Elite golfers are prone to having mismatched hip joints, leading to reduced movement and pain, research has shown.
One theory is that constantly practising golf swings may induce a change on one side, causing the ball joint in the hip to become more egg-shaped.
Scientists who set out to investigate hip problems in golfers were surprised to find that almost a fifth of European professional players complained of pain.
Further study showed that the pain seemed to be related to the shape of the hip joint. Top golfers were four times more likely to have an egg-shaped right hip joint than to experience the same problem in the left hip joint.
Such a pattern makes elite golfers unique - it is not seen in the general population. The condition, known as cam morphology, reduces the range of hip rotation and can result in pain.
Lead researcher Dr Edward Dickenson, from the University of Warwick, said: "Our findings have brought up new questions to be answered.
"What remains to be established is whether professional golfers develop these shapes because of the way they are using their hips or whether players with these hip shapes are more likely to become professional."
Data for the study was collected at the Scottish Hydro Challenge, a European Challenge Tour event in Aviemore, Scotland, last year.
It marked the first time a portable magnetic resonance imaging (MRI) scanner was taken to a golfing event.
Players were asked to complete a health questionnaire and 55 of them agreed to undergo an MRI scan of their hips.
Cam morphology was found in 16% of right hips (the rear hip during a swing in a right handed player) and 4% of left hips (the front hip during the swing in a right handed player) in professional golfers.