Manual Muscle Testing PDF

# Manual Muscle Testing ## Dr. Mohammed Elsayed PhD ### Objectives of the Lecture By the end of this lecture the student will be able to: * Define manual muscle testing. * Identify the purpose of muscle testing. * Recognize terminology related to muscle testing (strength, endurance, range of mu...

# Manual Muscle Testing ## Dr. Mohammed Elsayed PhD ### Objectives of the Lecture By the end of this lecture the student will be able to: * Define manual muscle testing. * Identify the purpose of muscle testing. * Recognize terminology related to muscle testing (strength, endurance, range of muscle work, active and passive insufficiency, isometric, concentric and eccentric contraction). * List functional classification of muscles (agonists, antagonists, synergists). * Recognize elements for assessment of normal muscle strength (patient's position, stabilization, substitution). * Highlight the role and effect of gravity in muscle testing. * Recognize factors affecting strength. * Manipulate the grading system * Know precautions and contraindications of muscle testing. ### Definition 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. ### Purpose of Muscle Test * To provide **information** that may be of assistance to a number of health professionals in differential diagnosis, treatment planning and prognosis. * To assess muscle strength, the therapist must have a sound knowledge of anatomy and **surface anatomy**. * The therapist must be a keen observer and be experienced in muscle testing to detect minimal muscle contraction, movement, and/or muscle wasting and substitutions or **trick movements**. * A consistent method of manually testing muscle strength is essential to assess accurately a patient's present status, progress, and the effectiveness of the treatment program. ### Muscular strength It is the maximal amount of **tension** or force that a muscle or muscle group can voluntarily exert in **one 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 the isometric contraction for a period of time. ### 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 parts, outer, inner, and middle ranges. * **Outer range:** Is from a position where the muscle is on full stretch to a position halfway through the full range of motion. * **Inner range:** Is from a position halfway through the full range to a position where the muscle is **fully shortened**. * **Middle range:** Is the portion of the full range between the **mid-point** of the outer range and the **midpoint** of the inner range. ### Active Insufficiency: The active insufficiency of a muscle that crosses two or more joints, occurs when the muscle produces simultaneous 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**. ### Passive insufficiency: When the two joint muscle is lengthened over the two joint at the same time it will cause pain after certain limit as touch toes from standing. ### Isometric (static) contraction: This is when there is tension developed in the muscle but no movement occurs, the origin and insertion of the muscle do not change position, and the muscle length does not change. ### Concentric contraction: Tension is developed in the muscle when the origin and insertion of the muscle move closer together, the muscle shortens. ### Eccentric contraction: Tension is developed in the muscle when the origin and insertion of the muscle move farther apart, the muscle lengthens. ### Functional Classification of Muscle: Muscles may be categorized as follows, according to the major role of the muscles in producing the movement. * **Prime Mover or agonist:** It is the muscle or muscles group that makes the major contribution to movement at the joint. * **Antagonist:** It is the muscle or muscles group that has an opposite action to the prime mover. The antagonist relaxes as the agonist moves the part through a ROM. * **Synergist:** It is the muscle that contracts and works a long with the agonist to produce the desired movement. Three types of synergists are described. * **Neutralizing or counter acting synergists:** Muscles contracted to prevent unwanted movements produced by the prime mover. For ex. When the long finger flexors contract to produce finger flexion the wrist extensors contract to prevent wrist flexion from occurring. * **Conjoint synergists:** Two or more muscles that work together to produce the desired movement. The muscles contracting alone would be unable to produce the movement. For ex: Wrist extension is produced by contraction of extensor carpiradialis longus and brives and extensor carpiulnaris. If the extensor carpiradialis longus or brevis contract a lone the wrist extends and radially deviates, if the extensor carpiulnaris contracts alone the wrist extends and ulnar deviates. When the muscles contract as a group the deviation actions cancel out and the common action of wrist results (extension). * **Stabilizing or Fixating Synergists:** Muscle that prevent movement or control the movement at joints proximal to the moving joint to provide a fixed or stable base from which the distal moving segment can effectively work. For ex: If the elbow flexors contract to lift an object off a table anterior to the body, the muscles of the scapula and glenohumeral joint must contract to either allow slow controlled movement or no movement elbow flexors with a fixed origin from which to pull. If the scapular muscles did not contract the object could not be lifted as the elbow flexors would act to pull the shoulder girdle downward toward the table top. ### Individual Versus Group Muscle Test: Muscles with a common action or actions may be tested as a group or a muscle may be tested individually. (For example, flexor carpiulnaris and flexor carpiradialis may be tested together as a group in the action of wrist flexion. Flexor carpiulnaris may be tested more specifically in the action of wrist flexion with ulnar deviation.) ### Muscle Testing Assessment Procedure: 1. **Explanation and instruction:** The therapist **explains** briefly the movement to be performed or **passively** moves the patient's limb. 2. **Assessment of normal muscle strength:** Assess and record the strength of the **uninvolved** limb to determine the patients' normal 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. 