Trunk

 

 

Take your body and cut off above your chest and just below your bottom. All the muscles left in the mid region comprise your trunk. They include the core muscles but also more powerful muscles including the glutes to help stabilise the body. For example the single leg squat, with weak glutes the knees will buckle in (valgus) and with a weak core the back will arch, the person will probably lose their balance and all in all they will look like Gollum – never a pretty sight if I say so myself!