Department of Exercise Sciences


The yips in golf: multimodal evidence for two subtypes

Cathy M Stinear, James P Coxon, Melanie K Fleming, Vanessa K Lim, Harry Prapavessis, and Winston D Byblow.
Published in Medicine & Science in Sports & Exercise (2006) 38 (11): 1980-9

Introduction

  • The yips is a motor phenomenon that affects golfers by resulting in involuntary movements during the performance of shots requiring fine motor control, such as chipping and putting.
  • Recently, a model was put forth which identified two subtypes of yips. Type I yips have a muscular/dystonic origin, whereas Type II yips are related to performance anxiety.

Aim
To determine whether a model of two subtypes of yips is supported by evidence from a range of physiological, behavioural and psychological measures.

Experiment One
Method

  • Twenty four golfers participated in this experiment, nine of whom reported no problems with putting (control group), and 15 of whom reported yips-like symptoms while putting.
  • Yips golfers were categorized as either Type I (n = 8) or Type II (n = 7) according to their symptoms.
  • Surface electromyography (EMG) was recorded from flexor carpi radialis (FCR), extensor carpi radialis (ECR) and biceps brachii (BB) muscles bilaterally during a putting task.
  • Performance measure: participants putted on an artificial putting surface to four different holes, which were 2.2 - 2.5 m from the starting position for the putt. Participants were instructed that for the putt to be considered successful, the ball had to enter and remain in the correct hole. Putting accuracy was recorded as a percentage of total putts.
  • Psychological measure: participants completed the Competitive State Anxiety Inventory (CSAI-2).
  • Participants putted under low pressure and high pressure situations by using performance-based monetary rewards and a confederate who claimed to be a golf expert (high pressure).

Results

  • Monetary reward affected putting accuracy (Table 2), such that accuracy was higher after the monetary reward ran out for the control and Type II groups, but not for the Type I group.
yiptbl2
* significant difference (P < 0.05) in accuracy before and after

  • Cognitive anxiety levels were different under high and low pressure conditions for control and Type I groups, but not for the Type II group (Table 3).
yiptbl3
Higher values for cognitive and somatic subtypes and lower values for self-confidence indicate increased state of anxiety. Significant difference (P<0.05) between high-and low-pressure conditions.

  • Both yips groups showed greater baseline activity in the forearm extensors than the flexors or biceps, whereas the control group did not (Figure 2). All groups showed greater forearm flexor activity during the high pressure condition than the low pressure condition.
  • The control group and Type II yips group showed equivalent peak muscle activity. The Type I group showed higher levels of peak muscle activity than the control group, especially under the low pressure condition.
yipfig2
Figure 2-Baseline and peak EMG activity expressed as a percentage of maximum voluntary contraction (MVC) for each arm (left, right) under high-pressure (HP) and low-pressure (LP) conditions. FCR, flexor carpi radialis; ECR, extensor carpi radialis; BB, biceps brachii. Filled bars, control group; white bars, Type I; gray bars, Type II; error bars, standard error.

Experiment Two

Method

  • Participants performed an anticipated response task, in which they viewed a circular analog sweep dial and were required to lift their finger off a button to stop the indicator 800 ms after the beginning of the sweep (total sweep duration 1000 ms; go trials).
  • In some trials, the sweep indicator would stop on its own before reaching the 800 ms mark (stop trials). In this situation, participants were instructed to not lift their finger.
  • Surface EMG was recorded from first dorsal interosseus (FDI) of the dominant hand.

Results

  • The Type I yips group had significantly larger error values relative to controls (Table 4).
yiptbl4
* Significant difference relative to control group.

  • The Type I yips group had a significantly greater probability of a partial response relative to controls at the 525 ms stop time (Figure 3).
yipfig3
Figure 3-Probability of EMG burst in prime mover (FDI) during a successfully inhibited response as a function of sweep-dial stop time (ms). * Significant difference (P < 0.05) between the control and the Type I yips group. Error bars, standard error.

General Discussion

  • The results of this study lend support to the model of two subtypes of yips.
  • The putting difficulties experienced by Type I golfers are likely related to impaired initiation and execution of movement, rather than factors related to performance anxiety.
  • The management of Type I yips could draw from the treatments used for occupational dystonia, such as writers cramp and musicians cramp.
  • The putting difficulties experienced by Type II golfers are related to performance anxiety, which may involve internally generated performance pressure, rather than the neural control of movement.
  • The symptoms of Type II yips are likely to respond best to treatment strategies that focus on the underlying causes of performance anxiety.

Acknowledgements

We would like to thank Dr Richard Masters for insightful suggestions and Louise Foley and Cheryl Murphy for their assistance with data collection. This study was funded by a University of Auckland Research Council Staff Research Grant.