Grand Slam tennis surfaces, Australian Open tennis, heat stroke, electrolyte imbalance, hard court heat, hard court injury, hypernatremia, hyopnatremia, salt, dehydration
Perfect Storm Injuries on Artificial Surfaces
In our Institute the search for organisms adapting to extreme environments usually takes us to sites far removed from everyday life: high mountain alkaline lakes, acid mines deep in the earth, basalt lavas underneath the ocean, Death Valley, ice caves in the Alps, and the ice lakes of Antarctica. At each site life is most often threaten by extremes in one or more of six environmental characteristics: temperature, water deprivation, sheer forces, electrolyte imbalance, and pH. Interestingly, one of the most extreme environments on planet Earth occurs much closer to home: the artificial playing surfaces increasingly common in football, soccer, and tennis.
The high temperatures (170o to 180o F) characteristic of artificial surfaces in hot, sunny climates can raise core temperature of an athlete to heat stroke levels and produce severe electrolyte imbalance. Both changes impair neurological and muscular performance.
In contact sports, such as soccer, football, and rugby, the neuromuscular alterations combined with the unyielding nature of these surfaces put athletes in danger of life-threatening head trauma.
In sports requiring sustained levels of precise coordination between legs, hands, and eyes to repeatedly execute rapid changes in direction, such as tennis, these surfaces increase the frequency of career-ending shoulder and knee injury.
We are currently exploring imaging technologies that might help detect and monitor what might be termed "Perfect Storm" injuries during prolonged competition in high temperature on artificial surfaces. The three converging "storms" are
1. Coefficients of friction for surfaces and shoes increase with increasing temperature.
2. Athlete core temperature and electrolyte changes alter nerve and muscle performance.
3. An unexpected event late in competition demands an exceptionally rapid response.
The first two changes lead to the improper execution of a well-practiced movement when the athlete tries to respond to the unexpected event.
The resulting injury often does not stop the athlete from competing at first. Unfortunately, returning to competition unaware of the damage sets the stage for repeated injury and, ultimately, surgical intervention.
Football Example - Subclinical concussions
In football, the classical example is a quarterback normally proficient at avoiding helmet-to-helmet hits, suddenly stands tall, peripheral vision fails, reactions slow transiently, and he goes down briefly following a helmet-to-helmet or helmet-to-ground event. In the "old days", he would get up woozie, joke that he "had his bell rung" and continue to play. At practice the next week his team notices he is "not quite as sharp". During the next game day, he does not defend himself quickly enough and sustains a severe second concussion.
Fortunately, for head injuries in professional football, numerous efforts are finally underway to intervene in high-risk contact events, formalize the evaluation of concussions, and evaluate the risks of returning to competition. The same cannot be said for professional tennis.
Tennis Example- Unstable strokes such as the Reverse Forehand
In tennis, a classical example of a perfect storm injury occurs when a deyhdrated or improperly hydrated player deep in a long match falls slightly behind in a point. The athlete suddenly executes what would, even in the best of conditions, be an unstable shot such as a running reverse forehand.
Now, tired, off balance, and falling backwards with hand-eye-foot coordination impaired from heat and electrolyte imbalance, a hot, sticky, unyielding court grabs a shoe. The athlete's trunk stops abruptly disrupting his gait and the kinetic chain. The athlete asks shoulder muscles to compensate for the forces that should have been provided by legs and trunk. Shoulder muscles contract too rapidly and the already appreciable torque and direction changes required by the reverse stroke produce a subclinical shoulder injury that goes unnoticed at first.
Over the next several months nagging shoulder and back pains increase, forehand and serve shot accuracy decays, and the initial injury slowly worsens into what will later be detected by MRI as a full tear, impingement, or avulsion. Following surgical repair, a series of decisions will be made without accurate information.
Unaware of the initial "Perfect Storm" event, surgeon, athlete, and rehabilitation staff can only attribute the injury they see to chronic overuse or misuse of, most likely, either the serve or forehand. Post-operatively, athlete and coach do not know if they can trust the athlete's strokes, training strategy, or playing frequency. With a lack of confidence in favorite strokes that must almost seem like betrayal, it is little wonder that so many elite players have great difficulty coming back to full form post-operatively.
Unfortunately, our understanding of single event (or recurrent) shoulder and knee injuries on artificial surfaces, is progressing only slowly. Preliminary studies of shoulder recovery for baseball pitchers indicate it is possible to monitor joint stress and recovery to determine limits on number of pitches and competition frequency. Unfortunately, the techniques are cumbersome.
We in the medical community need to provide athletes and their staff with methods to detect what begins as a subclinical (invisible) injury before it evolves into a career-altering disability. At the very least we need to help them pinpoint the cause.
What is needed is improvement in technology (and cost) for hand-held infrared and sonographic imaging. (See the accompanying entry on tennis injuries.) We need to make these techniques available to athletes for routine evaluation of shoulder and knee physiology following their matches as part of the post-match debriefing process. With the ability to routinely follow both the physiology and structure of at-risk joints, athlete and trainer can make informed decisions about competition frequency and stroke choices.