You can't stretch yourself! :P You only grow as tall as God made you to grow, buy hanging knee-ups is an exersize!
hang your eg upside down..
Do exercises that don't involve using the muscles and ligaments in your knee. situps/crunches, chin ups, weights etc.
The knee heals best when rested. The knee is a focal weight point and needs the rest along with cold compress to reduce swelling that could cause potentially painful fluid build ups.
Push Ups are great as long as you change them up every 3 weeks or incorporate different types of push ups into the mix with less reps and more reps every time. Such as ; Incline Push ups for upper side of pectorals, Regular Push ups for right side of pectorals, Decline Push ups for lower side of pectoral, Knee Push ups for right side of pectorals. Workout Routine: 1×20 Regular Push Ups 1×20 Incline Push Ups 1×20 Decline Push Ups 1×20 Knee Push Ups Then repeat 3 times Push Ups work several parts of the body and are known as a 'Compound Exercise.' They work the Pectorals (or chest), Abdominals , Triceps and Forearms. They also help with endurance. If you squeeze your chest while doing them the results will be better for you chest. In a week if you do 300 - 500 push ups a day you will see results to the right side of the pectorals.
do lots of leg lifts! this will help build lower abs. also knee ups will help
There are many good knee stretches that one can try to help their knees. Some stretches include step ups, abductor raises, wall slides, hamstring stretch and straight leg raises.
Lay on your back. bring legs up bent at the knee then try and touch your elbows to your knees
Some beneficial exercises for any knee problems are leg curls, straight-leg raises, bent-leg raises, and step ups. Also stretching helps with any stiffness or achy joints.
Work out more. Leg lifts, bent knee leg lifts on a raised surface, sit ups, crunches, the bridge etc...
You hang upside down from a bar with your legs over the bar supporting you. You then bend at the waist, raising you elbows to your knees. Do this several times, it is meant to strengthen the abdominal muscles.
You could get knee support for you knee at any pharmacy of sporting store. Just look for a knee brace. Knee braces are great because they will support your knee and they are cheap.