Sports imPULSE

Know Your Sport: Gymnastics - Jumping and Jiving

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, 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.

The USOC reviewed the high-speed footage of the athletes and the equipment in action.  Clicking frame by frame through the footage, they noticed an ever so slight, extra down/up in the athletes’ mechanics before launching. Even the gymnasts didn’t know they were adding the inefficient motion. They turned their attention to the floor itself and noticed that it was tuned incorrectly resulting in a rattling that caused the extra hiccup in the gymnast motion.

The little things do make a big difference, so the USOC has been testing various combinations of spring / foam floors which has offered some opportunity for improvement, but further research is necessary.  We've been writing on this blog for some time the importance of proper biomechanics and injury prevention, in this case the equipment exacerbated the problem, which went unnoticed without the help of high speed cameras.

Jockeys Figure Out The Science Of Speed

Over a century after a Yankee Doodle jockey revolutionized how racehorses are ridden, scientists are figuring out why a jockey’s posture speeds up the horse.

Hint, it’s not wind resistance. That tough balancing crouch saves the horse some energy.

In more than 100 years of recorded race times, the biggest improvement in speed — a 5 percent to 7 percent change in the U.S. and Britain — came around the turn of the 20th century when jockeys changed their posture

The jockeys’ crouch lets them isolate their bodies from the horse’s movement — the horse is moving up and down a lot more than its rider. When the horse’s feet hit the ground, its motion temporarily slows until accelerating again with push-off. Through incredible effort that makes the jockey’s legs act like a spring, his or her mass stays at a more constant speed. It’s basic physics, as I am told.  I think I missed that specific physics class.

The Secret of Hockey's Wrist Shot

It takes less than a second, but the wrist shot in hockey is one of the hardest skills in sports to master. Just ask the Pittsburgh Penguins and the Detroit Red Wings who are now facing each other in the Stanley Cup Finals. Both teams know the value of the "quick wrister" and the scoring chances it creates. Now, a team of Canadian (of course) researchers believe they have isolated the key components of a successful wrist shot using 3-D motion capture analysis.

Twenty five hockey players, ranging in skill from novice to varsity level players, were told to shoot pucks at targets located in the four corners of a goal until they had hit each target ten times. They were allowed 20 shots per target with their accuracy percentage recorded. Their sticks and pucks were marked with reflective stickers that could be seen by six 3-D motion capture cameras placed around the goal. Everything from the angle, pitch and yaw of the stick blade to the stick velocity and contact time between puck and stick were measured as possible variables for accuracy.

The findings by the research team noted that the flight of the puck is affected by gravity, the initial trajectory of the puck now becomes important. Just like a baseball pitch, the faster the object travels, the flatter and more accurate the trajectory. Imagine the flight path of a fastball versus a curve ball.  The team found that faster initial puck velocity when released from the stick significantly improved accuracy.

Also important was something called the blade's "roll angle" at puck release. Video of the expert players showed that when getting the puck ready to shoot they drag or draw in the puck and the stick's blade closer to their feet. This would let them use their wrists more to give the stick that well known "flick." The beginner players would more often push the puck forward without any pre-shot adjustment closer to their body.   More info can be found at Live Science.

Research in this area is relatively new.  However, it is good to see the emphasis on bio-mechanics on athlete movement and basic skills.  The increased understanding should help teaching and coaching to optimize skill development.

Improve Your Rowing Posture With Rowergo BRace

How can back pain be prevented AND performance improved for rowing machine users?  Meet the Rowergo BRace 9pronounced 'Bee Race').  The BRace is an accessory for an indoor rowing machine.  It is attached to the main bar of an indoor rowing machine under where your knees would be.  By replicating the kind of set up that an on-water rowing boat has, it keeps your legs from fully extending, thus helping maintain good posture which significantly reduces the risk of back injury, as well as setting up a more powerful body position, which can translate to an improvement in performance.

HOW DOES IT WORK?
The Rowergo BRace attached to the monorail of all Concept 2 rowing machines.  If is fully adjustable and is positioned under the rower's calf muscle to maintain a slight knee bend.  It is this need knee bend that allows the rower to physically maintain the correct posture for most efficient rowing.

Windmill Pitching Linked To Bicep Injury

From time to time we like to highlight aspects of bio-mechanics and the related importance on the development of the athlete and impact on a sports organization.

US researchers think that the "windmill" pitching motion may explain the high incidence of anterior shoulder pain seen in female softball players.

Although the conventional belief has been that the underhand throwing motion of softball places little stress on the arm there is a growing body of evidence to say that is not the case.

A study was conducted involving seven women -- three collegiate and four professional pitchers -- who underwent motion analysis and surface electromyography to evaluate the muscle firing pattern of their biceps in the course of a windmill pitch. Electromyography detects electrical potential generated by muscle cells when they contract.

The study, published in the American Journal of Sports Medicine, found that even though the upper arm movement in both baseball and fast-pitch softball gives the ball about the same velocity, muscle force during the windmill pitch was much higher.

Moreover, the maximum force, or maximum contraction, occurred not when the arm was cocked, as in baseball's overhand pitching, but when the arm circled around from the 9 o'clock position, almost fully extended back, to the 6 o'clock position, perpendicular with the ground, completing its windmill motion to release the ball. Consequently, the biceps, not the elbow, takes the majority of the stress.

