Competitive elite golf: a review of the relationships between playing results, technique and physique

Effects of Physical Training and Associations Between Physical Performance Characteristics and Golf Performance in Female Players: A Systematic Review With Meta-Analysis

ABSTRACT

Robinson, L, Murray, A, Ehlert, A, Wells, J, Jarvis, P, Turner, A, Glover, D, Coughlan, D, Hembrough, R, and Bishop, C. Effects of physical training and associations between physical performance characteristics and golf performance in female players: A systematic review with meta-analysis. J Strength Cond Res 37(12): e646-e655, 2023-The aims of this systematic review were to assess the association between physical performance and measures of golf performance, and the effects of physical training on measures of golf performance, in female golfers. A systematic literature search was conducted in PubMed, SPORTDiscus, Medline, and CINAHL. Inclusion criteria required studies to (a) have conducted a physical training intervention of any duration in female players and determine the effects on measures of golf performance, (b) determine the association between physical performance in at least one test and golf performance in female players, and (c) be peer-reviewed and published in English language. Methodological quality was assessed using a modified version of the Downs and Black Quality Index tool, and heterogeneity was examined through the Q statistic and I2 . Pooled effect sizes were calculated using standardized mean differences (SMDs) (with 95% confidence interval [CI]s) within a random-effects model, with Egger's regression test used to assess small study bias (inclusive of publication bias). Of the 2,378 articles screened, only 9 were included in the final review, with 3 of these being associative by design and 6 being training interventions. From an associative standpoint, clubhead speed (CHS) was reported in all 3 studies and was associated with measures of strength ( r = 0.54), lower-body power ( r = 0.60), upper-body power ( r = 0.56-0.57), and flexibility ( r = 0.52-0.71). When assessing the effects of physical training interventions, CHS was again the most commonly reported golf outcome measure ( n = 5). The random-effect model indicated that CHS significantly improves within each training group following training interventions (SMD = 0.73 [95% CIs: 0.32-1.14], Z = 3.50, p < 0.001), with trivial heterogeneity ( I2 = 0.00%, Q = 0.18; p = 0.9963) and no prevalence of small study bias depicted through the Egger's regression test ( z = -0.28, p = 0.78). From the available research, it seems that CHS can be positively affected from strength, power, and flexibility training interventions. From an associative standpoint, only 3 studies have been conducted solely in female players, with one showcasing questionable methodology. Future research should aim to carefully select test measures which better represent the physical capacities needed for the sport when determining the effects of and relationships with golf performance.

Physical determinants of golf swing performance in competitive youth golfers

This study investigated measures of physical fitness and golf swing performance in competitive youth golfers. Sixty-four golfers, subdivided into three handicap groups (CAT0, <1 handicap, n = 21; CAT1, 1-5 handicap, n = 20; CAT2, >5 handicap, n = 23), were assessed for isometric strength, power, movement competency and core endurance. Clubhead speed (CHS) and carry distance for 6-iron and driver were also measured. When controlled for maturity offset, CAT0 golfers produced significantly greater peak power, isometric absolute and relative peak force, movement competency, and jump distance than higher handicap golfers (all p < 0.05). Maturity status was strongly associated with CHS and carry distance for both clubs (R2 = 0.552-0.784). Linear regressions showed maturity offset explained a larger amount of variance in CHS (driver = 78.4%, 6-iron = 71.3%) and carry distance (driver = 55.2%, 6-iron = 57.4%) than handicap. Multiple linear regression analyses showed that peak power explained 79.4% and 82.4% of variation in 6-iron and driver CHS, respectively, while isometric absolute peak force explained 69.6% and 74.3% of the variation in 6-iron and driver carry distance, respectively. Subsequently, interventions targeting the development of peak force and power could aid golf swing performance in young golfers.

