Why Ankle Supports Help Prevent Sprains

By Steve McCaw

Part of Biomechanics For Dummies Cheat Sheet

An ankle sprain is one of the most common injuries in sport and recreation. Typically, the ligaments on the outside of the ankle are sprained when someone “rolls” his or her ankle.

Ligaments are tough connective tissue running from bone to bone to help support a joint. Ligaments consist primarily of the fibers elastin and collagen, aligned to provide support and flexibility to the joint. A sprain occurs when a ligament is stretched so far that the arrangement of the elastin and collagen fibers gets disrupted. Sprains range from mild (a slight disruption of the fibers) to severe (a complete tear of the ligament). When a ligament is sprained, the joint swells, it’s painful to move or to touch, and it takes a while for the joint to become stable and usable for walking. For some people, the joint never feels the same again, and repeat sprains occur more easily than the first one.

Many participants try to prevent ankle sprains — either an initial sprain or a reoccurrence — by wearing high-top athletic shoes or braces, or by having the ankles taped before activity. Research has shown that the use of ankle support helps reduce the risk of ankle sprains. However, the mechanism of how the additional ankle support prevents a sprain is still under investigation.

The support may increase the proprioception, or sensory feedback, from around the joint by stimulating sensors in the skin over the ankle. For this reason, the hair is not shaved off the leg before the tape or brace is applied on the joint (and the brace is worn under, not over, a sock). The idea is that the stimulation to the skin increases activity in the muscles crossing the joint so the muscles respond more quickly to restrain the joint and prevent the ligaments from getting stretched to the point of injury.

Ankle support may provide additional mechanical support to the joint, beyond that provided by the ligaments and muscle. Various designs and materials have been used in the manufacture of braces, and research continues to work on improving the design to provide better support for the ligaments. An ideal brace would not limit joint motion until the ligaments are stretched to the point just before where the elastic and collagen fibers are disrupted.

Another proposed idea is that people who choose to wear support for injury prevention are not as reckless as those who don’t wear support. Choosing not to wear equipment known to prevent injury, such as ankle support, may indicate that a person chooses performance over protection. For the same reason, such a person may hold back from getting into situations from which an injury is more likely to result.