Muscle Fatigue ...
Acceleration of muscle fatigue occurs when micro-scale damage is caused to the muscle tissue. A modern, wide blade paddle causes an immediate pressure increase which is the aim of the design – the blade ‘sticks’ in the water while the kayak moves past it. In contrast when the long narrow blade enters the water at the start of a stroke the pressure increase on the blade is gradual.
When paddling, the muscles of the arms, shoulders and torso are tensed at the start of a stroke. In this condition the sudden increase in pressure from the European paddle creates a mechanical shock which causes micro-scale damage to the tensed muscles (Lamont 1988b). This micro-scale damage is cumulative and makes the muscles feel stiff after a long day’s paddle.
The Inuit narrow blade avoids muscle shock because of the gradual pressure increase at the start of a stroke. Modern Inuit who have tried European paddles have been reported to remark that they are "too hard on the arms".
- from: Sea Blades: Fashion or Function? (2001) © Peter Lamont, Isle of Luing, Scotland.