Indeed the ideal is to use your upper body to support transfers rather than your legs and shoulders do tend take the brunt of this. As DJ has mentioned, taking care of yours shoulders is so important as any problem with them can affect transfers and independence.
Butiki, i struggled with transfers for months after my SCI because i damaged my wrist in my fall. It is much stronger now and transferring is better but i have to be careful. The problem was that with one wrist un usable my other wrist took a lot of the weight and i have carpel tunnel syndrome too as Lαrα did.
Sigh
freewheeler, I have RA, so issues with wrist a bit different, but principle of working with a neutral wrist position is the same. If you make a fist and keep wrist relatively straight and lean on finger part of fist, it is much easier on the wrist. Try this!
When I was AB, I helped a friend who was SCI and living from chair 100% to make her apartment accessible. Watching her transfers and learning how she needed to do things prepared me for my current situation. So, in rehab they were amazed that I could transfer as soon as I had "function" to do so--spinal shock slowed me down for a while. My balance is exceptional from working off ladders when AB. Now that rheumatoid arthritis is weakening my joints more, I must be more conscious of how I am moving to avoid more loss of function or permanent injury.