Radial & Ulna Deviation
These movements are best performed in the seated position as stabilization is easily achieved. In any position the alignment of the instantaneous axis of rotation should be 1cm proximal to a point between the radial and ulna styloid processes (see below).
Although stabilization is easily accomplished care should be taken not to overly compress the muscle bellies within the forearm (see blue box below) a compressive force of under 15kg should be maintained.
As velocities are known to reach thousands of degrees/second testing using a dynamometer will never be considered to be functional. Even if this speed could be achieved it is over such a small arc that the results gained would be fruitless. Generally it is accepted that 30 degrees/second is a slow speed whilst speeds over 300 degrees/second can be difficult to achieve. A maximum speed of 180 degrees per second is recommended.
