9 Richardson10 estimated that during a training year, a competitive swimmer makes 1.32 million strokes per arm. The cause of the painful shoulder in swimmers can be attributed to a myriad of stroke flaws. It has been reported that most swimming injuries are due to repetitive microtrauma and overuse,

with many of these injuries actually due to faulty technique.6 and 7 Repeated microtrauma (overuse) and subsequent pain and tissue injury to the supporting tissues (such as the rotator cuff and long head of biceps tendon) around the shoulder also lead to poor performance. The canoeing literature is more limited with less epidemiological data, but what little has been reported indicates EGFR cancer that shoulder injuries are common.1 and 11 In this case, the repeated paddling action is hypothesized

to be responsible for overuse injuries such as rotator cuff tendinitis and subacromial impingement.5 In common with swimming, these problems may be related to the sport-specific demands of increased shoulder range of movement, increased internal rotation and adduction strength, and prolonged shoulder-intensive training.11 Several studies have shown that athletes engaged in overhead sports demonstrate increased external rotation with a concomitant loss of internal rotation.12 and 13 Warner et al.12 found that anterior instability was associated with DAPT datasheet excessive external rotation and decreased internal rotation, which could then Bay 11-7085 be related

to the development of secondary impingement syndrome, but this study was in overhead throwing athletes. Ellenbecker et al.13 reported similar findings in tennis players. However, this situation might not be applicable to swimming and canoeing. As Weldon and Richardson14 reported, most shoulder pain is caused by instability, which in turn is related to the sport-specific demands of increased shoulder range of movement, increased internal rotation and adduction strength, and prolonged shoulder-intensive training. The shoulder flexion ROM is critical to both swimming15 and canoeing in order to provide maximum available reach prior when delivering shoulder extension, adduction, and internal rotation to produce greater motive force in the water. This motion requires the latissimus dorsi to generate a significant proportion of the force required.8 and 16 The constant loading of the latissimus dorsi with repetitive training will produce muscle hypertrophy, but will also likely result in increased muscular stiffness and resistance to elongation.17 Shoulder flexion requires an optimal length of the latissimus dorsi muscle in order to allow for full lateral rotation of the humerus and upward scapular rotation (maintaining the optimal subacromial space between the greater tuberosity and the acromion), thus preventing impingement during elevation.