Concerning the etymological 'back' problem I've been having since December, I might have found a decent cure. I had elaborated before that it's long been known that there appears to be a common word for 'back' or 'hip' across ancient Greece and Turkey: Classical Greek ischíon 'hip-joint' and Hittite iskis- 'back'. This pair just can't be a coincidence and an underlying Proto-Aegean term *iskʰis(a) seemed like a plausible fit to me.
However, I kept on feeling that unlike the previous words I've suspected to be Proto-Aegean, this one comes across as a little extra odd. Firstly I can't find a way of analysing the expected Aegean root into smaller meaningful morphemes and secondly the structure of the root seems unexpected for Proto-Aegean (eg. *s in syllable codae). Yet I know that this is at least better than the horrid attempts by Indo-Europeanists to reconstruct *h₁isgʰís- based only on two items from a very restricted geographical area. Surely this can't be correct either.
It was a tough problem so I did some yoga, smoked a spliff, watched some TV and then once my mind was distanced from the problem, I experienced a profound synaptic event. I realized that my subconscious mind had been wrestling with that initial i- for some reason. I was slow to heed my inner eye telling me of a common Hittite pattern. There's a long list of Hittite words which are the products of prothetic i- breaking up original clusters of the *sC(C)- sort. For example, ispant- 'to libate' < *spend-. So why then wouldn't iskis- be approached by IEists this way too? I suspect the answer is disturbingly circular since if one is hell-bent to deny the probability of a Greek loan from Hittite and is equally determined to make this a common IE root at all costs, then one must reconstruct this silly onset, *h₁i-.
Brainstorm time! Let's start from scratch and try this again. We have a common Greek and Hittite term for 'back' or 'hip'. Let's now just assume that the Greek word is a loan from Hittite, leaving only a single term to play with. Let's also assume that the initial i- in Hittite is prothetic like these other words. This gives us a Pre-Hittite term *skis-. Let's analyse this term as a native s-stem like some other body part terms implying that it's built on a verb stem *skei-. It just so happens that there is an identical IE root *skei- 'to cut, split'. Now, if this term originally referred to the 'spine' then it indeed 'splits' the back into two halves. Thus Pre-Hittite *skei-s- > iskis- would be 'that which divides' or 'that which is divided'. I suppose then that an Aegean or Minoan intermediary is unnecessary if the loan happened towards the closing of the 2nd millennium BCE.