Look around and you’ll find lots of linear plyos, but lateral plyos get little love. Most commonly people do heiden variations for lateral plyo work. However, just as people can write, Squat, in their program and have it be a wide stance and 90 degree knee bend variation or a hamstrings to calves Olympic style squat, different executions of the same exercise aren’t created equal and aren’t creating equal adaptations. I’m not to say what’s right and what’s wrong as most exercise has it’s proper context and it’s place, but I think it’s valuable to share how and why training elements within a certain program are done a certain way.
With lateral plyos I like to see square hips to push off and to land. Heiden’s are often done with a lot of twisting behind of the free leg to project (which carries over into the hips and spine) and correspondingly you often see this at landing as well. When implementing lateral plyos, I’m usually either trying to tax change of direction patterns/machinery or generally develop the glute system, lateral subsystem, and couples between hip and lower leg stabilizers (yes lateral plyos do have a place for athletes that run in predominantly straight lines). I prefer square hips for the above goals as it aligns the aforementioned lateral subsystem (glute, adductor, and opposite side QL and sets up hip/leg extension and lower leg toeoff to work directionally versus in a corkscrew propulsion and absorption pattern. To put it in a sport context, most football coaches, and for good reason, wouldn’t want to see their guys free leg flying past their stance foot when they are trying to make or will soon be making cuts.