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July, 1997: Perth, Western Australia:
NEW EMPLOYER:”?Working here at the , you and another of your colleagues will provide sports science services to each of the 16 sports we fund. You will each service half the sports.”
NEW GRADUATE (ME):Excitement! Which sports am I going to work with: athletics, swimming, gymnastics?
NEW EMPLOYER:”And the first sport we would like you to become involved with is “(mental drum roll)”… baseball.”
I felt my stomach hit the floor. Baseball! I didn’t even know it was played in Australia! And what would a 21-year-old girl, born and raised in Australia, know about it? In 4 years of sports science study at the University of Canberra, everything about this American game had managed to completely circumvent me. I knew more about the biomechanics of croquet than I did of baseball. And now I was facing an expectant coach and a squad of teenage boys all watching me, and I could see in their eyes the vivacity of their dreams of becoming professional players in U.S. Major League Baseball (See box below). Gulp …
Seven years on, I smile looking back at these moments of both panic and trepidation. I would never have thought these would be followed by a trip to the other end of the world (even less by a master’s degree and Ph.D.) or that I would spend time chasing solutions to the biomechanical problems associated with baseball.
My Journey Begins
WAIS coaches and players refused to let me wriggle off the hook. They would occupy my office, having brought along their gloves, baseball magazines, and stories, and would question me endlessly. “Watch this,” they’d say, “tell me why this technique works better with that bat than this one. …” They would also plant a cap on my head and tow me out to the practice field: “See that guy? He’s 6 feet tall and has an arm like a piece of elastic. So, why can’t he throw a decent curveball?”
It could have put me off baseball altogether, but it had quite the opposite effect. Baseball and I became inseparable and my involvement with the sport has been the most enriching experience of my career. It has taken me all around the world. I have learned about the motions required to produce some of the most remarkable performances in sports: hitting home runs and throwing balls at close to 100 mph. I have begun to understand the effect on the human body of such performances–the stress on joints and the effect on soft and hard tissues. It was my job to develop training programs that would allow athletes to execute these performances while protecting them from the inherent musculoskeletal dangers.
I became more and more fascinated by the biomechanics of the game. How could a player generate 7000 degrees per second of angular rotation in the shoulder joint to throw a fastball without having his arm falling off? How come hitting a ball with a metal bat gives so much more speed than with a wooden one?
My interest grew to the point where I became frustrated at the lack of interest paid to the game by the sports science community in Australia and consequently the scarcity of opportunities. Unless you work at a sports institute itself, there is no chance of employment as a sports scientist for baseball in this country, as there is little interest from the universities in sponsoring research in this area. It became clear that if I wanted to really take part in the game, I had to go to the home of the game itself: the United States.
The American Sports Medicine Institute
The American Sports Medicine Institute (ASMI) in Birmingham, Alabama, provided the opportunity I was looking for. They have a student internship program that enables college and master’s degree students to become involved in the clinical and applied biomechanics research programsthere. I found out about the ASMI laboratory because it had a reputation for restoring the careers of many injured major league hurlers.
Glenn Fleisig, co-founder of ASMI, is an internationally renowned expert on the biomechanics of throwing. He admits he was surprised to receive an enquiry from as far away as Western Australia and was even more surprised when the applicant actually turned up in January 1999. I arrived at ASMI shivering and blue with cold, having left the 110°F (43°C) heat of the Australian summer for the “depths” of a Birmingham winter. Here was true baseball mania!
The Science of Pitching
Fleisig’s group were commencing a 2-year epidemiological and biomechanical investigation of the causes of shoulder and elbow pain in Little League pitchers when I arrived, and I was given a role in that study for 6 months. We decided to focus on the three following possibilities for the origin of pain:
1. Overuse (throwing too many pitches)
2. Overstress (throwing curveballs before the skeleton is mature)
3. Poor throwing technique.
With regard to poor throwing technique, we identified a list of 24 variables that constitute “proper” pitching technique, based on previous studies of several hundred elite professional and college players conducted at ASMI. These variables include stride length, trunk angle, elbow angle and height of elbow above shoulder, the timing of the actions (e.g., Did the players stride? Did hip rotation and shoulder rotation follow a smooth sequence?) and so on.
We then enrolled 200 children in the study and followed them for a season to see which ones felt pain and which didn’t and to relate it to their technique. My task was to observe them at the baseball diamond while they were training, armed with “ordinary” video cameras. We obtained a videotape of the throwing mechanics of each, as well as upper-limb x-rays and records of how many and what type of pitches were thrown in all games and training over the season. I designed a technique analysis form to help me focus on all the important criteria. My goal was that it would be accurate enough to detect poor technique, helping me cross-check my results against a laboratory analysis of a subgroup of 20 players (given that it was impossible to film all 200 of them in the lab!).
So I put my cap on my head and my notebook under my arm in the mornings, sitting out behind a camera on the sunny windswept diamonds ? and took my suit and briefcase in the afternoons, welcoming subjects in our indoor laboratory at ASMI. We asked each of these players to throw 10 to 20 maximal-effect pitches while we recorded their pitch with our cameras. The lab is large enough to permit players to throw from a mound more than 13.4 metres (44 feet).
As illustrated in the photograph, plastic reflective markers were fitted onto the major joints in their bodies. The motion of these markers could be tracked using six infrared cameras filming at 200 frames per second while the player was throwing. We then used special software that can “join the dots” represented by the markers, to create a stick figure of the athlete. These make it relatively simple to measure joint angles and the speed and acceleration of each limb during the throwing motion and thus to calculate the forces at each joint.
Then came the long evenings of poring over computer-generated stick figures of people pitching and over video-stills. It was a lot of work, but it was fun and I enjoyed it. I was also able to attend ASMI’s annual 3-day convention on “Injuries in Baseball,” a timely reminder of the practical importance of the work our laboratory was undertaking.
The practical skills I gained during this 6-month study are still proving really useful in my biomechanics career. Not only did I learn about shoulder and elbow-joint motions during throwing and strength and conditioning programs, but I had the opportunity to meet more than 200 sports scientists, coaches, and orthopedic surgeons at the ASMI conference. One of these contacts led to my involvement in a 3-year investigation of the performance differences in wood and metal bats, including development of a 3D computer simulation to study bat performance.
In addition, I learned how to do videography, kinematics, and kinetic analysis techniques, and recruiting and retaining subjects. But what made my time at ASMI so special was the unique blend of supervision and autonomy the staff provided. ASMI recognized that independence of thought and action was an extremely important quality to be developed by graduate students, yet Fleisig’s team provided me with practical training in many aspects of applied biomechanical research. I also developed an understanding that a career in biomechanics involves much more than a graduate certificate: practical experience is essential. It is not enough to know the theory, for instance, of inverse dynamics if you can’t operate a camera or interpret a results chart in a way that a player (and in my case, his parents) will understand.
To me, ASMI is a model for the future of sports biomechanics. Close links with clinical practitioners–through ASMI co-founder and surgeon James Andrews–ensure that the research is not confined to the laboratory, but is effectively used in the prevention, management, and rehabilitation of injuries. Through the generosity of programs such as its Student Internship Program, ASMI provides a window through which college and graduate students can glimpse sports biomechanics at work, as well as inspiration for future careers in this sector.
Rochelle Nicholls, P.D., is a Postdoctoral Research Fellow at the University of Western Australia and may be reached at [email protected]