Infraspinatus

Looks like

A thick triangular muscle covering the back of the shoulder blade below its spine.

What it does

Turns the arm outwards and holds the humeral head in place.

Keeping it well

Weakness turning the arm out after a fall may mean a cuff tear; an injury in a younger person is worth scanning early.

Related conditions

• Botulism
• Fibromyalgia
• Frailty & falls in older age
• Frozen shoulder (adhesive capsulitis)
• Heat exhaustion & heatstroke
• Malnutrition & refeeding syndrome
• Muscular dystrophy
• Polymyalgia rheumatica
• Rhabdomyolysis
• Rotator cuff tear & impingement
• Sarcoma
• Sarcopenia
• Shoulder dislocation
• Tetanus