Thoracic Spine Thrust Manipulation Compared to Sham Manipulation in Individuals With Subacromial Pain Syndrome

The Penn Shoulder Score is a 100-point shoulder-specific questionnaire with three subscales: self-reported pain, function, and satisfaction with current use of the shoulder. The scores from the subscales are summed to determine the total score with the pain subscale score ranging from 0-30, function subscale score ranging from 0-60, and satisfaction subscale score ranging from 0-10. The total maximum score of 100 points indicates high function, low pain, and high satisfaction with the shoulder.

Pain will be measured using the verbal numeric rating scale (VNRS). Participants will be asked to rate their pain on a 0-10 scale with 0 indicating no pain and 10 indicating the worst pain imaginable. This pain rating will be obtained during active elevation of the arm in the scapular plane.

The participant will start with the involved arm at the side of the body. The investigator will confirm the location of the scapular plane by placing the subject's arm at an angle 40 degrees anterior from the frontal plane as measured with a standard goniometer. The digital inclinometer will be zeroed on a horizontal surface and then placed along the scapular spine of the involved arm. The initial reading from the inclinometer on the scapular spine with the arm at the side of the body will be recorded. The subject will then be instructed to elevate the arm in the scapular plane as high as he/she can go. The final reading from the inclinometer will then be recorded at the end of the subject's maximal arm elevation. The total amount of scapular upward rotation will be calculated as the change score by taking the difference between the final and initial readings. Downward rotation would be recorded as negative values and upward rotation would be recorded as positive values.

The participant will start with the test arm at the side of the body. The digital inclinometer will be zeroed on a vertical surface and then placed vertically along the posterior surface of the medial border of the scapula, using the root of the scapular spine and the inferior angle of the scapula as landmarks as previously described. The initial reading from the inclinometer with the arm at the side of the body will be recorded. The subject will then be instructed to elevate the arm in the scapular plane as high as he/she can go. The final reading from the inclinometer will then be recorded at the end of the subject's maximal arm elevation. The total amount of scapular posterior tilt will be calculated as the change score by taking the difference between the final and initial readings. Anterior tilt would be recorded as negative values and posterior tilt would be recorded as positive values.

Measurements will be made with the subject in standing. The participant will start with the involved arm at the side of the body. The digital inclinometer will be zeroed and positioned as described for the measure of upward rotation active ROM. The initial reading from the inclinometer will be recorded. The examiner can then passively elevate the humerus in the scapular plane to end-range elevation, producing passive upward rotation of the scapula. The examiner will move the subject's arm through the full available elevation ROM passively for two consecutive trials. At the point of maximal passive arm elevation on the second repetition, the inclinometer will again be placed along the scapular spine to obtain a measurement of upward rotation passive ROM. The total amount of scapular upward rotation passive ROM will be calculated as the change score by taking the difference between the final and initial readings.

Measurements will be made with the subject standing. The digital inclinometer will be zeroed and positioned as described for the measure of posterior tilt active ROM. The initial reading from the inclinometer will be recorded with the subject's arm at the side of the body. The examiner can then passively elevate the humerus in the scapular plane to end-range elevation, producing passive posterior tilt of the scapula. The examiner will move the subject's arm through the full, available elevation ROM passively for two consecutive trials. At the point of maximal passive arm elevation on the second repetition, the inclinometer will again be placed along the posterior surface of the medial border of the scapula to obtain a measurement of posterior tilt passive ROM. The total amount of scapular posterior tilt passive ROM will be calculated as the change score by taking the difference between the final and initial readings.

Performed as described previously by Borstad. A tape measure will be used to measure the linear distance in cm between the anterior-inferior edge of the 4th rib one finger width lateral to the sternum and the medial-inferior aspect of the coracoid process of the scapula. This measurement will be completed while the subject is standing in their usual resting position.

A handheld dynamometer (HHD) (Hoggan MicroFET2) will be used to assess force production in standard manual muscle test (MMT) position using a "make test" as previously described. The "make test" will require the examiner to instruct the subject to slowly push into the HHD and increase their force production to a maximal level over a 5-second period of time. Prior to maximal isometric testing, a sub-maximal (50%) effort trial will be performed to minimize learning effects. Two maximal effort trials will be performed with a 30-second rest between trials and the average of the trials (recorded in kg) will be used for data analysis. Additionally, subject body weight in kg will be recorded to allow for normalization of strength measures by dividing by subject body weight.

A handheld dynamometer (HHD) (Hoggan MicroFET2) will be used to assess force production in standard MMT position using a "make test" as previously described. The "make test" will require the examiner to instruct the subject to slowly push into the HHD and increase their force production to a maximal level over a 5-second period of time. Prior to maximal isometric testing, a sub-maximal (50%) effort trial will be performed to minimize learning effects. Two maximal effort trials will be performed with a 30-second rest between trials and the average of the trials (recorded in kg) will be used for data analysis. Additionally, subject body weight in kg will be recorded to allow for normalization of strength measures by dividing by subject body weight.

A handheld dynamometer (HHD) (Hoggan MicroFET2) will be used to assess force production in standard MMT position using a "make test" as previously described. The "make test" will require the examiner to instruct the subject to slowly push into the HHD and increase their force production to a maximal level over a 5-second period of time. Prior to maximal isometric testing, a sub-maximal (50%) effort trial will be performed to minimize learning effects. Two maximal effort trials will be performed with a 30-second rest between trials and the average of the trials (recorded in kg) will be used for data analysis. Additionally, subject body weight in kg will be recorded to allow for normalization of strength measures by dividing by subject body weight.