Internal intercostal muscle

Looks like

The middle layer of muscles between the ribs, fibres running at right angles to the outer layer.

What it does

Pull the ribs down during forceful breathing out, as in coughing, and stiffen the chest wall.

Keeping it well

Strain causes pain on breathing that improves over weeks. Chest pain with breathlessness or pressure needs emergency care.

Related conditions

• Botulism
• Fibromyalgia
• Frailty & falls in older age
• Heat exhaustion & heatstroke
• Malnutrition & refeeding syndrome
• Muscular dystrophy
• Pleural effusion
• Pneumothorax
• Polymyalgia rheumatica
• Rhabdomyolysis
• Sarcoma
• Sarcopenia
• Tetanus