Is Rob's theory far fetched? To me it's more solid than the Androgen Hypothesis.
I don't know how we'd verify your statement on Bieber. I think craniofacial growth is a likely mediator of scalp tension.
We'd need to measure his zygomatic arch and jaw line according to the references I drew up. Even then, Rob may argue that androgens have remodeled other muscles in the scalp.
One muscle that likely has a strong role to play in hair loss is the occipitofrontalis. It's a muscle researchers are still learning more about. It originates at the eye brow and underlies the superficial fascia. This muscle then re-emerges under the crown.
View attachment 91992
https://www.sciencedirect.com/science/article/pii/S0007122605000238
The mechanical tension theory explains why STR device and botox work. This is, in part, what Segura suggested in his 2015 paper. Again, I'll paraphrase key quotes and add the references below:
View attachment 91993
http://www.ijtrichology.com/article...;spage=95;epage=99;aulast=Tellez-Segura#ref23
'The aim of the present study was to analyze the correlation between stress distribution in the galea and clinical progression of male pattern baldness in order to know whether mechanical stress is involved in Androgenetic Alopecia phenomenon.'
'Conclusions: All these data suggest that mechanical stress determines Androgenetic Alopecia patterning and a stretch-induced and androgen-mediated mechanotransduction in dermal papilla cells could be the primary mechanism in Androgenetic Alopecia pathogenesis.'
'The result of this analysis indicates a constant linear dependence between elastic deformation of scalp and Androgenetic Alopecia patterning, which clearly identifies mechanical stress as an active factor in Androgenetic Alopecia.
The involuntary tonic contraction of occipitofrontalis muscle is related to psychological stress conditions, facial expression, the maintenance of visual field, and an aponeurotic tension model of human craniofacial growth'
Again, I'm no expert. I may have mis-interpreted some of the material I posted above. That said, it's a shame posts on mechanical tension and the galea don't receive as much attention as Brotzu and DHT.
Rather than group buys on underground lotions we may be able to test the galea theory against Finite Element Analysis, STR, Botox, Doppler Flowmetry and ultimately hair-counts.