Recurring ankle sprains: what if the problem lies elsewhere?

Ankle sprains are the most common injury in sports. They are often considered minor injuries that heal on their own. However, in 15 to 20% of cases, pain persists, instability develops, and recurrences become more frequent. Why do some ankles remain fragile despite proper treatment?

Recent research sheds new light on this. More than 80% of sprains occur without contact, during a simple loss of balance. This figure strongly suggests the existence of a predisposition. The cause: a mechanical dysfunction of the hindfoot called Functional Hallux Limitus (FHL). Behind this technical name lies a problem that is easy to understand: a tendon located behind the ankle does not glide smoothly, which blocks the natural mobility of the foot and alters the way the heel strikes the ground (fhl.science).

Normally, a key joint located below the ankle—the subtalar joint—functions as a natural stabilizer. It allows the foot to adapt to uneven ground, much like a boat's hull conforms to the waves. When this joint is blocked by the HLF (heel-foot syndrome), the foot strikes the ground in an unbalanced, outward-pointing position. Deprived of this protective mechanism, the ankle becomes vulnerable to sprains with every misstep. This blockage, present in more than two-thirds of the population, often goes unnoticed because standard clinical examinations do not look for it.

The good news is that this mechanism can be identified and treated. A precise podiatric assessment allows visualization of the foot imbalance during walking. Treatment then relies on targeted rehabilitation—mobilization of the hindfoot, specific stretches, and balance exercises—complemented by a foot support designed to recenter heel support and prevent the foot from rolling. Unlike traditional ankle braces, this approach addresses the cause of the imbalance, not just its symptoms. In resistant cases, a minimally invasive surgical procedure can release the trapped tendon.

If you experience recurring sprains or your ankle remains unstable, the problem may not be with the ankle itself. A thorough examination of your foot function could make all the difference.