Bend It: The Science of Gymnastics

While Sands is aware of full body vibration technology, he stresses that his research is based only on limb vibration. Research showing strength and weight loss potential from full body vibration has been contradictory at best. He also notes that full body vibration has a series of potential harmful effects and requires more data before widespread use.

To date Sands has worked with gymnasts, synchronized swimmers, divers and even figure skaters with universal results. The synchronized team like the contraption so much, they reversed engineered it and ordered one for each athlete to take home. The only problem Sands has is finding the right protocol. Apparently they all work. In different studies he’s altered the time on and off the machine and found positive results irrespective of timing. A welcomed complication, we’re sure.

Jump and Jive

It’s incredible what you can see at 500 frames per second. Tell someone to jump, and after asking how high, they’ll bend their knees to a point and then explode upwards and off the ground – down, then up. Simple and efficient. So why are the best gymnasts in the world adding an extra ‘down’ and ‘up’ when jumping on the spring floor and vault? The answer, according to Sands, lies in the floor.

In live footage, one might watch a gymnast on a spring floor and believe they jump just like we do (plus all those twisty things). But after a rash of injuries following the 2003 world championships held in the in the States, the USOC wanted to take a look at their equipment and ensure it wasn’t causing problems.

Sands decided to take high-speed footage [below] of the athletes and the equipment in action. What he found suggested a larger potential equipment fault. Clicking frame by frame through the footage, Sands saw an unexpected, ever so slight, extra down/up in the athletes’ mechanics before launching. Even the gymnasts didn’t know they were adding the inefficient motion. When Sands focused his attention on the spring floor itself, he found an answer to the conundrum. According the Sands, the floor is tuned incorrectly resulting in a rattling that caused the extra hiccup in the gymnast motion.

“Why they would want to bend twice I’m not sure. To comply with a normal takeoff the floor should go down when you go down and go up when you go up,” said Sands. “On a diving board you can move the fulcrum to make it behave the way you want it. Ideally you get the rhythm so you fall on the board when the board is at least going down. If you fall on it when it’s going up you waste a bunch of energy. What we think we’re seeing in spring boards and vault boards is like diving with a board that’s out of tune.”

Testing conducted on floors includes a dropping a weight on the mat to test the springs. While this provides some data, Sands notes it doesn’t accurately represent an athlete jumping and would never detect the minute problems. Sands has found one solution through lowering the stiffness of the springs, but this has an added, less desirable effect, of forcing the gymnasts to go longer on their somersault passes. Combined spring/foam floors could offer some opportunity for improvement but further research is necessary. Linking the issue to injuries or performance is premature at this point, but Sands knows the current situation is not optimal.

“It’s not only inefficient, but you’re going to put a lot of strain on the leg. They have to be staggeringly strong because the apparatus is tuned wrong. The effects on the athletes can only be counteracted by increasing their strength,” said Sands. “It’s a good recipe for rupturing an Achilles tendon”