Table 3.

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

Diagnosis	Pathophysiologic mechanism	Causes	References
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, 19–23]
	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]