MUSCLE TONE AND MANUAL MUSCLE TESTINGPHT 1261C Tests and Measurements

Dr. Kane

DEFINITIONS

Tone Factors affecting tone Postural Tone Hypertonia Hypotonia Dystonia

Spasticity – velocity dependent Clasp knife response UMN syndrome Clonus Babinski Sign

Rigidity Lead pipe Cogwheel

DEFINITIONS - CONTINUED

Hypotonia – flaccidity LMN syndrome Spinal Shock/Cerebral Shock

Dystonia Focal vs. segmental vs. posturing

Decorticate Rigidity Decerebrate Rigidity Opisthotonus

VARIATIONS IN TONE

Volitional Effort and movement Stress and anxiety Position and interaction of tonic reflexes Medications General Health Environmental temperatures State of CNS arousal or alertness Urinary bladder status Fever/infection Metabolic or Electrolyte imbalances

EXAMINATION OF TONE

Initial Observation of resting posture & palpation Common posturing – see Table 8.1 page 235 Palpation – consistency, firmness & turgor

Passive Motion Testing Responsiveness of muscles to stretch Vary speed for spasticity and clonus Grading Scale

0 = no response (flaccidity) 1+ = decreased response (hypotonia) 2+ = Normal response 3+ = exaggerated response (mild to moderate hypertonia) 4+ = sustained response (severe hypertonia)

Active Motion Testing/Special Tests Pendulum test Myotonometer

SPASTIC HYPERTONIA – MODIFIED ASHWORTH SCALE

Gold standard subjective 5 point ordinal scale Interrater & intrarater reliability is good Problems:

Inability to detect small changes Limited to extremity testing only

Grades 0 = no increase in muscle tone 1 = slight increase in muscle tone; catch & release 1+ = slight increase in tome with catch & minimal

resistance through rest of range 2 = marked increase in tone through most of ROM 3 – considerable increase in tone; passive motion

difficult 4 = affected parts rigid in flexion or extension

DEEP TENDON REFLEXES

Table 8.3 page 237 O’Sullivan Grading Scale

0 = no response 1+ = present but depressed, low normal 2+ = Average, normal 3+ = Increased, brisker than average; possibly

but not necessarily normal 4+ = very brisk, hyperactive with clonus;

abnormal Increased with UMN lesions; decreased with

LMN Reinforcement maneuvers

MANUAL MUSCLE TESTING

Palmer Chapter 2 Not applicable for strength testing in patients

who lack voluntary or active control of muscular tension (e.g. CNS disorders)

Not appropriate for spasticity May get inaccurate results due to gravity

and activation of stretch reflex Reliability – ½ grade intertester is acceptable

Follow proper procedures Give clear instructions Demonstrate and explain Improved with dynamometry

MANUAL MUSCLE TESTING - CONTINUED

Validity Palpate muscle Proper stabilization Prevent substitution muscles or patterns Not functional

MMT USES

1. Establish a basis for muscle re-ed and exercise; Develop plan of care Show progress Shows effectiveness of treatment Additional information before muscle transfer

surgery 2. Determines how functional a patient can

be. 3. Determines a pt.'s needs for supportive

apparatus – orthoses, splints, assistive devices

4. Helps determine a diagnosis. 5. Determines pt.'s prognosis

FACTORS THAT CONTRIBUTE TO EFFECTIVENESS OF MUSCLE CONTRACTION

Length of muscle when activated Active insufficiency

Type of contraction Eccentric > Isometric > Concentrically

Muscle Fiber Types Type I slow twitch – fatigue resistant Type II fast twitch – fatigue rapidly Must consider speed of contraction & resistance

applied Type II – require less resistance to reach “normal” grade

Speed of contraction Increased speed = increased tension ECCENTRIC Increased speed = decreased tension CONCENTRIC

ANATOMICAL FACTORS THAT AFFECT MUSCLE CONTRACTION

Number of motor units per muscle Functional excursion Cross sectional Area Line of pull of muscle fibers Number of joints crossed Sensory receptors Attachments to bone & relationship to joint

axis Age of pt. Sex of pt.

EVALUATING SKELETAL MUSCLE STRENGTH

Anatomical, physiological, & biomechanical knowledge of skeletal muscle positions and stabilization

Elimination of substitution motions Skill in palpation & application of resistance Careful direction for each movement that is

easily understood by the patient Adherence to a standard method of grading

muscle strength Experience testing many individuals with

normal muscle strength & varying degrees of weakness

FACTORS TO CONSIDER IN MMT

Weight of limb or distal segment with minimal effect of gravity (GM)

Weight of limb plus the effects of gravity (AG) Weight of limb plus gravity plus manual

resistance

FACTORS AFFECTING GRADING OF MMT

Amount of manual resistance applied (opposite torque exerted by muscle)

Ability of muscle to move through complete ROM

Evidence of presence or absence of muscle contraction by palpation & observation

Gravity and manual resistance GM – muscle contracts parallel to gravitational

force AG – muscle contract against the downward

gravitational force Grades are dependent on: age, sex, body

build, occupation, etc.

FACTORS AFFECTING MMT RESULTS Fatigue Joint ROM limitations

Range grade/strength grade (-20 degrees/4 (good) Pain Subjectivity Positions –AG/GM

Range Palpation Resistance –break or make method

Stabilization Provides support Prevents substitution motions

Substitution Recording measurements

PROCEDURE FOR SPECIFIC MMT

Position in AG position & stabilize – see page 31 Expose body part & drape appropriately Explain the test and demonstrate to patient Determine available ROM

PROM or AROM; test range; possibly goniometry Align body part to direction of muscle fibers Stabilize proximal segment Have patient move distal segment through test

ROM or hold at end range of motion Observe and palpate muscle belly Apply resistance – end range or through range Record grade & date & initial; document in SOAP