Professor Lennon is planning to do a research study to show the outcome of a serious back injury involving the spine and the possible effects on the part of the brain affecting balance and coordination. To conduct her study, she will need volunteers to have a painful spinal tap procedure which would simulate the damage associated with severe back injuries. The spinal taps have a slight chance of causing severe pain that could last for several days. There is also a very slight risk of nerve damage that could cause some short-term paralysis. Subjects will be informed of the risks involved and will be paid $1200 for the spinal tap and for a six night stay that will be required to evaluate the outcome after this procedure.