Lie on your back with legs bent and feet flat on the floor. Bring one knee in towards your chest and place your hands gently supporting behind the thigh. Whilst the leg is bent, point the toes.
Gently straighten the leg as you pull your toes towards you (pushing the heel towards the sky). Continue until you feel a slight pull in the back of your hamstrings, calves or bottom then bend the knee again as you point the toes away from you. Repeat 10 times on both sides.
Please note that this is a sciatic nerve mobilisation and so you do not need to hold the stretch or force it. You are simply nudging the nerve a little. Remember that when the knee is bent you point your toes and when it is extended you pull the toes towards you.
Mobilising an already irritated nerve can make things worse so of you have sciatic symptoms this may not be the best exercise for you.