different muscle engagement. When I do bicep curls I do strict standing curls(which is all bicep) and this to finish

yeah I’m skipping this one for today, cause I’m not doing shoulders😭🙏

if you observe the movement this one is “dragging” the arms back when the curl movement is completed or almost completed. A simple curl you just go up and down and the only muscle working is your bicep. With this one you are working biceps and a little above - I’m guessing sor of the shoulder muscle…

same