Ankle Sprains and Corticospinal Excitability

Physical therapists use many ways to treat joints that do not move well. One way takes 1-2 seconds. Another way may take up to 1 minute. Both stretches seem to work, but we do not know how. Certain changes in the brain and spinal cord may cause joints to become more flexible after these kinds of stretches. Right now, we do not have very much information about how these might work in people who have injured their ankle. This study will find out if changes in the brain cause better flexibility in the ankle joint after different kinds of stretches. In this study, subjects with a certain kind of ankle sprains and limited ankle joint flexibility will be assigned to 1 out of 3 groups. Subjects will not get to choose their groups. The first group will have an ankle stretch that lasts 1-2 seconds. The second group will have a stretch that last 1 minute. The third group will have their foot held without any stretching. We will use a machine to stimulate the brain and spinal cord to find out how these stretches affect the brain and spinal cord. The machine sends a magnetic signal to the brain, and we will measure how much signal gets through to the leg muscles using electrodes on the skin. We also will use 3 flexibility tests to find out how well each stretch worked. One test is with the subject lying on their stomach, and the others are with the subject standing up. To start the study, subjects will get their brain stimulated. They will then get their brain stimulated again one hour later. After the second stimulation, subjects will have their flexibility tested and then get 1 of the 3 treatments. After the treatment, subjects will get a last brain stimulation test and flexibility tests. We think subjects that get a fast stretch will have better brain function and flexibility than subjects that get the slow stretch or no stretch. To test our idea, we will compare how each group did with the brain stimulation and flexibility tests. We will also look at the relationship between brain function and flexibility.