rear wheel and chain adjustment query

[MC680x0]

What I think is happening to you I combat by sitting on ground behind the back wheel pushing the wheel forward putting pressure on the adjusters and as I tighten I'll also use foot to hold the wheel from twisting to the left.
Failing that get a friend to push on the wheel while you tighten

yes mate, this is what happening, its twisting to the left, even though I have set the r/h adjuster at the correct position then moved the locknut up and torqued it up; when I torque the axle nut, the r/h moves ? Weird.
I will come back tomorrow and post an update
thanks