Medicine: The Well-Trained Twitch

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The sobersided research scientists from U.C.L.A.'s Biotechnology Laboratory seemed bent on a most unscientific study. They were unashamed students of the art of the belly dancer, devotees of the deft ecdysiast who can twirl her breasts in opposite directions. But Engineer-Psychologist John Lyman, Engineer Gershon Weltman and the others on the team were not indulging in offbeat recreation. The well-trained wiggles and jiggles of strippers, they figured, could be the salvation of malformed thalidomide babies, or of thousands of amputees. "Present technology is up to building a sophisticated artificial arm," says Dr. Lyman. "We're trying to find the best techniques for controlling it."

A St. Louis belly dancer, who read of the lab's search for techniques, wrote to offer her services, but Lyman thinks he has something even more effective. The lab has built four silhouette profiles of the human body—front, back and both sides—drilled holes to designate the positions of individual muscles, and put light bulbs in the holes. When trainees with wafer-thin electrodes taped to their skin flex their muscles, the corresponding lights blink on. But contracting one muscle— and only one—at will, is an extremely difficult trick. The first group of a dozen volunteer trainees tended to illuminate whole sections of the mock-ups before they learned how to single out the right light.

So far, the U.C.L.A. team has taught amputees to isolate such muscles as the deltoid, a triangular muscle over the shoulder joint used to raise and extend the arm; the pectoralis, across the breast; and the latissimus dorsi, in the lower back.

By contracting these three muscles, one at a time or in combination, an amputee could transmit at least seven separate signals to an artificial limb. If five muscles could be brought into play, the number of combinations would be greatly increased.

Because such muscle-control techniques could prove useful to future astronauts, the team has a $6,000 research contract from California's Spacelabs Inc., also gets $25,000 a year from the Veterans Administration, and expects a grant from the U.S. Office of Vocational Rehabilitation. The investment has already produced one unexpected dividend: the silhouette training aid with the blinking lights may soon be employed to retrain polio victims in the use of available muscles.