Certified Rehabilitation Registered Nurse (CRRN) Practice Exam

What best defines a contracture?

1. Lengthening of muscle fibers

2. Adhesion formation

3. Shortening of muscle fibers

4. Inflammation of muscle tissue

The correct answer is: Shortening of muscle fibers

A contracture is defined as the shortening of muscle fibers, which leads to a reduction in the range of motion in the affected joint. This phenomenon often occurs as a result of prolonged immobility, injury, or certain medical conditions that limit muscle use. When muscle fibers shorten, they become less flexible and can make it difficult for a joint to move freely. This is why physical therapy and rehabilitation strategies often focus on stretching and strengthening exercises to prevent or manage contractures. In contrast, the other options describe different physiological processes. Lengthening of muscle fibers does not apply to contractures, as it refers to increased flexibility and extension rather than shortening. Adhesion formation relates to the development of fibrous tissue that can restrict movement, but it is not synonymous with contractures. Lastly, inflammation of muscle tissue pertains to conditions like myositis but does not directly define the muscle shortening aspect of contractures. Understanding these distinctions helps clarify the specific nature of contractures in a rehabilitation context.