Posture & Balance 3

Aging population

65+

Centenarian on the rise

W live longer than M

• Balance, posture, coordination decline 

• Falls leading cause of injury 

  • lose independence 

Aging + PA

Less than ½ Canadians get recommended PA

Mainly sedentary

PA + Posture and Balance

Natural aging declines balance, posture, coordination 

Less PA in daily lives 

Increased in falls risk 

Falls implications

Serious health outcomes; hospitalizations 

Leading cause of injury

Functional and social implications 

Chronic pain, reduced mobility, death 

Importance of balance, posture and coordination

Increased

• Fracture risk

• Fall risk 

• Less independent 

• Quality of life 

• Complete daily tasks 

Postural control

Ability to maintain body position AND stability to achieve/sustain balance by integrating sensory, cognitive and MSK systems 

Maintain orientation in space 

Coordination

Ability to execute SMOOTH, accurate, controlled motor responses to carry out desired activity

Interaction btwn muscles and joints to deliver smooth movement 

i.e. Walking and running 

Are coordination and postural control synonymous?

NO they are not the same, but they work synergistically. 

Distinction is the OUTPUT

Proactive balance strategy 

Same as anticipatory postural adjustment

BEFORE disturbance

Preparing mm for movement

Rely on brain to predict movement

Declines w/ age bc…

• Reduced strength

• less confident in movement 

Reactive balance strategy

Same as compensatory postural adjustment

AFTER disturbance (balance already challenged)

Rely on rapid sensory feedback 

• Vision, vestibular, somatosensory

• Quick msk response 

Declines w/ age 

Weak proactive strategy, rely on….?

Reactive

Important to train both 

Balance training - INDEPENDENT

Improves stability, cognition, QofL

Coordination training - INDEPENDENT

Improves cognition, movement fluidity

Combination of Balance and Coordination training

More improvements

• ADL, QoL (from socialization), less stress, coordination, balance, postural control

Tai Chi 

Multi-component program 

Maintain independence and wellbeing - improved QoL

Tai Chi & Posture and Balance

Combines coordination & balance

• Link continuous coordinated movements thru weight shift (joint flexion)

• Body moves from stabilizers (postural control) to mobilizers (coordination)

  • Stabilizing leg to other leg

Targets postural control, balance and cognition

Multi-component programs

Balance and coordination, strength & dual task

• Targets brain

Ex. single leg stance, tandem walking

Adapted Perturbation Training Experiment

Hands-free cycling for adults w/ limited mobility

Targets trunk mm to improve standing balance rxns 

Goal: Improve PROACTIVE + REACTIVE balance in standing

Intervention: 20x seated cycling for 20 mins for 12 weeks  

• Perturbation Based Training: ML perturbations 

• Stationary Cycling Training: no perturbations 

Completed walking tests pre-post. 

Results of Perturbation training experiment

Proactive + reactive balance improved

Less steps = MORE stable + lower fall risk 

• More resistant to balance disturbances 

Improvements in ML direction 

Balance is the interaction btwn

All systems

• Vision, strength, reflexes

• Posture, gait, coordination

• Biomechanics, msk, neural

Age related impairments that affect posture and balance - systems theory

Neural

• Cognitive changes: less focused on balance 

• Somatosensory changes: less proprioception 

• Neuromuscular changes: slower conduction, reduced mm activation 

Biomechanical impairments 

• Lack coordination

• Reduced APA & CPA 

• Gait abnormalities 

  • Shorter step length

  • Slower walking speed

MSK - natural loss 

• Less mm mass

• Bone loss

Impairments compound and interact

• Not occur in isolation

• Harder to stabilize self

Impacts many systems simultaneously

Aging and Hyper-kyphosis 

Postmenopausal women at higher risk 

• Decrease in estrogen 

• Less bone density

Hyper-kyphosis = >40 deg (excessive T spine curve)

Consequences of Hyperkyphosis

COM shift forwards

• Rely on hip/ankle strategy

Altered fxn

Spinal mm strain

Increased fall risk

Decreased QoL 

Importance of Trunk

Controls COM during perturbations (medio-lateral direction esp).

• Keeps COM within BOS 

Trunk control > less likely to take recovery step 

CoM velocity determines if step is needed 

Ways to recover from perturbationb

1. Stabilize trunk, control COM

2. Take a step 

Which strategy do you rely on more as you age?

Rely on reactive strategies 

• Bc Anticipatory Postural Adjustments weaken 

COP and Aging

Larger and FASTER CoP movements

• More sway = rely on reactive strategies 

• Due to decreased balance and postural control 

  • More than biomechanical changes 

  • Cumulative of natural decline 

• Higher postural sway velocity and range 

  • Overcorrection, always chasing 

Neuromuscular changes w/ Aging

Slower mm recruitment in vastus lateralis and gastroc

• Longer onset latency in anterior postural mm 

  • Calves had longer response time 

Larger % of max mm recruitment 

Slower corrective response to unstable 

• CNS slower @ processing perturbations and active correct mm 

Weaker, less accurate of a response 

Balance + Cognitive resources in aging

Balance requires cognitive resources

• Altered APA, CPA

• Delayed onset of mm activity 

• Rely more on reactive response

Anticipatory Postural Adjustment uses which muscles primarily?

Trunk and lower mm in sagittal plane

Glute medius fxn

Abduction and lateral stability

Activated after perturbation 

Sensory changes w/ Aging

Impaired sensory integration

Larger distribution velocity 

• Less stable, swayed faster when eyes closed 

Contributes to reduced balance control in elderly 

Elderly heavily rely on VISION for balance 

Somatosensory and vestibular system decline w/ age 

Can you train posture and balance?

Yes

Multi-component Program Benefits

Combines balance, coordination, resistance and aerobic exercise

Train all systems by combine balance w/ dual tasks

Ex. 12 weeks of combined program increased QoL

• Balance: Single leg stance, tandem stance, toe/heel walking, Romberg test, balance board, stair climbing

• Aerobics: step aerobics

• Posture: stability ball

Higher confidence in life

Benefits of Multi-component Programs

Better QoL, social engagement, fxnl strength, ADL performance

Tai Chi Benefits

Only good for ACTIVE BALANCE not static balance or walking speed

Less stress, improved mood + social support

Better postural control and stability under challenging sensory conditions