For the study, researchers examined 20 male golfers, 10 with the yips and 10 without. All study participants were evaluated in the laboratory using surface electromyography (EMG) testing to determine muscle activity. Participants were tested while sitting at rest, arms outstretched, and during handwriting; standing at rest, holding a putter at rest, and using their own putter to putt a total of 75 putts, varying from 3, 6, and 8 feet. The golfers then rated the quality of their strokes, noting the number of putts made and the distance from the hole for missed putts.
"None of the golfers had any abnormal movements in the rest position, outstretched arms position, or while writing or standing holding the putter," said study co-author Charles H. Adler, MD, PhD, of the Mayo Clinic in Arizona. "While only two of the golfers felt they had their yips in the lab, under all putting conditions, 50 percent of the golfers with the yips had EMG evidence of co-contractions of muscles in the forearm just prior to the impact of the putter with the ball. The co-contractions were similar to those of task-specific dystonias--or movement disorders--such as writer's cramp and musician's cramp."
None of the golfers without yips had evidence for co-contraction.
A trend revealed that the five golfers with yips who had co-contractions were older, had higher current and best previous handicaps, and had yips for fewer years than the other five with yips who did not have the co-contractions. There was also a trend for those five golfers with the yips to make fewer putts and have a greater degree of error in missing the putts.
The study was funded by the Mayo Foundation for Medical Research and Education.
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