The use of light wrist weights--a small but growing trend for enhancing aerobic dance-exercise workouts--may bring on the aches and muscle soreness associated with any new athletic activity, but these problems appear to be minor and transient.
That is the conclusion of an industry-funded study conducted at the Jane Fonda Workout exercise studio in conjunction with the Center for Sports Medicine-Dance Medicine at St. Francis Memorial Hospital in San Francisco.
The 10-week study examined the use of only one-pound, bracelet-style wrist weights and did not include hand-held weights or leg weights.
The results of the study were presented Saturday by Dr. James G. Garrick, director of the Center for Sports Medicine-Dance Medicine, during the third-annual International Dance-Exercise Assn. convention at the Disneyland Hotel.
"We have thus far seen no evidence that the use of wrist weights results in any increase in injuries . . . ," Garrick told hundreds of dance-exercise instructors gathered in the hotel's Grand Ballroom.
Fonda, whose Jayne Development Inc. co-funded the study with Spenco Medical Corp. (maker of the weights used in the study), had been scheduled to appear with Garrick.
But last Wednesday the actress was asked by the union representing Disneyland Hotel employees, who are in a labor dispute with the hotel, not to cross its picket line. In a statement read by her representative, Fonda, who had appeared with Garrick at the convention last year when the results of a study on aerobic injuries were presented, said "as a matter of principle I don't cross workers' picket lines."
Despite the fitness celebrity's absence, Garrick went gamely ahead as solo speaker, joking that after Fonda had spoken last year, he had told the audience that "maybe the most difficult thing in the world is to follow Jane Fonda in a program." This year, he said, he thought of something even more difficult: to speak instead of Jane Fonda.
Garrick, an orthopedic surgeon who has published numerous articles on sports injuries, observed that "during the first half of the 1980s, aerobic dance became the single largest, organized group fitness endeavor in the United States."
"Hundreds of thousands of participants, the majority of them women, committed themselves--many for the first time--to an ongoing program of fitness enhancement," he said. "Although critics have charged that the activity is both ill-conceived and dangerous, the facts remain that: First, there is now abundant, scientific evidence that such programs do indeed enhance fitness. And second, that the injury problems are no greater than those encountered in such alternative activities as tennis and running, and in all likelihood are appreciably less."
In his investigation into the use of wrist weights in aerobic dance-exercise, Garrick explained that 95 intermediate-level students and five instructors had been monitored over a 10-week period in which they wore one-pound bracelet-style wrist weights during their regular workouts.
Among the 95 students, he said, 38% had 56 "complaints" regarding what was happening to them during aerobics, and four of the instructors each had one complaint.
In the study, he said, 10 of the complaints were considered injuries. The injury rate, according to Garrick, is nearly identical to that seen in the original study in which the weights were not used. And, he noted, "none of these people with complaints sought advice from a physician or received medical care."
Although the most common complaints associated with aerobic dancing are shin, foot, ankle and knee problems, those types of problems decreased--although not to a statistically significant degree--in the people wearing wrist weights, said Garrick.
Complaints of back and shoulder problems, however, increased to a "statistically significant degree" in those people using wrist weights and, Garrick admitted, "We're not sure why."
"It may be that just the addition of one pound on the arm, which is increasing the weight on the arm on most of these people by between 15% and 25% . . . may be more burden than the muscles of your shoulder can tolerate well at first, and so the complaints of shoulder pain may be the result of this."
As for the complaints of back pain, Garrick said it was hard for him to imagine that the one-pound wrist weights put people into positions--bending over farther, for example--than they would without the wrist weights.
"I think what may have happened," he said, "is that with the use of wrist weights, there may be a greater tendency to hyper-extend the back when you're doing some of the aerobics."
Garrick stressed, however, that although there was an increase in complaints regarding the back and shoulder, there was no increase in injuries: problems that actually caused any disability regarding the back and shoulders.
Examine Pulse Rates
The second part of the study involved examining the pulse rates of 20 students wearing the wrist weights.