Muscle Tone Assessment Flashcards
- resistance of m. to passive elongation or stretch
- resistance increases with increasing amplitude and velocity of passive stretch
increased m. tone/spasticity (velocity dependent)
- caused by hyper-excitability of the stretch reflex
- sign of UMN damage
what diagnoses do you most often see spasticity?
UMN damage: CP, stroke, MS, SCI
simple way to differentiate spasticity and rigidity
increase speed when testing:
- spasticity will change with increasing speed
- rigidity will not feel different with increasing speed
if spasticity occurs which tracts/pathways are likely damaged?
lateral corticospinal tracts
what is clasp knife spasticity?
- type of spasticity
- initially high resistance but then lets go at end of joint range (more than a catch)
- seen most when flexing a joint/stretching an extensor (triceps, quads)
- no Ashworth number
clonus
muscular spasm involving repeated (often rhythmical) contractions
what part of the body do you observe clonus?
most commonly tested at the ankle (forced DF while relaxed) but can be seen elsewhere including jaw, wrist, patella, etc.
resistance to passive movements involving both agonist and antagonist muscles (both directions whether or not the m. is on stretch)
rigidity (not velocity dependent)
cardinal sign observed in Parkinson’s disease
rigidity
ratchet-like jerks
cogwheel rigidity (seen more in UE with PD)
rigidity posturing
- decorticate (flex UE)
- decerebrate (ext UE, worse prognosis)
decreased m. tone
hypotonia or flaccidity
does hypotonia/flaccidity occur b/c of LMN or spinal shock?
spinal shock; 24-48 hrs of hypotonia and absent DTRs followed by hypertonia and exaggerated DTRs
hyperkinetic movement disorder characterized by tone and involuntary repetitive twisting (writhing motions) movement in large portions of the body
dystonia (impaired tone)
tone varies and is affected by:
- volitional movement
- stress, anxiety
- position
- medication
- health
- environmental temp.
- state of the CNS (arousal, alertness)
procedure for assessing m. tone
- palpate m. belly
- PROM, speed up as you go
- all limbs/joints
- compare R and L
- compare UE and LE
- cue pt to stay relaxed
Modified Ashworth Scale
0 = no inc. in m. tone 1 = slight inc. in m. tone, manifested by catch and release or by minimal resistance at end ROM when moved in flex/ext 1+ = slight inc. in m. tone manifested by a catch followed my minimal resistance throughout less than half of the ROM 2 = marked inc. in m. tone through most of ROM, but affected parts easily moved 3 = considerable inc. in m. tone, passive movement difficult 4 = affected parts rigid in flex/ext
DTR scoring/scale
0 = absent 1+ = present, but depressed 2+ = normal 3+ = brisk 4+ = very brisk, hyperactive with clonus
major pathological reflexes
babinski and hoffman’s sign
reflexes present in infancy that become integrated by CNS; obligatory responses that dominate motor behavior are always considered pathological
primitive reflexes
synergistic patterns
- abnormal obligatory movements that emerge with spasticity
- inability to perform isolated movements at each joint
- PT records when patterns occur, under what circumstances, and variations observed
- flexion/extension synergies of UE and LE
MMT validity with neuro conditions
- based on movement capabilities
- isolated movement may not be possible
- in that case, MMT is not reliable or valid
inhibits isolated movements making MMT unreliable/not valid
presence of synergies, spasticity, abnormal posturing, contractures
how to estimate strength if MMT is unreliable/not valid
- observation of active movement (i.e. squats, sit to stands, heel raises/toe raises)
- modified MMT position documented in notes
