hira,
G V manip is a valuable tech to Rx diff conditions if used discriminately & with appropriated protocol. Dx shld be accurate, clear pt for absolute and relative contraindications of G V, use prediction rule for tech to be effective, & apply only & when 100% confident with pt safety and tech efficacy. i do manip and i like its immediate dramatic results. but beleive me we are obssesed with myth of manip and its cracking sound, otherwise there are so many other manual mob techs which can yeild equally excellent immediate results. if one can get same results without chalanging pt's safety, why G V be carried out? G V should be the last option on table. Can be 1st option if 100 % or more confident with its all aspects.
G V HVLT can only be performed by a practioner having advance training in this area in form of degree prog or state approved certification. practicing G V manip on pts without training in this area is not ethical and not allowed.
hope it answers your questions.