Extension exercises are those which stretch the calf and the hamstrings to allow the leg to straighten (0 degrees extension) or the knee to bend slightly backwards (e.g. -1 degree extension, backward bending is measured in minus numbers).
There's loads, but I like to keep it simple and easy. Sit on a chair, rest your heel on something a little higher up. Press down on your thigh, you will feel the stretch through the back of your leg. Alternatively, lean forwards, that will really put the pressure on. No need to make it hurt, and you can do it loads of times a day.
Loads of ROM (flexion) stretches seem to me to put force through the knee, not what's needed. So I have started doing this one using my son's skateboard (there must be one of those in any house that's had children about!), the beauty being that I use my arms to pull the legs gently backwards, no force going through the knee.
When ROM (flexion) gets good, actually sit on the skateboard, feet either side of course, and put hands on the floor to rock you backwards and forwards.
Extra information. It occurs to me that not everyone might know how to do stretching exercises properly.
First, no pain. Discomfort just to the point of pain is OK.
Extension: Press down/lean forward until you don't want to go any further, hold for about 10 secs, gently release. Swap legs and repeat. Repeat this set maybe 5 times.
ROM (flexion): Pull forward until you don't want to go any further, hold 10 secs, relax. Wait 10-20 secs and repeat. Repeat the set maybe 5 times.
Repeat this extension/ROM (flexion) set every hour, or even more often if it suits.
Swelling won't notice until the next day, if any. If there's none, repeat the sets; if there is some, back off to even more gentle, or have a rest day.
And now, laydeez'n'genlmen, my latest idea in a new super high technology approach to quad strengthening. Be prepared to be amazed, stunned and all kinds of stuff. First, examine the detailed picture below:
A fireplace with two piles of books, you think. Ha! You're right! But not any old books, oh no, Encyclopedia Britannica, bitta respect please.
On top of them some copies of classic Winning magazine, cycling from the 80s, and an old bit of shelving.
Top stuff.
The idea is that I sit on the bit of shelving and and stand up again, getting a nice pull in the quads without upsetting the knees. The number of books used makes it the right height, wizard innit!
Heels are close up to the books for maximum effect.
The key to the hi-tech aspect is that every so often I take 2 magazines away
(one from each side, you can't fool me!), to lower the height a tiny bit. When they're all gone I remove an
encyclopedia from each side and put the magazines back. Slowly getting more strength-bearing range of motion.
Look upon my works ye mighty and despair!
And a close up.
The wee doggy is called 'Bones', belongs to my eldest daughter, and is good at supervising.