Understanding the Windlass Mechanism: the foot’s natural arch support.

Each foot contains 33 joints, 26 bones, 19 muscles (10 of which are contained solely within the foot), all of which coordinate our ability to move and interact with our environment. We run, walk, skip, step, hop, all because the numerous structures in our feet allow us to. Collectively, these structures function to allow the foot to transition between acting as a shock absorber and a rigid lever.

In order for all of these structures to be allowed to perform their duties, they must be operating in an environment (barefoot or in a shoe) that doesn’t limit their performance. Unfortunately most of today’s (and yesterday’s and last century’s) footwear trends include a narrow toe box which squeezes the toes (especially the big toe) towards midline. This squeeze impacts the ability of the smaller muscles of the foot to perform their jobs. And these are the muscles that are responsible for creating a stable and supportive arch; these are the muscles that allow our foot to act as a shock absorber and a rigid lever.

Furthermore, when big toe alignment is altered to where the big toe moves towards the smaller toes, this can also impact a mechanism within the foot, which is responsible for foot stability, the Windlass Mechanism.

The windlass mechanism gets its name from the action of winding a rope or cable around a cylindrical drum, which tightens the rope and lifts a heavy object. In the context of the foot, the "rope" is represented by the plantar fascia, a thick band of connective tissue that runs along the sole of the foot, and the "cylindrical drum" is represented by the first metatarsophalangeal joint (the big toe joint). This mechanism comes into play during activities such as walking and running.

Windlass: tightening of a rope around a cylindrical drum.

When the foot is at rest or in a non-weight-bearing state, the plantar fascia is relaxed. However, as we shift our weight onto the foot, the plantar fascia begins to tense up. This tension is most pronounced when the big toe is dorsiflexed (extended) or the toes are extended during the push-off phase of walking or running. When the plantar fascia tightens, it acts like a cable, pulling the first metatarsal head (the end of the long bone that forms the base of the big toe) closer to the heel. This tightening effect helps to raise the arch of the foot, making it more rigid and stable.

Windlass Mechanism

The windlass mechanism involves several key components of the foot that work in concert to provide: plantar fascia, first metatarsophalangeal joint (big toe joint), and metatarsal bones (long bones in the foot).

🦶🏻The plantar fascia is a thick band of connective tissue that runs from the heel bone to the base of the toes. It acts as the primary tensioning structure in the windlass mechanism. When the plantar fascia tightens, it raises the arch of the foot, enhancing its stability and support.

🦶🏻The first metatarsophalangeal joint, the joint between the big toe (hallux) and the first metatarsal bone. During dorsiflexion of the big toe, the plantar fascia pulls on the first metatarsal head, contributing to the arch's elevation and foot stability.

🦶🏻The metatarsal bones, particularly the first metatarsal, play a significant role in the windlass mechanism. When the first metatarsal is pulled upward by the plantar fascia, it helps support the arch and maintain the foot's stability.

By appreciating the role of the windlass mechanism, we can make informed choices about footwear (wide toe box!), exercise, and foot care, ultimately promoting better foot health.