Table 2. Components of balance control.

Sensory system CNS Motor system
Afferent input Organization of sensory input and choice and triggering of motor responses 

Efferent output 
Somatosensory system:
- proprioceptors: muscle  spindle type I and II, Golgi  tendon organ, joint receptors
- cutaneous and subcutaneous  receptors Vision:
- retina
Vestibular system:
- semicircular canals and  otholiths in the inner ear
Myotatic stretch reflex
Long-loop reflexes 

Internal representations
Learned skills
Synergistic action
Sensory strategies
Adaptive mechanisms
Anticipatory mechanisms
Automatic movements
Voluntary movements 

Muscles of the upper and lower extremities
Trunk and neck muscles
Neuromuscular synergies:
- ankle strategy
- hip strategy
- stepping strategy
- mixed strategy