Eccentric training for shoulder abductors improves pain, function and isokinetic performance in subjects with shoulder impingement syndrome: a case series

background: conservative treatments have been proposed for people with shoulder impingement syndrome (sis), such as strengthening of the rotator cuff and scapular muscles and stretching of the soft tissues of the shoulder. however, there is a lack of studies analyzing the effectiveness of eccentric training in the treatment of sis. objectives: to evaluate the effects of eccentric training for shoulder abductors on pain, function, and isokinetic performance during concentric and eccentric abduction of the shoulder in subjects with sis. methods: twenty subjects (7 females, 34.2 sd 10.2 years, 1.7 sd 0.1 m, 78.0 sd 16.3 kg) with unilateral sis completed the study protocol. bilateral isokinetic eccentric training at 60o/s for shoulder abductors was performed for six consecutive weeks, twice a week, on alternate days. for each training day, three sets of 10 repetitions were performed with a 3-minute rest period between the sets for each side. the range of motion trained was 60° (ranging from 80° to 20°). the disabilities of the arm, shoulder and hand (dash) questionnaire was used to evaluate functional status and symptoms of the upper limbs. peak torque, total work and acceleration time were measured during concentric and eccentric abduction of the arm at 60o/s and 180o/s using an isokinetic dynamometer. results: dash scores, peak torque, total work and acceleration time improved (p<0.05) after the period of intervention. conclusions: this study suggests that isokinetic eccentric training for shoulder abductors improves physical function of the upper limbs in subjects with sis.