Testing muscle function L12 Flashcards
The motor system can be divided into
pyramidal
extrapyramidal
Where do most UMN of the corticospinal tract decussate
medulla
Where do not many UMN of the corticospinal tract decussate
Level in the spinal cord
Further inputs to the motor system=
pre-motor cortex
Cerebellum
Directly (spinal reflexes)
LMN innervate
skeletal muscle
Extrapyramidal system involved in
reflexes
balance/ co-ordination
postural control
fine control of complex movement
UMN lesions are in
the brain or spinal cord
UMN lesions result in
muscle weakness
increased muscle tone
Exaggerated reflexes
babinski
LMN result in
muscle weakness reduced muscle tone (flaccidity) Diminished/ absent reflexes muscle atrophy Fasciculation
Extrapyramidal lesions (basal ganglia) =
Dystonia
Akathisia
Parkinsonism
Dyskinesia
Dystonia=
continous spasms
akathisia=
motor restlessness
Parkinsonism=
rigidity, bradykinesia, tremor
Dyskinesia=
irregular jerky movements
Cerebellar lesions=
ipsilateral loss of coordination Past-pointing Disdiadochokinesia ataxic gate ect
Disdiadochokinesia=
can’t change direction in movements)
Causes of UMN lesions
Stroke
MS
Brain injury
Cerebral palsy
Causes of LMN lesions
Bell’s palsy (C7)
Guillan- barre syndrome
Motor neuron disease
Brown-sequards syndrome=
damage to one half of the spinal cord
Brown- sequards causes—>
Loss of ipsilateral fine touch/ proprioception
Loss of contralateral pain/ temp
Anterior cord syndrome –>
loss of pain/ temp
Preserved fine touch/ proprioception
central cord syndrome–>
variable sensory loss
motor deficits greater in upper limb than lower
Isometeric contraction
muscle activated held at a constant length
isotonic contraction
contraction against natural resistance
Isotonic contraction can be
concentric or eccentric
Concentric=
shortening
eccentric=
lengthening
