Correct way to do reverse crunches and what's the progression to do them correctly?

Question

I recently realized I've been doing reverse crunches wrong which lead me to do some research on how to do them correctly.

I looked this up on youtube and I couldn't find an answer because it seems like everyone does it differently. Which one is the right way to do it?

See the example belows:

1. Example 1 : To me this lady does like a bit of leg raise and at the end the actual reverse crunch
2. Example 2 : This guy instead seem to me more focused on bringing his knees towards his chest rather than moving his pelvis off the ground.
3. Example 3 : This to me seem closer to what I think it's correct, although I think the lady gets a bit of energy when lifting her pelvis off the floor by raising the legs at the beginning of the repetion.
4. Example 4 : At 2:50 I think this is actually the right technique (or at least someone would need to achieve). The lady isn't putting her hands on the ground, the lifting of the pelvis is really slow and controlled, and finally there's no so much swinging of the legs around.

Is it just me? I personally see a lot of difference among these techniques.

Also the follow up question, I can't really manage to lift my pelvis like in 4, so what could be a sequence of exercises that would allow me, on the long run, to achieve a similar form at least.

Thank you.

Answer 1

Exercise names is a really complicated thing because everyone tends to find a slightly modified version of the same exercise to be better and over time a lot of versions of the same motion are created, all with the same name.

for this reason there's no real consensus of what a real reverse crunch is the same way there's no real consensus on many other exercises

If a crunch is a spinal flexion by contracting the small muscles between the spinal bones and the abdomen and the result of that motion is the chest reaching the pelvis then a reverse crunch is whatever movement uses brings the pelvis up to the chest.

If you have difficulties with an exercise you need to ask yourself one question:

Do I want to do that exercise?

If the answer is NO then just don't do it and pick another exercise, if however the answer is yes for whatever reason... Maybe you believe that particular exercise looks cool, then you just have to do any other motion that either mimics that movement in an easier manner or with less range of motion until you are able to do the real thing. Other options include training the muscles used in the movement with other exercises until you can do the exercise you wanted to do in the first place by brute strength alone.

To become strong enough to flex your pelvis towards your chest planks are a good start and after you are able to hold them for about 30 seconds you can either keep building uk endurance on them which will carry over to any other abdominal exercise or you can progress by doing another exercise. The second progression is simply hanging on a bar and trying to lift yourself up in a front lever, arms and legs straight and just try to incline your body to at least 85% degrees and as you become stronger lift yourself to 70% maybe.

If you can do those things you will be able to crank as many crunches as you like until you are bored to death.

Disclaimer I must say that some people have the belief that any exercise that flexes the spine is a back killer even though there is small evidence on that, but for pure precautions I suggest doing exercises where your back is completely and unnaturally straight like a pole, specially when you go into a public gym, people are weird and really dogmatic, so if you don't want to be bothered avoid those exercises in public places.