Analysing the one-leg jump, part V: What does the calf say?!

OK, so we’ve made it throughout the entire kinetic chain in the one-leg jump, covering the upperlegs (we talked about the quads and the hamstrings) and we’ve also discussed other aspects of what is happening good, or bad, in a one-leg jump plant. And in our discussion about the calves and their role, we’re still going to be in the “amortization phase” of the discussion topic.

We have yet to talk about the actual driving, or take-off, phase, when you actually both generate concentric power (upward thrust) and using the momentum that you’ve accumulated in the run-up phase, assuming you had the strength in your shock absorbing muscles not to collapse in the plant to begin with.

This is why before we’re able to jump we must be able to plant and not collapse in that plant. And this is the reason why the muscles that you won’t concentrically use that much, like the quads (and the calves too, in some extent (more about this in a moment)) – need to be strong. You simply can’t have a weak chain when you talk about jumping, especially off one leg. It’s interesting, but a lot of two-foot jumpers can still jump well with weak hamstrings, because they bend their knees and put their hamstrings at a disadvantage anyway. So they can get away with using the combined strength off two legs, but that strength can and often times is limited to just the glutes, quads and calves, leaving the hamstrings out of this equation.

In the one leg jump, you want your entire kinetic chain strong. This includes (and overemphasizes) the hamstrings.

But enough about that, let’s return to our calves. So what exactly is that they’re doing in a one leg jump?

Well, for one, they help absorb tension in the amortization phase. They have two functions in terms of movement: to plantar flex the foot (ankle) and to bend the knee. So in this respect, they have the same biarticulate nature as the hamstrings do. This means that the calves are subjected to the same rules of active and passive insufficiency: the calves are in passive insufficiency when the foot is dorsiflexed (foot pointed upwards) and the knee is extended, and they’re in active insufficiency when the foot is plantar flexed (foot pointed downwards) and the knee is bent.

This will become important when planning what exercises to use for the training of the calves. For example, there are people in my gym that think that doing seated “calf raises” builds the calves. But as we’ve just discussed, that cannot be the case since the knee is bent in that particular position which means the calves become inactive, and the soleus muscle is taking over at that point. The soleus is a slow-twitch (~75% slow twitch) muscle that has little bearing in athletic movements (the calves are around 50-50 in terms of their slow-twitch to fast-twitch muscle fiber orientation).

So, OK, the calves absorb the force in the plant and they prevent the knee from collapsing as well. Because they plantar flex the foot, this means that they also prevent the tibia from traveling forward. This assists in what the quads are trying to prevent from happening in the plant, when they act as knee anti-flexors eccentrically (or isometrically, preferably).

We can thus conclude that the calves assist the quads big time in the plant by doing their job, and that there is a direct proportionality between the amount of knee bend someone will have in a one-leg jump plant and the calf and quad strength of that person:

If the calf is weak and can’t prevent the tibia from traveling forward because it cannot plantar flex the foot with force, then the quad will be asked to compensate by contracting harder as the anti knee-flexor that it is at that point.  And if this is the case, then the quad will be recruited more, which in turn turns off the hamstrings (because, like we’ve already established, the hamstrings are the quads’ antagonists, and they need to relax for the quads to do their job). Relaxing the hamstrings means that a) you’ve lost a potential hip extensor, b) you’ve lost knee stability, c) the knee will travel forward to load the quad more, which in return will shorten BOTH the calves and the hamstrings, putting them at a disadvantage.
So as you can see, just because you have weak calves, there’s a whole chain reaction going on in the entire kinetic chain (pun intended). And this is what we need to understand about the calves: they will create havoc in the entire kinetic chain if they’re weak, because all the power from the upperleg muscles that we have needs to be transferred to the ground, using the right position and the right leverages, through the calves and the corresponding Achilles’ tendon.

And if the calves are weak, then everything is just lost: the power, the leverage, the body position, everything. The calves themselves don’t contribute concentrically much at all. If you get out of your chair right now, stand up, lock your knees and try to jump using just the calves, you’ll barely get off the ground. But their function as force transferring “tools” for the stronger upperleg muscles and their function as anti-leg collapsers is just that important.

