Movement starts at your feet (when walking, hiking, etc.). The feet have the most bones in the human body. The knees react to the feet when you are weight bearing. When seated in a chair you can strengthen the knee joint without the influence of your hips and feet.
That’s what this experience is all bout.Treat your knees and feet to these movements. Review the many movements of the lower leg.
Tibial internal and external rotation
Knee flexion and extension
Plantar flexion and Dorsi flexion
Inversion and Eversion
You can follow this audio right from your chair.