MANUAL MUSCLE TESTING MMT DR. SAIMA AZIZ (PT) DPT (KU), MSPT (DUHS), FD-MRT (LASH) Senior Lecturer IPM&R, DUHS LECTURE OUTLINE Principles of manual muscle test Functional classification of muscle Types of manual muscle test Grade of muscle test Assessment, contraindications and precautions of manual muscle testing Factors affecting muscle strength Muscle testing terminology LEARNING OBJECTIVES At the end of the session the participants should be able to: Define muscle strength and their functional implications Discuss basic considerations in performing muscle strength testing Differentiate methods of doing muscle strength testing • Discuss Daniels and Worthingham’s manual muscle testing PRINCIPLES OF MANUAL MUSCLE TESTING DEFINITION Muscle testing is a procedure for evaluating the function and strength of individual muscles and muscle groups, based on effective performance of a movement in relation to the forces of gravity and manual resistance through available range of motion It is an evaluation system for the diagnosis of disease or dysfunction of the musculo-skeletal and nervous systems PURPOSE Diagnostic Examine the improvement or deterioration of a patient’s status over time Determine the extent of strength loss Outcome measures in clinical research Determine the need for compensatory measures or assistive devices Helps in the formulation of the treatment plan AND Evaluates the effectiveness of treatment IMPORTANCE Muscle origin, insertion and action Function of participating muscles Standardized method Proper positioning and stabilization Patterns of substitution Ability to detect contractile activity Ability to palpate muscle or tendon Ability to detect atrophy IMPORTANCE Awareness of deviation from normal ROM , laxity or deformities Identify muscles with the same innervation Relationship of diagnosis to sequence and extent of test Ability to modify test procedures as necessary Effect of fatigue Effect of sensory loss and movement Limitations It has limitations in the neurological disorders, where there is an alteration in muscle tone, altered reflex activity or if there is a loss of cortical control due to lesions of the central nervous system. BASIC CONSIDERATIONS Observation Palpation Positioning Stabilization Resistance Validity and reliability OBSERVATION AND PALPATION • Observe the size and contour of muscles • Palpate contractile tissues POSITIONING • • • • Patient comfort Depends partly on the effect of gravity Use antigravity positions as applicable Two jointed muscles STABILIZATION • Used to isolate the desired action to a specific joint • Stabilize the part proximal to the part being tested • Stabilization of the proximal attachment of the muscle through RESISTANCE Force that acts in opposition to a contracting muscle Applied in the direction opposite the line of pull Must never be sudden or jerky Applied uniformly Long lever arm vs. Short lever arm Break test vs. Active resistance test Break Test • Resistance applied at the end range • Patient is asked to hold the part at a point and examiner “breaks it” Active Resistance Test • Application of manual resistance against actively contracting muscles • Examiner gradually increases resistance until maximum tolerance VALIDITY AND RELIABILITY • Coordinate the muscle testing findings with other standard diagnostic procedures • The amount of pressure used to test may vary between persons performing the test. • Comparison of both sides is a better indicator of loss • Affected by Difference in testing methods Magnitude of resistance Force application, point of application, speed Factors Patient factors Therapist factors Environmental factors Others • Patient Factors – Age – Gender – Pain – Fatigue – Lower motor neuron disease Therapist factors Environmental Experience factors Manner and content Temperature of instructions Interaction Distractions Other factors Muscle factors Psychological factors Methodological factors Subjective Factors Examiner’s Objective Factors impression of the Ability of the patient amount of to move the body part resistance to give against gravity before the actual Ability of the patient examination to complete full range Amount of of motion resistance that Ability of the patient the patient to hold the position tolerates during once at the end of the the actual test range of motion Other Factors Amount of manual resistance applied Ability of the muscle to move the part through the full ROM Effect of gravity MUSCLE TESTING ASSESSMENT PROCEDURE: 1. Explanation and instruction: • The therapist demonstrates and/or explains briefly the movement to be performed and/or passively moves the patient's limb through the test movement. 2. Assessment of normal muscle strength: • Initially assess and record the strength of the uninvolved limb to determine the patient’s normal strength and to demonstrate the movement before assessing the strength of the involved side, considering the factors that affect strength 3. Patient position: • The patient is positioned to isolate the muscle or muscle group to be tested in either gravity elimination or against-gravity position. Ensure that the patient is comfortable and well supported. The muscle or muscle group being tested should be placed in full outer range, with only slight tension. 4. Stabilization: • Stabilize the site of attachment of the muscle origin, so the muscle has a fixed point from which to pull. Prevent substitutions and trick movements by making use of the following methods: • a) The patient's normal muscles: For example, the patient holds the edge of the plinth when hip flexion is tested and uses the scapular muscles when gleno-humeral flexion is performed. b) The patient's body weight: • Used to help fix the shoulder or pelvic girdles. • For example, when assessing hip abduction muscle strength in side lying, the patient holds the non-tested limb in hip and knee flexion in order to tilt the pelvis c) The patient’s posteriorly and fix the pelvis and lumbar spine. position: d) External forces: • May be applied directly by the therapist or by devices such as belt and sandbags. e) Substitution and trick movements: • When muscles are weak or paralyzed, other muscles may take over or gravity may be used to perform movements, normally carried