“My knees hurt whenever I go to sit in a chair. What’s causing this?”
This is a really common problem as we age, and it is likely a movement related issue. HOW you are transitioning from standing to sitting is likely directly related with your level of discomfort, not just pathology alone. Let me explain this point with an example of squatting—something we all do, all the time.
There are two fundamental ways to squat, which is the essential movement you are describing when transitioning to sitting from a standing posture. The first way to squat is what is commonly known as a ‘knee dominant strategy’. In a knee strategy, the torso is upright with respect to gravity and the knees are forward the toes. By contrast, a ‘hip dominant strategy’ is defined as the trunk leaning forward, hips backward, and the knees staying behind toes. A knee strategy causes greater compressive forces at the knee; a hip strategy redistributes some of that load to the hips.
Most people tend towards a knee bias with squatting—chest upright and knees forward the toes. More stress to the knees ultimately can lead to the development of knee pathology and pain. The easiest most effective way to manage your pain with squatting is to make sure that your movement transitions from a knee to a hip dominant position.
When transitioning from standing to sitting, make sure that your chest comes forward while maintaining a neutral spine, sending your hips backward and actively squeezing/engaging your glutes. Continue in this fashion ensuring your knees do no progress forward the toes and when you look down you observe your knees in alignment with your hips/feet (not “knocked kneed”). If you execute this movement properly you will find that your hips are more engaged, and your knees will likely feel a whole lot better.