How do you learn to keep your back straight?
Poor posture is a common problem that negatively affects movement mechanics for almost all exercises. Trying to improve posture and technique can be difficult. In this podcast, I discuss common issues, what exercises to address them with, and how to start from zero if you have no capacity for athletic movements
I refer to the book "Intervention", by Dan John=http://amzn.to/2trwPw6
which is an excellent guide how to learn how to move if you are truly movement limited.