April 18, 2010 -- The yips -- those sudden, involuntary movements that send a critical putt careening wide of the hole -- have been the curse of golfers since time immemorial.
Now a researcher is suggesting that the yips are actually a movement disorder on par with writer's or musician's cramp, rather than a function of stress or anxiety over the outcome of a match.
"I believe that's the case in a subset of golfers," Dr. Charles Adler of the Mayo Clinic in Scottsdale, Ariz. told MedPage today after his presentation at the annual meeting at the American Academy of Neurology in Toronto. "Identifying that subset is my goal."
That's not to say anxiety doesn't play a role, Adler said. Experts in movement disorders are well are that stress and anxiety can cause symptoms to worsen, even when the condition is normally well controlled by medication, he said.
"I get that from my patients all the time," he said. "They say: 'Doc, you've got me controlled real well, except when I'm nervous.'"
But the study he presented here suggests that a specific, visible involuntary motion is involved in many cases of the yips -- or, as Adler prefers to call the condition, golfer's cramp.
To investigate, Adler and colleagues enrolled 25 golfers who complained of the yips and 25 who did not, matched for age, sex, and golf handicap.
They were each asked to attempt 70 putts of six and 12 feet, either straight or breaking in one direction or the other, on an outdoor practice green. Movements of the wrist were tracked with surface electromyography, while hand finger motions were followed with a specialized device, the CyberGlove II.
In addition, all the putts were videotaped and later scored for involuntary movements.
When the participants were analyzed according to their subjective history, there were no significant differences either on the electromyography or CyberGlove results, Adler reported.
But the video evidence showed that 17 of the participants had a visible involuntary movement during the putting session, he reported. Of those, 15 were among the group with a subjective history of yips and two had never complained about the problem.
When the CyberGlove results were re-analyzed on that basis, there was significant difference in specific types of hand movements between those with yips and those without.
In a previous study, Adler had found that golfers who complained of the yips had co-contraction of the wrist flexors and extensors, although the difference did not quite reach statistical significance.
In this study, 41 percent of those with video evidence of the yips had such co-contraction, compared with 18 percent of those in the other group. Again, however, the difference did not reach significance, he reported.
Adler concluded that golfer's cramp should not be diagnosed without visual evidence of an involuntary movement and that measurement of hand pronation and supination may be the best way to identify the condition.
A problem in the research, he told MedPage Today, is that there is no test for dystonias, and in many cases "we don't even know what normal is."
The yips are "something that has impacted many golfers," according to Dr. Stewart Factor of Emory University in Atlanta, who moderated the session at which the data was presented but was not part of the study.
Factor told MedPage Today that many dystonias -- such as writer's cramp -- are thought to be related to overuse. If it occurs in golfers with a low handicap -- which implies having played a lot of golf -- the yips may have the same link, he said.
A key difference from the earlier study, Factor said, is that Adler redefined the yips "so that you actually had to see the movement to make the diagnosis," a methodology in accord with how doctors diagnose other task-specific dystonias.
One of the issues with the research so far, he said, is that it was performed under artificial conditions.
"Maybe he needs to study people out on the course in real conditions," Factor suggested.