Help your knees!! Seriously. I found this ages ago when my knee acted up from squats or even just too much bending in yoga. This is a list with videos and images of GREAT, easy exercises you can do to strengthen the muscles that support you knee, gently! Great to do before bed as these aren't intense, just efficient!
Try this Chair Workout from Pumps & Iron. Set a timer for 40 rounds of 30 seconds of work and 10 seconds of rest. You’ll go through the sequence 5 times. I LOVE LOVE CHAIR WORK OUTS! They help me when kiddos are sleeping