Strong Enough? Thoughts from Thirty Years of Barbell Training

by Mark Rippetoe

For example, in a clean the power is generated by the extension of the knees and hips applied by the feet against the ground, and it is transferred up the back and down the arms to the bar. The efficient transfer of power along the trunk segment is possible only if the muscles that stabilize the trunk are able to hold it in perfect isometric contraction during the transfer. Any laxity in the back causes some of the power that would ideally get to the bar to be absorbed. In the same way that towing a car with a long spring is not as good an idea as using a chain, a mobile segment absorbs force that an immobile segment would transmit.