Striving for a supercharged golf swing could play havoc with your back, according to US doctors.
The modern "X-factor" swing favoured by many professionals may hit balls harder and further but it can also put extra strain on the spine, the Barrow Neurological Institute experts say.
They look at the example of Tiger Woods in their research, which is published in the Journal of Neurosurgery: Spine.
The 43-year-old player recently made a comeback after serious back issues.
Swinging the golf club at measured speeds of 129mph at the April 2018 Master's Tournament, Tiger Woods appears to be back to physical fitness.
And he has said that he now has a greater understanding of what he "can and can't do" this season.
"A lot of it has been training, trying to get stronger," he said.
An X-factor golf swing tries to get maximum rotation of the player's shoulders relative to their hips at the top of the backswing.
This big rotation creates wound-up potential energy - the X-factor - but Dr Corey Walker, Dr Juan Uribe and Dr Randall Porter, from Barrow, say it may come at a cost, twisting the lumbar spine.
The spinal surgeons have been studying how the golf swing of present-day professionals, including Tiger Woods, differs from those of golf veterans, such as Jack Nicklaus and Ben Hogan.
They say players' physiques and techniques have changed significantly over recent decades.
Modern players are more muscular and have more powerful downswings and this can put increased force on the spinal disc and facet joints, they believe.
And over time, it can result in a damaging process that the authors call "repetitive traumatic discopathy" (RTD).
Wear and tear
But it's not just the backswing that might injure the lower spine.
During an explosive downswing, lateral flexion can result in a 'crunch" of the side of the spine, putting strain on the disc and facet joints on one side of the spine, they say.
Dr Walker said: "We believe Tiger Woods's experience with spinal disease highlights a real and under-recognised issue amongst modern era golfers.
"Tiger was using the mechanics of the modern day swing and that places a tremendous amount of strain on the back.
"It's still a theory but we are starting to see the late stages of this in some of our patients.
"We are seeing younger and younger elite level golfers with degeneration in their lower back."
He said any golfer, elite or not, who experienced pain should seek expert help.
Woods had fusion surgery on his lower spine to get back to fitness. He also did a lot of physiotherapy and strengthening exercises in the gym.
Consultant physiotherapist Nigel Tilley, who has worked on the PGA European Tour, the Ryder Cup and with Team GB, said the research should be treated with some caution.
"If you scanned a lot of people in their 40s, you would see some disc degeneration," he said. "That doesn't mean the necessarily have a back problem with it though.
"And Tiger has had a very long golfing career doing repetitive movements, so it's perhaps not that surprising that he has had back problems.
"But there's certainly been a change in swing style among players in the last 20 years.
"It's become much more powerful and it can put more force on the spine. "
He said it was important for golfers to control that speed to avoid injury.
"Strengthening and conditioning exercises in the gym can help reduce injuries," he said.
"If you are training properly, there's no reason why you can't resist these forces and have no problems or injuries.
"And golf is a great sport. I wouldn't want anyone to be put off doing it. You can play it at a very high level for a very long time."
Dr Andrea Fradkin, associate professor in exercise science at Bloomsburg University said "Many injuries can be avoided by a good warm up."
Tiger Woods's back story
- He won the US Masters at Augusta in 1997 with a record score, aged 21, making him the youngest man and the first black American to earn the title
- His lower back pain began about 2013
- In March 2014, he withdrew from the final round at the Honda Classic because of lower back pain and spasms
- Later that month, he had surgery (laminotomy and microdiscectomy procedures) to relieve nerve compression
- He needed more surgery to his spine in 2015
- In 2017, he had his fourth back operation - spinal fusion - to stop the pain