The Influence of an 8-Week Strength and Corrective Exercise Intervention on the Overhead Deep Squat and Golf Swing Kinematics

ABSTRACT

Langdown, BL, Bridge, MW, and Li, F-X. The influence of an 8-week strength and corrective exercise intervention on the overhead deep squat and golf swing kinematics. J Strength Cond Res 37(2): 291-297, 2023-It has previously been suggested that performance of the overhead squat (OHS) is a useful predictor of loss of posture in the golf swing. Using an 8-week intervention to improve OHS performance, this study assessed this suggestion and analyzed the impact of any resultant physical adaptations on golf swing kinematics. Thirty-seven golfers (handicap = 14.8 ± 13.3) were randomly split into a control group ( n = 16) and an intervention group ( n = 21)-who completed an 8-week strength and flexibility program. Pre- and postintervention OHS assessments and 3-dimensional (3D) 6-iron swing kinematics were captured. The level of significance set for the study was p < 0.05. Despite the intervention group's significant improvement in OHS thigh angle ( p < 0.001), there were no significant changes in 3D swing kinematics between the groups and over pre- and posttesting for address ( p = 0.219), top of the backswing ( p = 0.977), and impact ( p = 0.994). In addition, regression analysis revealed that the 4 measured OHS variables were significant and small predictors of swing kinematic variables at the top of backswing and impact (ranging from R2 = 0.109 to R2 = 0.300). These may, however, be spurious relationships as swing changes could be expected following the intervention if they were indeed true predictors of the postural variables. The use of the OHS to understand the cause of loss of posture during the golf swing is therefore not recommended because many other variables could influence swing kinematics. It may, however, be a useful assessment tool for strength and range of movement, provided that any motor learning issues are resolved before results influencing conditioning programs.

The relationship between driving distance and different types of contraction in core muscles in Korea elite female golfers

BACKGROUND

This study compared and examined the relationship between the concentric, eccentric, and isometric muscular contraction measurements that are commonly used to assess trunk strength and power, and the driving distance in elite female golfers. The purpose of this study was to utilize as a basis to evaluate the driving distance-related physical training program design and its efficacy.

METHODS

Eighteen female golfers from A club in Gyeonggi province are recruited. The driving distance, medicine ball throwing, isokinetic trunk flexor, and extensor strength and power, and isometric strength in the 3D electromagnetic motion analysis system were assessed. The statistical analysis adopted the Students' t-test to adjust the different units in each assessment method, and then interrelation and correlation analysis between the driving distance was conducted.

RESULTS

The result of this study is as the following: the medicine ball throwing, isokinetic trunk extensor power, isometric trunk flexor, and extensor strength, and left and right flexor and rotator strength showed high correlation with the driving distance. In the comparison between strength factors, isokinetic trunk extensor strength had a high correlation (R²=0.452), while the medicine ball throw and isokinetic trunk extensor power were reported a higher correlation in order (R²=0.740). In the overall comparison analysis, the isometric trunk left rotation, and isometric trunk extensor had an R² value of 0.893.

CONCLUSIONS

Consequently, the isometric trunk rotational strength and extensor strength had the highest correlation with the driving distance. This result can be used to design the physical fitness program for golfers.

Reducing Knee Joint Load during a Golf Swing: The Effects of Ball Position Modification at Address

As the modern golf swing has changed, the incidence of knee pain in professional golfers is increasing. For those with previous knee injuries, developing a golf-swing modification that reduces knee loading may be necessary to recover performance after injury. The purpose of this study was to test whether ball position modification reduces knee joint load in a golf swing. Thirteen male professional golfers participated in the study. Golf swings were captured using a three-dimensional motion capture system and two force platforms, with conditions for self-selected ball position and eight additional ball positions. Knee internal rotation and adduction moments were calculated. The length of one golf ball (4.27 cm) backward ball position (closer to the golfer) significantly reduced the peak internal rotation moment of the lead knee (- 13.8%) (p &lt; 0.001) and the length of one golf ball (4.27 cm) away from the target ball position significantly reduced the peak adduction moment of the lead knee (- 11.5%) (p &lt; 0.001) compared with that of the self-selected ball position. Based on these observations, we conclude that the backward ball position modification might be suggested for golfers with anterior cruciate ligament injuries, and the away from the target modification might be suggested for golfers with medial compartment knee osteoarthritis.

