Comparison of Exercise Interventions in Adults With Subacromial Impingement Syndrome

The purpose of this study is to compare two different physical therapy exercise programs in persons who have shoulder pain in order to determine if they have a different affect on pain level and ability to use the injured shoulder after treatment. Both exercise groups will attend physical therapy for an hour,two to three times a week, for eight weeks. The first two weeks of therapy sessions will involve learning the exercises and testing to determine what weight to use during exercises. One group will perform a traditional therapy exercise program for shoulders using hand weights. The other group will perform a version of the same shoulder exercises but with a different exercise technique. Exercises in both programs are part of the standard of care for shoulder impingement in physical therapy but one program concentrates on the lowering portion of the exercise (eccentrics) while the other emphasizes the lifting portion of the exercise (concentrics). Both groups will perform the same warm-up, stretching, and cool-down exercises. Participants will also be required to perform a daily home exercise program of stretches and range of motion that will take about 20 minutes to complete. Exercise testing will determine the hand weight resistance used by each person during their therapy sessions and re-testing will occur every two weeks to determine any changes in the weight used for the exercises to keep them challenging. Pain level, ability to use the injured arm for daily activities, strength, and amount of movement in the shoulder, will be measured at the start of physical therapy and after five and eight weeks (end of study) of the exercise treatments. A concurrent study investigating the reliability of the shoulder motion and strength measurements used in the larger study will also be performed.

Research hypotheses:

1. Adults with shoulder pain who complete the eccentric progressive resistive exercise intervention will demonstrate significantly greater improvements in the outcome measures at three weeks, earlier in the intervention, than the concentric progressive resistive exercise intervention group.
2. Adults with shoulder pain who perform progressive resistive exercise interventions, regardless of contraction type, will demonstrate significant improvement in the shoulder outcome measures at three and six weeks of intervention.