Now apart from the obvious jokes about me being from New Zealan
d, we have lots of sheep, and I should get a real girlfriend, this is actually quite a serious Physio term we use when describing one of the dangers of Vibration Training. Especially on High Energy Platforms.
Quite simply it is when the "sideways" forces of the vibration is above a welcome % of the upwards forces. This exact % is unknown and by logical conclusion may in fact be different for most people, depending on age and previous injuries etc.. but the idea of the safety poses is to eliminate all possible problems so we never have to find out, always thinking worse case scenario. Now some people are saying we are too safe, and in reality it wont happen, just a theory, but I experienced it just the other day while testing an uncontrolled Pivotal unit.
This is what happened....
The machine goes up to 34 Hz, only 7 hz higher than the recommended level for an athlete of 27Hz. So I tested it on multiple levels , including the highest setting. Straight away I could "feel" my joints moving sideways in each vibration, and even though it was slightly uncomfortable I would say most people would not be able to pick up on it. They would of just thought it felt "hard". I only did a few minutes on that highest setting, I was actually planning to go a bit longer and I changed pose to see if it could be stopped, but it continued to "shear" no matter what I did. It started to worry me I might really get injured so I stopped. That was 10pm at night .
By morning my right knee was slightly swollen and sore to move , my left not too bad but still full of fluid. Now the importance of that is that fluid collects around an injury to help with the healing process , so actual damage had taken place. It had gone from a theory to reality just like that , and what also concerned me is most people would have just put it down to the "delayed soreness" of a good solid workout. It only took a day or so to go away , but I would not want to repeat the experience anytime soon.
Now I hurt myself on a runaway Pivotal machine that should never have been built or released , a unit that by going too fast flung my bodyweight sideways enough to create the shearing action we try to avoid, but here are other ways to create the same pressure even on a Lineal unit......
(1) "Swinging" or pulling back on the handle bars during a basic squat pose. Think about this.... for every inch of pressure you swing back on the opposing pressure must go on your knees. That’s just basic physics, but then you have to add the force of the plate to that pressure. Not a smart thing to do if you are on a powerful machine.
(2) Some seemingly harmless massages where the direction of the vibration is working at right angles to the joint. I see quite a few of these as promoted as Physio poses, which is correct, but ONLY on Physio/Therapy low energy machines. Also in this category are the massages that are throwing your spine sideways, this is not how the spine was designed to take force, and it will put it under undue stress .
(3) Uncontrolled 3D movement on a Lineal platform . Some companies actually say this is a good thing, they say it will "increase your balance", which might be passable for the truth on a low energy platform but not when you get to a real workout machine. Your joints don’t "learn" to take sideways pressure. They just get worn out like joggers knees.
(4) Abdominal workouts ......
(a) Propping yourself up on your elbows so the vibrations are working at right angles to your shoulders. This may be acceptable at the gym, where you are on a Swiss Ball or workout bench, but neither of those items are hammering your joints at 6 times your own body weight are they ?
(b) Doing a sit up on a plate. The vibrations are traveling directly at a right angle to your spine.
Important note: Abdominal workouts at the gym and Vibration plates are seldom compatible if you look for shearing issues, be wary of trainers just transferring knowledge and poses from one apparatus to the next unless you are sure they are smart enough to understand the physics involved. Ask them and if you get a generic " but I do that at the gym" answer. Walk away. Its your spine we are talking about here.
As I have mentioned before , it is our job to be ahead of these safety issues , we must learn safety principles now before High Energy Platforms become popular and widespread, and with almost every major brand looking to build bigger and better before too long they will be standard in Gyms and Studios alike , it is coming like it or not.
We have to prepare for that eventuality while the industry and consumer general knowledge is still young and malleable. We know from the past from things like jogging that "shearing injuries" can take years to come through. We must be smarter than before and understand you cant just re-educate the consumer on a whim because our "tools" change.
It will be to late , and that sheep would have bolted.