Muscle Tone Assessment

Question 1

• resistance of m. to passive elongation or stretch

- resistance increases with increasing amplitude and velocity of passive stretch

Answer 1

increased m. tone/spasticity (velocity dependent)

• caused by hyper-excitability of the stretch reflex
• sign of UMN damage

Question 2

what diagnoses do you most often see spasticity?

Answer 2

UMN damage: CP, stroke, MS, SCI

Question 3

simple way to differentiate spasticity and rigidity

Answer 3

increase speed when testing:

• spasticity will change with increasing speed
• rigidity will not feel different with increasing speed

Question 4

if spasticity occurs which tracts/pathways are likely damaged?

Answer 4

lateral corticospinal tracts

Question 5

what is clasp knife spasticity?

Answer 5

• 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

Question 6

clonus

Answer 6

muscular spasm involving repeated (often rhythmical) contractions

Question 7

what part of the body do you observe clonus?

Answer 7

most commonly tested at the ankle (forced DF while relaxed) but can be seen elsewhere including jaw, wrist, patella, etc.

Question 8

resistance to passive movements involving both agonist and antagonist muscles (both directions whether or not the m. is on stretch)

Answer 8

rigidity (not velocity dependent)

Question 9

cardinal sign observed in Parkinson’s disease

Answer 9

rigidity

Question 10

ratchet-like jerks

Answer 10

cogwheel rigidity (seen more in UE with PD)

Question 11

rigidity posturing

Answer 11

• decorticate (flex UE)

- decerebrate (ext UE, worse prognosis)

Question 12

decreased m. tone

Answer 12

hypotonia or flaccidity

Question 13

does hypotonia/flaccidity occur b/c of LMN or spinal shock?

Answer 13

spinal shock; 24-48 hrs of hypotonia and absent DTRs followed by hypertonia and exaggerated DTRs

Question 14

hyperkinetic movement disorder characterized by tone and involuntary repetitive twisting (writhing motions) movement in large portions of the body

Answer 14

dystonia (impaired tone)

Question 15

tone varies and is affected by:

Answer 15

• volitional movement
• stress, anxiety
• position
• medication
• health
• environmental temp.
• state of the CNS (arousal, alertness)

Question 16

procedure for assessing m. tone

Answer 16

• 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

Question 17

Modified Ashworth Scale

Answer 17

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

Question 18

DTR scoring/scale

Answer 18

0 = absent
1+ = present, but depressed
2+ = normal
3+ = brisk
4+ = very brisk, hyperactive with clonus

Question 19

major pathological reflexes

Answer 19

babinski and hoffman’s sign

Question 20

reflexes present in infancy that become integrated by CNS; obligatory responses that dominate motor behavior are always considered pathological

Answer 20

primitive reflexes

Question 21

synergistic patterns

Answer 21

• 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

Question 22

MMT validity with neuro conditions

Answer 22

• based on movement capabilities
• isolated movement may not be possible
• in that case, MMT is not reliable or valid

Question 23

inhibits isolated movements making MMT unreliable/not valid

Answer 23

presence of synergies, spasticity, abnormal posturing, contractures

Question 24

how to estimate strength if MMT is unreliable/not valid

Answer 24

• observation of active movement (i.e. squats, sit to stands, heel raises/toe raises)
• modified MMT position documented in notes