precision of the results obtained. Pearson Product Moment Correlation was completed to examine the relationship between each independent measure (KJOC, QD) separately with regard to each of the core stability measures. The mean values obtained on all core stability measures in both SDF and NSDF groups had extremely large standard deviations that indicate increased variance and decreased precision of the results obtained. (r2), The authors again neglected to include confidence intervals as well as coefficient of determination decreasing the my confidence in the actual amount of variance, accuracy of the relationship and does not examine the actual magnitude of effect with regard to dependent variables on each independent variable separately. The authors found “moderate” positive correlations between the DLL core stability measure and KJOC subjective questionnaire score, r=0.394 (p<0.05) and “weak“ negative correlation between the right leg SLBT core stability measure and QD scores, r=-0.271. However, The Guide to Evidence-Based Physical Therapist Practice defines a “moderate” and weak” correlations as r-value ranges between 0.51-0.75 and 0.0-0.25 respectively, making the authors results somewhat misleading regarding the strength of correlations between deficits in balance and core-stability with instance of SDF as categorized on the primary outcome measures (KJOC, QD). Based on the literature, the true positive and negative correlations are “fair” rather than moderate and weak. • The actual calculation and proof of Power analysis’ however, implied that the authors wanted to achieve 80% power making the Beta Error level 20% • With regard to the mean values on the SLBT which were found have significant between group difference (p=0.38), the DDS research calculator was utilized to calculate the necessary sample size of each group to reach a power of 0.80 and significance level of 0.05. The results indicate that a sample size of N=21 is necessary in both groups meaning that there was over 20% chance that the mean scores of the SDF group occurred by chance rather than true correlation between deficits in balance and SDF. The authors would have to increase there alpha level to 0.15 to achieve a power of .80. However this means that there would be a 15% chance of type I error, leading one to conclude that supposed effect or relationship exists when in fact it does not. With the amount of variability in results as demonstrated by the large standard deviations, lack of inclusion of confidence intervals as well as only fair to moderate strength of correlations found during the Pearson Product Correlation, it seems as though the authors decided to leave the significance level at 0.05 and neglect to expound objectively on the negative effects of their small sample size within the SDF on the power of the results. Clinical Implications: Though the subject population was composed of over-head, open-chain oriented upper-extremity activities, the studies purpose was similar to my clinical question regarding the contribution of decreased core stability and/or postural control in the development of shoulder dysfunction. The evidence does support the incorporation of independent and/or simultaneous core stability/postural control interventions in the prevention, treatment and rehabilitation of rock climbers with shoulder dysfunction. More research is needed with regard to reliability and validity of core-stability and balance measures with predicting shoulder dysfunction. More RCTs, longitudinal cohort studies with follow-up as well as case-series focused on core stability and balance perturbation in the rehabilitation of shoulder dysfunction of both the general population as well as closed chain oriented sport/vocation. These types of studies would be more apt to show the true strength of correlation between core stability and shoulder dysfunction with less variability and more precision, increasing my confidence in the implementation of such interventions with regard to my own patient population.

## II Title:

Primary Repair Versus Conservative treatment of First-Time Traumatic Anterior Dislocation of the Shoulder: A Randomized study with 10-year follow-up (2007)