There are currently no standard examination positions for the shoulder. During movements of the gleno-humeral joint there are always relative movements within the scapulo-thoracic junction. These are usually described as fitting a set of established normal patterns. These must be considered when testing the shoulder. When testing or exercising the shoulder its vital that the patient has sufficient warm-up before performing any movements.
No studies are available which can completely describe the instantaneous axis of rotation during diagonal movements. I would usually use a position which allows the ROM you wish to test/exercise through. As can be seen below in this seated test the alignment of the axis of rotation will often be altered even with thoracic and pelvic stabilization. These problems are magnified if you test in the standing position but this is more functional. These types of shoulder movement have been suggested to mimic those in 'real' situations better than any other shoulder movements.
Testing for research purposes is possible but careful consideration has to be given to stabilization.
As velocities in some sports (any involving throwing an object) are known to reach thousands of degrees/second (Pappas et al., 1985) testing using a dynamometer will never 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 speeds of 60 degrees/second and multiples of this should be used. Speeds over 300 degrees/second have been found to be difficult to achieve by even baseball pitchers (Cook et al., 1987).
