Swimming Technology: History of its evolution
My swimming coach at Indiana University, Doc Counsilman, was the first coach to use slow-motion underwater film to study swimmers back in the 1970’s. From his underwater window in the diving well at Royer Pool, Doc would run his Bolex 16 mm film camera at the highest speed possible, filming Spitz, Kinsella, Hickcox, McKenzie, Jastremski, Stamm, me and many others in super-slow motion. Then he would run to develop the black-and-white film (at his own expense) so he could have it in time to show us in his small office on Sunday mornings precisely how we swam so fast.
By taking a close look at the underwater movements of the great swimmers of the time, Doc uncovered the most important technical aspects of the four strokes. What happened beneath the surface is the part of swimming that no other coach could see with such clarity or understanding, without having these slow-motion films. For his groundbreaking work and extraordinary book, The Science of Swimming, Doc is considered by most swimming coaches to be the father of swimming science.
Doc Counsilman was a pioneer in the science of swimming, employing many technologies to further our understanding of swimming. Here he is pictured with Mark Spitz and me, co-captains of the I.U. team that year
Since Doc’s time, it has become much easier and less expensive for coaches to photograph their swimmers underwater. Using relatively inexpensive high-quality video cameras and software, virtually any coach can analyze the motions of his swimmers instantly. Those underwater images of the swimmers are extremely important for coaches to understand the details of the swimmer’s underwater technique. However, in the end, no matter from what view or how well the swimmer’s motions or angles can be measured, the analysis of a video is just subjective.
In recent years, we have also seen wearable technology become much more common. These devices, connected to the proper software, have the capability of measuring key metrics, such as a swimmer’s velocity, stroke rate, stroke count, distance per stroke, heart rate and more. All of these metrics add to our understanding of swimmers’ techniques and our ability to train them properly. But it is still not enough information.
To really understand what makes swimmers fast or not, we need more. We need to be able to measure the two important forces that determine each swimmer’s speed: drag and propulsion. As we swim down the pool, those two forces are constantly changing and are in a tug-o-war with one another. It is easy to say that we need to increase propulsion and decrease frontal drag, but how? Without measuring those forces, we won’t know.
Estimating the propulsion from the pull has now been made possible through Smart Paddle technology, using force-plate and motion sensors placed within a small hand paddle worn by the swimmer. While many coaches and swimmers still believe that more propulsion is generated from the forearm than the hand, it is not. Because of its shape (flat) and its higher velocity, the hand generates most of the propulsion from the pulling arm. An accurate measurement of the forces at the hand gives us a good idea of the total propulsion from the pull. These paddles measure the forces in all three vectors, vertically, horizontally and backward (propulsion). Often, low propulsion is not the result of a weak pull, but rather from the swimmer generating hand forces in the wrong direction. Without the Smart Paddle technology, we would never know that.
Estimating active drag forces caused by a moving swimmer is much more challenging. Those measurements would be best accomplished by accurate modeling of the swimmer, using animation software replicating the precise size and shape, location and motions of all parts of the swimmer. Then, through computer analysis, using hundreds of thousands of differential equations, the active drag and propulsion forces could be calculated. While using this technology is possible, it is extremely expensive and cumbersome, with limited availability. Its accuracy is also dependent on taking precise measurements and making accurate assumptions, which may or may not occur.
Passive drag forces (holding a fixed position) are much easier to measure using available towing technology and software (Drag/Propulsion Meter (PDM) by AP labs). We have used this technology to measure certain and commonly seen body, head, arm, hand, leg and feet positions that are thought to increase frontal drag. This technology can also be used to compare the drag forces of selected tech suits or racing caps.
We use the PDM technology to measure a specific drag-causing problem. In this study, we were comparing the drag caused by the feet hanging versus pointing the toes. The feet pointing down increased frontal drag by 41% at 2.3 m/sec
To estimate the frontal drag and propulsion forces, we use the peaks of the acceleration and deceleration curves for each swimmer, synchronized to video. The peak acceleration occurs precisely when the peak propulsion forces occur, and the peak deceleration occurs precisely when the frontal drag forces peak. By viewing the video at these peak times, we can usually determine the cause of them. While neither is a precise measurement of drag nor propulsion, using acceleration and deceleration peaks is a user-friendly and inexpensive way to estimate these forces.
We use the peaks and troughs of the acceleration/deceleration curve below (orange graph) to estimate the amount of propulsion and frontal drag and to find the causes of each in the video
The simultaneous and combined use of Smart Paddle (SP) and Velocity Meter (VM) technology, synchronized to the swimmer’s video, is what we currently use at The Race Club to analyze swimmers. While they may be the best commercially-available technology, they are still not necessarily easy to use. The actual measurements do not take long, perhaps 30 minutes or so, to measure all four strokes and kicks. That is just the start. The uploading of files, editing, data extraction from the videos, analysis and the video discussion with the clients takes about 10 hours per study. For each stroke (or kick), we derive from 17-25 different measurements for analysis and have two excel sheets full of data derived from each technology. All of this data is important to help our understanding of the swimmer.
The SP technology (left video) measures forces applied to the hand in three vectors. The VM technology (right video) measures the velocity, acceleration and deceleration every .02 seconds. The two technologies are used simultaneously.
The important data and information, including graphs, are taken from each technology study to be analyzed along with the videos.
We applaud all technology which helps swimmers and coaches improve. In terms of truly understanding each swimmer completely, and how to help him or her improve, the combined use of SP and VM technology, synchronized to video, is currently the gold standard. If you want to take a deep dive on your swimming technique, come to The Race Club for this testing. Let us put you under our microscope.
Yours in Swimming,
Gary Sr.
For the Most Advanced Swimming Technique Videos