Balance and Coordination

I. Balance = the ability to control the center of gravity over the base of support in a given sensory environment

A. Biomechanical Components of Balance

1. Base of Support (B.O.S.): the area within the perimeter of the contact surface between the feet

a. wide base = greater stability, narrow base = less stability

2. Center of Gravity (C.O.G.): the central point within the limits of stability area

a. Centralized C.O.G = greater sway boundaries; abnormal C.O.G = unstable within sway boundaries

3. Limits of Stability (L.O.S.): the greatest distance in any direction a person can lean away from midline without changing the original base of support

a. To maintain balance, the C.O.G must be kept within the limits of stability

b. Postural strategies are used to restore balance if sway occurs outside the limits of stability

B. Components of Balance Maintenance

1. Postural strategies – for standing balance

a. Ankle strategy – ankle flexor/extensor muscles are activated to counter anterior and posterior sway

b. Hip strategy – hip flexion and extension used to redistribute C.O.G within the B.O.S

c. Stepping strategy – taking a step to widen the B.O.S and create a new sway boundary

2. Protective reactions – includes the above strategies for standing balance and use of upper extremities for sitting balance

3. Equilibrium reactions – includes head/trunk postural movements in sitting and standing

C. Clinical guidelines

1. Biomechanical Deficits

a. Inadequate range of motion

b. Pain

2. Musculoskeletal Deficits

a. Muscular weakness

b. Abnormal tone

3. Sensory Deficits– any one area, combination of areas impacts balance

a. Impaired proprioception – from joint or skin receptors, muscles ® problems with assessing limb position in space

b. Impaired visual processing of physical surroundings ® problems with orienting visual input in relation to surrounding objects

c. Impaired vestibular system (internal gravitational reference that determines the orientation of the head in space) ® problems with postural control, eye-head coordination

4. Other factors affecting balance – fear, drug side effects, shoe type

D. Balance exercises

1. Purpose and Goals

a. Specific to client and diagnosis

a. Musculoskeletal diagnoses

b. Vestibular diagnoses

c. Neurological diagnoses

b. Relating exercise to function

2. Techniques and Guarding

a. Preparing the exercise environment

b. One person vs two person guarding

3. Guidelines for progression – moving from basic to advanced

a. Activity/Position-specific

a. Sitting

b. Standing

c. Walking

b. Equipment-specific

a. Standing Frame

b. Parallel Bars

c. Balance boards

d. Swiss Balls

e. Other

II. Coordination = the ability to effortlessly perform smooth and controlled movements (optimal interaction of muscle function). Agility is the combination of coordination and speed that allows the ability to perform activities that require a rapid change in movement or direction. Coordination and agility are tied closely to balance.

A. The cerebellum is the primary center in the brain for coordination of movement

B. Causes of coordination impairments

1. Neurological – brain injuries, movement disorders, spinal and peripheral nerve injuries

2. Other – alcohol/drug intoxication, poisoning, infectious diseases

C. Purpose and Goals for working on coordination

1. Fine motor skills

2. Hand-eye skills (the ability of the visual system to coordinate visual information received and then control or direct the hands in the accomplishment of a task)

3. Relating exercise to function

D. Exercise progression – basic to advanced

1. Upper extremity

2. Lower Extremity

3. Combined upper/lower extremity

4. Hand-eye coordination

5. In conjunction with balance activities

Examples of balance, coordination and agility exercises in varied positions and settings (professional, commercial, layperson and student)

http://eahec.ecu.edu/Telehealth/lessons/reach%201.mpg

ttp://www.youtube.com/watch?v=Dyump5ypi9o

http://www.youtube.com/watch?v=UfQQDaHHOwE

http://www.expertvillage.com/videos/balance-exercises-foot-ankle.htm