Dose Response Effects of Cervical Spinal Manipulative Therapy (SMT) on Pressure Sensitivity of Myofascial Trigger Points

Specific Aim 1: To determine if the effect of cervical spinal manipulation on the pressure pain thresholds in a myofascial trigger point in the infraspinatus muscle can be enhanced and/or extended after a second cervical spine manipulation is given during a single subject visit. H1: There will be a statistically significant increase in pressure pain thresholds in the myofascial trigger point in the infraspinatus muscle after the second cervical spine manipulation, as compared to the first. Specific Aim 2: To determine if the effect of two cervical spinal manipulations on pressure pain thresholds in a myofascial trigger point in the infraspinatus muscle will be present at 48 hours follow-up. Data will be collected for descriptive purposes and hypothesis generation.