Chronic ankle instability (CAI), a pathological condition characterized by repetitive bouts of the ankle giving way, commonly develops following a lateral ankle sprain injury. Individuals with CAI have been shown to exhibit deficits in postural control and alterations in movement dynamics, which have been suggested to be contributing factors to the recurrent injury paradigm. The purpose of this investigation was to conduct a comprehensive biomechanical analyses to examine the influence of CAI on postural control and movement dynamics during a single leg squat, side-cut task, and single leg landing on an inverted surface. Fifteen participants with CAI and fifteen participants without CAI completed the study following a between-subjects design, with limb serving as the repeated measure during the single leg squat. Each participant completed a single leg squat, side-cut task, and unexpected and expected single leg landings on a tilted surface. Results from the single leg squat and single leg landings on the tilted surface were analyzed using a 2 x 2 mixed-model ANOVA, while results from the side-cut task were analyzed using an independent samples t-test. Statistical significance was considered for all dependent variables when p < 0.05. Individuals with CAI demonstrated impaired postural control, as indicated by reduced time-to-boundary, during the single leg squat compared to controls. Altered ankle joint kinetics and increased sagittal plane hip joint stiffness were observed in the CAI group compared to controls. With regards to the single leg landings on the inverted surface, during the unexpected landing condition the CAI group displayed altered neuromuscular control and ankle kinematics. However, when the landing on the inverted surface as expected, the CAI group exhibited similar motor control strategies to the control group. Findings from this study indicate CAI alters postural control and movement dynamics during functional and dynamic movements, which may be used by researchers and clinicians to develop rehabilitation protocols to restore maladaptive movement patterns in individuals that develop CAI.

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< 0.031) while no significant interaction was found for ankle strength (p>0.76). For subjective measures, no significant group-by-time interaction was found for the FAAM (p>0.548), 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.

1 Abstract Title Ankle sprain, conservative versus operational treatment: A literature review Aim The main purpose of this thesis is to assess and review the efficacy of main types of conservative and surgical interventions applied on ankle sprain injuries, as also the factors that influence the clinical outcomes in patients undergoing the selected treatment procedures. Method This thesis is a literary research, reviewing articles from relevant journals and books. Information and data sources were retrieved from English, released between 1980 and 2016, using electronic databases and reference lists of articles. The following databases were searched for the highest possible amount of relevant articles, with an attempt to reduce publication and/or selection bias: PubMed, EMBASE, CINAHL, The Cochrane Library (Cochrane Database of Systematic Reviews), Web of science and Medline. Preliminary searches began at the inception of the project, and the full search was concluded in October 10th , 2016. A restriction for the type of publication (meta-analysis, systematic review, clinical trials, comparative trials, practice guidelines and case studies) was applied when allowed by the databases research tools. Results The analysis of the reviewed studies resulted that conservative treatment approaches is the main...