Mechanics of rowing accelerations

Mechanics of rowing accelerations

This newsletter will include explanations regarding the mechanics of the boat, rower and system accelerations, along with answers to common questions on the matter.

Firstly, a few general points. The rower is the only source of active force and power in the system moving it forward, and can apply force/power at two points only: at the handle Fh and stretcher Fs (Fig.1). During the drive, a negative (directed backwards, opposite movement direction) stretcher action force Fs is transferred through the boat-rigger to pin force Fp and, together with positive handle force Fh create a torque, which results in a negative blade action force Fb pushing the water backwards. According to Newton’s 3rd law, every action force creates an equal, but oppositely directed reaction force, so negative blade action force Fb creates a positive reaction force – blade propulsive force Fbr – which is the only external force moving the system forward.

Handle and stretcher force are both required and equally important to create oar torque and blade propulsive force.



In stationary conditions, a rower cannot change the ratio of handle/stretcher forces as it is defined by the oar gearing.

In normal dynamic rowing, a rower CAN change ratio of the handle/stretcher forces:

By emphasising the leg drive or upper body and changing the ratio of the handle/stretcher forces, a rower can distribute acceleration of the system between their own mass and the boat.

Legs – trunk – arms is the most logical and biomechanically efficient sequence of body segments.

Q: What about using a stern tubing fountain to control boat acceleration?

A: You can use this method, but common recommendations to keep “the fountain staying put” are simply wrong. In efficient rowing, the fountain should be nearly down at the catch, then should jump up rapidly at the drive beginning.

©2023 Dr. Valery Kleshnev

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