there are many who has this muscle. I don't know the name of the muscle or how can I do it so open.I cut the picture from a bodybuilder just to show you this.How he did this ?I train my body abs ,chest ,legs, biceps, triceps etc but I want to obtain and those "opened muscles areas" Image -check it . I am not talking about obliques .Thanks
That is the Latissimus Dorsi, or most commonly called 'the lats'. A muscle group of the back.
Good exercises to build them are deadlifts, pullups and rows, or any pulling movement really.