Biomechanics Test Positioning

   It is important to use bony landmarks and proper positioning for measuring range of motion because the normative values that we use to determine if there is any deficit within the range of motion in a joint is based on specific bony landmarks and proper positioning. By following these reference points we will be able to get a more accurate assessment of the clients range of motion and the implications of the values we get in our measurement. Using landmarks and positioning can also help improve both inter-rater and intra-rater reliability. Inter-rater reliability is important because once again we want to know that the values we get are consistent with others' measurements since we use normative values to determine deficits. Intra-rater reliability is important because we tend to re-measure range of motion to determine if there has been improvement and to see if treatment is effective and following these measurement protocols, we are better able to reduce the risk of measuring differently, skewing results from measurement to measurement. The purpose of the "test position" is important because different positioning can effect the movement of a joint since there can be anatomical limitations or advantages to a joint in different positions. The effect of gravity is also important to consider and can change from position to position which is why it is important to always initially test in an against gravity position, when applicable, and only then if the gravity proves to be too great of a resistance to then use a gravity eliminated position. A gravity eliminated position is useful to test range of motion when a person lacks the strength to overcome gravity, because it is still important to note if there are other limitations to range of motion aside from a lack of strength.