question about movements in exercises

[funckygarcon]

now, it's been more than 3 months since i first started reading about the world of body building and i think i'm now in a decent level of knowledge. however i have a question that i don't seem to find the answer to, would u help me out?

the question is:
I see a lot of people in my gym doing for example: different sorts of curls (barbell curl, dumbbell curl, cable curl...etc) i'm fine with that, however the thing that has intrigued me is that all 3 movements are only one movement: you lift the weight then lower it in a vertical motion, there is nothing changed between a lift and another. Am i right in thinking that training in a single range of motion is futile? i mean, why not make it like this for example? 1- Barbell Curl 2- Hammer curl (notice that the angle of grip is different)3- cross-body dumbbell curl (the curl is along the stomach and not vertical) 4- Barbell reverse curl (palms down curl)

don't you think that it makes more sense than doing the same movement with different equipments? sorry if this question was long but i just wanna know if i'm right

 

[buddhabuilder]

Just like the exercises you mentioned, there is a big difference between a barbell curl and a cable curl. The angle and range may be similar in these latter two, but the way the muscle is having to work to deal with free weights as opposed to cables are very different. Also the barbell, dumbell, and cable curls isolate the bicepts, while hammers, cross body, and reverse curls involve other muscles in the arm, mainly for arms.