05-05c: Tone, Motor Control Flashcards
Definition of tone
- Resistance of muscle to passive elongation or stretch (PROM)
- Not a contracture
- Not voluntary resistance to movement
Reasons for Tone
- Physical inertia
- Intrinsic mechanical-elastic stiffness of muscle and connective tissue
- Reflex muscle contraction (tonic stretch reflex)
What affects tone
- Voluntary effort
- Anxiety and pain
- Position and interaction of tonic reflexes
- Ambient temperature (cold facilitates, warm inhibits)
- Medication
- State of arousal
Hypertonia
Increased tone about normal resting levels
Hypotonia
- Decreased tone below normal resting levels
- Low tone can include flaccidity
- Diminished resistance to passive stretch
- Stretch reflexes are dampened or absent
- Limbs “floppy”, easily moved
- Associated with LMN lesions
- Can use quick stretch to activate spindle fire
Dystonia
- Impaired or disordered tonicity
- Involuntary movements involving large portions of the body
- Hyperkinetic movement disorder
- Associated with CNS lesions involving basal ganglia; inherited conditions; Neurodegenerative diseases (Parkinson’s); Metabolic disorders; Torticollis; Writer’s cramp
Types of hypertonicity (2)
Spasticity, Rigidity
Spasticity
- Characteristic of UMN lesions
- Velocity dependent resistance to passive stretch (larger and quicker the stretch, the stronger the spasticity)
- Clasp-knife response (sudden inhibition or letting go; sudden release)
Chronic spasticity may result in…
- Contractures
- Abnormal posturing
- Deformities
- Functional limiations
- Disability
Clonus
- Cyclical, spasmodic alternation of muscular stretch of a spastic muscle
- Normal; common in plantar flexors, wrist and jaw
Clonus Scale
1 = no clonus 2 = minimal clonus (1-2 beats) 3 = moderate clonus (3-9 beats) 4 = sustained clonus (10+ beats)
Rigidity
- Lesions of basal ganglia
- Characteristic of uniform resistance throughout the entire ROM
- Velocity independent resistance to passive ROM
- Leadpipe: Heavy load makes high resistance
- Cogwheel: Catch-release jerkiness, commin in UE movements in pts with Parkinson’s; May have tremor on top of rigidity
Chronic rigidity may result in…
- Stiffness
- Inflexibility
- Significant functional limitations
Spasticity vs. Rigidity
- Spasticity: Increase in muscle tone (velocity dependent)
- Rigidity: No effect in tone (not velocity dependent)
Decorticate Rigidity
- Results from severe brainstem involvement (BI)
- Pt is in coma
- Abnormal flexor pattern
- UE in flexion (elbow, wrist, fingers, shoulder adduction), LE in extension (Ext, IR, PF)
Decerebrate Rigidity
- Results from severe brainstem involvement (BI)
- Pt is in coma
- Abnormal extensor pattern
- UE in extension (elbow ext, wrist flex, fingers flex, forearm pronation, shoulder adduction), LE in extension (Ext, IR, PF)
Tone Scale
0 = No response (flaccidity) 1+ = Decreased response (hypotonia) 2+ = Normal 3+ = Exaggerated response (mild to moderate hypertonia) 4+ = Sustained response (severe hypertonia)
Modified Ashworth Scale
0 = No increase in muscle tone 1 = Slight increase in muscle tone, manifested by catch-release or by min resistance at end of ROM when affected part is moved in flexion/extension 1+ = Slight increase in muscle tone, manifested by a catch, followed by min resistance throughout the remainder (less than half) of ROM 2 = Marked increase in tone through most of ROM, but affected parts easily moved 3 = Considerable increase in tone, passive movement difficult 4 = Affected parts rigid in flexion or extension
- “Gold standard” for hypertonicity
- Inability to detect small changes
- Limited application (only for extremity)
- Inability to distinguish soft tissue viscoelasticity and neural changes
Documentation of tone includes…
- Location
- Type of tone
- Symmetrical/Asymmetrical (both sides? one side?)
- Resting postures (Position at rest)
- Factors that influence tone (speed of movement, anxiety, pain)
- Effects of tone on function
Development of motor/functional skills
- Mobility
- Stability
- Controlled mobility
- Skill
Skill
Ability to consistently perform coordinated movement sequences for purposes of attaining an action goal
Mobility/Transitional Mobility
- Ability to move through functional ROM (from one position to another independently and safely)
- Initiating, controlling and terminating movement
Stability/Static Postural Control
Ability to maintain a position or posture with center of mass (COM) staying over the BOS with body not in motion
Controlled mobility/Dynamic balance
Ability to move within WB position or rotate around a long axis
- Maintain postural stability and COM over BOS while parts of body are in motion
Motor control theory
- Ability to produce, regulate and alter mechanisms that produce movement and control posture
- Task-specific training to reduce impairment
Motor control interventions do…
- Resolve impairment (body, not cellular level)
- Retrain using functional tasks (reprogram brain)
- Design/implement recovery strategies
- Design/implement compensatory strategies (last option when recovery is insufficient)
Plasticity/Neuroplasticity
Ability to modify or change at the synapse level either temporarily or permanently in order to perform a certain function
- (neuro) Capacity for brain and nerve cells to repair and change in response to experience or environment
- allows recovery of function after injury or disease
Motor learning
Ability to perform movement as a result of internal processes that interact with the environment and produce a consistent strategy to generate the correct movement
- Relatively permanent changes in ability to perform skilled behavior
- Includes practice and experience to facilitate (i.e., piano, drumming, typing)
Postural control
- Ability of the motor and sensory systems to stabilize position and control movement
- Maintain posture while performing functional tasks
Strategy
- Plan used to produce a specific result or outcome that will influence structure or system
- Treatment = development of most effective strategies
Compensation
- Adoption of alternative behavioral strategies to complete a task
- Different muscles, movement, adapteive equipment substitute for loss of function
- AFO, crutches, cane, splints = compensatory devices
Motor recovery
- Reacquisition of movement skills lost through injury
- Movements may be modified, but task completed without compensation
- Relies on neuroplasticity
Fugi-Meyer
- Ordinal scale measures recovery after CVA
- Brunnstrom’s sequence of recovery
- Assesses 1) joint movement and pain, 2) balance, 3) UE motor function, 4) sensation, 5) LE motor function
Fugi-Meyer Scoring
- Each item scored 0-3
- Cumulative, max score is 100; can be interpreted as percentage of motor recovery
- Lower the score, higher the disability
Rivermead Motor Assessment
- NDT approach to neurological recovery
- Self-report
- 3 sections: 1) Gross function, 2) leg and trunk, 3) arm
- Each section has subscale of tasks that increase in difficulty
Rivermead Motor Assessment Scoring
- 1 for completion of task, 0 for inability
- Can stop test if cannot perform 3 tasks in a row
Upright motor control test
- Incorporates upright posture and WB
- Simulates stance and swing phases of gait
- Requires 2 people to administer (one to stabilize, one to cue
- 2 sub tests: Flexion Control (swing phase), Extension Control (stance phase)
