Ever had a physiotherapist wrap a measuring tape in a figure eight around your ankle? If you sprain your ankle, this measurement can tell how much swelling there is from the injury. Therapists sometimes compare these measurements over time, to see whether you're getting better.
 
But how well does the figure-of-eight reading gauge pain and function? Is amount of swelling related to patients' ability to do activities after an ankle sprain? These authors wanted to find out.

Twenty-nine patients were in the study. They were all active in the military. Two-thirds of them were men. Their average age was 31, though ages ranged from 18 to 59.

Patients came into the clinic about three days after an ankle sprain. The authors watched patients walk in; then they gave a score for how much weight patients put on their hurt legs. Patients' ankles were measured with the figure-of-eight. Amount of swelling was determined by comparing patients' injured and uninjured ankles.

Patients filled out two questionnaires. The questions had to do with the amount of pain patients had at different times. Questions also asked about patients' ability to do sports and daily activities.

As the authors expected, results from the two questionnaires were very similar. And questionnaire results were strongly related to how much weight patients were able to put on their hurt legs.

However, the figure-of-eight was not related to any of these measures of pain and function. This suggests that ankle swelling may not be a good measure of how patients are getting along after an ankle sprain.

The authors think that the figure-of-eight is helpful in determining whether swelling has gone down over the course of treatment. But it is not a good way of gauging whether patients are returning to the activities of their daily lives. When it comes to treatment results, questionnaires may do a better job of showing changes in ankle pain and function.