Personally, I played for 7-8 years as a child with an inadequate shoulder rest. It was just a crescent shaped foam covered with cuordory and fastened to the violin with elastic bands. It seemed to be the standard starter level shoulder rest then. It led to bad habits of raising my left shoulder and clutching the violin. I remember wanting a better shoulder rest, but had no idea that my problems with relaxing my left hand were related until I read information in Michael’s posts and lessons. I do not have a long neck, but a good shoulder rest is essential for me to progress with vibrato and makes shifting much better, too. It was one of several factors that led me to quit violin – I freaked out when told to relax my hand, but I was stuck and not progressing to my satisfaction. I had no idea that I needed a better shoulder rest. I thought it was just something that I wanted and too expensive.