Vastus lateralis

Looks like

The largest quadriceps head, on the outer thigh, from the upper thigh bone to the kneecap.

What it does

Straightens the knee and powers standing up, climbing and jumping.

Keeping it well

A common site for injections and muscle biopsies; squats and step-ups keep it strong.

Related conditions

• Botulism
• Chronic venous insufficiency
• Dermatomyositis and polymyositis
• Fibromyalgia
• Frailty & falls in older age
• Growing pains
• Heat exhaustion & heatstroke
• Lymphatic filariasis (elephantiasis)
• Lymphoedema
• Malnutrition & refeeding syndrome
• Muscle strain (pulled muscle)
• Muscular dystrophy
• Osgood–Schlatter disease
• Poliomyelitis
• Polymyalgia rheumatica
• Restless legs syndrome
• Rhabdomyolysis
• Runner's knee (patellofemoral pain)
• Sarcoma
• Sarcopenia
• Spinal muscular atrophy
• Tetanus
• Trichinellosis
• Varicose veins