Biomechanics Blog Post #2

It is very important to palpate bony landmarks when measuring ROM to have a high inter-rater and intra-rater reliability. This allows for multiple therapists to palpate the same bony landmark so they are measuring from the same location. It also gives the same therapist a landmark to come back to when remeasuring the joint. Doing this ensures you are measuring from the exact same position for ROM in the same joint. Also, using the proper positioning when measuring ROM makes certain you will measure the joint’s full range of motion. If body is improperly positioned then the measurement will be faulty and the client’s joint will not be measured to it’s maximum potential. For example, if you are measuring knee flexion ROM and you place your client’s leg off the table then you have the potential to improperly measure the joint’s full ROM with the leg not positioned properly.

    The purpose of the “test position” for a MMT is to ensure the muscle can reach optimal contractibility. You want to place the muscle is in the proper position so that it can reach full contraction. For example, placing an individual’s leg hanging off the treatment table is OPTIMAL for performing a MMT on quadriceps extension. This allows the greatest contraction of the muscles. If you placed the individual’s leg on the treatment table in a flexed position, the muscle would not be able to produce as great of a contraction. Another reason for “test position” is so that the therapist can be in the best position to apply pressure for the “break test.” The therapist needs to be in a good position so that he/she can apply the right amount of pressure for this test; if he/she doesn’t then the client will receive an improper reporting of their muscle strength. Also, the therapist needs to be in proper positioning to apply the pressure on the distal portion of the joint they are testing. The therapist should never apply pressure across multiple joints because this will give a faulty reading of the muscle strength of the joint being tested. If the therapist and client is in the proper position then the therapist will be able to apply pressure on the distal portion of the joint being measured.

    Lastly, the relevance of the gravity eliminated position is for clients that cannot move through the full available ROM and will be scored below a 3 on the MMT scale. Individuals needing to be tested in a gravity eliminated position do not have the muscle strength to move through the full available range of motion against gravity, so they will need to be tested without gravity in order to measure their muscle strength. Some individuals will not have any muscle activity at all.