I-Acromioclavicular joint:
The acromioclavicular joint is subjected to repeated microtrauma and increased stress to the subchondral bone on the distal clavicular side, predisposing to subchondral fractures and distal clavicular osteolysis (fig. 1 and 2). Acromioclavicular joint cartilage damage and accelerated osteoarthritis might follow. Radiographs help showing more advanced stages with distal clavicular cortical erosions and joint space widening. The superiority of MRI is in demonstrating early and occult abnormalities before becoming evident at X-ray. Fluid sensitive sequences show bone oedema while T1 is better at showing cortical erosions and subchondral fractures [4–7].
II-Rotator cuff:
Repeated arm lifting result in continuous friction and perhaps impingement of the rotator cuff tendons in the subacromial tunnel. Subacromial bursitis and various forms of supraspinatus tendinopathies and often tears are encountered as a result in weightlifters. Ultrasound and MRI are helpful allowing accurate evaluation of the size and extent of tears (fig. 3, 4 and 5) [8, 9].
III- Capsulo-labrum injuries:
Flexing the shoulder onto an extreme overhead position increases the risk of injury-causing shoulder instability. Different types of labrum injuries have been previously reported including SLAP tears, anterior and posterior glenohumeral instabilities with subsequent impaired function besides the persistent pain that hinders adequate training and practice. MR arthrography is helpful in delineating labral tear extent and pattern, capsulo-labrum and ligaments attachments, and cartilage integrity (fig. 5 and 6) [9–12].
IV-Pectoralis major muscle injury:
Although rare in general population, pec-tears are typically common in weightlifters and body builders (fig. 7). The muscle is fan shaped composed of three heads: clavicular, sternal and abdominal; merging into a tendon which inserts along the bicipital groove. The injury is commonly incomplete rupture of the myotendinous junction of the sternal head. A complete tear of its tendinous attachment is less common. MRI is excellent at diagnosing these injuries considering optimizing the field of view and acquisition angles to fully visualize the muscle and its tendon [13–15].
V- Biceps tendon injury:
The biceps tendon is more common to fail and rupture distally at the radial tuberosity. Proximal rupture of the long head tendon has also been reported (fig. 8 and 9). Both ultrasound and MRI are helpful in determining biceps rupture, whether partial or complete, tendon retraction, the presence of hematoma, myotendinous junction and muscle belly and importantly assessment of associated injuries likel rotator cuff tendon or labrum tears [16, 17].
VI- Scapulo-thoracic joint:
In active athletes, continuous sliding movement of the scapula over the rib cage result in soft tissues irritation at the scapulothoracic space that might manifest as bursitis (fig. 9). Subsequent audible or palpable click might be encountered in what is described as snapping scapula syndrome. The latter also includes various underlying anatomical and mechanical etiologies encompassing variations in the anatomy of the scapula bone, periscapular muscles dyskinesia and space occupying lesions [18].