Bone Stress Injuries: Intro


I spend my days in an outpatient orthopedic physical therapy clinic primarily serving trainees in Basic Combat Training (aka BCT, basic training, or boot camp). We see what most expect from a high-tempo training environment consisting of physical training, obstacle courses, combatives training, ruck marches, and field training: ankle sprains, knee pain, shoulder dislocations, etc. However, the MOST COMMON injuries we see and manage in physical therapy are bone stress injuries (BSIs). This post’s purpose is simply to review BSIs while future posts will dive further into diagnosing and management.

As the name implies, BSIs are stressed bones resulting in physiological changes to the bone itself. In the disease-free population without underlying metabolic disorders, BSIs are overuse injuries caused by repetitive stress to the bones, most often to the lower extremities. The “stress” is from high-impact activities like running, jumping, rucking, and marching. Even prolonged standing can create stress. The stress is cumulative and starts as mild inflammation and swelling within the bones. However, as the stress accumulates, the inflammation and swelling increases inside the bone and can ultimately lead to a fracture to the bone’s cortex (outer shell).