out by the weak muscles. FACTORS AFFECTING 'STRENGTH Age: Strength apparently increases for the first 20 years of life, remains at this level for 5 or 10 years and then gradually decreases throughout the rest of life. The changes in muscular strength by aging are different for different groups of muscles. Gender: Males are generally stronger than females. The strength of males increases rapidly from 2 to 19 years of age at a rate similar to weight and more slowly and regularly up to 30 years. The strength of females is found to increase at a more uniform rate from 9 to 19 years and more slowly to 30 years It has been found that women are more 28 to 30% weaker than men at 40 to 45 years of age. Type of muscle contraction: Muscle size: More tension can be developed during an eccentric contraction than during an isometric contraction. The concentric contraction has the smallest tension capability. The larger the cross-sectional area of a muscle, the greater the strength of this muscle. When testing a muscle that is small, the therapist would expect less tension to be developed than if testing a large, thick muscle. Speed of muscle contraction: When a muscle contracts concentricity, the force of contraction decreases as the speed of contraction increases. The patient is instructed to perform each movement during muscle test at a moderate pace. Previous training effect: Strength performance depends up on the ability of the nervous system to activate the muscle mass. Strength may increase as one becomes familiar with the test situation. The therapist must instruct the patient well, giving him an opportunity to move or be passively moved through the test movement at least once before muscle strength is assessed. Fatigue: As the patient fatigues, muscle strength decreases. The therapist determines the strength of muscle using as few repetitions as possible to avoid fatigue. The patient's level of motivation, level of pain, body type, occupation and dominance are other factors that may affect strength. CONTRAINDICATIONS & PRECAUTIONS Do Not Harm (use gentleness) Know ROM limits Follow procedure Record • Promptly • Accurately Manual assessment of muscle strength is contraindicated where there is: 1. Inflammation in the region. 2. Pain: • as it will inhibit muscle contraction and will not give an accurate indication of muscle strength. Testing muscle strength in the presence of pain may cause further injury. 3. Extra care must be taken where resisted movements might aggravate the condition, as in: • a) Patients with history of or at risk of having cardiovascular problems. • b) Patients who have experienced abdominal surgery or patients with herniation of the abdominal wall to avoid unsafe stress on the abdominal wall. c) Situations where fatigue •May be detrimental to or exacerbate the patients condition. Patients with extreme debility, for example malnutrition, malignancy or severe chronic obstructive pulmonary disease. These patients do not have the energy to carry out strenuous testing. OTHER TEST RESULTS Weakness – defined as a strength below fair in non weight bearing muscles; below fair + in weight bearing muscles Contracture – degree of shortness in muscle, so it cannot move through ROM Substitution – weak muscles are supported by other muscles to move GRADING SYSTEM Numerals Letters Against gravity test 5 Description The patient is able to move through: N (normal) The full available ROM against gravity and against maximal resistance, with hold at the end of the ROM (Hold for about 3 seconds). 4 G (good) 4- G- The full available ROM against gravity and against moderate leading resistance. Greater than one half of the available ROM against gravity and against moderate resistance. 3+ F+ Less than one half of the available ROM against gravity and against moderate resistance. 3 F The full available ROM against gravity. 3- F- Greater than one half of the available ROM against gravity. 2+ P+ Less than one half of the available ROM against gravity. Gravity eliminated test: The patient is able to actively move through: 2 P The full available ROM gravity eliminated. 2- P- Greater than one half the available ROM; gravity eliminated. 1+ T+ Less than one half of the available ROM; gravity eliminated. 1 T (trace) None of the available ROM; gravity eliminated and there is palpable or observable flicker contraction. 0 0 (zero) None of the available ROM; gravity eliminated and there is no palpable or observable MMT: GRADING Normal ( N or 5 ) Full range against maximum resistance and gravity Good ( G or 4 ) Full range against moderate resistance and gravity “Gives” or “yields” at the end of the range given maximum resistance Functional threshold for the lower extremity Fair Plus ( F+ or 3 ) Full range against mild resistance and gravity “Gives” or “yields” to some extent at the end of its range given moderate or maximum resistance For users of orthosis Fair ( F or 3 ) Full range against gravity “Gives” at the end of the range against mild resistance Functional threshold for the upper extremities – Poor ( P or 2 ) • Full range, gravity eliminated – Poor Minus ( P- OR 2 - ) • Partial range gravity eliminated – Trace ( T or 1 ) • Visible or palpable contraction • No movement of the body part – Zero (0) • No visible or palpable contraction CLINICAL APPROACH FOR MMT “CONSIDERATIONS” Always start the test at grade 3 In case a movement needs to be tested in the non-standard position , indicate the position used When in doubt about the grade assigned to a muscle group place a (?) beside the grade Note special cases ( MMT of fingers or toes, UMNL ) Freedom from discomfort or pain Presence of all materials needed for the test REFERENCES • Hislop and Montgomery(2002): Daniels and Worthingham’s Muscle Testing: Techniques of Manual Examination(7th ed) Philadelphia:WB Saunders Company. • Clarkson & Gilewich(1989), Musculoskeletal Assessment. Joint Range of Motion and Manual Muscle Strength: Williams & Wilkins. • Kendall,McCreary, Provance: Muscle Testing and Function (4th ed)Baltimore: Williams and Wilkins, 1993. • Magee(1997) Orthopedic Physical Assessment(3rd ed) Philadelphia: WB Saunders Company. Recommended book for MMT • Techniques of Manual Examination. Helen J.Hislop and Jacqueline Montgomery