From Bill Hartman:
“The greater our ability to manipulate the internal pressures regardless of the task, the greater our tendency to move well or accomplish a task. When we fail to shift or manipulate the internal pressures, movement is restricted or biased.
Either we simply cannot execute a task effectively or we may be limited to such a degree that we lose the ability to dissipate or distribute stress, tension, or pressure throughout the body. In this case, focal pressure and tensions may result in pain. Ask any couch potato how their back could just start hurting for no reason.
Remember the last time you had to sit on an uncomfortable chair for an extended period of time and your butt started to hurt. Too much pressure in one place for too long. Pain can simply be the same problem.”
You'll get hurt if you do not move at all, not move in the wrong position, or move wrongly. And you'll get hurt anyway as you age as you're, um, aging. That's why I laugh when sedentary people (who complain of aches and pains anyway) decide to remain sedentary because they're "afraid to get hurt".
Just get up and moving, hopefully in a correct and safe manner, and just do your best.