Table 3 Potential pathological pathways of development of chronic surf-induced shoulder complaints

Muscular imbalance/scapulothoracic dyskinesis

Imbalanced training of external and internal rotators

External rotation only occurs when the arm is out of the water, Pectoralis major, subscapularis and latissimus dorsi well trained in propelling movement of paddling

[16, 19,20,21,22,23]

Muscle fatigue

[25]

Impairment of subacromial space predisposing impingement

Cycling movement of flexed forward and internally rotated shoulder.

Possible anterior glenohumeral displacement.

Possible repetitive decrease of subacromial space

[19, 29, 30]

Forcible elevation at start of pull phase.

Comparable to Neer sign

[31]

Decreased thoracic extension

Possible repetitive decrease of subacromial space

[10, 16, 31]

External factors

Material: wetsuit strain

Impaired ROM, faster cuff fatigue, higher deltoid activity

[20, 27]

Environmental factors

Water temperature, current/water flow

[4, 21]

Material: board type

More shoulder complaints in longboarders

[16]

Further research required; applicable to surfers?

Shortening of pectoralis minor?

Anterior scapular tilting

[16, 19, 28, 29, 32, 33]

Neuropathy of suprascapular nerve or thoracic longus nerve?

Impaired external rotator strength leading to scapular dyskinesis

[34]