Week 10 : Falls / Balance Flashcards
Define balance
a state whereby the projection of the centre of mass (COM) falls within the stability limits of the base of support (BOS)
• Stability limit is the point at which balance is lost and corrective action is required
• Core component of functional activities
• Incorporates the concepts of posture and movement
define postural control
control of posture and movement in attaining a state of balance
• Motor action that occurs following integration of sensory, perceptual, cognitive and motor processes
• Aims of postural control:
– Postural equilibrium/ stability (maintain upright position and maintain COM within stability limits of BOS during internally and externally initiated movement)
– Postural orientation (gravity, vertical, internal references, the environment)
Sensory input and balance - input
Visual Input
– Reference for upright vertical
– Predicting forthcoming threats to balance
• Somatosensory System (Proprioception)
– Reference for body position relative to the supporting surface and other body parts
• Vestibular System
– Reference for head position and movement of head in relation to gravity
sensory input and balance - main functions
• Sensory Feed Forward
– Allows preparation for movement
– Requires input from internal and external environment – Strongly linked to previous experience
• Sensory Feedback
– Allows ongoing regulation and appropriate muscle adjustments during movement
integration
Minimal cognitive processing by the cortex for postural control
– Contribution dependent on task complexity and the capability of the individual’s postural control system
• CNS intervenes if a sensory conflict exists when it must weight the sources and reject the potential source of error
Motor output and balance
refers to displacement of COM in relation to the BOS during movement
motor response by which balance recovers determines whether the displacement of COM causes a fall
motor adjustments are flexible and varied dependent on the task, the environmental context and the individual
as appropriate motor response requires
- muscle strength, endurance, ROM
- fine grading of agonists, antagonists, synergists
- appropriate co-contraction
- high level of reciprocal innervation
movement strategies
ankle strategies
hip strategies
step strategy
outstretched arm
balance reactions - equilibrium reactions
postural sway
subtle changes in muscle tone required to maintain equilibrium
balance reactions - righting reactions
response to displacement of the COM beyond the stability limits in an attempt to regain equilibrium
-may involve movement of the head, the trunk or limbs
balance reactions - saving/protective
step or extended upper limb
- establish a new BOS and restore equilibrium
Common impairments in neurological patients
motor dysfunction
MSK
decreased muscle strength, trunk stability, decreased ROM, altered muscle tone
common impairments in neurological patients
motor dysfunction
biomechanics
decreased stability limits, decreased balance responses (magnitude and velocity), altered movement strategies
common impairments in neurological patients
sensory dysfunction
altered sensation
decreased ankle proprioception, vestibular system damage, dizziness, visual deficits
common impairments in neurological patients
sensory dysfunction
altered sensory integration
difficulty dividing attention between tasks, impaired ability to use sensory weighting, delayed or inadequate anticipatory response, altered perceived stability limits, abnormal perception of vertical via somatosensory systems
balance assessment : functional observation
- set an appropriate balance task
create a safe situation (environment, assistance)
incorporate various environmental contexts and tasks
challenge their behaviour (decreased BOS, raise COM, displace COM towards stability limits, unstable surface, alter visual input)
Assess all aspects of balance responses (posture and movement, balance strategies/reactions, planes of movement
balance assessment : functional observation
observe the patient performing the balance task
can they balance in a specific posture
can they balance during movement
if they can balance, what strategies do they use to achieve balance
does the patient use compensatory strategies to maintain balance
are these compensations effective
is the goal completed successfully
do they interact with their BOS during their movement
what happens to the balance if sensory input is reduced?
Balance assessment : outcome measures
Tinetti Balance Berg Balance scale BOOMER Rhomberg's test/sharpened Romberg's CTSIB Functional reach test Functional activities Sitting; supported sitting, sitting arm raise, sitting forward reach Standing: supported standing, standing arm raise, standing forward reach, static tandem standing, weight shift Walking : timed 5m walk, tap and step
Balance training
trained simultaneously as part of functional motor actions
- sitting, standing, mobility and transfers
- control and stability of the COM is specific to each task and the conditions in which it is carried out
increasing evidence that challenging balance in standing, with the aim of reducing the BOS and practising controlled movements of the COM is the optimal way to improve balance during performance of everyday actions
Mobility requires accurate sense of balance, sufficient lower limb strength, and sufficient soft tissue extensibility and joint flexibility
training programmes should include exercises that require a fast build up of force and propulsive muscle activity (power)
continued balance training
strength relates directly to functional motor control and both can be improved by intensive and functional based training that is challenging for the individual
- progress to extend capabilities of patient
- functional tasks strengthen muscles concentrically and eccentrically
- increase intensity by increasing reps, increasing step height, lowering chair height, reducing hand support
maximise skill through progressively challenging the tasks according to destablishing effects (complex environment, unpredictable demands)
define a fall
an event which results in a person coming to rest inadvertently on the ground or other lower level
• Do not include an intentional change in position
• Do include when a person inadvertently comes to rest on furniture, against a wall or other object or person
falls may result from
loss of balance
tripping
slipping
legs giving way
fear of falling
post fall anxiety syndrome
negative consequence of falls
resultant self imposed activity restrictions and loss of confidence in the ability to ambulate safely can lead to further functional decline, depression, feelings of helplessness and social isolation, which in turn places an individual at a higher risk of another fall
risk factors for falling
limitations in activity for daily living or mobility
impaired balance
impaired gait
reduced vestibular function visual impairments reduced peripheral sensation reduced muscle strength poor reaction time
falls assessment : screening
screening recommended for
- all patients who present with/report a fall
- all neurological patients
- all vestibular patients
- all patients >65 years
- all patients with known risk factors for falling
questions
- any falls within the past year?
- frequency, context and characteristics
post screening - does not warrant full multifactorial assessment
discuss with the patient offering education and advice related to falls and any potential risk factors is still recommended
falls risk assessment gold standard
multifactorial MDT approach
fall assessment : risk assessment
identification of fall hx gait, balance and mobility, and muscle strength osteoporosis risk perceived functional ability and fear relating to falling visual impairment cognitive impairment neurological examination urinary incontinence home hazards CV examination meds review
Falls assessment : outcome measures
TUG Tinetti scale functional reach DGI- dynamic gait BOOMER BERG balance scle ABC FES - fall efficacy scale
falls prevention
most falls among older individuals are associated with identifiable and modifiable risk factors for which preventive efforts are more effective
current evidence supports multi-strategy , multifactorial falls prevention intervention
Falls prevention strategied
exercise programs environmental hazard modifications education programs cognitive behavioural program assistive devices technological aids footwear and foot problems hip protectors lifestyle interventions
medication review vision assessment CV interventions bone strenghtening meds/supplements nutrition
exercise programs
challenging and progressive balance exercises performed in weight bearing positions that minimise the use of upper limbs for support
targeted to patient’s deficits/risk factors/impairments and lifestyle
summary
balance =postural control =sensory input and balance, integration and motor output and balance balance assessment balance training
falls -falls and fear of falling epidemiology -risk factors -falls assessment -falls prevention
