Study on the Effectiveness of Strain Counterstrain in the Treatment of Chronic Ankle Instability Resulting from a Lateral Ankle Sprain

Purpose: To determine the effect of Strain Counterstrain (SCS) on strength, dynamic balance and subjective sense of instability in individuals with chronic ankle instability (CAI). Subjects: Twenty seven volunteers (17 females and 10 males) between the ages of 18 and 55 (mean ± SD age: 33.6 ± 8.8) with a history of CAI who met the inclusion/exclusion criteria were randomly assigned to the control group (n= 13) and the experimental group (n=14). Methods: All subjects signed an informed consent, completed a demographic questionnaire and the foot and ankle ability measure (FAAM), and underwent a standard evaluation, ankle isokinetic testing and the star excursion balance test (SEBT) at the onset of the study. All subjects participated in a home exercise program and received a SCS treatment or a sham treatment once a week. At four weeks all subjects repeated the initial testing and completed a global rating of change (GROC) form. The primary aim was examined with a 2-way analysis of variance (ANOVA) with the treatment group (SCS versus sham) as the between subjects independent variable and time (baseline and four weeks) as the within subjects independent variable. Results: A significant group-by-time interaction was found for seven directions in the SEBT (p\u3c 0.031) while no significant interaction was found for ankle strength (p\u3e0.76). For subjective measures, no significant group-by-time interaction was found for the FAAM (p\u3e0.548), but the GROC revealed a significant difference (p=0.014) in the mean score for the experimental group (3.92 ± 1.66) when compared to the control group (2.43 ± 1.66). Conclusions: Although SCS does not appear to have an effect on strength and subjective ankle function in subjects with CAI, it appears that SCS can lead to an improvement in dynamic ankle stability and the subjective sense of ankle instability. Recommendations: Continued research on the effectiveness of SCS in CAI and other sprain injuries is needed to confirm the results of this study. Given the significant rate of ankle sprain recurrence in this population, long-term studies are necessary. Lastly, very little evidence exists on the effects of SCS and the theoretical framework of this technique