What stretches are suggested for an injured and stiff knee?

Some thoughts...: When it comes to knee pain--"motion is lotion" keep your knee moving through stationary cycling. Quad strengthening such as leg presses and body weight squats are helpful. Quad and hamstring strengthening and stretching is very helpful. Another good exercise is the walking lunge.

Depends on diagnosis: There are many different types of injuries. Each type of injury requires has its own plan of care. Treatment may vary depending on the diagnosis. Have it evaluated by your physician and get the appropriate plan of care for your condition.