Your posterior chain basically takes into account all the muscles, tendons etc that form a chain from your foot all the way up the back of your legs. By stretching out all of it you can see much bigger improvements than just stretching me muscle group.
Initially we want you to get a measure of your flexibility. Try and touch your toes with straight legs and legs together. See how far you can get, maybe get someone to take a photo... Once we've done all this stretching you'll do it again and see the difference. Results will get better with repeated stretching but you can usually see a difference almost instantly.
The first thing your going to do is loosen off your foot. It's where you posterior chain starts and if it's tight everything is going to feel tight. Take a tennis ball and roll one foot over the top of it. Apply gentle pressure to the bottom of your foot as it may be tender. Roll it around the underside of your foot for a minute or so on each side. Take a little rest then repeat. Each time you repeat apply a bit more pressure to try and break through the tightness / pain. Even if it doesn't feel like it's doing anything you've got to carry on!
So your foot has loosened up and now it's time for your calf. To stretch out your calf you'll need a wall. Stand in a split stance, with one leg back and one leg forward. Lean into the wall and place both hands on it. Bend you front leg but keep the back one nice and straight. Also keep your back foot flat on the ground. To feel the stretch you need to lean further and further forward. Don't go too far or you'll be fighting your own stretch reflex. Once you feel the stretch hold it for 10 seconds or so then start to move the other leg. Move it forward and back, side to side then try and twist your hips a little, the whole time keeping the stretch on the back leg. Repeat 5 times on each side.
Next, sit down with your legs out in front of you. Bend you legs so a thy can reach your toes. Grab hold and then start to straighten your legs. Go as far as you can comfortably (don't push it too far or you're just fighting your own stretch reflex), hold for 10-15 seconds then relax. Repeat up to 5 times, going a little further each time.
Next it's time to loosen up those butt muscles! Still got your tennis ball from earlier? Great! Pop the tennis ball on the floor and sit on it. Yes sit on it. Keep your bum muscles relaxed and allow the tennis ball to apply firm pressure to one side at a time. You'll probably feel tender in the deeper layers of the muscle. If you find a tender spot then hold that position for about 10 seconds then move on. Repeat on both sides 3 times. It's is myofascial release of your butt muscles (see earlier post about this).
Whilst we're talking about myofascial release it'd be a good idea to read that post and go over all your leg, butt and lower back muscles with a foam roller or the tennis ball to loosen it all off.
Do this everyday for a couple of weeks and you won't believe the difference. It would be great if you could take a photo of your before and after and post them on Facebook. Tag JB Health in it so we can see the progress!
Any questions or for more specific advice do get in touch.