Thank you Jo55 - the technique you describe sounds very similar to one I do at Yoga - basically lying on two yoga blocks lengthwise along head and spine with arms and scapula hanging over. I told my Yoga teacher your advice and she nodded enthusiastically - she said I need two sandbags on my shoulders to weigh them down.....have you tried this.

Towelhorse...I will try to help but please forgive me if my understanding of all these neurotalk is a little beyond me...and gets a bit scrambled up.

You say your point is - rather than nerves are being outstretched by laying on chi balls, relief is obtained because the nerve is decompressed which improves scapular instability.

This would concur with a piece I've found from a text book years ago and kept copies of.....I will try to scan at library and put on site but don't hold out too much hope as I'm not too good at these type of things....anyhow

The first thing would seem to identify the root cause of the instability it seems instability of scapular is caused by glenohumeral instability or rotorcuff instability.

I quote the following

"the tests are performed with the patient in suprine lying and involve passive movement into the 'apprehension test' position of 90degree abduction and 90deg of lateral rotation. In this position a gentle anteriorly directly pressure is applied to the head of the humerus. If the patient experiences marked apprehension with or without pain, then this is indicative of gross glenohumeral instability, as in the case of recurrent dislocations. Pain without apprehension could indicate either a primary impingement or mild anterior instability with secondary impingement.

Differentiation between anterior instability with secondary impingement from primary impingement is possible by performing the 'relocation test'. This simply entails positioning the patient in the above apprehension testing position and then placing a posteriorly directed force to the humeral head.

Patients with primary impingement experience no change in their pain level, while those with anterior instability and secondary impingement experience a lessening of their pain. This results from the posteriorly moving humeral head relieving the impinging pressure on the underside of the rotator cuff against the posterosuperior genoid rim".

It may be that you are both correct (not that I want to defend their point)
Sounds to me that pain is caused because of the rotator cuff pressing onto the genoid rim(?) and the chi ball perhaps changes the position of the humeral head which perhaps stretches the nerves and at the same time decompresses the nerve which pull apart the rotator cuff and genoid rim.
Or am I talking out my....

Its difficult to try to reason these things out when you don't have a clear picture of the parts e.g. what is a genoid rim, and I think you also need to see a visual demonstration of how things things move and function in relation to each other.

I hope that little piece may have helped
It's so frustrating when people don't understand what you're trying to get at...I hope I haven't missed the point......If I have don't try harder to explain....I've gone down that road.....it means that I just don't and perhaps can't comprehend because of a lack of full knowledge on the subject. Perhaps someone outthere can supply the knowledge you need.

Take Care
I'd think about another occupation though if even light works are causing you a problem.....can you go on the sick? A job isn't worth ruining your health for....I learnt the hard way. i know its difficult wife & child to support.....

Travel with Love

The Slug