Adarq.org

Kellyb: What is a black person. Serious question.

Raptor you are right. The knee and hip (or quad vs glute) contribution to the vertical jump is variable depending on the individual. Based on biomechanical testing it can be as much as 57% glute to 23% quad on one extreme to 49% quad and 28% glute at the other end, depending on the individual.

Do you think you can change that in an individual or it's strictly related to structure. Obviously it's related to strength as well but do you think someone can suddenly change his jumping style and get higher instantly? I think so and I've done it, and you talked about that (immediate increase) in the VJB if I remember right.

I had one guy that was playing with me who was pretty strong etc but would just go and plant both feet at the same time (ala Justin Darlington) and jumping using his quads a lot (his legs were straight under him and knees were going forward a ton). So I said "how about you throw your legs foward more, in front of you" and he wouldn't understand... so I showed him...

And then what do you know? The next jump doing this, despite him ALWAYS jumping the way I described, quad bound, he got like 4-5 inches higher. I mean, I was expecting "some" improvement but not like that!

Do you think you can change that in an individual or it's strictly related to structure. Obviously it's related to strength as well but do you think someone can suddenly change his jumping style and get higher instantly? I think so and I've done it, and you talked about that (immediate increase) in the VJB if I remember right.

You can definitely influence it to a decent extent.  Try doing a regular RVJ or a series of them and pay attention to how the movement feels. Then do some glute stim...like a few sets of back extension stim or reverse hyper stim....even a hang snatch can work. Then rest a few minutes and do another series of RVJ. Pay attention to how the movement seems to change. You should notice the movement feels smoother, you won't need/want to dip down as far and you'll inherently be primed to drive off the balls of your feet. If your quads are overpowering the movement you'll probably feel it in your knees a bit when you go full bore.  

Backwards depth drops are another decent option although just based on feel they seem to really overload the ankles more than the forward version for some reason.

"I think the muscles you use to amortizate depend on where the body center of mass is. If it's forward then the quads will be loaded because you'd otherwise collapse at the knees. If the legs are reached forward a lot and the butt is therefore behind a lot, then you'd collapse at the hip instead so the posterior chain is activated."

-Totally agree, this is what I was thinking would be the result of this horizontal depth jump, but the amortization is too fast for the hips to really contract. I think you mentioned those hip dominant people have alonger amortization phase? Maybe that is why I did not feel anything in the hips.

Kellyb: i read the entire study, really cool.
My takes on it though. The depth jumps used very high angles of flexion for the hips and knees. I think this may be one reason why the subjects' leg press improved much more than expected. It has routinely been shown that dynamic strength training using 50% 1RM improves 1RM, so perhaps one reason why the strength gains were seen is that even less of a % of 1 RM is required to improve max strength as long as the range of motion is fairly decent. They did not seem to mention this.

All of this can be applied to an RVJ, or this speed depth jump. You can try to be stiffer at the knees or hips to overload any joint. This study though did not illuminate what the biomechanical contributions to work output are by the joints of this type of depth jump. So I'd like people to go try it and report results.


About backwards depth jumping, I love those, and I think we could safely run backwards then absorb the shock as well to overload the pchain. That's really what I was looking to do with this exercise, as I feel as if I cannot reach out before a vertical jump very well. But now it seems to be overloading my quads. It may be due to my natural limb structure favoring quadricep.

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My takes on it though. The depth jumps used very high angles of flexion for the hips and knees. I think this may be one reason why the subjects' leg press improved much more than expected. It has routinely been shown that dynamic strength training using 50% 1RM improves 1RM, so perhaps one reason why the strength gains were seen is that even less of a % of 1 RM is required to improve max strength as long as the range of motion is fairly decent. They did not seem to mention this.

"Yes, you can improve strength using shock training, but it's not a very efficient means of doing so IMO. The stress put on your skeletal system and cartilage is too great, particularly once you get past the beginner level."



What I was wondering here was how the participants increased their leg press strength significantly through the depth jumps. I was hypothesizing that the hip and knee flexion for the HDJ and KDJ turned the exercise more into a power exercise. I wonder how fast they were jumping compared to the ADJ. Also, I was thinking that if the above were true strength gains would be similar to those seen by dynamic strength effort methods.

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All of this can be applied to an RVJ, or this speed depth jump. You can try to be stiffer at the knees or hips to overload any joint. This study though did not illuminate what the biomechanical contributions to work output are by the joints of this type of depth jump.

Look a little closer:

Biomechanical analysis of the modified plyometric depth jumps was also performed to analyze joint contribution through total work done at each joint (Holcomb et al., 1996a). Total work at the hip, knee, and ankle joints was 80%, 5%, and 15%, respectively, during the hip depth jump. Analysis of the knee depth jump revealed contributions of 37% at the hip joint, 49% at the knee joint, and 14% at the ankle joint. The joint contributions during the ankle depth jump were reported to be 24%, 20%, and 56% at the hip, knee, and ankle joints, respectively. Therefore, each depth jump primarily stressed the particular joint for which it was named.

The main thing you should take from that study IMO is the specialized depth jumps over a 12 week period of time didn't increase vert (or anything else really) anymore than the normal depth jumps or improe anything as much as the strength training group. RJ went thru all this stuff for ages before he finally saw the light. You're more likely to tear yourself up and get injured by making your special exercises overly specific then you are to get gains above and beyond what you normally would.  I suggest when you do depth jumps you do them in a manner that feels natural and allows you to get a good jump in. If you want to influence or change muscular contributions use exercises that engage the correct muscle groups, boost their recruitment/function/strength, then reintegrate that back into the depth jump (or any other jump). In other words, isolate then integrate.

When I said "this type of depth jump," I was referring to the one that this thread is about. The speed depth jump, which is slightly different form the ones in this study, and how we do not know the biomechanical contributions of the muscles in that movement since the study was not about it.

Notice I have been trying to say that this speed depth jump I am speaking of is pretty much the same as regular depth jump, in that you can start just as slowly with a 4 step runup, or a faster three step runup, similar to starting off a 12 inch box before progressing to higher boxes. I also said we should stop arguing the specificity of this because it is not much more specific than a regular depth jump I have realized. They are both specific but in differing ways. ( I changed my opinion from the first post). I think it can have similar advantages, and it is fun. Actually, it's exhilarating so I encourage you to try it... and adarq, I want you to at least try it and post results.