first lecture of MMT.pdf

Evaluation and Measurement (Manual Muscle Test) Dr. Mohamed Naeem Ass.Prof of Physical Therapy Basic Science DEFINITION OF MMT: Manual muscle testing is a procedure for the evaluation of the function and strength of individual muscles and muscles group based on effect...

Evaluation and Measurement (Manual Muscle Test) Dr. Mohamed Naeem Ass.Prof of Physical Therapy Basic Science DEFINITION OF MMT: Manual muscle testing is a procedure for the evaluation of the function and strength of individual muscles and muscles group based on effective performance of a movement in relation to the forces of gravity and manual resistance through the available ROM. Purposes and uses of MMT: 1. The severity of problem can be understand. (It is diagnostic Tool) 2. Determine the extend & degree of muscular weakness resulting from disease or injury. 3. The therapist must be a keen observer and be experienced in muscle testing to detect minimal muscle contraction, movement, muscle wasting and substitutions or trick movements. 4. We can planning our treatment goals as patient's present status and progress 5. MMT is an Important tool for all the members of the Rehabilitation team. 6. Prevents deformities by locating problem areas. 7. Help and Evaluate effectiveness of treatment to the therapist. DEFINITION OF Terms Muscular strength: The maximal amount of tension or force that a muscle or muscle group can voluntarily exert in a maximal effort; when type of muscle contraction, limb velocity and joint angle are specified. Muscular endurance: The ability of a muscle or a muscle group to perform repeated contractions against resistance or maintain an isometric contraction for a period of time.  Type of muscle contraction 1. Isometric contraction: Tension is developed in the muscle but no movement occurs; the origin and insertion of the muscle do not change their positions and hence, the muscle length does not change. 2. Isotonic contraction: The muscle develops constant tension against a load or resistance. There are two types: a) Concentric contraction: Tension is developed in the muscle and the origin and insertion of the muscle move closer together; so the muscle shortens. b) Eccentric contraction: Tension is developed in the muscle and the origin and insertion of the muscle move further a part; so the muscle lengthens.  RANGE OF MUSCLE WORK: The full range in which a muscle work refers to the muscle, changing from a position of full stretch and contracting to a position of maximal shortening. The full range is divided into three parts: 1. Outer range: From a position where the muscle is fully stretched to a position halfway through the full range of motion. 2. Inner range: From a position halfway through the full range of motion to a position where the muscle is fully shortened. 3. Middle range: The portion of the full range between the mid-point of the outer range and the midpoint of the inner range.  GROUP OF MUSCLE ACTION: 1. Prime mover or agonist: A muscle or muscle group that makes the major contribution to movement at the joint. 2. Antagonist: A muscle or a muscle group that has an opposite action to the prime movers. The antagonist relaxes as the agonist moves the part through a range of motion. 3. Synergist: A muscle that contracts and works along with the agonist to produce the desired movement. There are three types of synergists: a)Neutralizing or counter-acting synergist b) Conjoint synergist c) Stabilizing or fixating synergist a) Neutralizing or counter-acting synergists: Muscles contract to prevent any unwanted movement produced by the prime mover. For example, when the long finger flexors contract to produce finger flexion, the wrist extensors contract to prevent wrist flexion from occurring. b) Conjoint synergists: Two or more muscles work together to produce the desired movement. For example, Knee flexion c) Stabilizing or fixating synergists: These muscles prevent or control the movement at joints proximal to the moving joint to provide a fixed or stable base, Active insufficiency: The active insufficiency of a muscle that crosses two or more joints, occurs when the muscle produces movement at all of the joints it crosses and reaches such a shortened position that it no longer has the ability to develop effective tension. When a muscle is placed in a shortened position of active insufficiency it is described as putting the muscle on slack.  Muscle testing assessment procedure: 1) EXPLANATION & INSTRUCTION: The therapist demonstrate 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 STRENGHT: Always assess and record the strength of the unaffected side limb to determined the patient’s normal strength. 3) Patient position 3) STABILIZATION: I. PROXIMAL HAND – At Origin of muscle & proximal joint giving stabilization. II. DISTAL HAND – Distally offering resistance or Assistance depend upon performance. ❖ The plinth or mat table for testing must be firm to help stabilize the part being tested.  The site of attachment of the muscle origin should be stabilized, so the muscle has a fixed point from which to pull. Substitutions and trick movements are avoided 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: It is used to help fix the proximal parts (shoulder or pelvic girdles) during movement of the distal ones. c) The patient’s position: For example, when assessing hip abduction strength in side lying, the patient holds the non-tested limb in hip and knee flexion in order to tilt the pelvis posteriorly and to fix the pelvis and lumbar spine. d) External forces: They may be applied manually by the therapist or mechanically by devices such as belts and sandbags. 