Ulna

Looks like

The forearm bone on the little-finger side, thick at the elbow and slender at the wrist, felt along its whole length.

What it does

Forms the hinge of the elbow and the fixed axis the radius turns around.

Keeping it well

Breaks when an arm is raised to block a blow. A forearm fracture needs both ends checked, as the other bone often dislocates.

Its parts

• Ulnar styloid process
• Right ulna
• Left ulna

Related conditions

• Acromegaly
• Compartment syndrome
• Fractures
• Fragility fracture
• Frailty & falls in older age
• Hyperparathyroidism
• Lymphangitis
• Osteogenesis imperfecta (brittle bone disease)
• Osteomalacia & rickets
• Osteomyelitis (bone infection)
• Osteoporosis
• Paget's disease of bone
• Sarcoma
• Vitamin B1, C and other deficiencies
• Vitamin D deficiency