Range of Motion and Manual Muscle Testing- The Basics

Landmarks are used to help identify locations or provide directions frequently in everyday life, but what are bony landmarks, and how are they used? Bony landmarks are points on bones that can be palpated on the skin and used in determining where to place goniometers when testing for range of motion. These landmarks are important because they provide guidance on where to place the fulcrum (the center) and where to position the stationary arm and the mobile arm of the goniometer. By using the bony landmarks, a practitioner can ensure that they are measuring the range of motion properly, and inter-rater reliability can be increased which means there is more consistency when measuring across practitioners.

Proper positioning is also another important aspect of measuring range of motion. If a client is not positioned properly, then the measurements for range of motion might be wrong from the start. One example of this is measuring the range of motion in the knee. Knee range of motion is measured in a supine position and allows flexion of the hip. If the knee were to be measured in a prone position, the range of motion would not be as great due to passive insufficiency. When passive insufficiency occurs in the knee, the quadriceps muscles, a multi-joint muscle, are stretched to their maximum ability. Because of this, the knee is unable to flex completely thus presenting a range of motion that is less than the actual ability.

Having a proper range of motion measurement also allows for the determination of the proper "test position" when completing manual muscle testing. The positioning for manual muscle testing requires that the client is working against gravity. This means that the motion needs to be occurring in a upward direction. The joint being tested must also be around the halfway point of its range of motion. At this point, it possesses the ability to form the most cross bridges between actin and myosin. The practitioners proper positioning when completing manual muscle testing is important as well. The practitioners resistance must be positioned as to not cross another joint because then more than one joint is involved in the test.

The gravity eliminated position is relevant when a person cannot complete a at least half of their range of motion against gravity. In this circumstance, the outside force of gravity is too much for a person to be able to complete their full range of motion. The practitioner would have to position this person so that the movement is completed parallel to the ground. For example, a person could sit next to a table and then flex or extend their elbow in a transverse plane so gravity is not a factor in the movement.