- Muscle tightness. Athletes should always stretch.
- Muscle imbalance, which can occur during high-speed activities.
- Poor conditioning. Weak muscles are less able to cope with stress.
- Muscle fatigue, which makes muscles more susceptible to injury.
- Old age or adolescence.
Athletes who participate in football, soccer, basketball, running, sprinting and dancing are especially at risk and should take extra precautions, the academy says.