The Relevance of Test Positioning
Test Positioning is the position the client is in while they are being measured for range of motion (ROM) and manual muscle testing (MMT). When measuring ROM, the therapist will have the client in the optimal testing position and use bony landmarks to know where to place the goniometer. For example, when measuring elbow flexion ROM the proper positioning of the client would be supine with arms at their sides. The goniometer's axis will be placed on the lateral epicondyle, the stationary arm will be on the lateral part of the humerus pointing towards the acromion, and the moveable arm will be on the lateral part of the radius in line with the radial styloid process. When the elbow flexes, the moveable arm moves with the radius, but the stationary arm and axis stay in the same position. The bony landmarks where the goniometer is placed allow for a reference point so the therapist can accurately measure ROM. If the goniometer was not placed at the same bony landmarks after the elbow was flexed, the ROM measurement would not be accurate. Also if the client was not in the proper position that is optimal for elbow flexion, their measurements would be not as accurate to what the client can achieve. Having accurate ROM measurements gives the therapist an idea of where the client is at so they can set goals and later remeasure to see if the client has made progress.
Manual muscle testing (MMT) is where the action the client is trying to achieve has resistance applied to test the strength of the muscle as well as to see if they are compensating anywhere to perform the movement. When performing MMT the client has to be in the position where the action they are performing is against gravity so the resistance can also be against gravity as this allows for optimal resistance. The resistance should be applied in the same way as a third class lever so the effort is closer to the axis and the resistance is applied further from the effort. For example in elbow flexion, the axis would be the elbow, the effort would be the biceps brachii, and the resistance would be applied to the anterior forearm. The client would be sitting or supine with their elbow in mid flexion (~45 degrees) as this allows for the greatest number of cross-bridges to form in the sarcomeres which is the optimal position for resistance. The therapist would push down on the anterior forearm while the client would try to flex against gravity as well as the resistance. The purpose of using proper test positioning during MMT is to ensure the muscles you are testing are the ones being used and to be able to determine if the client has any weakness.
MMT also has a gravity eliminated position where the client performs the motion, but not against gravity. For elbow flexion the client would sit at a chair next to a table and rest their extended arm on the table. The client would then flex the elbow by bringing their hand towards their body while keeping it rested on the table. This kind of testing is relevant for those who cannot perform the motion against gravity such as if the person has lost sensation or is regaining strength. The gravity eliminated position would show the therapist that the client has the ROM, but lacks strength.
