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.

Inclusion criteria

• Age 18-60 years
• Onset of ankle sprain at least 2 weeks prior to enrollment
• Foot and Ankle Ability Measure Activity of Daily Living subscale score less than or equal to 80%
• Ankle dorsiflexion range of motion less than or equal to 5 degrees

Exclusion criteria

• Current status of assisted ambulation (eg, use of cane or crutches)
• Inability to bear weight through the affected extremity immediately after injury combined with tenderness to palpation of the medial and lateral malleolar zones, styloid process of the 5th metatarsal, and navicular
• Positive anterior drawer or talar tilt dimple test
• Volume of the affected limb greater than 10% of the unaffected limb
• Previous history of ligament or bony reconstructive surgery to the ankle and foot
• Concomitant injury to other lower extremity joints
• Medical conditions that serve as contraindications to mobilization/manipulation and transcranial magnetic stimulation, such as presence of pacemaker, metal in head, pregnancy, neurological disorders, recent use of stimulants or medications known to lower seizure threshold, and personal or family history of seizures