Some Chiropractors including me use muscle testing to gain an idea of what you are using on the inside of your body to perform the tasks that you ask of yourself on a daily basis. For example I might rotate my body at my waist or I might achieve mechanical motion initiation from the lower leg. Without getting too technical there has been controversy over the use of muscle testing. I can’t speak for all Chiropractors when I describe intent and the reason behind why use muscle testing. A new-ish technology of ultrasound is called elastography. It is this technology that has been able to demonstrate a delay in contraction of musculature where reduced elasticity is detected on elastography. An old muscle test called the arm fossa test in the chiropractic technique system of sacro-occipital-technique (SOT) is taught from the perspective of look for a delay in muscular activity. In short elastography has shown, just last year, the correlation Chiropractors have passed on to each other since the 1930’s between elasticity and muscular contraction delay.
Journal of Bodywork and Movement Therapies (JBMT) 22 (2018) 673-84