Back shoulder muscle training with machine

This video explains about training the back shoulder muscles with a machine. The steps are, sit up straight on the machine, puff out your chest, pull your back muscles back. Use your shoulders to pull the machine lever to the side/widen/stretch your arms. Use your hands as hooks only, try to use the strength to pull to the side from your shirt muscles.Standard 12-15 repetitions, 3-5 sets. For the initial repetitions, the weight should be above 12 repetitions. If it gets heavier, reduce the repetitions in the next set. Increase the weight until the weight is below 7 repetitions. Good luck!