The Yips: A Focal, Task-Specific Dystonia
Funding source: Allergan
Charles H. Adler, MD, PhD, Mayo Clinic
John N. Caviness, MD, Mayo Clinic; Debra Crews, PhD, Arizona State University; Marco Santello, PhD, Arizona State University; Kanav Kahol, PhD, Arizona State University; Joseph Hentz, MS, Mayo Clinic
- Compare multiple finger and wrist joints postures and movements during putting, utilizing a CyberGlove on the right hand, in yips-affected golfers and age- and sex-matched unaffected golfers.
- Compare the prevalence of co-contraction of the wrist flexors and extensors while putting, using surface EMG recordings, in yips-affected golfers and age- and sex-matched unaffected golfers.
1.1.1 Background And Rationale
Dystonia affecting athletes has received little research attention and there has been a lack of awareness or interest among both physicians and athletes. As dystonia and occupational cramps affect people who write, type, and play a musical instrument, it is logical to believe that dystonia also affects people who play sports. Golfers all know about the “yips”, a term used to describe golfers who miss key putts in tournaments (recently mentioned as happening to Tiger Woods at the Masters). It is estimated that up to 30% of golfers with years of experience and moderately low handicaps develop the yips.(Sachdev, Mov Disord, 1992;7:326-32; Smith, et al. Sports Med, 2000;30:423-37) This syndrome is characterized by an inability to appropriately complete a golf stroke, most often putting and chipping strokes. Most individuals with the yips describe a jerking or shaking movement that interrupts their swing. In many cases the yips are disabling and the golfer, including professional tour players, give up golfing. The etiology is poorly understood and scientific study of the yips has been minimal. In a survey of 2,630 advanced golfers (handicap <12) a total of 1,031 (39%) golfers (986 men and 45 women) responded, and 541 (52%) reported experiencing the yips.( Smith, et al. Sports Med, 2000;30:423-37)
Electrophysiologic studies of task-specific dystonias show an excessive amount of muscle activity in agonists and antagonists during the tested movement.(Ghez, et al. Adv Neurol 1988;50:141-155) Our group recently completed a pilot electrophysiology study of 20 male golfers (10 yips-affected and 10 age- and handicap-matched golfers who did not complain of the yips) in a laboratory setting.(Adler et al. Neurol 2005;64:1813-4) Utilizing surface EMG recordings while the golfers putted, we found that 200 msec prior to impact of the putter with the ball there was co-contraction of wrist flexor and extensor muscles in 5/10 of the yips-affected golfers but in 0/10 of the yips-unaffected golfers (p=.06, exact McNemar test). These data suggest that some yips-affected golfers have a focal dystonia. This pilot study was limited by the small number of golfers and the data being collected inside a laboratory on a flat, small putting surface rather than on a real golf putting green with undulations and “breaks”.
The etiology for the yips, and for all task-specific dystonias, remains unclear and requires further study. The primary treatment for task-specific dystonias is botulinum toxin. While treating the yips has predominantly been by changing putter or grip (much like is tried with writer’s cramp), and by psychological interventions, there have been no studies of botulinum toxin injections for treatment of the yips.
The proposed study will compare joint position of the right hand and fingers as well as forearm muscle contraction patterns in yips-affected and unaffected golfers. Having the control group is critical to determining whether the yips are a form of focal, task-specific dystonia. While golf remains a game to many, it is a major form of entertainment and relaxation, as well as a professional sport. The impact of proving the yips are a focal dystonia would likely have far reaching effects and may lead to further investigation of dystonia as well as treatment with botulinum toxin in golfers and in other athletes.