MUSCLE TONE AND MANUAL
MUSCLE TESTING
PHT 1261C Tests and Measurements
Dr. Kane
DEFINITIONS
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Tone
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Factors affecting tone
Postural Tone
Hypertonia
Hypotonia
Dystonia
Spasticity – velocity dependent
Clasp knife response
 UMN syndrome
 Clonus
 Babinski Sign
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Rigidity
Lead pipe
 Cogwheel
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DEFINITIONS - CONTINUED
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Hypotonia – flaccidity
LMN syndrome
 Spinal Shock/Cerebral Shock
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Dystonia
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Focal vs. segmental vs. posturing
Decorticate Rigidity
 Decerebrate Rigidity
 Opisthotonus
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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
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EXAMINATION OF TONE
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Initial Observation of resting posture & palpation
Common posturing – see Table 8.1 page 235
 Palpation – consistency, firmness & turgor
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Passive Motion Testing
Responsiveness of muscles to stretch
 Vary speed for spasticity and clonus
 Grading Scale
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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
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SPASTIC HYPERTONIA – MODIFIED
ASHWORTH SCALE
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Gold standard subjective 5 point ordinal scale
Interrater & intrarater reliability is good
Problems:
Inability to detect small changes
 Limited to extremity testing only
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Grades
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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
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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
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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
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Follow proper procedures
Give clear instructions
Demonstrate and explain
Improved with dynamometry
MANUAL MUSCLE TESTING - CONTINUED
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Validity
Palpate muscle
 Proper stabilization
 Prevent substitution muscles or patterns
 Not functional
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MMT USES
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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
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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
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FACTORS THAT CONTRIBUTE TO
EFFECTIVENESS OF MUSCLE CONTRACTION
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Length of muscle when activated
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Type of contraction
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Active insufficiency
Eccentric > Isometric > Concentrically
Muscle Fiber Types
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Type I slow twitch – fatigue resistant
Type II fast twitch – fatigue rapidly
Must consider speed of contraction & resistance
applied
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Type II – require less resistance to reach “normal” grade
Speed of contraction
Increased speed = increased tension ECCENTRIC
 Increased speed = decreased tension CONCENTRIC
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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.
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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
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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
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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
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GM – muscle contracts parallel to gravitational force
 AG – muscle contract against the downward
gravitational force
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Grades are dependent on: age, sex, body build,
occupation, etc.
FACTORS AFFECTING MMT RESULTS
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Fatigue
Joint ROM limitations
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Pain
Subjectivity
Positions –AG/GM
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Range
Palpation
Resistance –break or make method
Stabilization
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Range grade/strength grade (-20 degrees/4 (good)
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
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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
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