APPLIED ANATOMY OF MUSCLES OF UPPER LIMB

Winged scapula

• A winged scapula (scapula alata) is a skeletal medical condition in which the shoulder blade, or shoulder bone, protrudes from a person’s back in an abnormal position.

Causes

• Winging of the scapula is divided into two categories, medial and lateral, according to the direction of winging.
• Medial winging is more common, being caused by serratus anterior paralysis.
• This is typically due to damage (i.e. lesions) of the long thoracic nerve.
• This nerve supplies the serratus anterior, which is located on the side of the thorax and acts to pull the scapula forward.
• Serratus anterior palsy is a dysfunction that is characteristic of traumatic, non-traumatic, and idiopathic injury to the long thoracic nerve.
• The second category is the lateral winging which is caused by injury of the spinal accessory nerve.

Answer is A (Facio-Scapulo-Humeral Dystrophy):

Weakness preferentially affecting the facial and shoulder girdle (proximal weakness of upper limb) together with winging of scapula in a young adult suggests a diagnosis of facio-scapulo-humeral dystrophy.

• Autosomal Dominant (Positive Family History(2)
• Abnormal gene 4q (4q35 deletion)
• Childhood to young adulthood (may be delayed to 5th decade)
• Mild 1^st CPK (Normal Dystrophy)

Ans. is ‘d’ i.e., Serratus anterior

Winging of scapula

• In this condition the vertebral border of scapula becomes more prominent when patient tries to push against wall.
• It occurs in paralysis of the serratus anterior muscle in long thoracic nerve palsy.

Ans. is ‘a’ i.e., Long thoracic nerve palsy