MANUAL MUSCLE TESTING The clinical assessment procedure is

MANUAL MUSCLE TESTING The clinical assessment procedure is used to grade the strength of muscle in relation to the forces of gravity and manual resistance Joe Schoess, PT, DPT, OCS

MMT Pioneers Dr. Robert Lovett and Wilhelmina Wright (1920’s) • Introduced MMT, origin stems from the Rx of poliomyelitis • Their system had 3 grades • Normal / Partially Paralyzed / Wholly paralyzed Daniels & Worthingham (1940’s) • Developed against gravity and gravity eliminated positions Henry and Florence Kendall • Refined techniques with % grading • Published 1 st edition of their text in 1949 Florence Kendall (1919~2006) is considered an icon in Phys Therapy She was born in Warman MN, the 11 th child of Swedish immigrants

Conditions with marked weakness • Polio • Spinal cord injury (SCI) • Physical impairments associated with stroke • Multiple sclerosis (MS) • Peripheral nerve injury (PNI) • Tendon/muscle injury and surgery • Other? ? ?

Objectives / Aims • Understand MMT procedures and terminology consistent with Kendall text • Identify factors that influence testing procedures • Apply MMT grading system to objectify strength • Deliver a MMT break test (isometric contraction)

Manual Muscle Testing: Considerations • MMT is a clinical method used to quantify (grade) strength • The grading system has been standardized, and for the most part, has been accepted across medical professions • Though the grading system has been standardized, the delivery of the resistive force and the interpretation of a muscle’s response remains somewhat open for debate • For example, can anyone really define ‘normal’ strength?

Additional Considerations Muscle strength is quantified in clinical practice • To guide judgments on diagnosis, prognosis, & treatment • To measure progress, and assess the efficacy of treatment Listed below are other strength measurement tools • Hand held devices (myometer) • Free weight, and isotonic rep-max testing methods • Isokinetic and isometric strength testing machines • Others ? ? ?

Terminology • Test position: describes how the patient is position • Gravity eliminated or against gravity • Fixation: methods used to support the extremity or sometimes, to apply counter-pressure • Manual resistance: the gradual application of force delivered in the opposing direction of the muscle being tested • Break test: isometric resistance with gradual build up until point the patient’s resistance is overcome • Substitutions: compensations in posture, position or movement displayed by the patient during testing • Caused by weakness, poor instructions, inadequate fixation

Quantifying Strength • Isotonic • Testing strength with constant external resistance • Isokinetic • Resistance through ROM at a constant velocity • Isometric* • Generate force against an immovable resistance • MMT • Hand held dynamometry

How Do We Use MMT? • MMT is used as an evaluation tool and to indicate functional performance • MMT provides us with information to assist with differential diagnosis, prognosis, and treatment • MMT serves as a method of measuring progress to establish efficacy of our treatments

Background Information • Anatomy: • surface • bony landmarks • muscles • • origins insertions actions Innervations

Grading Systems • Accuracy in grading involves proper positioning, application and direction of resistance, fixation of the patient • Grade by • Letter: • Number: 0 T P F G N 0 1 2 3 4 5 • Percentages- 0%, 5%, 20%, 50%, 80%, 100%

Number System • 0: no contraction • 1: contraction without movement (T) • 2 -: partial movement in horizontal plane • 2: full movement in horizontal plane (P) • 2+: hold against minimal resistance in horizontal plane (gravity-eliminated position) • 2+: partial ROM against gravity

Number System Cont • 3 -: gradual release from gravity test position • 3: holds test position without resistance(F) • 3+: holds test position with minimal resistance • 4: holds test position with moderate resistance (G) • 5: holds test position with max resistance (N)

Letter System • 0: No evidence of muscle contraction • Trace: Palpable muscle contraction • Poor: Movement in horizontal plane • Fair: Can hold part against gravity, but not against resistance • Good: Can hold against moderate resistance • Normal: Can hold against maximum resistance

Other Factors • Gravity • factor in grades above a grade 2 • factor in about 60% of the extremity muscles • Not a factor in smaller mm ex wrist, fingers, toes • a one-test position is used when gravity is not a factor • slightly different grading system • specific muscles

One-Test Position GRADING SCALE • utilized with muscles where gravity has little effect on joint • 0: no muscle contraction • 1: muscle contraction without movement • 2: partial ROM • 3: full ROM without resistance • 3+: full ROM with minimal resistance • 4: full ROM with moderate resistance • 5: full ROM with max resistance

Other Factors • Pain • ROM limitations • Spasticity • Fatigue • Patient population: geriatrics & pediatrics • Mobility Limitations

MMT Basic Rules • Subject position: position needs to offer best fixation of the body part being tested • Stabilize: typically done proximal to the part being tested • Test position: patient positioned to maximize the effect of gravity on the muscle being tested. Test here first if possible • Test position: utilize the horizontal plane whenever testing muscles too weak for against-gravity testing • 1 -joint muscles: end-range joint position • 2 -joint muscles: mid-range joint position

MMT Basic Rules • Apply resistance: in the opposite direction of the muscle being tested • Speed of resistance: gradually apply resistance to the muscle • Allow patient to “get set and hold. ” • Long lever arm: use whenever possible for better strength discrimination • Short lever arm: use if accessory muscle(s) do not provide sufficient stabilization

MMT: Real world application Verify that there are no precautions or contraindications Obtain permission and feedback (both verbal and non-verbal) from patient before and during testing Use the correct test position for the targeted muscle(s) Verify that your patient can use the muscle to move a joint through full ROM Use methods of touch to help the patient identify the muscle targeted for testing Use appropriate WIDE hand placements and grips, and deliver an appropriate application of force during testing Perform a BREAK test method of assessment Compare strength results to the contralateral side Score and correctly interpret the results with words or letters of the interval grading scales and become proficient in scoring results with both methods

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