by Charles Poliquin Iron Man Magazine
Q: What’s your opinion about kettlebell swings and throws for improving sports performance and preventing back pain?
A: The basic kettlebell has a U-shaped handle attached to a round weight. Having the handle farther away from the center of mass than on a dumbbell makes it ideal for throwing. The throwing movements go beyond just swinging it between your legs and throwing it forward or behind your head, as you can also use the kettlebells for rotational movements. That has to be done correctly, however, or you can create harmful shearing forces on the spine.
The natural movement of the spine for throwing involves extending it (negative torsion) during the throw and flexing it (positive torsion). You do not want to use a strict horizontal movement, such as rotating the spine around a single axis. From an anatomical standpoint, those exercises will not effectively train the oblique muscles because the obliques have a vertical orientation to the torso. They are called obliques because of their orientation on the trunk, just as the vastus medialis oblique is so called because of its position on the inside of the knee.
So if you are a discus thrower, shot putter, hammer thrower or javelin thrower—which surely constitutes 132 percent of the readership of IRON MAN magazine—then kettlebells can be a valuable tool and thus a good investment for a strength coach.
As for the answer to your second question about the use of kettlebells in preventing back pain: Yes and no. According to spine biomechanics expert Stuart McGill, dumbbell swings create a high level of posterior shearing forces on the L4-L5 vertebrae that may cause back pain in some people. Also, consider that because you develop momentum during the swing, it’s possible that the exercise can move the spine into a position that can cause injury—especially with someone who is extremely inflexible.
The four takeaway points here are that kettlebell swings and throws 1) are valuable for throwers if performed properly and 2) produce shearing forces on the spine that may cause back pain in some people.