at my old gym when i was a lot lighter they had a machine for pullups where it assisted you in the weight, and from using this i worked up to where i could do about 9 regular pullups on a bar with my bodyweight...now at my new gym they have a similar machine but it basically sucks, it doenst feel right and i dont feel my back working at all when i use it and its the only one they have...and i havent done pullups in a while and now im only repping out like 3 or 4 with my bodyweight, what can i do to get them, up?