Risk factors associated with shoulder pain and disability across the lifespan of competitive swimmers.
Tate A, Turner GN, Knab SE, Jorgensen C, Strittmatter A, Michener LA. J Athl Train. 2012;47(2):149-58.
Swimming is a sport that is commonly associated with shoulder injury and pain. Similar to other overhead sports there are anatomic and biomechanical adaptations that occur but in swimming it is often more difficult to detect due to swimming being a bilateral sport. In addition, it is still unknown which of the adaptations are linked to shoulder pain and disability which makes creating injury prevention programs difficult. Therefore, the purpose of the study was to determine if swimmers with shoulder pain (in 4 age groups; 8-11 years, 12-14 years, 15-19 years, and masters) had different physical characteristics, training methods, or swimming exposures compared to swimmers without shoulder pain. The study included 236 female swimmers ranging in age from 8 to 77 years old. The swimmers completed three questionnaires to determine their swimming exposure, shoulder pain and dissatisfaction (Penn shoulder score), and shoulder function (Disabilities of the Arm, Shoulder and Hand; DASH). In addition, the authors measured several physical characteristics, which included passive shoulder range of motion (ROM), shoulder strength, pectoral muscle length, core endurance, and scapular dyskinesis. For shoulder ROM, they assessed internal and external rotation at 90° of abduction, flexion (with the elbow maximally flexed) for triceps tightness, and flexion (with shoulder external rotation) for latissimus dorsi tightness. For strength, the authors assessed internal and external rotation at 90° of abduction, horizontal abduction, shoulder elevation, serratus anterior, lower and middle trapezius. Pectoral muscle length was measured at rest and on stretch at 90° of abduction. Core muscle endurance was assessed with the side bridge test. One examiner assessed scapular dyskinesis visually with a grading scale of normal, subtle, or obvious dyskinesis (winging or abnormal movement) with weighted shoulder flexion and abduction. They found that young swimmers (under 12 years old) had shoulder pain; however, older swimmers had pain, dissatisfaction, and disability. High school swimmers had the most reported exposure and shoulder symptoms. Exposure and previous injury was found to be associated with shoulder pain in the high school and masters groups. Participation in another sport was associated with less shoulder pain. The young symptomatic swimmers (under 12 years old) were found to have reduced shoulder ROM (flexion and latissimus dorsi tightness), muscle weakness (middle trapezius and internal rotation). While the 12 years or older symptomatic swimmers had reduced pectoral muscle length and decreased core endurance.
This is the first study of its kind in swimming and I commend the authors on an extremely great job of providing a complete examination of swimmers. Examining a large amount of physical characteristics in swimmers across the lifespan will allow clinicians to identify the adaptations that develop in swimmers in the presence of pain. To identify true risk factors longitudinal studies are required. However, similar to studies in baseball, the authors found that exposure was related to shoulder pain. Baseball has recently adopted pitch limits in youth leagues; however, swimmers have no such regulations in place. Swimmers often practice twice a day and 5 to 6 days a week. Clearly this amount of repetition may be problematic and may need to be addressed in swimming. Several physical characteristics were found to be associated with shoulder pain. Shoulder flexibility and pectoral muscle length are were associated with shoulder pain and are easy to address by implementing stretching programs to address these negative adaptations. The question still remains at what point do these athletes have too much flexibility? In addition, muscle strength and endurance seem to be problematic. Again, these factors are easily corrected in prevention programs. Imbalances at the shoulder and core can weaken the kinetic chain and therefore cause compensations or increased amounts of stress on certain tissues. Do you see similar adaptations in your swimmers? Do you perform a preseason screen on your swimmers to identify these adaptations?
Written by: Stephen Thomas
Reviewed by: Jeffrey Driban