Golfers swing to biomechanical research

A golf instructor might be impressed by the technology that biomechanists use to analyze a golfer's swing, the markers and cameras and motion analysis software. But after the numbers have been crunched, all of that technology isn't going to tell a golf pro much that he or she doesn't already know about the kind of driving mechanics that result in optimal performance.

Consider, for example, a recently presented study from the acclaimed golf laboratory at the University of Pittsburgh Medical Center, which found that the magnitude of upper body coiling during the backswing and the velocity of its uncoiling during the downswing have a direct impact on ball velocity (which in turn is related to driving distance). No previous study had scientifically documented this biomechanical connection. But instructors have been extolling the merits of the so-called x-factor concept since it was first described by Jim McLean (yes, a golf pro) in Golf Magazine in 1992.

Recognizing that the golf pro's hands-on experience is at least as valuable as laboratory data, investigators are increasingly taking a collaborative approach to golf research. Studies of specialized fitness programs, based on golf-specific exercises that instructors have been using for years, are demonstrating that such training can not only improve performance on the links but also may help prevent injury. And the fact that such programs are being featured in magazines like Golf suggests that maybe the game has something to learn from researchers after all.

"This is a trend I see more and more nowadays, where instead of turning to a magic pill or expensive equipment, athletes are trying to work on themselves," said John Jolly, a former member of the UPMC golf research team who is now a research engineer at Arizona State University's Biodesign Institute. "It seems that no matter what, each sport requires some sort of training outside of the sport itself, whether it's lifting weights or something else."

Focus on fitness

The Neuromuscular Research Laboratory at UPMC is the "it girl" of golf study, a media darling whose cutting-edge analyses of swing mechanics have spent less time in the public spotlight than its use of the same analytical technology to create customized fitness programs for golfers. Each participant in UPMC's Total Golf Fitness Program undergoes a battery of biomechanical tests to identify strength, flexibility, and balance parameters with the potential for improvement, and a home-based exercise regimen for that golfer is tailored accordingly.

Take the x-factor concept, for example. After a study of 100 golfers confirmed the importance of upper body rotation and rotational velocity for increasing ball velocity (see sidebar, "Coiling data highlight x-linked dominance,"page 30), UPMC researchers identified golf-specific exercises that could improve x-factor and x-factor velocity-exercises that, incidentally, were featured in the February issue of Golf. These exercises would be emphasized in designing a training regimen for a fitness program enrollee in whom tests had found room for improvement in the x-factor department. Which, essentially, applies to all golfers not named Tiger.

"Most golfers don't have a lot of torsional flexibility and strength," said James M. Smoliga, DVM, a doctoral student in the NMRL, who presented two of the group's studies in June at the annual meeting of the American College of Sports Medicine. "Those are things we can help them improve."

And, research suggests, this type of physical improvement can lead to improvement in golf performance. In a study of 15 golfers presented at the 2005 ACSM meeting and scheduled for publication this year in the Journal of Strength and Conditioning Research, UPMC investigators found that an eight-week regimen of strength, balance, and flexibility exercises was associated with significant improvements in driving distance, carry distance, ball velocity, and clubhead speed. With regard to the x-factor specifically, upper torso rotational velocity at the acceleration point of the golf swing increased by 31.7 degrees per second.

Collegiate conditioning

The UPMC researchers may have attracted the lion's share of the publicity, but they aren't the only ones to have demonstrated the effectiveness of training and conditioning in improving golf performance. A study of 10 male and six female collegiate golfers, published in the February issue of JSCR, found that 11 weeks of strength, power, and flexibility training resulted in a significant increase in clubhead speed.

The athletes trained for three 90-minute sessions per week. Each session began with a trunk strengthening routine and ended with a flexibility program focusing on the neck, shoulder, trunk, and hamstrings. The middle portion of each session was devoted to a resistance exercise regimen, in which medicine ball drills were performed every session but other exercises varied according to the day of the week.

From the start of the 11-week program to the end, the average clubhead speed for the entire group increased by 0.7 m/s, a statistically significant change. Putting distance control, defined by the accuracy with which a golfer putted a ball a distance of 4.6 meters on a flat surface, improved by a statistically significant 29.6% in the male study subjects; improvements of 20.4% in the group overall and 6.8% in the women represented a trend toward statistical significance.

The improvement in clubhead speed, although statistically significant, is markedly less than the 4.6 mph (2.06 m/s) increase in clubhead speed reported by the UPMC researchers.

"A longer duration, periodized program might elicit greater increases in performance," said Maj. Brandon K. Doan, PhD, director of the Human Performance Laboratory at the U.S. Air Force Academy in Colorado and lead author of the study. "Additionally, individually tailored exercise programs may result in greater gains than a group exercise program."

