Skip to main content

Is flexion dangerous? Perhaps not, according to science.

Eddie Hall lifting 500kg with a flexed spine

Preamble: Why forces on the low back are about the same regardless of how you lift

Part 1: Pig spines in a machine are injured by flexion… or are they?

Read the study: Callaghan & McGill, 2001

Part 2: Pig spines in a machine are injured not by flexion, but rather by LOAD

Read the study: Gooyers et al., 2015

Part 3: Studies on lifting biomechanics in live humans

Part 4: Combining live human studies with cadaver studies shows discs are subject to LESS load as the spine flexes

Read the study: Dolan et al., 1994

And, just for good measure, Legendary Moments In Deadlift History.

Many, many world-record deadlifts done with LOTS of spinal flexion. As we saw in the Dolan et al. paper, humans can generate much higher forces with the spine in flexion. Here are many examples of that.

These people built up load tolerance gradually over many years. It’s not the alignment, it’s too much load too soon that is the important risk factor in lifting.