The human body is a precision machine. The brain receives about 2 billion messages per second and  balances them all into a functional whole. Thus we can run into problems when it has been slightly off kilter for a number of years and we try to do a dramatic adjustment of any kind. Like cracking walnuts with a jack hammer. It will confuse the nervous system as will any one-sided focus. A little precision instruction, awareness of function and design can have great results.
 
Learn how to ask the right questions when considering a particular exercise: What is the goal? What is the joint motion, what muscles are involved? How can an exercise be modified to be healthier, safer and more efficient?