Athlete efficiency

by David McDonald

High-speed cinematography and a new generation of portable computers are, for the first time, making it possible to study closely the efficiency and risk factors of particular physical movements in actual competitive situations, McGill University researchers told a recent seminar conducted at the National Sport and Recreation Centre by the Coaching Association of Canada.

The researchers are members of McGill’s interdisciplinary Biomechanics and Sport Medicine Clinic and Research team.

Among the findings so far, said mechanical engineer Dr. Lewis Vroomen and physical education specialist Dr. Mike Greenisen, is the discovery that a standing start for runners is both more efficient and less likely to cause injury than a conventional crouched start.

“We have just about proven the point,” said Vroomen, “that the standing start is less damaging to the hamstring than the crouch.”

The findings as applied to hurdling, suggested Greenisen, create an interesting paradox.

On the one hand, he said, the hurdler employing a standing start reaches the first hurdle faster, while, on the other hand, he spends more time in the air during his actual hurdle.

“Everywhere the hurdler has his feet on the ground and is running after a standing start, his velocity is greater than when he performs a crouch start,” said Greenisen. “It would seem that a slight change in mechanics to spend less time in air could result in significantly faster hurdling.”

The McGill team, which includes orthopedic surgeons, mechanical engineers, physiologists, physical therapists, educators, and coaches, is currently studying everything from ballet to the biomechanics of throwing.

Surface electrodes attached to a subject’s body are capable of transmitting electromyographical* data — information on which muscle does what in a particular action — to low-cost portable computers, say the scientists.

* An electromyograph is a device used for kinesiological analysis. Surface electrodes are attached to the skin directly over the muscle to be evaluated. The electrodes pick up the microvoltage generated in the muscle tissue, thereby permitting the researcher to determine the relative contribution of a muscle to a particular muscle movement. Myo comes from the Greek mys, meaning muscle.

The data collected by the portable computers can then be analysed by more sophisticated computers in the McGill laboratories and synchronised with high speed — up to 500 frames per second — film of the subject.

“The things that you can see by the aid of this record, which can’t be seen by the naked eye, we at first found astonishing,” said Greenisen.

He went on to speculate on the degree to which top athletic performances of the past could have been improved with the aid of modern technological tools.

He cited the example of American sprinter (and later professional football star) Bob Hayes, who won the gold medal in the 100m at the 1964 Tokyo Olympics with a time of 10.0 sec.

“Hayes probably ran 102m per 100m sprint because he didn’t run in a straight line,” said Greenisen. “He tended to zigzag down his lane.

“By no stretch of the imagination should we say that Hayes was an efficient runner. And certainly somewhere in his development he was cheated, and no one will ever know what his abilities were in the 100m.

“All we saw was brute, physiological, god-given power.”

Greenisen conceded that it would probably be difficult to correct a mature athlete’s biomechanical inefficiencies because of the time factor involved.

The question, he said, was how to find six months to unlearn and retrain a top athlete when he is expected to be competing all the time.

Greenisen said his group was particularly interested in studying elite athletes and passing its findings on to the community level. Here, he suggested, coaches could train their young athletes to be more efficient and also teach them how to avoid injury-producing movements.

“We see it fitting in nicely with the preventive medicine aspect,” he said. “If children are coached and taught properly, then somewhere down the road we should be eliminating such problems as Little League elbow.”

He cautioned that children should not be treated as “miniature adults”, that the immature musculature demands special approaches to training.

The best subjects to study, said Greenisen, are elite athletes, whose skills tend to approach an ideal.

“It’s been our experience,” he said, “that four or five national-level performers give us much more reliable data than 30 subjects randomly selected from a university physical education class.

“We see so many differences on high-speed film records and electromyography records between the semi-skilled and the highly skilled.

“We’ve come to the opinion that the proof of the pudding in research with respect to biomechanics in sports is to look at the skilled performer.”

Greenisen called upon the national sport governing bodies to make their top athletes available for testing in the future.

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