Motion Analysis Can Now Used Be Used To Ski Faster

Bio-mechanical analysis isn't just for baseball players anymore.  Professional skiers can now learn how to ski faster with the aid of a new system used to capture 3D motion of athletic movements called Fusion Motion Capture.

Fusion Motion Capture, developed by Massey University PhD student Matthew Brodie, is a system which uses small sensors attached to the athlete’s limbs, helmet and soles to generate raw data from an athlete’s movement. The numbers are then crunched with the aid of a computer to reproduce accurate estimates of the position, velocity and acceleration of the athlete. 

Using Fusion Motion Capture ("FMC"), it is now possible to capture motion and dynamics of alpine ski racing throughout the ski run while maintaining high resolution. This represents the first time full body motion of an athlete skiing an entire course can be captured. 

FMC is developed to capture motion in large spaces which is impractical for video motion capture. Previous video analysis required several weeks to measure only a few turns, with FMC,  it is now possible to collect and analyze several hundred turns in a single day. 

Bio-mechanical analysis through FMC can not only optimize skiing motion, but can provide insights into race strategy and equipment changes, which can increase an athlete's speed.  For example, it is now possible to measure how ski friction and wind drag can affect performance and apply this info for respective race strategies.  

And to think, I'm happy if I make down the mountain in one piece...

Motion Capture for Baseball's 2K9

Sports Illustrated magazine called Tim Lincecum "the freak," and for the motion capture specialists at 2K Sports, getting a good computer model of baseball star Tim Lincecum's unique, and violent, pitching motion presented a special challenge.

Last month, Lincecum, an average 24-year-old whom you would never pick out of a lineup as a superstar ballplayer, won the National League Cy Young award, given to the league's best pitcher. The same day, the San Francisco Giant found out that he'd been chosen as the cover athlete for Major League Baseball 2K9, 2K's hit baseball video game.

 We've highlighted several motion capture options over this past year as this is an important field to obtain accurate measurement to aid in injury prevention.  At 2K's motion capture facility, Lincecum begins by putting on a spandex suit and technicians placing a series of reflective markers all over his body. These, are designed to capture and reflect the light from 56 motion capture cameras spread throughout the facility so that the computers can record the minute movements of the athlete.  This is then translated into a 3D model of his skeletal structure that is used as the base for his in-game avatar.

To blend the many motions together and create a single smooth move for the game, the technicians take different recorded motions and blend them together creating a blended pose, thus eliminating what would normally look like a jerky transition.

Although, this motion capture activity was specifically for a video game, I look forward to the day when motion capture will be more commonplace for everyday athletes.

Wireless Motion Sensors - They Can Now Help Treat Football Injuries

Does this sound familiar?  You've just had a sports injury and during the rehab process your therapist or sports medicine specialist hooks you up to a number of sensors to start taking the necessary readings.  The challenge is with all those wires.

The Core:Tx(R) rehab product and therapy system from Performance Health Technologies looks like it solved the wire problem.  Designed to enhance existing rehabilitation as well as preventative and strengthening protocols, Core:Tx(R) turns rehabilitation into a wireless, game-like challenge that is entertaining and works for a variety of patients recovering from both neuromuscular conditions and joint injuries.

Core:Tx(R) is a patent-pending wireless system built on PHT's innovative MotionTrack(TM) platform, used by professional sports teams. It combines hardware and software operating on a PC as well as a soap bar-sized motion-sensing device that can be attached anywhere on the body with adjustable straps. This device senses the user's limb motion relative to the joint and continuously transmits that information wirelessly to the software. This real-time visual feedback helps keep the patient engaged in the therapy routine, while simultaneously aiding neuromuscular reeducation and strengthening muscles throughout an adjustable range of motion.

We are beginning to hear about more about wireless motion analysis systems, but haven't seen any in action.  If anyone has seen any, please drop us a comment.

The Athletes' High Tech Help Desk

We all know the growing popularity of competitive sports in the US, that is why we dedicate this blog to highlight technologies that assist the athlete, coach, scout, team and organization.  Given this popularity, it might not be surprising to know that 10 million sports injuries are treated each year across the nation.  The most common sports injuries, according to the NIH (National Institutes of Health) are sprains, strains, knee injuries, swollen muscles, Achilles tendon injuries, shin splints, fractures and dislocations

Sports injuries are not only reserved just for competitive sports -- they also occur while training, weight-lifting or simply going for a jog.

To extend the career of an elite athlete or for the weekend warrior to simply enjoy their favorite activity, prevention becomes of paramount importance and relies on conditioning the body and monitoring how the body is used.

Development of new technologies are enabling sports physicians to understand better what causes sports injuries, which in turn aids in preventing them. By monitoring how athletes carry out their repetitive movements, such as pitching a baseball, serving a tennis ball or throwing a football, experts can single out what types of movements strain the muscles and result in injury.

The Motion Monitor by Innovative Sports Training can give physical therapists real-time, objective measurements of joint movement in athletes' bodies and create corresponding animation of how the athlete moves.

Other technologies enable biomechanics specialists to examine athletes' movements in the same way you watch movie animation. Using high-speed motion capture cameras, hidden force plates in the floor and electromyography (yes, that was a tough one for me too)  equipment, a 3-D animation is created of the athlete's movement that can be viewed from multiple angles providing the specialists with highly valuable perspectives.

Now, I wonder if they can do something for my golf swing....