It's also possible that there may be a "ceiling effect" in which those athletes who are already performing at an elite level before starting a training program have less to gain. Lending support to this theory is the fact that clubhead speed increased by 3.36% in the six female subjects, all freshman members of a women's golf team in its first year of existence, and by only 0.61% in the 10 more experienced male subjects. The average baseline clubhead speed in the male subjects was 49.82 m/s (111.6 mph), which is approaching speeds generated at the professional level (anecdotally estimated to average between 110 and 115 mph). By comparison, baseline clubhead speed in the UPMC study averaged 95.3 mph.

Strategies for seniors

A similar ceiling effect may have been a factor in an April 2004 study on the effect of fitness training on older golfers, published in the Journal of Aging and Physical Activity by researchers from the University of San Francisco. As in the collegiate analysis, the JAPA study found that an exercise program was associated with clubhead speed increases that were statistically significant but smaller in magnitude than those reported in previous studies of younger golfers.

Nineteen male golfers, whose average age was 64 years, completed an eight-week conditioning program consisting of at least 24 sessions. Each session included one set of 12 repetitions on each of 10 weight machines at 80% of the participant's 10-repetition maximum weight (with weights increased after the 12th session and thereafter as indicated), followed by static and dynamic stretching and a 10-repetition golf-specific exercise that involved swinging a weighted club.

Average clubhead speed in those 19 golfers increased from 85 mph to 87.1 mph; in a control group of 12 male golfers who did not participate in the training program, average clubhead speed decreased from 80.3 mph to 79.8 mph. Because the baseline clubhead speed in the exercise group was relatively high for the age group in question, the researchers hypothesized that less training-related improvement was seen in the 19 test subjects than might have been seen in more typical older adult golfers.

The results of a new study from the same group, scheduled for publication in JSCR, appear to support this theory. In that study of 18 male golfers whose average age was 71 years, the 11 subjects who completed an eight-week training regimen demonstrated a statistically significant clubhead speed increase of 3.9 mph, but also entered the program with a baseline clubhead speed of 79.1 mph-almost 7% lower than in the 2004 study.

The more recent USF study, however, also utilized a different type of exercise program. Adapted from the National Academy of Sports Medicine's Optimum Performance Training Model, it included spinal stabilization and balance exercises in addition to flexibility and resistance training.

"Balance is essential," said Christian J. Thompson, PhD, an assistant professor of exercise and sport science at USF. "With the prevalence of falls in the older population, balance training should be a part of all older adult exercise programs and can play an important role in falls prevention."

A study from Oklahoma State University, however, suggests a low correlation between balance measures and golf proficiency. Golfers with lower handicaps (0 to 16) had significantly greater directional control than those with higher handicaps, but only for movement to the left. No other statistically significant between-group differences were reported for other limits of stability and rhythmic weight shift measures. The results were presented at the ACSM meeting.

Primed for prevention

Although none of the aforementioned studies have looked specifically at the effect of exercise training on injury prevention in golfers, anecdotal reports from participants suggest that may be an additional benefit, Smoliga said. But in golf as in any other discipline in the biomechanics mainstream, an intervention is only as effective as the level of compliance that can be achieved. And even golfers who pay for a customized exercise prescription from the UPMC Total Golf Fitness Program can't always find time to actually do the exercises.

"Sometimes life gets the best of them," Smoliga said.

But research by Andrea Fradkin, PhD, conducted in her native Australia before she joined the UPMC laboratory staff, suggests that exercises performed just prior to teeing off can help prevent injury. Her program, which takes eight or nine minutes to complete, includes dynamic stretches, static stretches of the major golf muscles (shoulders, lower back, and wrist) and air swings.

"You don't always know if people will comply with a fitness program that they have to do three or four times a week," Fradkin said. "Whereas this is easier for them."

In a study presented at the ACSM meeting, Fradkin and colleagues reported only 10 injuries in 178 golfers who used the warm-up protocol during a six-month period, compared to 58 injuries in 166 golfers in a control group. The results are consistent with a May study by Fradkin and colleagues, which surveyed 522 female golfers and found that those who reported not warming up on a regular basis were more likely to have suffered golf-related injuries in the past year than those who regularly warmed up before playing. Those findings were published in the Journal of Science and Medicine in Sport.

And injury prevention isn't the only benefit of the protocol. In a December 2004 study published in the British Journal of Sports Medicine, Fradkin and colleagues found that an almost identical warm-up routine was associated with clubhead speed increases of up to 24% in 10 male golfers who warmed up before play or practice five times per week for five weeks. Clubhead speed did not change significantly in 10 control subjects during the same time period.

Although high-profile instructors like Mike McGetrick have been advocating pre-tee warm-ups in the pages of golf magazines since the early '90s, the protocol developed by Fradkin and colleagues hasn't graced the pages of Golf, Golf Digest, or Golf World.

At least not yet.

Jordana Bieze Foster is a freelance writer based in Massachusetts and a former editor of BioMechanics magazine.

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