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Mowder-Tinney 2020 1
Balance Introduction
J.J. Mowder-Tinney PT, PhD, NCS, CSRS, CEEAA, C/NDT
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.
Mowder-Tinney 2020 2
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
Mowder-Tinney 2020 3
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
Mowder-Tinney 2020 4
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
Mowder-Tinney 2020 5
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
Mowder-Tinney 2020 6
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.
Mowder-Tinney 2020 7
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
Mowder-Tinney 2020 8
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
Mowder-Tinney 2020 9
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!!