Biomechanics Reflection #2

Bony landmarks are used as reference point when using a goniometer to measure a client's range of motion because they provide a consistent starting point. Locating the bony landmark instructs therapists where to place the goniometer's fulcrum, or axis and shows which arms go with which bone when measuring ROM. Palpating for bony landmarks not only gives the same therapist a starting point to place the goniometer but provides the same reference point for other therapists as well. Bony landmarks allow the measurements to have consistency or validity no matter who is taking the measurements.
Another important aspect about measuring ROM is the is positioning of the body segment being measured. Optimal positioning for contraction is the position that allows the most cross bridges to form within sarcomeres. Having the body segment in the appropriate position helps to ensure the accuracy of the test. For example, a body segment in mid-ROM is the optimal position for performing Muscle Movement Testing (MMT). This position puts a client's muscles in the optimal contracting position making it an excellent way to test their muscle strength. When using MMT if a client is unable to hold the specified muscle contraction for the optimal 4 seconds the therapist will then place the client in a gravity eliminated position. In this position, the joint being measured is placed in a parallel position in relation to the ground. This placement provides a position where there is no resistant forces acting upon the client's muscles.