Together, these two exercises provide simple ways of stretching and mobilising the entire posterior chain, from heels to back of neck. The emphasis can be changed by manipulating two sets of forces: how much you pull your shoulders to your thighs, and how much you straighten your legs.
Because of the proportion of the body's muscles involved, the emphasis is on the posterior superficial fascial layer—you may feel the main effects anywhere from the neck, middle back, lower back, hamstrings and even calves. The secret power of this movement is to use the quadriceps to bring on the stretch—this activates the agonist-antagonist reflex, so the net effect is that the body is stretching itself. This is the fastest way to remap what the brain believes is the maximum length of all the tissues involved.
In execution, the stretch is simplicity itself, though it is best to make sure that you are not holding your breath while working (when the head below the heart, necessitated by the standing position, there is always a chance of feeling a bit faint when you stand back up).
And please note the suggestions re. alternately straightening, then bending, each leg in turn; if done briefly, this provides a strong, yet brief, hamstring stretch on the straightening leg; this is tolerated well (because brief and novel) and, because the feet are in full contact with the floor, we find that the brain remapping that this technique is optimised for lasts and translates (for example) into a better paschimottananasa (if you are a yogi) or a better pike position (if you are a gymnast or calisthenics practitioner).
We feel that these effects are achieved by resetting the length--tension relationship of the hamstrings; this is mediated by the somatosensory cortex and is a function of what the brain believes is appropriate for these muscles AND your past patterns of use. Change these, and your hamstrings will change.
Hi, Kit here. Today I'm going to show you a standing lower back and middle back stretch, and it also can be modified to be an excellent hamstring stretch as well. So just watch this. I'm going to be holding my hands behind my legs like this. I'm going to take a breath in. And on a breath out I'm going to bend forward at the hips like this, and notice that I've got a decent bend in my legs as well. Then I'm going to hold my hands behind the legs like this. I take a breath in, and to make it into a lower back stretch, I simply try to straighten my hamstrings like this, and you'll probably see that this part of the back is getting a decent stretch. Now I can make that stronger and make it one side of the back by just trying to straighten one leg like this, or just trying to straighten the other leg like this.
I can make it even stronger by pulling myself closer to the knees like this, letting my head drop down and relax completely, and then watch, gently trying to straighten the legs. And to make it stronger still, I then pull my face to my knees like this. Now depending on where you're the tightest, this can affect anywhere from just below the neck here, all the way down to the top of your glutes. Also, play with how hard you pull the chest towards the legs versus how hard you're trying to straighten each or both legs. Again, like many of our latest exercises, this is a very strong fascial stretch, and because your feet are flat on the floor, you'll find it can be quite a strong calf muscle stretch in the end position as well. Anyway, try it and let us know what you think of it.