It’s frustrating how much bodybuilding research there is in terms of sets, reps, and all sorts of factors to build up muscle and how little there is in terms of height. Note that most of this research does not come from science it comes from tons of independent bodybuilders.
With muscle building we know that stressing the muscles in general increases their size. Bodybuilders don’t wait for calf and pec implants to get bigger muscles.
We don’t know though how to lengthen bone? We don’t know what stimulus to apply? Actually we have a pretty good idea.
To induce chondrogenic differentiation(chondrocytes are the basis for the growth plate) one method is to induce a hydrostatic pressure of at least 0.1 MPa. A blood pressure cuff during a heart beat generates about 120mmHg which is about 0.015MPa an order of magnitude of what we need. To get 0.1MPa we’d need a blood pressure of about 750mmHg which would probably cause death. There has to be a way for the body to safely induce hydrostatic pressure of 0.1MPa-10MPa’s to induce chondrogenic differentiation. HP levels of the articular cartilage can vary between 1-5MPa in response to physiological(occurs normally) stress. There are two possible ways to make up the difference in the hydrostatic pressure deficit(0.015MPa versus 0.1MPa or ideally higher) fluid flow and bone deformation.
Ultrasound levels of 30–200 mW/cm2, Frequency=1–1.5 MHz are one possibility(you’d target in the epiphysis). Note I have not tested this so attempt at your own risk! Muscular contraction can also increase marrow hydrostatic pressure. You’d probably need to use external electrical stimuli to generate the muscular contraction needed to induce significant hydrostatic pressure. Again I can not say whether or not this is safe or not!
An increase in hydrostatic pressure also results in an increase in fluid flow which may be the primary inducer of chondrogenic differentiation rather than the HP itself. Thus you could find ways to induce fluid flow directly and in conjunction with an increase in hydrostatic pressure to get the needed stimulus to induce chondrogenic differentiation.
The growth plate is exposed to high hydrostatic pressure via the bone pressing down on it. If we create a fibrous layer in a neo-growth plate region maybe the hydrostatic pressure to encourage a growth plate will occur naturally. Note that LSJL does encourage fibrous tissue differentiation. If we can create a fibrous tissue layer, the compression force of the bone itself will create the hydrostatic pressure and induce chondroinduction.
Fluid flow induces recruitment of integrins to focal adhesions. This alteration in cell signaling by fluid flow directly could induce chondrogenic differentiation.
So we know the key to growing taller is to induce a new growth plate in the bone as bone tissue is not mechanically suited for interstitial growth. We know that this can happen at around 0.1MPa hydrostatic pressure in the bone epiphysis. It’s possible to make up for a deficit in hydrostatic pressure levels via other factors like fluid flow via dynamic lateral compression. There’s also the possibility of using ultrasound and electrical muscle stimulation. Such levels would have to be supranormal as no muscle stimulation of longitudinal bone growth has yet to be reported. Since it is supranormal all the effects are not known so it would have to be tested somewhat for safety first.