What's the number one goal of an athlete who's been injured? Get back into the game! Trainers and physiotherapists see this a bit differently. They want to return athletes to sport quickly, but without reinjury.

Reinjury is very common with ankle sprains. Rehabilitation restores ankle motion. Even so, up to 80 percent of athletes injure their ankles again. This is a puzzle to experts in sports medicine. A group of physiotherapists studied this problem more closely.

The therapists measured ankle motion in 12 athletes who had ankle sprains on the outside of one ankle. This is called lateral ankle sprain. The therapists also looked at normal gliding motions of the bones that make up the ankle joint. All 12 athletes could fully move their injured ankles, but the normal gliding motion within the ankle joint hadn't been restored. The reasons for this are unclear.

When treating an ankle sprain, it's not enough to exercise the joint and stretch the muscles to restore joint motion. Treatment must also focus on the specific motions of the anklebones. Restoring bone glide may help prevent further injuries.