Association Between Chronic Ankle Instability and Sacroiliac Joint Dysfunction
Condition: Sacroiliac Joint Dysfunction
MeSH terms: Joint Diseases
Study type: Observational

Summary: 
      chronic ankle instability previously approved in many studies that it may lead to more
      proximal adaptations and negative long term consequences. one of those studies reported,
      ankle instability patients has hamstring muscle shortening in comparison with non sprained
      subjects. another one concluded that gluteus maximums muscle has delayed activation and
      weakness in CAI patients. Both muscles (hamstring and gluteus Maximus ) contribute to
      sacroiliac joint stability. therefore, this study asked a novel research question, was
      sacroiliac joint dysfunction (SIJD) associated with CAI?
    

Detailed description: 
      The sample size of this study had been calculated based on the primary outcome that was the
      association between CAI and SIJD after a pilot study done in order to detect odd's ratio. ,
      calculation made by a program developed by the Centers for Disease Control and Prevention
      with the following inputting data :

      Two-sided confidence interval 95%, power 80%, ratio of controls to cases 1, percent of
      control exposed 4.5% , odds ratio 32%. The sample size calculations required for this study
      was 28 participants (14 in each group).

      Data distributions was checked for normality using Shapiro-Wilk test and for equality of
      variance using Box's test. Box and whiskers plots were used for detecting the outliers.
      Descriptive statistics calculated for demographic data. Intraclass correlation coefficients
      (ICC) and standard errors of measurement (SEM) were calculated to estimate the intratester
      reliability and precision of measurement for the static pelvic rotation

      The outcomes of these study were:

        1. Association between CAI and SIJD represents through odd's ratio (primary outcome)

        2. Pelvic torsion difference between CAI and control Calculated by Mann- Whitney test
           (secondary outcome)

        3. Correlations between pelvic torsion with perceived ankle instability and number of
           giving way episodes calculated Pearson correlation coefficient(secondary outcome) Effect
           size analysis was calculated to determine the clinical significant difference.
           Statistical analysis was conducted using the statistical package for social studies
           (SPSS) for windows, version 24 (SPSS, Inc., Chicago, IL). The normative data presented
           as Mean ± standard deviation (SD) while non-normative data presented as median.
           Significance was set at p < 0.05 and total study power was set 80%
    

Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Recruited from faculty of physical therapy through announcements for volunteering to
        participate in noninvasive study include patients complaining of ankle instability and
        others did not have any injury in their ankle before
      
Keywords: chronic ankle instability; Sacroiliac joint dysfunction