Center of pressure during stance and gait in subjects with or without persistent complaints after a lateral ankle sprain.
Kros W, Keijsers NL, van Ochten JM, Bierma-Zeinstra SM, van Middelkoop M. Gait Posture. 2016 Jul;48:24-9. doi: 10.1016/j.gaitpost.2016.04.022. Epub 2016 Apr 29.
Take Home Message: People with persistent complaints 6 to 12 months after an ankle sprain walk differently than those without persistent complaints.
Following a lateral ankle sprain, many patients may suffer deficits acutely that linger long after an initial injury. We can identify people with chronic ankle instability – one aspect of persistent symptoms – by measuring center of pressure (COP) during certain tasks. Unfortunately, it is unclear if this is true for a larger group of patients with persistent symptoms after a lateral ankle sprain. The authors of this study explored if COP measures during single-leg stance and gait differ between people with and without persistent complaints 6 to 12 months after a lateral ankle sprain. The authors defined persistent complaints based on how participants rated their recovery with a 7-point scale (no complaints = fully recovered or strongly improved). Fourteen out of 44 participants had persistent complaints. After being put into groups the participants also completed a Visual Analog Scale for pain, and the Ankle Function Score to measure their pain and function. Participants performed barefoot walking, and single leg stance with and without vision on the RSscan footscan. Patients with persistent complaints exhibited a more laterally located COP during the early mid stance and push-off phase of their gait compared with people without persistent symptoms.
While many researchers focus on chronic ankle instability at 12 months after an ankle sprain these authors looked at patients with persistent complaints at 6 to 12 month post lateral ankle sprain. Hence, the authors examined people recovering from a lateral ankle sprain in a different manner from the norm for chronic ankle instability. Despite these differences, the authors’ findings agree with those found among people with chronic ankle instability. Participants with persistent complaints exhibited a laterally located COP. The authors hypothesized this may be the result of a more cautious roll off during gait. Hence, some individuals adopt coping mechanisms to decrease the load and subsequent pain at the ankle. This is important because while these alterations are done as a protective measure these loading changes can also put someone at risk of re-injury. Since these changes in gait may start as early as 6 months post injury we need to recognize them early. Furthermore, these findings should remind clinicians to focus on gait retraining to prevent the development of poor foot biomechanics.
Questions for Discussion: What can be done to address the laterally located COP that can develop following a lateral ankle sprain? How does this article change the way you view treating a lateral ankle sprain, knowing that persistent complaints can be seen at least six months post injury?
Written by: Revay O. Corbett, MS, ATC, PES
Reviewed by: Jeffrey Driban