While sprains and strains most commonly occur in younger, athletic men and women, older people with muscle weakness, balance problems, and limited flexibility are also prone to falls and other injuries that can stretch or tear a ligament or muscle. "A sprain is the result of a specific traumatic event-such as tripping and falling on an uneven sidewalk, a stairway, or other irregular surface. Sprains are difficult to prevent," says Gary Calabrese, PT, director of Sports Health and Orthopaedic Rehabilitation at Cleveland Clinic. "Strains, on the other hand, are usually related to the overuse of a muscle. So they should be preventable with a good exercise regimen that keeps the muscles strong and flexible."