Biomechanics Blog 2: Test Positioning

Occupational therapists implement assessments such as range of motion and manual muscle testing on clients. When conducting these assessments there are specific positioning protocols to follow and specific bony landmarks to use. When measuring range of motion (ROM), we use a goniometer. The goniometer has an axis, stationary arm, and moving arm. It's important to palpate the bony landmarks, so you can place the axis and both arms in the correct position/starting point on the client. Palpating bony landmarks also allows us to feel for any abnormalities that may affect ROM. This is important to look for because the client may use compensatory movements. For example, when measuring the ROM of elbow flexion, you would palpate the lateral epicondyle of the humerus so you could place the axis at that correct starting point. You would also need to know where the acromion process is, to line the stationary arm, and where the radial styloid process is to line the moving arm with. Having the goniometer in the correct position will allow the practitioner to get an accurate angle measurement as well as determine if the client used any compensatory movements such as elevating their shoulder to further flex their elbow.

As I mentioned, another assessment an OT may conduct is manual muscle testing (MMT). This measures the effective performance or function of a muscle and movement. MMT helps determine what muscles are involved and what muscles are weak/having trouble during the movement. However, when doing this assessment, it's important to have the client in correct positioning. The positioning of the client determines if they are doing the movement against gravity or doing the movement with gravity eliminated. During MMT against gravity, the movement should be going against gravity (in an upward direction), and the resistance should be going down. For example, MMT for elbow flexion, the client would be in a sitting position with their elbow flexed mid-range. While the client is flexing (moving upward), the practitioner would be applying resistance (downward) distal from the elbow joint. If a client cannot do the MMT against gravity, the practitioner will place the joint or sometimes the person in a position that is gravity eliminated. This position is usually side lying, making sure the action is moving parallel to the ground. Placing the client in a gravity eliminated position is also relevant if they are having trouble with the resistance being applied from the practitioner. With gravity eliminated, no resistance is applied, the practitioner is supporting the joint.

Retrieved from: http://clipart-library.com/