Ankle sprains frequently occur in sports such as rugby and football, but also may result from a simple trip over an un-seen curb. Following an ankle sprain there is a decrease in ankle stability. This is caused by decreased ligament tone and associated reduction in proprioceptive ability.
Traditional rehabilitative advice (after rest, ice, compression, and elevation) states to immobilise and return to activity when pain has subsided, with plaster casts frequently being used. Taping or bracing the ankle to take pressure off the joint should allow the patient to fully heal.
While this sounds very sensible, research shows this is not the most effective approach to rehabilitation.
The bulk research on this topic (for example McKeon et al) demonstrates that balance training programmes are the most effective means of returning full function to a sprained ankle.
Obviously some rest from activity is required to allow tissue healing to take place. But it is important to ensure the principle of active rest is followed. The ankle should be mobilised in a controlled way throughout the tissue healing period to prevent loss of range of motion.
Balance board exercises should be then implemented as soon as possible. Balance work requires the patient attempts to keep the joint in a neutral zone, and as such this should not stress the repairing ligaments of the ankle. This type of training is essential for returning proprioceptive control to ankle musculature after trauma.
Retraining proprioceptive ability leads to decreased likelihood of sprain recurrence, decreased chance of other complications, and in athletes a lower impact on future levels of performance.
The rationale for balance training as put by Professor Hertel of the University of Virginia:
"There are neural receptors in ligaments. When you damage the ligament, you damage the neuro- receptors as well. Your brain no longer receives reliable signals from the ankle about how your ankle and foot are positioned in relation to the ground. Your proprioception — your sense of your body’s position in space — is impaired. You’re less stable and more prone to falling over and re-injuring yourself."