Ots stretching on my office chair

I have the lot which in theory requires the tunica to be stretched more. Is it ok to hang the weight over my chair back? Or would it be better if I used a hook or pulley? The chair is obviously more convenient, and I’m not sure how practical it would be to set up a pulley in my situation, so this is why I’m asking. Just seems that maybe the weight isnt exact if it’s on the chair back where it has some resistance. Thanks in advance.

Sorry, I meant hanging, not stretching. Any suggestions?

Yes that is ok, But as you wrote the weight will not be exact because of the chair, So you will have to go by how it feels.

You could also fasten a hook under your desk for SO hanging.