PoloMetrics is an innovative means to measure, quantify and analyze athlete’s movements in the water.
The system was recently developed by Genadijus Sokolovas, Ph.D., the USA Swimming Director of Physiology & Director of Sport Science from 2000 to 2008 and is the water polo equivalent of SwiMetrics. Both PoloMetrics and SwiMetrics are used to measure the instantaneous velocity and force of athletes moving in the water. The athletes’ data is synchronized with underwater video to provide an easy-to-understand teaching and analytical tool for water polo coaches and players (see examples below).
An example of a PoloMetrics eggbeater testing is shown below. The teenage player’s maximum eggbeater height is 42.3 cm which was reached in 0.76 seconds. Her maximum eggbeater velocity was 0.87 meters per second. Repeated tests when the athlete does alternative movements (e.g., bend knees at a lesser angle or extend legs) can empirically demonstrate to the athlete and coach how to improve and what areas to work on.
Photo 1. Right leg eggbeater
Photo 2. Pushing water down with both legs
Photo 3. Moving right arm above the surface and leg extension
PoloMetrics (aka ShootMetrics) is also a means to analyze various aspects of shooting. A concrete example of PoloMetrics shooting analysis is below where a young 11-year-old player was asked to fake once and then shoot. The test demonstrated to the young player how he fakes at his maximum elevation, but shoots as his body is coming down. The overlay of his data with the underwater video helps the young athlete and his coach to visually appreciate how his body is moving through the water and what specifically to improve upon.
Photo 1. Initial fake
Photo 2. Shot
PoloMetrics (aka GoalieMetrics) can also be used to test and analyze for lateral movement, comparing an athlete’s movement to the right and the left, an especially important test for goalies (see two examples below):
PoloMetrics (aka SwiMetrics) can also be used to help athletes and coaches understand the strengths and weaknesses of their sprinting head-down stroke, their head-up freestyle, dribbling with a ball and their initial 3-4 strokes after transitioning from a vertical position to horizontal (after a turnover or defensive stance). In the PoloMetrics examples below, the velocity curve (white line) is dramatically different between the female and male athletes. The more jagged velocity curve of the male indicates greater propulsion from his kick.
The Velocity Curve
The velocity curves in all PoloMetrics tests are a representation of the instantaneous velocities measured and recorded 60 times per second. The PoloMetrics equipment, which is positioned poolside near the swimmer, measures and records the instantaneous velocity (V, m/s) at specific points in the swimming, shooting or eggbeater motions. The test results are synchronized with DartFish software to superimpose the velocity curves with the underwater video in real time.
PoloMetrics Testing Protocol
For eggbeater and shooting tests, athletes are asked to conduct a variety of movements at the side of a pool, ideally in 6 – 8 feet of water:
- Eggbeater up
- Eggbeater to left
- Eggbeater to right
- Eggbeater up with defender
- Fake + shoot
- Shoot with defender
For swimming tests, athletes are asked to conduct a variety of 10 – 15 yard game-pace swims in a lane near the side of a pool:
1. Pull with buoy
2. Head-up sprint freestyle
3. Regular (head-down) sprint swimming
4. Dribbling with ball
5. Start from vertical position and sprint
The system includes a portable PoloMetrics machine that is positioned at the edge of a pool, a Coach Cam underwater camera and a laptop with proprietary SwiMetrics software and Dartfish. The athlete is tethered to the system with fishing line that is tied to a belt around the athlete’s waist. Athletes can receive immediate feedback after each test and/or receive a CD of their data and underwater video for their subsequent study on their own computer. The PoloMetrics system has been compared to a portable wind tunnel for players with instant feedback.
The SwiMetrics system can be set up within 20 minutes and has been used in several countries by national swim teams and by swimmers from Southern California to New York. The PoloMetrics system is currently only available in the U.S. PoloMetrics tests are available from Steven Munatones of Huntington Beach, CA ([email protected]).
SwiMetrics Test and Case Study
Michael Phelps, Natalie Coughlin, Dara Torres, Ryan Lochte, Aaron Peirsol, Brendan Hansen, Amanda Beard, Jason Lezak and many other Olympians, both in swimming and water polo, have benefitted from this technology and analyses.
In early 2008, Dara Torres was the talk of the swimming world. Could a four-time Olympian, a 41-year-old mother and former world record holder make a comeback? Could she win a medal?
Dara was tested at the US Olympic Training Center in 2007. She did a series of 20-meter swims to measure her swimming velocity and enabled her to discover her swimming inefficiencies. Small flaws in Dara's swimming technique were identified – including a reduction in speed when she breathed to the left side versus when she breathed to the right. As a result, Dara started breathing only to the right despite the fact that she had bilateral breathed all her life. Later, Dara did her personal bests at the age of 41, made the Olympic team and won three silver medals at the Beijing Olympics to become one the world’s most heralded athletes of 2008.