While kettlebells do not get much use by the typical powerlifter, former physical therapist and trainer Scott Iardella shares the benefits of the KB swing for back health (which he defines as possessing a back that is strong and free of injury).

In it, he discusses an interesting study by spinal health expert Stuart McGill, MD based on muscle activation during the KB swing, which included Pavel Tsatsouline as one of the subjects. According to Iardelli:

The study demonstrated significant results in regards to glute activation with the most impressive numbers produced by Pavel’s one hand swing. Pavel generated such powerful muscle activity, his contralateral (opposite side) gluteal muscles fired at 100% MVC (maximal voluntary contraction). Without question, the one hand swing is a proven solution to activate the glutes.

The author goes on to say:

The swing greatly contributes to high levels of muscular activation in the posterior chain, as well as abdominals. The hip hinging mechanics, neutral spine, and powerful strength and conditioning benefits make it one of the most innovative movements we have to optimize and restore back health. As a former back patient and rehabilitation professional, I would conclude that the properly performed kettlebell swing is essential for a high performing and pain free back for most people.

Note that he states "most people" since the mechanics are not good for a small segment of the population. For more info: http://www.strongfirst.com/optimizing-back-health-with-the-kettlebell-swing/