Posture, Balance, and Gait Changes Flashcards
Reactive postural control
Governs unexpected movements of COM within or outside BOS
Perturbations
Anticipatory postural control
Postural adjustments made before a movement
Tossing a ball
Adaptive postural control
Modification of a motor response due to a change in environmental conditions or task demands
Incline
Younger input from…
Visual input birth-3
Adult input
Somatosensory
If impaired, vestibular system kicks in
Eye-head stabilization
Eyes and labyrinths (establish difference btwn egocentric and exocentric motion)
Provide orientation of head in space
Egocentric motion
Body moves
Exocentric motion
Environment moves
MSK system
Regulated by viscoelastic properties of mm, GTO, and DESCENDING motor control
Motor coordination
Ability to coordinate mm activity to control performance
Requires appropriate mm tone and anti-gravity strength
Ankle strategy
Distal to proximal activation for ant/post stability
Hip strategy
Proximal to distal activation for ant/post stabilization
Step strategy
All planes
If ankle and hip strategy aren’t enough to re-establish COM within BOS
Predictive central set
Postural readiness
3 purposes for anticipatory postural adjustments
- Keep postural disturbance to a minimum
- Prepare for movement
- Assist in development of force or velocity
Righting rxns
Orienting head with horizon
Equilibrium rxns
Balancing over a point
Nashner Model of Postural Control and Stance
Less BOS? More use of hip strategy
Eyes open v eyes closed balance testing in children
Vision should not be occluded during first three years due to relying on this input
Fxl reach test
Self-perturbed balance and fall risk
Clinical test of sensory integration and balance
Foam and dome
Posture and movement changes with age
Older adults more variable
Floor to stand more asymmetrical
Posture and balance decline because…
Change in static posture Loss of flexibility, mm strength, mm tone Vestibular impairments Sensory input and integration Visual changes Medications and poly-meds
***Many changes due to inactivity and lack of practice
Postural changes with age
Increased kyphosis
Loss of flexibility and decreased postural rxn leads to…
Less organized motor patterns
Diminished motor coordination
When to use hip strategy
Unstable surface
Smaller BOS
Fast moving environment
Visual changes with age
Less ability to pick up contours and depth cues
Vestibular changes with age
Loss of hair cells that sense direction of endolymph in semicircular canals
Vestibular nerve (VIII) changes with age
Reduction in number of fibers
Vibratory sense changes with age
Declines in LE
Tripping over your own feet
While ankle and hip were most important, there are studies showing that stepping strategies are more important in recovering balance
Training stepping pattern is more important
Older adults tend to cross-over or collide limbs when utilizing stepping strategies
Anticipatory postural adjustments stabilize…
PRIOR to voluntary movement
Rxn time in adults
Negatively affected
Longer onset latencies in postural mm…
LE > UE
Torque generating capacity
Decreases with age
Example: hip ABD
Static postural control
Ensures stability by maintaining COM within BOS
Independent ambulation by…
11.5 mos (50% of infants)
Critical variable in development of independent ambulation
Extensor mm strength
Initial gait pattern
Wide BOS Arms in high guard px Short swing phase Lack of heel strike and push-off ER of hips
2-3 years old and ambulation patterns
Reciprocal arm swing
Heels strike
3-4 years of age and ambulation
Narrowing of BOS
Increased time in single limb stance
Children ambulation
Mature gait pattern kinematics by 4 years
Consistent heel strike and knee flexion in early stance
7 years old and ambulation
COM at L3
Adult kinematic pattern more refined
May see further refinement of spatial and temporal aspects of gait up to 15 years of age
4-7 years ambulation
You can pick out normal adult gait cycle
Key parameters that show change as gait matures to an adult level (4)
- SLS duration increases with age and maturation
- Walking velocity increases with age and limb length
- Cadence decreases with age and limb length
- Step length increases with age and limb length
Normal aging gait changes
Decreased gait velocity Decreased stride length Decreased peak knee extension ROM Decreases knee flexion in swing Slightly increases ankle dorsiflexion Decreased ankle PF power
Decreased strength and ambulation
Increased pelvic tilt (weak abs)
Decreased vertical displacement of body during gait
Decreased gait velocity
Decreased cadence (decreased DF strength)
Decreased balance and ambulation
Increased BOS
Decreased gait velocity
Increased time in double limb support
Increased use of visual scanning
Fall
Unexpected event in which an individual comes to rest on the ground, floor, or lower level
Older adult fallers gait characteristics
Comparison to NON-FALLERS
Decreased stride length
Decreased walking speed and cadence, especially with dual task
Increased double support time, especially with dual task
Conservative approach when negotiating an obstacle (smaller steps)
Mediolateral instability
Greater stride freq across various gait speeds
Inability to maintain peak gait speed
Increased stride to stride variability
Sometimes adults have higher gait speed. Why?
They don’t like walking and want to get it over with
Decreased time on single limb
Use momentum so they don’t utilize as much energy
Mediolateral instability
More predictive of falls
Factors contributing to falls in older adults (9)
Difficulty corralling COM when perturbed
Greater mediolateral instability
Difficulty modulating step length to avoid obstacles
Decreased speed
Decreased step length
Slower rate of ankle torque development in trip response
Increased difficulty in performing another task while walking
Decreased hip ABD torque generating capacity
Decreased trunk axial rotation
Fall Prevention Intervention Strategies (5)
Reduce risk factors Multifactorial fall risk assessment PA and balance training Higher risk? Home Hazard Assessment Low heel and resistant-soled shoes should be worn inside and outside the home
Fall Risk Factors
Mm weakness History of falls Gait deficit Balance deficit Use of assistive device Visual deficits Neurological deficits Arthritis Impaired ADL's Depression Cognitive impairment Age > 80 years Medication Cardiovascular deficits
Therapeutic exercise + balance training =
Increased…
Balance LE strength Safety Physical and functional capacity Ability to perform IADL's and ADL's
