In the supine position, which muscle groups are commonly at risk for contractures?

In the supine position, which muscle groups are commonly at risk for contractures?

• A. Shoulder extensors, adductors, and internal rotators
• B. Hip flexors and external rotators
• C. Knee flexors
• D. Ankle plantar flexors

Answer: (A)

When someone is immobilized in the supine position, muscles that are held in a shortened posture for long periods are the ones most at risk for contractures. Lying on the back with the arm by the side naturally places the shoulder in adduction and internal rotation, with a tendency toward slight extension. In that position the internal rotators and adductors of the shoulder become chronically shortened (for example, subscapularis, teres major, pectoralis major, and latissimus dorsi). The shoulder extensors are also recruited to maintain this posture, reinforcing the shortened state of those muscle groups. Over time, this combination leads to contractures in these shoulder muscle groups.

When someone is immobilized in the supine position, muscles that are held in a shortened posture for long periods are the ones most at risk for contractures. Lying on the back with the arm by the side naturally places the shoulder in adduction and internal rotation, with a tendency toward slight extension. In that position the internal rotators and adductors of the shoulder become chronically shortened (for example, subscapularis, teres major, pectoralis major, and latissimus dorsi). The shoulder extensors are also recruited to maintain this posture, reinforcing the shortened state of those muscle groups. Over time, this combination leads to contractures in these shoulder muscle groups.