Which injury occurs when fatigued muscles transfer overload to the bone, resulting in a tiny crack?

• A. Strains
• B. Tendonitis
• C. Stress fractures
• D. Tennis elbow

Answer: (C)

Fatigued muscles lose their ability to absorb and dissipate repetitive forces, so the load is transferred to the bone. With continued submaximal stress, microdamage accumulates in the bone tissue, producing a tiny crack known as a stress fracture.

This focuses on a bone injury from overuse, unlike a strain, which is damage to muscle fibers; tendonitis, which is inflammation of a tendon from overuse; or tennis elbow, a tendon-related condition at the elbow. The typical signs are localized bone pain that worsens with weight-bearing activity and may linger after rest, with tenderness directly over the affected bone. Preventing these injuries involves gradually increasing training loads, including rest days and cross-training, and ensuring good nutrition and footwear to support bone health.