MC Posture and Balance

Question 1

Balance – definition

Answer 1

The ability to control one’s center of mass (COM) with respect to the base of support (BOS).

Question 2

Base of Support (BOS)

Answer 2

BOS is the area of the body in contact with the support surface

Question 3

Postural Stability = Balance

Answer 3

Balance is the ability to keep the vertical projection of the center of mass (COM) within the limits of base of support

Question 4

Center of Pressure (COP)

Answer 4

• COP is the center of the distribution of total forces applied to the support surface
• COP represents the average “location” of these forces. It is a point on a 2-D plane!

Question 5

Stability Limits or “cone of stability”

Answer 5

Stability limits refer to the boundaries within which the body can maintain stability without changing the base of support.

Question 6

Balance: Commonly described subjectively…

Answer 6

• Zero: unable to maintain balance or no attempt made
• Poor: able to balance with or without UE support for 5 seconds or less
• Fair: able to balance with or without UE support from 15 - 60 seconds and/or able to hold against slight resistance
• Good: able to hold balance against moderate resistance

Question 7

4 Types of Balance

Answer 7

Static
Dynamic
Protective
Functional

Question 8

Static Balance (Time)

Answer 8

• time as objective measure

- maintain position over time

Question 9

Static Balance (resistance)

Answer 9

• resistance is the objective measure

- maintain position against manual resistance measured using HHD

Question 10

Static Balance (AFF)

Answer 10

• Anticipatory, feed-forward

- Reach in various directions within arm’s length

Question 11

Dynamic Balance (RFB)

Answer 11

• Reactive, Feedback

- Manually displace COM toward the edges of the BOS to elicit the equilibrium reactions

Question 12

Dynamic Balance (AFF)

Answer 12

• Anticipatory, Feed-forward

- Reach in various directions beyond arm’s length to elicit trunk and arm balance reactions

Question 13

Protective Reactions

Answer 13

• Reactive, feedback

- Slow/quick displacement of the COM outside the BOS to elicit a change in BOS (arm and/or leg movement)

Question 14

Functional Balance

Answer 14

• Anticipatory, feed-forward and reactive feedback

- Utilization of effective balance strategies while performing a set of functional tasks which progress in difficulty

Question 15

Balance(T)

Answer 15

• Time is the objective measure
• BalanceT is frequently tested in sitting and standing
• However, balance can be tested in any of the developmental positions

Question 16

Static BalanceT - Time

Answer 16

Maintain a position over time

Question 17

Static BalanceR - Resistance [Subjective Assessment]

Answer 17

• Attempt to assume near-normal posture with/without BUE support
• -sit, stand, developmental positions
• Maintain the position against gradual, matched manual resistance (“min, mod, max”)
• -Co-contraction-rhythmic stabilization
• -Tonic holding-alternating isometrics
• Verbal cue: “hhhhoooolllllddd”

Question 18

Static BalanceR - Resistance [Objective Assessment]

Answer 18

• Objectively measured using a hand-held dynamometer
• Published as Sitting Strength
• -Procedures for sitting strength written in details i

Question 19

MicroFet2 - Hand-Held Dynamometer

Answer 19

• measures peak force (pounds)
• Low threshold – 0.8–150 lbs. (0.1 lb. increments)
• High threshold – 3–150 lbs. (1.0 lb. Increments)

Question 20

Static Balance Basic Procedures Patient Position - Sitting

Answer 20

• Sitting on a height-adjustable table
• Feet flat on the floor
• Hips and knees at 90 dg
• Maximize thigh contact on support surface - stable BOS
• UE unsupported or supported
• -Supported – using bilateral upper extremities for support
• -Unsupported – hands not in contact with the support surface

Question 21

Static Balance Basic Procedures: PT force application

Answer 21

-Anterior – mid-sternum
-Posterior – mid-upper back between scapula
-Right and left lateral – acromion
Instructions “hold, do not let me move you” or “push as hard as you can”
-Gradual build up of force (over 3-4 seconds) and gradual release of force (over 3-4 seconds)
-Stop test when displace the subject approximately 1 inch (break test)
-2 practice trials and 3 actual trials (mean of actual trials)

Question 22

Sitting Strength (Static Balance) Test – Intra-Rater Reliability

Answer 22

Unsupported:
Intra-class Correlation Coefficients (ICCs) = 0.80 – 0.98

BUE Supported:
ICCs = 0.83 – 0.99

Question 23

Sitting Strength (Static Balance) Test – Inter-Rater Reliability

Answer 23

Unsupported:
ICCs = 0.93 – 0.98

BUE Supported:
ICCs = 0.95 – 0.99

Question 24

Static Balance AFF -Anticipatory, feed-forward

Answer 24

• Reach in various directions within arm’s length (goal = stability)
• Patient is anticipating what muscle actions or motor control is necessary to prevent falling due to the progressive weight of the arm
• Biomechanics of weight of arm (COM of arm relative to distance from axis of rotation)

Question 25

Dynamic Balance RFB - Reactive, feedback

Answer 25

- Manually displace the COM toward the edges of the BOS to elicit the equilibrium or balance reactions - Reactive, Feedback balance = Patient is responding to therapist manual perturbations (stimulus > response = feedback)

Question 26

Sitting Equilibrium Reactions

Answer 26

- Lateral right displacement or perturbation - Lateral left displacement or perturbation - Anterior displacement or perturbation - Posterior displacement or perturbation

Question 27

Standing Equilibrium Reactions

Answer 27

- Lateral right displacement or perturbation - Lateral left displacement or perturbation - Anterior displacement or perturbation - Posterior displacement or perturbation

Question 28

Dynamic BalanceAFF - Anticipatory, feed-forward

Answer 28

- Reach in various directions beyond arm’s length to elicit trunk and arm (sitting) and whole body (standing) balance reactions - Pt is anticipating what muscle actions or motor control is necessary to prevent falling due to the progressive weight of the arm - Know AFF actions of the trunk and legs in sitting and in standing

Question 29

Multi-Directional Reach test (MDRT)

Answer 29

Objective measure of dynamic sitting and standing AFF balance “reach as far as possible; you must return to upright independently”

Question 30

MDRT Procedures - Sitting

Answer 30

- Equipment - metal meter stick, rolling chair with out arm rests (preferably brakes), clear clipboard - Begin in an erect sitting posture, feet flat on floor, arm near wall (not touching), hand in a fist, shoulder raised to 90° flexion - Meter stick placed at acromion height - Initialreading taken using the 3rd PIP joint of fisted hand - “Reach as far as you can in the (appropriate-forward, diagonal, sideways) direction; you must return to upright independently.” - 3 trials are recorded in the anterior, right lateral, right diagonal, left lateral, and left diagonal directions.

Question 31

Dynamic Balance – Protective Reactions

Answer 31

- Protective reactions - Reactive, feedback balance - PT manual perturbations to elicit patient change in BOS to accommodate COM beyond BOS - 1st Slow perturbations to just beyond BOS or “edge of cone of stability” - -Sitting arm movements - -Standing leg movements – step and cross-overs - 2nd, relatively faster perturbations (yet safe)

Question 32

Functional Balance

Answer 32

- Utilization of effective balance strategies while performing a set of functional tasks which progress in difficulty - Example Outcome Measures - -Berg Functional Balance scale - -Tinetti balance scale - -Mini-BEST test