2.9 Tone and Reflexes Flashcards
tone
- amount of tension a muscle has at rest
- resting tone works against gravity to hold our limbs in position
resting threshold of tone
always signals going to muscle and up and down the spinal cord
What does someone who has high resting tone need to get to normal “relaxed”?
needs a lot of inhibitory signals to get to relaxed
What does someone with low resting tone need to get to contraction?
needs a lot of excitatory signals to contract the muscle
types of tone
- normal
- hyper
- hypo
two categories of hypertonicity
- spasticity
- rigidity
Spasticity is dependent upon
velocity
How is spasticity velocity dependent?
- if you move the limb slowly, can get through full ROM
- moving it quickly will increase the contraction
types of spasticity
- clonus
- spasms
- dystonia
- spastic co-contraction
What is the scale used to grade spasticity?
Ashworth scale
clonus
- UMN problem, usually found in distal extremities
- put a stretch on the muscle, it excites it
- unless you move them out of the position that produced the clonus, it potentiates itself and continues
- typically not a detriment to therapy
How do we refer to clonus?
by how many beats it has
spasm
involuntary contraction
spasm and therapy
typically not a detriment to therapy unless every time they do a motion, it creates a spasm
- constant twitching in the eyelid
- can get to where they become blind
blepharospasms
type of spasticity where we don’t really know why they have it
dystonia
dystonia
- can range from full body, cervical (torticollis), other areas
- not a clear cut definition
- affects number of different age groups
Who commonly gets spastic co-contraction?
CP
How does spastic co-contraction affect gait?
agonists and antagonists are both firing at the same time, can’t create coordinated, smooth movement
using spasms to advantage
a patient can figure out how to elicit and manipulate their spasms to facilitate a certain movement
rigidity and the brain
- UMN lesions
- flow through pyramidal tracts
rigidity and velocity
- not velocity dependent
- resistance to movement is present at low speed joint movement
- don’t have to hit certain velocity of movement or joint angle to get it to catch
two types of rigidity
- cog wheel
- lead pipe
cog wheel rigidity
“ratchet” action
puuuuuush then pop.
lead pipe rigidity
- don’t get it to move
- like trying to bend a lead pipe
How is rigidity similar to spastic co-contraction?
typically have agonist and antagonist contractions at the same time
movement of distal or proximal joints: spasticity and rigidity
spasticity: movement around rigid joint may elicit more spasticity
rigidity: movement around rigid joint doesn’t elicit more rigidity
Rigidity: if you’re able to get any additional ROM, what happens?
it will stay there
rigidity leads to
- loss of ROM
- loss of function » falls
problem with hypotonicity
flaccidity
flaccidity: lesion location
- LMN lesions
- extrapyramidal tracts
DTR levels: biceps
C5-C6
DTR levels: brachioradialis
C5-C6
DTR levels: triceps
C6-C8
DTR levels: patellar
L2-L4
DTR levels: plantar (achilles)
S1-S2
normal for reflexes:
2+
higher than normal reflexes
3+
clonus
5+
When should we be concerned about DTR?
if there’s a consistent difference between sides
reflexes other than DTR
- abdominal
- cremasteric
- bulbocavernous
- anal sphincter
abdominal reflex
- scratch skin of abdomen
- umbilicus moves
cremasteric
- only SCI
- stroking of proximal thigh skin creates scrotal lift
bulbocavernous
- only SCI
- grab tip of penis, pinch, pull
- will get a contraction of the penis trying to contract back in
anal sphincter
- only SCI
- anal wink test
abnormal reflexes
- jaw
- snout
- glabellar
- Hoffman’s
abnormal reflexes: jaw
- CN V
- stretches masseter, teeth clamp down
- CN involvement with MS
abnormal reflexes: snout
- CN VII
- upper lip creates puckering
abnormal reflexes: glabellar
- CN VII
- repeatedly tap the forehead between the eyebrows
- usually blink a lot
abnormal reflexes: Hoffman’s
median nerve
