part 1: 744 Postural Control Slides

a systems framework for postural control

conceptual model representing many components of postural control studies by researchers

normal postural control: the task of postural control involves _____

stability definition

orientation definition

normal postural control: strategies underlying stance postural control:

normal postural control: strategies underlying stance postural control: motor strategies

normal postural control: strategies underlying stance postural control: sensory strategies

normal postural control: strategies underlying stance postural control: sensorimotor strategies

normal postural control: strategies underlying stance postural control: attentional strategies

What are the different neural subsystems that contribute to the control of postural orientation and stability?

proactive vs reactive

_________

Don’t forget about the feedforward part – anticipatory part (occurs in advance but can also occur in conjunction with feedback)

If its feedback unexpectedly its reactive (when something changes)

If its feedback with ___ its proactive

Normal Postural Control: what is a more accurate label

motor systems in postural control: steady state balance

motor systems in postural control: steady state balance: alignment

motor systems in postural control: steady state balance: muscle tone

motor systems in postural control: steady state balance: postural tone

motor systems in postural control: Reactive balance control

_________

Reactive balance, defined as the recovery of stability following an unexpected displacement of the COM, requires movement strategies that are effective in bringing the COM back within stability limits determined primarily by the BOS.

*** these are A-P direction

This does not explain an unexpected sideways or angles direction

___________

Movement patterns used to recover balance are categorized into fixed-support (ankle and hip) and change-in-support (stepping and reach-to-grasp) strategies. Healthy young adults can adapt to changing task and environmental constraints by shifting relatively quickly from one postural movement strategy to another.

Reach and grasp is also an option

Know change in support vs fized support (feet moving, feet not moving)

forward sway vs backward sway ankle strategy

_______

Timing is important with these

What side of the body, do they start proximally or distally,

1.If forceplate is moving backwards (indicated by the arrow pointing back)

1.When it goes back, he leans forward and the backside lights up

Bottom: forceplate is forward, person leans back, muscles in front fire

forward sway vs backward sway hip strategy

_______

NOTICE THE ANKLE IS QUIET

They are not using the ankle which is why we go to hip strategy

**focusing on ankle, hip, stepping

Standing in tandem on a curb: hip (why is it not ankle – because the hips are the ones that are mainly correcting you – ankles are at a biomechanical disadvantage when they are stacked like that (removes them from equation))

Standing on a firm surface with a small nudge to your back: ankle (small and firm surface MATTERS – when you are not on a firm surface your ankles don’t really work – on a firm surface your toes or heels correct, on a soft the sink and don’t work)

Standing as a large dog pounces on your chest: stepping

Standing on a soft, uneven surface: ankle

movement strategies depends on ____

motor systems in postural control: motor strategies - reactive

multidirectional perturbations

motor systems in postural control: motor strategies - reactive - multidirectional stability

______

The CNS activates synergistic muscles at mechanically related joints, possibly to ensure that forces generated at one joint for balance control do not produce instability elsewhere in the body.

motor systems in postural control: motor strategies: Postural motor strategies are used in

motor systems in postural control: clinical applications of research on reactive balance

motor systems in postural control: proactive (anticipatory) balance control

___________

Postural muscles are also activated before voluntary movements to minimize potential disturbances to balance that the movement may cause. This is called anticipatory postural control.

Older adults:

Children: can be as basic as weightshifting and leaning; reaching for anything bending picking things up

Athletes: sport specific things that dose not involve reacting to a loss of balance or perturbation/threat

motor systems in postural control: clinical applications of research on PROACTIVE balance control

association between CORE TASKS and classification of balance dysfunction

________

An (X) indicates that performance of the core task without any task or

environmental variations may help detect deficits associated with the designated classification

of balance dysfunction.

In the other instances, task or environmental variations of the core task

may be required to detect specific postural control deficits in anticipatory and reactive postural

control. LOB = loss of balance.