I found volunteer work by emailing multiple private practices. You can even make cold calls. I've noticed its getting a little more competive but look beyond what in front of you. Check all kinds of rehabilitation centers, special disabilities camps, day cares. Also you have to be willing to travel. I had to take a bus and two trains for one of my volunteer places. In the end it worked out because she wrote me great recommendations and I got into graduate school. Not to mention you can start networking. If all else fail you can volunteer at a hospital and try to get placed in their rehab department.