Secondly, you can practice biceps, step on your feet, and hold the other end in your hand to do dumbbell bending.
You can also connect the triceps, just like rubbing your back in the shower. But don't move your hand, and your upper arm extends upward.
Then practice your shoulders, step on them with your feet, stretch your hands forward, and lift your arms with the strength of your shoulders.
. . . . The action of practicing chest muscles must be squeezing the chest, which means that the spring of the spring stretcher must be on the back, and then the hands are close to the chest at both sides of the body. Because the spring can only be pulled, not retracted. So we have to put the spring in the back, but there is a problem. If the spring is on the back, pinch the handle at the back when opening and closing.
I don't think spring stretchers can exercise chest muscles.