onto the foot during forward motion, the ankle joint reacts with a small "collapsing movement" inwards (the natural range of motion being different from one individual to another). That's pronation - it’s an essential part of the normal gait cycle and helps to absorb the impact of each step (even more so when running or jumping).
Deltoid Ligament - the muscle saver
Unlike muscles, ligaments are passive, so they don't get tired. Many forces that would otherwise have an impact on the muscle are absorbed by the ligaments. In that sense, the deltoid ligament can be called "a muscle saver" - protecting the tibialis posterior from impact forces.
Deltoid Ligament//Illustration by Yotam Giladi - Tailor Made Medical Illustration
When feet are flat on the ground, the deltoid ligament will stabilise and control pronation and keep it within its normal range of motion. If, however, the foot is elevated, e.g. by stiff, thick outsoles as in the photo below, the ankle joint will shift off balance.
Shoes with an elevated sole therefore hamper the normal movement of the ankle joint and can cause chronic over-pronation that over-stretches the deltoid ligament and causes the tibialis posterior to work harder than it should.
So what to do if your soles are wearing down on the inside edge, your ankles seem weak and your calves hurt?
Easy - take care to keep your feet flat on the ground and avoid wearing shoes with heels or elevated soles.
Go flat from heel to toe and let your pronation and deltoid ligament run wild ;)
Anna, Ran & Team Wildling