Neuro Exam: Postural Control

What is postural control?

The ability to maintain the body’s centre of mass (COM) within the base of support (BOS) for posture and movement.

What are the two main components of postural control?

Postural orientation (body alignment) and postural stability (balance).

Define COM, BOS, and LOS.

COM = point where body mass is centred; BOS = area under the body including contact points; LOS = limit where COM can move without losing balance.

What are the four main types of postural control?

Steady-state, anticipatory, reactive, and adaptive control.

Describe steady-state control.

Maintaining a posture with minimal sway (e.g., quiet standing).

Describe anticipatory postural control.

Feedforward activation preparing for voluntary movement.

Describe reactive postural control.

Feedback-based response to external perturbations.

Describe adaptive postural control.

Modifying responses to changing tasks or environments.

What are the three sensory systems contributing to postural control?

Visual, somatosensory, and vestibular.

What is sensory reweighting?

The CNS adjusts reliance on sensory systems depending on context (e.g., vision ↑ when somatosensory input ↓).

What are the main motor structures involved in postural control?

Spinal cord, brainstem, cerebellum, basal ganglia, and cortex.

Role of cerebellum in postural control.

Coordinates, adapts, and fine-tunes postural responses.

Role of basal ganglia in postural control.

Regulates tone, scales movement, and selects postural strategies.

What are the main postural strategies?

Ankle, hip, stepping, suspensory, and weight-shift strategies.

When is the ankle strategy used?

For small, slow perturbations on a firm surface.

When is the hip strategy used?

For larger, faster perturbations or on narrow supports.

When is the stepping strategy used?

For large, fast perturbations — expands BOS to maintain balance.

What is postural synergy?

Coordinated activation of multiple muscles to simplify balance control.

How does cognition influence postural control?

Attention and dual-tasking affect adaptability and stability.

How does postural control develop across the lifespan?

Visual dominance early in childhood → adult-like somatosensory reliance by ~12 years; declines again with ageing.

How does ageing affect postural control?

Reduced strength, slower reactions, greater visual reliance, and less adaptability.

Name 3 common clinical tests for postural control.

Berg Balance Scale, Timed Up and Go (TUG), Functional Reach Test.

What is the focus of sensory strategy training?

Varying sensory input (vision, surface, head position) to improve sensory flexibility.