Physical Therapy in Corpus Christi for Ankle
Q: Just how long does it take to recover from an ankle sprain? Can you get back to normal in six weeks? Eight weeks? At all? When is ankle rehab needed? These are the questions this group of athletic trainers addressed in their biodynamics research lab at the University of North Carolina (Charlotte).
A: By testing ankle movement three days after an ankle sprain and a second time eight weeks after the injury, the researchers were able to compare the results with a group of normal, healthy adults who had not injured their ankles. They found significant differences in ankle laxity (looseness) between the groups.
A special tool called an instrumented arthrometer was used to measure ankle stability. No one has ever used this device right after injury and compared it to later measurements. This is the first study to do so and to report the results. As with any first (pilot) study, a small number of individuals were included. There were 16 young adults with recent ankle sprains and 16 healthy controls.
The ankle sprain group all had a mild to moderate lateral ankle sprain (lateral means along the outside of the ankle). The sprains were graded as I or II, which means there was at least a partial tear of the ligaments along the lateral side of the ankle. Swelling, bruising from hemorrhage into the area, pain, and loss of motion were commonly reported signs and symptoms.
The ankle sprain group was told to use ice and to elevate the ankle in order to help with the swelling. They were allowed to use an Ace bandage wrapped around the ankle to provide some compression and reduce the swelling. But no one was enrolled in a formal rehab program. That way, they could really assess the natural recovery of this type of injury.
This information is important because ankle sprains are common, especially among athletes. But also because many people end up spraining the same ankle over and over. Persistent pain and giving way of the ankle results in a condition called chronic ankle instability (CAI).
Why does this happen to some people, but not others? The answer to that question remains unknown. One theory is that the damaged ligaments never really heal. Without strong, intact ligaments, the bones can shift more and the joint becomes lax or loose. Joint laxity leads to mechanical instability, which results in CAI. But CAI can persist in patients who have had appropriate rehab following the injury. Even with a year's time to recover, they still have excess motion in the joint.
The arthrometer results showed more anterior (forward) motion of the ankle and more inversion rotation (foot turns inward) in the ankle sprain group compared to the control group. The amount of extra inversion motion available after injury gradually declined during the eight weeks following the injury. No change was observed in the amount of forward displacement between day three and week eight.
The groups also filled out several surveys answering questions about daily function. Analysis of their answers showed a significant loss of function on day three that gradually got better by week eight. But the level of function in the ankle sprain group did not equal the level of function in the control group (or even the level of function of their other, uninvolved ankle).
The authors say they think using the arthrometer gave much better results than just manually testing ankle motion. Using the arthrometer may actually give a better indication of when an ankle sprain is mild, moderate, or severe -- a grading scale that helps guide treatment choices. At the same time, not having the ankle sprain patients in a rehab program may have affected the outcomes. It's possible they would have gotten better faster with an appropriate program.
Future studies need to compare patients with an ankle sprain who do have rehab and those with an ankle sprain who do not. Since many people sprain their ankles without ever seeking help, knowing if rehab might help could place a higher premium on follow-up. Athletes interested in the fastest recovery time possible may be especially helped by this information.
The curious fact that even with rehab, one-third of ankle sprain patients still report instability may be because they were immobilized for a period of time right after the ankle sprain. The authors speculate that preventing joint motion early on may inhibit ligament healing. If this is true, then the current standard of care for the initial injury must be re-evaluated. And, it's possible that a longer period of rehab (beyond eight weeks) is really needed for optimal results.
Reference: Tricia J. Hubbard, PhD, ATC, and Mitchell Cordova, PhD, ATC. Mechanical Instability After an Acute Lateral Ankle Sprain. In Archives of Physical Medicine and Rehabiliation. July 2009. Vol. 90. No. 7. Pp. 1142-1146.