4. **Stabilization:** * **The patient's normal muscles:** * As the patient holds the edge of the plinth when hip flexion is tested. * The patient uses the scapular muscles when glenohumeral flexion is performed. * **The patient's body weight:** Used to help fix the shoulder or pelvic girdles. * **The patient position:** For example, when assessing hip abduction muscle strength in side lying, the patient holds the non-test leg in hip and knee flexion in order to tilt the pelvis posteriorly and fix the pelvis and lumbar spine. * **External forces:** * External pressure applied directly by the therapist. * Devices such as belt 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 the movements normally carried out by the weak muscles. ### Screen test: A screen test is a method used to streamline the 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 muscle test result and/or. 3. Observing the patient perform functional activities, for example: shaking the patients hand may indicate the strength of grasp, i.e. the finger flexors. 4. Beginning all muscle testing at a particular grade, this is usually a grade of 3. The patient is instructed to actively move the body part through full range of motion against gravity based upon the results of the initial test the muscle test is either stopped or proceeds. ### Conventional Methods Manual grading of muscle strength is based on three factors: 1. **Evidence of contraction:** No palpable or observable muscle contraction (grade 0) or a palpable or observable muscle contraction and no joint motion (grade 1). 2. **Gravity as a resistance:** The ability to move the part through the full available range of motion **gravity eliminated** (grade 2) or against gravity (grade 3) the most objective part of test. 3. **Amount of manual resistance:** It is 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 to denote variation in the range of motion. | Numerals | Letters | Description | |-------------------|---------|-------------| | Against gravity test: | | | | 5 | N | The muscle is able to move through: Full available ROM against gravity and against maximal resistance. | | 4 | G | Full available ROM against gravity and against moderate resistance. | | 4 | G- | Greater than one half the available ROM against gravity and against moderate resistance. | | 3+ | F+ | Less than one half the available ROM against gravity and against moderate resistance. | | 3 | F | Full available ROM against gravity. | | 3- | F- | Greater than one half the available ROM against gravity. | | 2+ | P+ | Less than one half the available ROM against gravity. | | Gravity eliminated test: | | | | 2 | P | The muscle is able to actively move through: Full available ROM with gravity eliminated. | | 2- | P- | Greater than one half the available ROM with gravity eliminated. | | 1+ | T+ | Less than one half the available ROM with gravity eliminated. | | 1 | T | None of the available ROM gravity eliminated and there is palpable or observable flicker of a muscle contraction. | | 0 | 0 | None of the available ROM gravity eliminated and there is no palpable or observable muscle contraction. | ### Factors Affecting Strength * **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. * **Sex:** Males are generally stronger than females. * **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. * **Muscle size:** The larger the cross sectional area of a muscle, the greater the strength of the muscle. * **Speed of muscle contraction:** The force of muscle contraction decreases as the speed of contraction increases. The patient is instructed to perform each muscle test movement at a moderate speed. * **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 and learns the test situation. The therapist must instruct the patient well and give the patient an opportunity to move through or be passively moved through the test movement at least once before strength is assessed. * **Joint position:** * Angle of muscle pull. Length tension relation: The tension developed within a muscle depends up on the initial length of the muscle. Regardless of the type of muscle contraction, a muscle contracts with more force when it is slightly stretched. The tension decreases when the muscle is fully stretched to the greatest length possible within the body. The tension decreases when the muscle is fully contracted. * **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. ### Contraindication of Muscle Testing: 1. Inflammation is present in the region. 2. Testing muscle strength in the presence of pain may cause further injury. ### Precautions During Applying Muscle Testing: * **In patient with a history of or at risk of having cardiovascular problems.** * **In patients who have experienced abdominal surgery or patients with herniation of the abdominal wall to avoid unsafe level stress on the abdominal wall.** * **In situations where fatigue may be detrimental to or exacerbate the patients' condition, as patients with extreme debility.** ### Thank You.