Reverse hyper machines are rare in commercial gyms, but you can find them in powerlifting gyms and CrossFit boxes. Here's what you need to know if you have the opportunity to use one.
1 – Single-Leg Reverse Hyper
If reverse hypers don't come easily your first try, then master the single-leg version before moving on to the bilateral variation. Make sure the non-working leg is out of the way of the pendulum. Start with your weaker leg first, then repeat with your stronger side.
2 – Swinging Reverse Hyper
This involves flexion and extension of the spine and is mostly a concentric-only movement. This variation seems to be common with Westside powerlifters who want to increase their concentric posterior chain power. Forcefully drive the pendulum up on the concentric (lifting) phase, then let it swing passively during the eccentric (lowering) phase.
3 – Strict Reverse Hyper
Minimize load and momentum with the strict hyper. This is an underused version in strength training circles.
4 – Neutral-Spine Reverse Hyper
It's virtually impossible to keep your spine neutral with these. So the neutral-spine reverse hyper is a misnomer. So just minimize spinal and pelvic motion and produce most of the motion with your hips. This requires eccentric absorption with the hams to restrain the pendulum and prevent spinal flexion at the bottom of the movement. It also requires a strong glute contraction at the top to limit spinal hyperextension.