You can imagine the calves as the tires of a car: you can have a Formula 1 car with a 800 horsepower engine and a great gearbox (read: explosive athlete), but if you put tricycle soft wheels on this car you will get nowhere (read: bad calves). You need to have a good connection between this ultra powerful car and the ground that it tries to apply its power to, or it won’t work.

Another interesting thing you can observe in great one-leg jumpers is that they always seem to finish on the big toe of the jumping-off foot – pretty much regardless of the plant (or angle) they use. That’s a sign of great ankle extension and also it tends to show that the entire triple extension happened correctly, and that the glutes were involved.

The foot itself also has something called “Meissner corpusculi”, which are the most sensitive nerve endings in the human body. The only other areas that have these corpusculi are the fingertips and the external sexual organs. What does this tell you? Well, it tells you that the body was constructed through evolutionary means to receive a tremendous amount of information through the feet. So the feet, controlled by the calves, the tibialis anterior muscles and a handful of other smaller muscles, receive information from the ground and convey that information to the body (to the CNS) to facilitate proper proprioception.

Proprioception is the body’s ability to be aware of the position of its limbs (for this case). And increased proprioception is synonymous to increased performance and decreased injury risk. This is why I personally jump the best in running shoes – they provide a more low to the ground connection with the surface I’m playing on, giving me better proprioception, and they also allow the foot to move properly and allow the ankle to be mobile, like it has been designed to be. Yes, you can make the argument that because the running shoes have a foam sole, you will lose a lot of energy through the deformation of that material. But I’d rather have that than faulty mechanics and bad proprioception. I completely shut down athletically when I play in basketball shoes, with just a few exceptions. It seems like almost every basketball shoe is created to be very rigid and to completely disconnect you from the ground, making you lose any kind of proprioceptive feedback and transforming you into a quad dominant person by limiting ankle mobility.

For this reason, I like to train the calf muscle-tendon complex doing both calf raises (takes care of the muscle part) and barefoot plyometrics and sprints (takes care of the Achilles tendon and good proprioceptive feedback). I do this on the track. Don’t do barefoot training on hard surfaces!

One final point I would like to make is something that hasn’t been talked about to my knowledge: how come people that are good one leg jumpers and get stronger, while also gaining weight, are jumping lower off one leg even as they are stronger relatively?!

Imagine a hypothetical person: he’s 1.85m tall and weighs 75 kg and has a 1RM squat of 100 kg. He strength trains and is now at 1.85m tall, 90 kg, and has a 1RM squat of 165 kg. Does this guarantee that he will jump better off one leg? Logic would say yes. But in real life it usually doesn’t happen. How so? His relative strength has improved, and he’s nowhere near the point where “he’s too strong to gain power from that additional strength that he gained”. While in the first case his relative strength in the squat was 100/75 = 1.3x, now he’s at 165/90 = 1.83x

The problem is that while the upperleg muscles tend to improve a ton, the calves usually get left behind. They don’t adapt as fast if at all. So you’re going to have a guy with a significantly better relative squat number, only to have the same guy being limited by the calves that are no stronger than when he began improving his squat. And remember, he’s now 15 kg heavier! And THIS is the reason why he can’t jump off one leg better, despite his squat strength gain – his calves are being overloaded and can’t do their job, so he’s collapsing in his plant or, in his successful attempts, he just can’t put into the ground all that upperleg power that he’s worked so hard to build by improving his squat!

So I guess, after this long article, it’s obvious to you to acknowledge how important the calves are for one leg jumping – have weak calves and no matter how strong your upperlegs are, you’re going to suck. This is also the reason why just a few of the big guys in the NBA are/were great one leg jumpers – think LeBron, Charles Barkley or Josh Smith – yeah, they have the structure for one leg jumping, they have the strength – but they also have great calf and foot function – this is what allows them to get up off one leg despite being heavy and muscular.
In the next article we’ll talk about the tendon part of the equation, in what you might find to be the most interesting part of this series of articles.

Finally, I leave you with this:

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