But that had me thinking: leverage (by physics definition) is the presence of mechanical advantage through a lever. So parts of the dragon boat stroke must follow that of the lever. So let's explore this idea by modelling the stroke as a simple mechanical system and figure out what we can learn from it.
|Simple lever at equilibrium|
|Lever with offset fulcrum|
|Single sided lever|
The takeaway here is that for maximum mechanical advantage, you want to apply force into a system where the length from your force application to the fulcrum is as great as possible.
Modelling The Stroke
To attempt to apply this information to the stroke, we need to figure out how the stroke is similar to a lever. Since we affect the paddle is two places (the top hand and the bottom hand), we can assume one is the force and the other is the fulcrum.
Top-hand Fulcrum Model
|Top-hand fulcrum model|
|The top-hand model as a lever|
So what we learn from this model is that chocking up on the paddle is actually decreasing our force output into the water. Now the problem here is that according to this model we always have loses of force output due to the difference of the distance between the bottom hand and the blade.
Bottom-hand Fulcrum Model
|Bottom-hand fulcrum model|
|The bottom-hand model as a lever|
But this model has problems. The most obvious is that the bottom hand does not stay stationary when paddling because you would end up with a very short stroke. But that doesn't invalidate this model all together.
|Applying a forward translation to the bottom-hand fulcrum model|
Assuming the stroke can be modeled as a lever mechanical system, we can learn that maximum force application efficiency can be achieved through applying force on the top hand. The bottom hand will still be involved to move backwards as the boat moves forward, but to act as a fulcrum, the bottom arm should be firm and solid (i.e. straight elbow).
Also, in all possible cases, choking up on the paddle will decrease force output into the water.