M USCLE T ONE AND M ANUAL M USCLE T ESTING PHT 1261C Tests and Measurements Dr. Kane

D EFINITIONS Tone Factors affecting tone Postural Tone Hypertonia Hypotonia Dystonia Spasticity – velocity dependent Clasp knife response UMN syndrome Clonus Babinski Sign Rigidity Lead pipe Cogwheel

D EFINITIONS - CONTINUED Hypotonia – flaccidity LMN syndrome Spinal Shock/Cerebral Shock Dystonia Focal vs. segmental vs. posturing Decorticate Rigidity Decerebrate Rigidity Opisthotonus

V ARIATIONS IN T ONE 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

E XAMINATION OF T ONE 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

S PASTIC H YPERTONIA – M ODIFIED A SHWORTH S CALE 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

D EEP T ENDON R EFLEXES 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

M ANUAL M USCLE T ESTING 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

M ANUAL M USCLE T ESTING - CONTINUED Validity Palpate muscle Proper stabilization Prevent substitution muscles or patterns Not functional

MMT U SES 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

F ACTORS THAT C ONTRIBUTE TO E FFECTIVENESS OF M USCLE C ONTRACTION 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

A NATOMICAL F ACTORS THAT AFFECT M USCLE C ONTRACTION 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.

E VALUATING S KELETAL M USCLE S TRENGTH 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

F ACTORS TO C ONSIDER 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

F ACTORS A FFECTING G RADING 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.

F ACTORS AFFECTING MMT R ESULTS 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

P ROCEDURE F OR S PECIFIC 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