The effect of chiropractic adjustment of innervation versus attachment site in the treatment of chronic, active myofascial trigger points of infraspinatus

M.Tech. (Chiropractic)PURPOSE: Shoulder pain has been identified to be one of the most common musculoskeletal problems found in a variety of different countries, showing characteristics of chronicity and recurrence. It is considered to be a main contributor towards nontraumatic upper limb pain. One of the identifiable causes of chronic or reoccuring shoulder pain may be attributed to myofascial pain syndrome which is caused by MTrP’s and produces symptoms that are similar to that of other shoulder pain syndromes. The infraspinatus muscle as an integral component of the rotator cuff complex is subject to high tension biomechanical strain as well as neuromuscular tension. While therapeutic interventions have been devised to treat varying degrees of biomechanical and neuomuscular tension, little evidence exists establishing which of these treatment regimes is most effective in treating myofascial trigger points. The purpose of this study was to compare different regional chiropractic adjustments relative to the attachment site and the innervation segment of the infraspinatus muscle and to identify the most effective treatment protocol with regard to chronic, active infraspinatus myofascial trigger point dysfunction. DESIGN: A selection of thirty participants were recruited for this study. The participants were divided into two groups of fifteen participants each. Group A received a chiropractic adjustment to the glenohumeral joint, the attachment site for infraspinatus muscle. Group B received a chiropractic adjustment to the cervical spine segments associated with the innervation to the infraspinatus muscle. Cervical spine restrictions specific to levels C4/C5 and/or C5/C6, and glenohumeral joint restrictions were determined using motion palpation techniques. All participants received a total of six treatments over a three-four week period. MEASUREMENTS: Subjective measurements were obtained by the Functional Rating Index Questionnaire and the Numerical Pain Rating Scale. Objective measurements were obtained using the hand-held pressure algometer and counting the number of active infrapsinatus myofascial trigger points. The data was collected on the first, fourth and seventh consultations. OUTCOME: With regards to the subjective readings, the results from the Functional Rating Index Questionnaire for the intragroup analysis indicated that the glenohumeral joint adjustment group showed the greatest improvement over time (15.5%). No statistically significant differences were noted for the intergroup analysis. The intragroup analysis of the Numerical Pain Rating Scale indicated that the glenohumeral joint adjustment group showed the greatest improvement over time (68.8%). The intergroup analysis indicated that there were no statistically significant differences. vii With regard to the objective measurements, the intragroup analysis of the pressure algometer readings indicated that the glenohumeral joint adjustment group showed the greatest improvement over time (21.7%). There were no statistically significant differences with the intergroup analysis. The intragroup and intergroup analysis of the number of active infraspinatus myofascial trigger point dysfunction showed no statistically significant differences between the groups or within each of the groups over time. CONCLUSION: The results showed that both treatment groups protocols were effective in reducing chronic, active infraspinatus myofascial trigger point dysfunction. Small differences were noted between the two treatment groups with regards to the subjective and objective findings. The glenohumeral joint adjustment group showed the greatest clinical and statistical improvements over the three-four week trial period