Saw this and reacted.
Before 2015, at age 66, I was really very crispy. I can hear the loud CCCCRRRRAAAAACCCCKKKK when I turned my neck, when I raised my upper extrermities and when I moved my knees. However, with daily flexing and stretching exercises (my regimen – see link below), at age 70 in 2019, the ccrraacckk sound is now lesser. I am not very crispy anymore.
Advice to all people, old ones better still, start at young age: do adequate stretching and flexing exercises everyday to prevent the CCCCRRRRAAAAACCCCKKKK. They will also prevent joint pain and muscle pain, etc.
Speaking from personal experience. This contribute positively to healthy aging.
HOW TO LIVE LIFE IN THE CONTEXT OF HEALTH.