Scapular winging is due to dysfunction of which muscle or nerve?

Scapular winging is due to dysfunction of which muscle or nerve?

• A. Trapezius dysfunction only
• B. Pectoralis minor dysfunction
• C. Serratus anterior or spinal accessory nerve dysfunction
• D. Rhomboids dysfunction

Answer: (C)

Scapular winging happens when the muscles that hold the scapula against the chest wall can’t do their job. The key stabilizer is the serratus anterior, which keeps the medial border of the scapula flat against the rib cage and helps rotate the scapula upward for overhead reach. If serratus anterior is weak—often from injury to the long thoracic nerve—the medial edge of the scapula sticks out away from the thorax during pushing or lifting, producing winging. Another important contributor is the trapezius, controlled by the spinal accessory nerve. When trapezius is not functioning properly, the scapula loses stable positioning and can wing, especially during arm elevation. Pectoralis minor dysfunction can tilt the scapula forward and contribute to altered motion, but it doesn’t cause the classic winging pattern on its own. Rhomboid weakness affects retraction and stability but is less likely to produce prominent winging. So the best explanation for scapular winging is dysfunction of serratus anterior or the spinal accessory nerve (affecting the trapezius) because both are major stabilizers of the scapula against the thorax.

Scapular winging happens when the muscles that hold the scapula against the chest wall can’t do their job. The key stabilizer is the serratus anterior, which keeps the medial border of the scapula flat against the rib cage and helps rotate the scapula upward for overhead reach. If serratus anterior is weak—often from injury to the long thoracic nerve—the medial edge of the scapula sticks out away from the thorax during pushing or lifting, producing winging. Another important contributor is the trapezius, controlled by the spinal accessory nerve. When trapezius is not functioning properly, the scapula loses stable positioning and can wing, especially during arm elevation.

Pectoralis minor dysfunction can tilt the scapula forward and contribute to altered motion, but it doesn’t cause the classic winging pattern on its own. Rhomboid weakness affects retraction and stability but is less likely to produce prominent winging.

So the best explanation for scapular winging is dysfunction of serratus anterior or the spinal accessory nerve (affecting the trapezius) because both are major stabilizers of the scapula against the thorax.