
Originally Posted by
bluethunder
Basically your back should be only slightly arched if at all. But sometimes when doing flies you can arch to get a really good stretch. Regarding pinching your shoulder blades I a little confused on what you are trying to say. If you mean squezzing the pecs then the shoulders might come forward slightly. If you are getting sore from one way of doing it(not a pain) then its working for you and see no problem continuing. Also arching back is depends on what you are trying to do ie. isolating the muscle or power lifting..