What exactly is balance?

Macpherson et al. (1997) contend that the maintenance of posture is the co-requisite for all coordinated movement, and when studying the restoration of motor function after injury or disease, it is essential to consider not only the specific motor task, but to also consider the postural control that is an integral part of that task.

Sensorimotor systems underlying postural control provide us with the ability to balance all the forces acting on the body, resulting in the ability to: (Horak & Macpherson, 1996)

1) keep the body in a desired position - Static Equilibrium, or

2) move the body in a controlled way - Dynamic Equilibrium.

Systems Theory leading to a Task-Oriented Clinical Approach IndividualTask “a skilled action” Environment “characteristics of the performer” “configured to fit the environment”

Balance INDIVIDUAL ENVIRONMENT TASK

1) Static Equilibrium INDIVIDUAL ENVIRONMENT TASK

2) Dynamic Equilibrium INDIVIDUAL ENVIRONMENT TASK

BALANCE Anticipatory Mechanisms (internal) Proactive Mechanisms (external) Reactive Mechanisms Sensory Systems Body Schema Neuro- muscular Synergies Musculo- skeletal Components

Sensory Systems Visual – PROACTIVE control Vestibular – Body Schema Somatosensory – REACTIVE control

Musculoskeletal Components Flexibility Strength Power Endurance Bone density Posture

Reactive Mechanisms

Sensorimotor Strategies

Neuromuscular Synergies

Proactive Mechanisms

Anticipatory Mechanisms

What are these tests...testing? Functional Reach Test Berg Balance Test Sensory Organization Test Timed Up and Go Test Dynamic Gait Index Romberg

Constraints Model