Mowder-Tinney 2020 1

Balance Introduction

J.J. Mowder-Tinney PT, PhD, NCS, CSRS, CEEAA, C/NDT

jjmowder@gmail.com

Learning Objectives

• Identify various components and impairments that contribute to balance deficits.

• Compare and contrast different causes of balance deficits.

Balance Definitions

• The ability to orient the body in space, maintain an upright posture under both static and dynamic conditions, and move without falling.

• The ability to respond to internal and external disturbance, to realign body segments, and to protect oneself from falling is essential in everyday tasks.

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Falls

• Stroke is among the leading risk factors for falls in the older adult and increases the risk for falling two to sixfold

• This population has more than seven times the risk of experiencing a fracture

• 40-70% fall within 12 months post-stroke

T h is P h o t o b y U n k n o w n A u t h o r is l ic e n s e d u n d e r C C B Y - N C - N D

•“There’s a physiological definition which incorporates proprioception, vision, and other components that clinicians tend to agree on. But there also is a functional definition that refers to the ability to change positions, maneuver through the environment, and withstand perturbations, which clinicians don’t always agree.”

•Mary Tinetti 1993

Postural Control is Complex

• Postural control is what allows balance – balance is output

• An entity that includes many systems and is not simple

• Includes interaction between individual, task the individual is performing, and the environment

• More than 130 different risk factors for falling have been noted

• We rarely find THE problem for balance therefore avoid cookbook approaches

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Dynamic Balance

Can they move within a posture?

Can you maintain posture when walking?

Can you move with varying environment?

Can you move with varying sensory input?

Strategies

• Ankle• Sway is slow, small, and near midline• Muscles activated distal-to-proximal

• Hip• Sway is faster, larger, and outside midline• Muscles activated proximal-to-distal – reach 10in.

• Suspensory• Stepping

• This strategy is used frequently but is the most difficult to learn – I have a whole course on this topic if you want more examples

Considerations for AssessmentMedical• Hypotension• Bladder Dysfunction

Medications• 4 or more increases risk• Digoxin, diuretics, antiarrhythmics, antipsychotics

Cognition• Fear of falling directly related to self-imposed activity

reduction• Risk factors: environmental issues

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Considerations for Assessment

• Onset – sudden vs. gradual, frequency• Environmental factors• Activities at time of fall

Fall history

• Somatosensory• Vision• Vestibular

Sensory – Where am I?

• Strength• ROM/flexibility• Endurance

Motor – Where do I go?

• When, how long, what kind

Dizziness description

Cognition

• Psychological trauma and fear-of-falling cause self-imposed activity reduction

ê Strength

ê Flexibility

ê Mobility

Further é RISK of future falls

Controlling Cognitive

Risk Factors

• Lighting problems, floor and hallway clutter and throw rugs, bathroom safety issues regarding slippery floors and tubs and inaccessibility, lack of rail on stairs, low or unstable furniture, shelves too high or low• Regular bathroom schedule for

facilities• Provide check off lists for your family

to take home and review and bring back• Have family take pictures and bring

them in to show you

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Trail Making Test – B (TMT-B)

• Limitations in executive function result in slower gait speed and decreased mobility skills.

• TMT-B has shown to screen for executive function utilizing visual scanning, speed and attention.

• Incorporate this test into your screening for cognition and balance risk.

Somatosensory Receptors

Receptor Information

Muscle spindles and Golgi tendon organs

Muscle length and tension

Joint receptors Joint movement and stress

Cutaneous mechanoreceptorsPacinian Corpuscle: vibrationMeissner’s Corpuscle: light touch and vibrationMerkel’s disc: Local pressureRuffini endings: skin stretch

Visual Receptors

• People become more visually dependent with age

• Multiple fallers had impaired depth perception, impaired contrast sensitivity, and low-contrast visual acuity

• Need to tease out if perceiving correctly

• Distorted vision• Neglect

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Visual Tests to Always Complete

• CN III (Oculomotor)• CN IV (Trochlear)• CN VI (Abducens)

Smooth Pursuits

• CN III (Oculomotor bilaterally)

Convergence

Saccades

Additional Visual Considerations

•Consider depth perception with stairs – do they wear bifocals?

•Macular degeneration

•Glaucoma

Visual Dependence

• It is a general term for a person who has increased reliance on their vision.

•This decreases the appropriate utilization of the somatosensory system on even surfaces.

•Resulting in an increase in fall risk especially when vision is impacted – like walking in the dark.

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Modified Clinical Test for Sensory Interaction on Balance (mCTSIB)

The modified version is more commonly used by clinicians

Four conditions are tested: EO firm, EO foam, EC firm, EC foam

Foam: remember that closed cell foam gives rebound and sensory information, open cell allows you to float in the middle with density of 1.8-2.4

Shumway-Cook & Horak 1986

Test Condition

Potential Impairments Challenge Considerations

Eyes Open, Firm Surface

Musculoskeletal – range or strengthCardiovascularGaze stabilization

Resistance strengthening –proximal Dual challengeVariation in sensory

Eyes Closed, Firm surface

Poor integration or re-weighting of sensoryMusculoskeletalDependent on vision

Eyes closed activities or visual distractorsDual task activities

Eyes open, Foam surface

Gaze stabilizationMusculoskeletal

Strengthening LesGaze stabilization activities

Eyes Closed, Foam surface

Poor use of vestibular systemDependent on vision

Head turnsEyes closed activitiesIncrease re-weightingPostural transitions

Which Sensory System Is It?

• If standing with eyes closed on firm surface but having patient turn their head from side to side what sensory system is not being used?

• Vision

• Which system are you trying to stimulate? • Vestibular

• Which system is being relied on? • Somatosensory

We will look at this again when we discuss the BESTest

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Vestibular System

• Vestibular system identifies self-motion as different from motion in the environment, and serves as a “referee” when the two other systems are in conflict

• Provides input as to head position to gravity, speed, and direction

• Stabilizes head• Stabilizes gaze during head movement

Vestibular Inputs• Vestibular receptors cannot work alone since it is

unable to distinguish between nodding the head in isolation or the head moving with the trunk when bending over

Receptor Information

Semicircular Canals

Angular acceleration(fast head movements like walking, trips,

falls)

Otoliths Linear position or movement(slow head movements like postural sway)

PERIPHERAL VS CENTRAL SYMPTOMS

Symptom Peripheral CentralImbalance Mild Severe

Hearing loss Common RareNausea and Vomiting Severe Moderate

Oscillopsia Mild SevereNeurologic Symptoms Rare CommonLateropulsion or tilt Commonly found

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Vestibular Ocular Reflex (VOR)

• The VOR system reflexively drives eye movements in a direction that is equal and opposite to those of the head to allow us to maintain our gaze on an external target during movement.

• It coordinates eye and head movement in order to keep an object in focus.

• If there is a problem, then visual acuity decreases with head movement.

Lencer R, Sprenger A, Trillenberg P. Smooth Pursuit, Optokinetic Nystagmus and Vestibular Ocular Reflex. Eye Movement Research: An Introduction to its Scientific Foundations and Applications. 2019 Oct 16:117.

Review of Key Aspects to Consider

We want to have a clear understanding of the status of each sensory system and any

potential limitation.

Sensory systems are a critical component for balance and take in all the information needed to

determine their balance.

See you soon!!