Correct body position is important; but how can we know whether we\’re doing it if we can\’t see ourselves? Unfortunately I don\’t have a mirror on rides except the handle-bar variety; and it doesn\’t let me see myself. Even if it did, it won\’t help me if I don\’t know what to look for!
One suggestion is to watch your shadow; but you have to have the right conditions at the right time of day to benefit from that. Even having a coach alongside would do only so much, I suspect.
Developing good posture habits means that you need to be constantly aware of what your body is doing. On top of that, even if you have that awareness, how can you be sure that what you\’re doing is correct?
As to the lower back, I have rather a tendency to arch my lower back backwards. After a while it starts to ache, and I have to pay special attention to keeping it straight.
My right hand has something of a tendency to go numb and tingling. I think that\’s from gripping too tightly, which can easily happen in wind conditions that make the bicycle hard to control.
Holding correct posture is complicated when you\’ve got a loaded Camel-Bak on your, well, back. But I think I\’d rather be slouched than have dehydration problems. All the same, I need a mirror that lets me see myself as I ride!