The dreaded yips, which can render even the best golfer unable to successfully sink the shortest putts, may not be all in the mind.
Bernhard Langer struggled to overcome the yips
Researchers have found that the condition, widely thought to be a psychological problem, may have a physical basis.
The yips is a condition that involves a tremor, freezing or involuntary jerking of the hands when attempting golf shots, particularly short putts.
High profile sufferers have included German US Masters winner Bernhard Langer, Ryder Cup winning captain Sam Torrance and the legendary multiple major winner Sam Snead.
Previous research has indicated it adds nearly five strokes to an affected golfer's 18-hole score.
Lead researcher Dr Aynsley Smith, of the Mayo Clinic in Rochester, Minnesota, said: "For many years the yips was seen as a purely psychological problem, something that was all in the golfer's head.
Anxiety can make the problem worse, but it appears there is a physical element that may be the underlying problem
"This latest study provides further reason to believe that there is a physical component for many if not most yippers."
The researchers asked experienced golfers to describe their personal experience of the yips.
More than half (55%) described physical symptoms, such as involuntary jerking of the hands during putting.
In contrast, only 22% gave descriptions consistent with psychological causes - for instance nervousness and tight feeling in the body prior to and during the put.
Dr Smith believes that for some people the yips is caused by anxiety, or choking under pressure.
But she also believes that in some cases a physical condition called focal dystonia is to blame.
A dystonia is a neurologic disorder characterized by involuntary movements such as spasms of a body part. It may be related to overuse.
"These are highly accomplished golfers who experience the problem after many years of successful competition, and we see similar fine motor problems in others, such as professional musicians, who must assume unnatural postures for prolonged periods," said Dr Smith.
"Anxiety can make the problem worse, but it appears there is a physical element that may be the underlying problem."
The Mayo Clinic researchers plan a putting tournament this spring with 16 "yippers," one-half from each category.
By measuring factors such as confidence, heart rate, grip force, stress hormones and the videotapes of each putt, they hope to better understand the problem and whether medications may help relieve symptoms.