5 ) 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.  BREAK TEST: ▪ Resistance applied at the end of tested range is termed as BREAK TEST. ▪ For one joint muscle resistance is applied at End of ROM. ▪ The isometric hold (break test) shows the muscle to have a higher grade than the make test. Active Resistance Test An alternative to the break test is the application of manual resistance against an actively contracting muscle or muscle group APPLICATIONS OF RESISTANCE: Resistance is applied slowly & gradually. Increasing or decreasing manual resistance. Increasing length of weight arm. Apply presence opposite to the line of pull (Grade 4,5) Apply force distally. It varies between the persons. Use long lever to applied resistance whenever it possible. 4) CONVENTIONAL METHODS: Manual grading of muscle strength is based on three factors: * Evidence of contraction: No palpable or observable muscle contraction (grade 0) or a palpable or observable muscle contraction with no joint motion (grade 1). * Gravity as a resistance: The ability to move the part through the full available range of motion with gravity eliminated (grade 2) or against gravity (grade 3). * Amount of manual resistance: The ability to move the part through the full available range of motion against gravity and against moderate manual resistance (grade 4) or maximal manual resistance (grade 5). * Adding (+) or (-) to the whole grades: This is needed to denote variation in the range of motion. Movement through less than half of the available range of motion is denoted by a “+” (outer range), while movement through greater than half of the available range of motion is denoted by “-“ (inner range). CONVENTIONAL GRADING: Numerals Letters Description Against gravity tests: The patient is able to move through: 5 N (normal) The full available ROM against gravity and against maximal leading resistance, with hold at the end of the ROM (for about 6 seconds). 4 G (good) The full available ROM against gravity and against moderate manual resistance. 4- G - (good -) Greater than one half of the available ROM against gravity and against moderate manual resistance. 3+ F + (fair +) Less than one half of the available ROM against gravity and against minimal manual resistance. 3 F (fair) The full available ROM against gravity. 3- F - (fair -) Greater than one half of the available ROM against gravity. 2+ P + (poor +) Less than one half of the available ROM against gravity. Gravity eliminated tests: The patient is able to actively move through: 2 P (poor) The full available ROM with gravity eliminated. 2- P - (poor -) Greater than one half the available ROM with gravity eliminated. 1+ T + (trace +) Less than one half of the available ROM with gravity eliminated. 1 T (trace) None of the available ROM with gravity eliminated and there is palpable or observable flicker contraction. 0 0 (zero) None of the available ROM with gravity eliminated and there is no palpable or observable muscle contraction.  SCREENING TEST: A screen test is a method used to control muscle strength assessment, avoid unnecessary testing and avoid fatiguing and / or discouraging the patient. The therapist may screen the patient through the information gained from: 1. The previous assessment of the patient's active range of motion. 2. Reading the patient's chart or previous muscle test result. 3. Observing the patient while performing functional activities. For example, shaking the patients hand may indicate the strength of grasp (finger flexors). 4. All muscle testing procedures must begin at a particular grade; this is usually grade “fair”. The patient is instructed to actively move the body part through full range of motion against gravity. Based upon the results of this initial test, the muscle test is either stopped or proceeds.  FACTORS AFFECTING STRENGTH: 1). Age: A decrease in strength occurs with increasing age due to deterioration in muscle mass. Muscle fibers decrease in size and number; there is an increase in connective tissue and fat and the respiratory capacity of the muscle decreases. 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. The progressive decrease in strength is clearer in the forearm flexors and muscles that raise the body (anti-gravity muscles). 2). Sex: Males are generally stronger than females. 3) Type of muscle contraction: More tension can be developed during an eccentric contraction than during an isometric contraction. The concentric contraction has the smallest tension capability. 4) Muscle size: The larger the cross-sectional area of a muscle, the greater the strength of this muscle will be. When testing a muscle that is small, the therapist would expect less tension to be developed rather than if testing a large, thick muscle. 5) Speed of muscle contraction: When a muscle contracts concentrically, 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. 6) 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. 7). Joint position: It depends on the angle of muscle pull and the length-tension relationship. The tension developed within a muscle depends upon the initial length of the muscle. Regardless of the type of muscle contraction, a muscle contracts with more force when it is stretched than when it is shortened. The greatest amount of tension is developed when the muscle is stretched to the greatest length possible within the body (if the muscle is in full outer range). 8). 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.