Balance Examination: Clinical Procedure

• Balance examination is a clinical procedure.

What is Balance?

• Balance is the dynamic process by which body position is maintained.
• Equilibrium is maintained at rest (static equilibrium) or in steady state motion (dynamic equilibrium).

Why Do PTs Care About Impaired Balance?

• One in four older adults fall each year.
• Less than half of older adults who fall tell their healthcare provider.
• Falling once doubles the chance of falling again.
• One in five falls cause a serious injury, such as broken bones or a head injury.
• Each year, approximately 3 million older people are treated in emergency departments for fall injuries.
• More than 800,000 patients a year are hospitalized because of a fall injury.
• Falls are the most common cause of traumatic brain injuries.
• Approximately 38,000 deaths occurred in people older than 65 years of age in 2021 due to falls.
• One death occurs every 13-20 minutes due to falls.
• Impaired balance affects prevention, recovery, and performance.

Balance Vocabulary

• Center of Mass (COM) refers to the point at which the body's mass is evenly distributed.
• Center of Gravity (COG) refers to the vertical projection of the COM to the ground.
• Base of Support (BOS) refers to the area beneath the body that is in contact with the support surface.
• Limits of Stability (LOS) refers to the maximum distance a person can lean away from their BOS without changing it.
• Momentum can be defined as the quantity of motion of a moving body, equal to the product of its mass and velocity.

Questions to Ponder About Balance

• What is the relationship between COG, BOS, LOS, and balance?
• When does one have the greatest balance?
• How is COG and BOS changed in different postures/situations?
• How does momentum affect balance?

Impaired Balance Contributors

• Balance impairments can be caused by impairments in the balance control system, aging and medications.

Balance Control

• Complex motor control task involving detection and integration of sensory information, body position, and motion in space and execution of appropriate musculoskeletal responses to control body position within the context of the environment and task.
• Balance control depends on the musculoskeletal system, the nervous system, and contextual effects.

Balance Control Definition Breakdown

• Balance control involves integration of sensory information to determine an appropriate motor response.
• Sensory input comes from detection of sensory information, body position, and motion in space.
• Motor output involves execution of appropriate musculoskeletal responses to control body position within the environment and task.

Balance Control Diagram

• Central integration is the process of selecting a body movement pattern in order to maintain balance.
• Motor outputs consist of ankle, thigh, trunk, neck, and eye/head movements.
• Sensory inputs consist of visual, vestibular, and somatosensory information.

Inputs (What do you know about these?)

• Visual input relates to the position of the head relative to the environment, and direction and speed of head/body movements.
• Head movement and position information comes from Vestibular input.
• The somatosensory system provides input related to position of the body, relayed via muscle proprioceptors, joint receptors, and skin mechanoreceptors, and is the fastest to be processed.

Types of Balance Control

• Steady State Control includes maintaining a stable, upright posture
• Static balance control refers to balance at rest.
• Dynamic balance control refers to balance during support surface and/or body movement.
• Automatic balance control is when balance control is automatic.
• Reactive balance control involves reacting to unexpected external perturbations.
• Anticipatory balance control involves reacting to expected changes.
• Adaptive balance control involves learning from previous experience.
• Feedforward (open loop motor control) involves no time for sensory feedback, preprogrammed muscle synergies, and automatic response.
• Closed loop control involves precise movements that require sensory feedback.

Strategies

• Ankle strategy involves small perturbations on a firm surface.
• Weight shifting (lateral) involves shifting weight from one leg to the other.
• Suspension involves lowering the center of gravity.
• Hip strategy involves larger perturbations.
• Stepping strategy involves stepping to regain balance.
• Combined strategy involves using multiple strategies at once.

Factors for Balance Strategy Selection

• Balance strategies vary depending on the speed/intensity of balance disturbance/perturbation.
• Strategy is determined by characteristic(s) of support surface and/or magnitude of displacement of COG/COM.
• The factor is also determined by patient awareness to the balance disturbanc, pt posture at the time, and previous experience.

Central Processing/Sensory Organization

• Sensory organization involves determining accurate information from inaccurate information, and selecting and combining accurate information.
• The processing areas include the basal ganglia, cerebellum and supplemental motor area.
• The processing system is able to compensate if one input is not working well.

Environment (How do different situations affect our balance?)

• Different environments can affect our balance. Task (How do different tasks affect our balance?)
• Quiet stance, perturbations, lifting and walking all affect balance. Aging (How does aging affect our balance?)
• Aging, box 8.2, fear and medication all affect balance.

Balance Examination: History

• History should include typical history/mechanism of injury/timeline of events and typical symptomology.
• Special considerations/questions should include how many falls, how they occur, environmental conditions, other symptoms and health care conditions/medications and fear.

Balance Examination: Objective

• Observation, ROM, flexibility/muscle length, strength, posture, sensation and systems review
• Balance Related Tests and measures assess coordination, sensory input, sensory organization.
• Include reaction tests and other tests by balance category.

Specific Tests

• Tests include the Berg Balance Scale, Tinetti (POMA), Balance Error Scoring System (BESS), Modified Clinical Test of Sensory Organization and Balance (mCTSIB) and mini BESTest.
• Functional Gait Assessment (FGA), TUG, Four Square Step Test, Functional Reach, Push/Release and SOT.

Test Selection Considerations

• When selecting a test, it is important to be familiar with the test/outcome measure, and to confirm that it is appropriate for the client.
• Must have right equipment as well.
• The test must measure the right impairment.

Test interpretation

• Crucial to analyze what being examined specifically (by groups of activities within an outcome measure)
• Control, input, output issue should be determined.
• Determine fall risk.
• Be able to identify types of interventions.

Balance Lab Prep

• Self-guided with opportunities to ask questions.
• Outcome measures generally have good instructions.
• Sign up and work with groups.
• Have one person in group who is the expert on a particular outcome measure(s) and walk through the process together.
• Think beyond the basics, focus on cuing and interpretation.