The short golf backswing: Effects on performance and spinal health implications

Abstract

Background: Full recoil golf swings have been implicated in back pain and injury in golfers. Evidence suggests that a restricted backswing may reduce the potential for injury without compromising performance. Objective: To examine both golf swing performance and selected muscular actions of the trunk and shoulder during a full recoil swing as compared with a modified short backswing. Methods: Electromyographic (EMG) recordings were taken bilaterally from the lumbar, external oblique, latissimus dorsi, and right pectoral muscles in 7 golfers during a full recoil swing and a modified short backswing. High-speed videotape was used to measure back swing angle reduction. Clubhead velocity (CHV) and ball-contact accuracy were quantified by using a swing speed indicator and clubface contact tape, respectively. Results: Shortening of the backswing by 46.5° ± 24.7° had no effect on stroke accuracy as measured by mean deviation from the target spot on the club (19.0 ± 7.8 mm vs 19.3 ± 9.2 mm). CHV was not significantly reduced (33.9 ± 2.5 m/s vs 31.2 ± 2.2 m/s). However, EMG root-mean-square was decreased 19% in the right oblique muscle from 750 to 250 ms before impact (P < .05). During the acceleration phase, activation of left lumbar muscle decreased by 12%, whereas activation of right latissimus muscle increased by 21%. Although left lumbar muscle activity during the follow-through increased 14%, there was a substantial (17%) but nonsignificant decrease of activation of trunk muscles (P = .11). There was a general trend toward an increased activation of the shoulder musculature from 250 ms before impact to 500 ms after impact. Conclusion: These data support the idea that short backswings in golf may reduce trunk muscle activation and possibly reduce back injury and pain without negatively impacting swing accuracy or CHV. However, the short swing increases shoulder muscle activation and may, in turn, promote risk for shoulder injury. (J Manipulative Physiol Ther 2001;24:569-75)

Introduction

It has been estimated that 62% of over 25 million young and old golfers in America incur an injury directly related to their sport.¹ In addition, at any given time, 10% to 33% of touring professionals play while injured, with half the group likely to develop chronic problems.² Although injuries to the shoulder, elbow, and wrist are common, injuries to the low back appear to be most prominent among professionals and amateurs.

The most common cause of injury in both professional and amateur golfers is believed to be the repetitive swing motion.3, 4 Poor swing mechanics are the second most frequent cause of injuries.3, 4, 5 Direct evidence for the role of poor swing mechanics in low back pain for golfers is nonexistent because the lower back is susceptible to injury from a number of additional and varied sources. Prolonged overuse of back muscle and the ligamentous attachment at spinal joints and/or a constrained posture may lead to a gradual weakening and atrophy of the structures around the joint.6, 7, 8 Nevertheless, medical and golf experts have long suspected that back pain in the game of golf is as much related to swing-imposed axial torques on the spine as it is to poor mechanics.3, 4, 5, 9

In support of this hypothesis, health researchers have provided convincing epidemiologic and experimental evidence linking trunk rotation, either independently or in concert with other motion, to the high incidence of back injury in the workplace.9, 10, 11 White and Panjabi⁷ have suggested that disk failure in low back pain is due to combined torsion and bending loads at the joint. Facet joint and disk injury contribute to torsional injury and pain.¹² Furthermore, in addition to torsional and bending loads, the low back must contend with significant lateral bending, shear, and compression forces that, in golf, generate estimated peak compression loads of more than 8 times body weight in both amateurs and professionals.¹³ In contrast, running and rowing appear to generate only 4 and 7 times body weight, respectively.¹³

Efforts to prevent back injury typically focus on strengthening and flexibility exercises and not on the golf swing itself.¹⁴ Such golf exercise programs may allow the back to better withstand the biomechanical stress of the full recoil swing; however, the potential for injury still exists because it is the execution of the full recoil swing that induces injuries.1, 2, 4

In describing the rotation differential (angle) between the hip and shoulder, McLean¹⁵ states, “to increase your differential and add power to your swing, you must turn your shoulders as far as possible while restricting the turn of your hips.” Such a twisted position at the top of the backswing positions the golf club at least parallel to the ground and is said to develop optimal clubhead velocity (CHV) on the downswing. The evidence suggests, however, that such a rotated and twisted backswing and follow-through position instead promotes injury.3, 6, 16, 17 It has further been reported that the length of the back swing and extent of torso rotation does not correlate with CHV at ball impact.18, 19, 20 Indeed, a short backswing with minimal rotation provides a similar CHV and a more consistent CHV at ball impact than a long backswing with maximum torso rotation.²⁰

Although the data have documented no significant decrements in CHV with a restricted backswing, it is not clear that a shorter backswing reduces stress and strain on the spine and spinal musculature. It is plausible that the restricted backswing may protect from overexertion of the back musculature. The hypothesis for this study was that greater activation of the shoulder musculature may conserve CHV in the presence of reduced activation of the trunk musculature during the modified short backswing.

The purpose of this study was to examine neural activation of the trunk and shoulder muscles during 2 types of golf swings: (1) a full recoil backswing, and (2) a modified short backswing. The latter was designed to reduce torsional rotation of the spine by shortening the length of the backswing. Ball-contact accuracy and CHV were measured to evaluate swing performance.