Arthrogenic Muscle Inhibition in Ankle Instability

Abstract

Ankle sprain is the most common injury among athletes and in the general population. A previous ankle sprain is a major risk factor for re-injury or the development of instability. Instability may be related to the neuromuscular changes after the injury. These include arthrogenic muscle inhibition (AMI), which is likely to be influenced by central regulatory mechanisms that lead to reduced muscle activation after injury. Our aim was to determine whether AMI is present in subjects after acute ankle sprain or in subjects with ankle instability. The literature search were performed in PubMed, Cochrane Library, EMBASE (Ovid) and Medline databases. We used a combination of English keywords. In addition, the literature lists of included studies were reviewed. Studies were screened regarding the inclusion and exclusion criteria. We included five studies investigating the presence of AMI in subjects with ankle sprain or /and instability. Statistically significant reduced activation of m. soleus was reported in four studies. In two studies, reduced activation of m. peroneus longus was reported, but only in subjects with ankle instability. Conclusions: We found that AMI, manifested as reduced activation of m. soleus and m. peroneus longus, is present in subjects with ankle sprain or instability. Inhibition is present bilaterally only in the acute phase. The mechanisms of AMI are most likely not only under local control, but also under central control. Keywords: Ankle sprain; Ankle instability; Arthrogenic muscle inhibition