Sometimes, which really means most of the time, people tend to gravitate towards the exercises that “seem” the easiest to execute regardless of whether they are good for them or not. The seated or 45° leg press is one of those machines that the average or inexperienced fitness enthusiast will use to “strengthen” the legs. There is an even larger population of bodybuilders that will rack up the leg press with 800-1,000lbs just because they can.
Speaking from experience, it is totally f#*&ing awesome to press that amount of weight. It may not have been the best choice of exercise to load up with a butt load of 45lb plates but sometimes we make choices that are just plain dumb.
The truth about the leg press is that when performed incorrectly (like most people do it) it will cause your pelvis to break away from the spine and cause herniations in your lumbar spine. I could spend some time and take you through spinal anatomy but lets just use the analogy of a disk as a jelly donut and a herniation happening when you step on in causing the jelly to shoot out the little hole.
Now, the problem isn’t the exercise itself but rather the end range of motion. The machine operates in one plane and doesn’t account for the fact that there is a chance that people have varying degrees of hip mobility. Hmmm, who’d of thunk it.
Throughout your lifetime, you only get so many bends in your spine according to Dr. McGill and most of them are used during poor posture, doing things like sitting hunched over a desk, and like so many in the gym: still doing full flexion crunches. Under that premise, doing a leg press might not be the cause of your back problems but in some cases may be the cause of your jelly donut having a wrecking ball dropped on it.
Personally, I do NOT teach clients to use the leg press but have in the past used it as a teaching or rehab tool. Here are a few examples:
- Coming back from knee surgery or rehab
- To teach proper knee tracking
- To work hip stability with your 80yr old grandmother
- Teach the basics of a squat pattern…just the basics, literally
Important: Keep the load very light.
My recommendation to replace this device of pain and misery: learn to move well, then move often. Duh.