Card Set Information
Coordination and Balance
Ability to execute smooth, accurate, and controlled motor responses.
Control of discrete movements of the extremities.
Control of multi-joint movements for posture and gait, including the trunk.
Coordinated movement requires muscles and joints activated with appropriate _____ & _____.
Timing and Scaling
Time to initiate movement, time to move, and time to terminate movement.
Gradation of forces for a particular task.
Age related changes impacting coordination:
- Decreased strength
- Slowed reaction time
- Decreased flexibility
- Postural changes
- Alterations in sensation, perceptual skills, and visual & hearing acuity.
Cerebellar impairments impacting coordination:
Hypotonia, Dysmetria, Dysdiadochokinesis, Tremor, Dyssynergia, Ataxia, Dysarthria, Asthenia, Rebound phenomenon, Nystagmus
Basal ganglia impairments impacting coordination:
Bradykinesia, Akinesia, Rigidity, Tremor, Chorea, Athetosis, Choreoathetosis, Hemiballismus, Dystonia
Dorsal column impairments compacting coordination
- Decreased proprioception
- Decreased kinesthesia
- Decreased discriminative touch
Timing and grading of muscles of the trunk and LE's to maintain an upright position with the COG over the BOS in a given sensory environment.
Environmental conditions, real or imagined, that provide sensory information; the context in which an action occurs.
State of remaining fixed or steady against the force of gravity.
Body is at rest while maintaining a position.
Body or parts of the body are moving while repeatedly realingning the COG over the BOS.
Greatest distance in any direction that a person can sway or will sway without altering the original base of support or losing balance.
Limits of stability (LOS)
An automatic response of muscles to changes in COG.
Muscles act in synergy thereby freeing higher brain levels from attending to aspects of maintaining balance.
Postural adjustments made in preparation for voluntary movement (feedforward).
Anticipatory of proactive
Automatic responses to disruptions of stability from a specific stimulus (feedback).
Compensatory or reactive.
Components of Balance:
1. Biomechanical / musculoskeletal
2. Coordinated normal motor strategies
3. Sensory organization
5 main areas of movement capabilities:
1. Alternate or reciprocal motion
2. Movement composition
3. Movement accuracy
4. Fixation of limb holding
Compensatory motor strategies used to maintain balance:
1. Ankle strategy
2. Weight-shift strategy
3. Hip strategy
4. Stepping or grasping strategies
- Delayed onset of muscle action
- Co-contraction of muscles resulting in stiffness
Examples of what?
Ability to reverse movement between opposing muscle groups.
Alternating or reciprocal motion
Muscles working together.
Movement composition or synergy
Ability to gauge and judge speed and distance.
Maintain control in response to alterations in COG or BOS.
Equilibrium or postural stability
Muscles feel soft, little resistance.
Inability to judge distance or range of movement.
Impaired ability to perform rapid alternating movements.
- Movement decomposition
- Movement performed in a sequence of component parts.
Loss of coordination in gait, posture, and movement pattern with diffficulty in initiating, rate, rhythm, and sequencing.
- Disorder of motor component.
- Scanning speech characteristic of cerebellar involvement: slow with prolonged syllables and inappropriate pauses.
Generalized muscle weakness.
Inability to stop motion following an isometric contraction.
Rhythmic, oscillatory back and forth movement of the eyes.
Decreased amplitude and velocity of movement.
Inability to initiate movement.
Seen at rest; decreases with purposeful movement; increased with stress.
Involuntary, rapid, irregular, jerky movements.
Slow, involuntary, twisting movements; "wormlike"
Large, sudden, flailing movements.
Involuntary sustained muscle contractions.
Cone of stability:
12 degrees A-P
16 degrees M-L
(Normal stance width of 4 inches)
Primary sensory systems used for sensory organization:
Detractors from balance:
Loss of sensory acuity
Faulty scaling and timing of muscle activation
For hip strategy, which muscles contract when the body gets perturbed anteriorly?
Abdomen and quads
For hip strategy, which muscles contract when the body gets perturbed posteriorly?
Erector spinae and hamstrings
- Small perturbations well within the LOS
- Muscle activation distal to proximal
- Pelvis is the key point of control
- COM moves in frontal plane primarily with hip abductor and adductor muscles
- Response to rapid and/or large external perturbations or on marrow BOS
- COG near LOS
- Muscle activation proximal to distal
- Results in realigning pelvis over the BOS
- Large, fast perturbations
- Often used before the others or in combination with other strategies
Stepping or grasping strategies
Lowering BOS in an unstable surface (ice)