Voluntary Movement- Corticospinal tract Flashcards
What is the role of corticospinal tract in movement
Sensory Input–> vestibular inputs, kinaesthesia, vision
Motor systems–> primary motor pathways, basal ganglia, cerebellum
Other relevant systems–> PROM and joint health, strength, cardioresp function
Describe voluntary movement
automatic, fast, controlled and coordinated/accurate
Define resting muscle tone
the underlying level of stiffness in the muscle
define postural tone
what is holding you up at this time–> baseline level of muscle activity
Define voluntary movement
Movement from a thought
Define automatic movement
Subconscious movement
Define negative effects of UMN/LMN
Loss of what existed
Define positive effects of UMN/LMN
new features
What are negative features of UMN syndrome
PRODUCING MOVEMENT
- Loss of dexterity (fractionated/voluntary movement/motor control)
- Weakness
- Fatigue
What are positive features of UMN syndrome
REGULATING MUSCLE TONE
- Spasticity
- clonus
- Exxagerated DTR’s
- Associated movements
- Spastic dystonia
- Spastic co-contraction
- Spastic hypertonia
- Spasms
What is spasticity
motor disorder characteristed by a velocity-dependent increase in tonic stretch reflexes (muscle tone)
-resulting from hyperexcitability of stretch reflexes
What is rigidity
resistance to passive movement that is not velocity dependent
What is loss of fractionated movement
Loss of ability to stabilise one body segment and move the adjacent body segments with control and purpose
-loss of ability to control stabilisation and movement at multiple joints for purpose of skilled movements
Explain how the positive features of UMN syndrome occur
- Descending influences from cortex modulate spinal reflexes
- Lesion to COrticospinal system= loss of descending influences
- Initially spinal/cerebral shock= hypotonia (hence diminished reflexes in early stages of UMN as well)
- Chronic lack of modulation on spinal reflexes= hyperreflexia/spasticity
How do you do a formal assessment of tone
Observation of posture
- palpation of muscle tension
- resistance to rapid passive movt.–> velocity dependent (difference b/q fast and slow)
- Tendon reflexes and babinski
How does spasticity present
- Resistance to stretch–> velocity dependent
- Clonus= rapid stretch at end of range
- Clasp-knife phenomenon= muscle contracting rather than relaxing when lengthening it
- Hyperreflexia
Describe a severe presentation of loss of fractionated movement
- Minimal ability to produce movement at all (movt. at all, through range and in opposite direction)
- Moderate severity of loss of fractionation= influence of abnormal movement synergists
What are normal movement synergies
muscles contract in couples to produce degrees of freedom of movement
What are abnoral movement synergies from UMN
Stereotyped movements that dominate voluntary movement after upper motor neuron lesion
Only certain way that the movt. can occur, not variable, hence stereotyped
What are secondary impairments of UMN syndrome
(separate impairment, not a compulsory part of UMN)
- Contracture
- Loss of PROM
- Secondary to constant positioning in shorted range–> not a compulsory outcome