Pedal to the Metal: Velocity and Power in High-Level Golfers

ABSTRACT

Parker, J, and Lundgren, LE. Pedal to the metal: Velocity and power in high-level golfers. J Strength Cond Res 35(12): 3425-3431, 2021-In most rotational power assessments, discrete variables are used for subsequent examination; however, movements are continuous, and data can be collected in time series. The purpose of this investigation was to examine the velocity- and power-time series characteristics of a standing rotation test and identify relationships with golf performance. Thirty-one golfers performed a golf-specific rotation test (GSRT) with 3 different resistances (6, 10, and 14 kg) in a robotic engine system. Time series of velocity and power was calculated from the raw data, and each repetition was then normalized to 0-100%. Principal component analyses (PCAs) were performed on velocity and power waveforms. The PCA used an eigenvalue analysis of the data covariance matrix. The relationship between clubhead speed (CHS) and all principal components (PC) was examined using linear regression. Ten velocity parameters and 6 power parameters explained 80% of the variance in the data. For velocity, the first 2 PCs identified both magnitude and phase shift features while PCs 3-5 identified difference features. For power, the first 2 PCs identified both magnitude and phase shift features, the third PC identified a phase shift feature, and the fourth PC identified a difference feature. The highest relationship with CHS was shown for GSRT with 14 kg in PC2 for power (R2 = 0.48, p < 0.001). The PCA of the GSRT power test could distinguish intraindividual differences, external loads, and sex-based differences. Athletes should focus on accelerating smoothly through the movement, particularly with heavier loads, and not pulling aggressively at the beginning of the rotational movement to achieve maximum power.

Relating Competitive Golfers' Perceived Emotions and Performance

The present study examined relationships between golfers' self-perceived emotions (e.g., irritability, nervousness, tension), task-oriented coping, perceived control, and performance during a golf competition. We implemented a process-oriented golf analysis in which competitors rated these variables hole-by-hole in a competitive golf round. Within a two-level Bayesian multivariate autoregressive model, we showed that (a) within persons, emotions and task-oriented coping were reactions that stemmed from performance on the previous hole; and (b) between persons, player skill level predicted both better scores and the ability to limit the influence of negative affect on performance. These findings highlight the complex nature of the relationship between emotions and performance. Future studies might use a similarly ecologically valid research design to more precisely measure aspects of time and potentially moderating effects of player skill level and personality. An increased understanding of the dynamic relationship between emotions and performance can promote the development of effective psychological interventions for optimal performance outcomes.

Effect of concurrent training on trainability performance factors in youth elite golf players

Background

Due to the early specialization of golf players, examining the within session sequence of training should be considered to enhance performance and prevent injury risk. The present study analyzed the effects of an 18-week concurrent training developed before or after a specific golf session in adolescence elite golfers on several performance factors.

Methods

Sixteen right-handed male golfers, were randomly divided into two groups: after golf specific training (AG) (n = 8, age: 16.77 ± 0.58 years) and before golf specific training (BG) (n = 8, age: 16.93 ± 0.59 years). AG and BG players followed a concurrent physical conditioning program (CT) after or before the golf specific training, respectively. Body mass, body fat, muscle mass, jumping ability (CMJ), ball speed (Sball), golf movements screens (GMS), power in a golf swing-specific cable woodchop (Wmax) and the perceived training load (TL) in golf specific training (TL-G) and TL in CT (TL-CT) were measured on three separate occasions.

Results

BG demonstrates a lower TL-CT than AG (p < .001, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}${\eta }_{p}^{2}=0.90$\end{document}ηp2=0.90) along the training program without effects on TL-G, achieving significant percentage of change on CMJ (9.38%; p = .165; d = 0.73), GMS (50.52%; p = .41, d = 0.91), Wmax (16.93%; p = .001; d = 2.02) and Sball (1.82%; p = .018; d = 0.92) without interaction effects on anthropometric measures.

Conclusions

Performing CT sessions before the regular golf training can improve specific performance factors with a lower perceived TL than the same training carried out after the regular golf training.

The correlations between physical attributes and golf clubhead speed: A systematic review with quantitative analyses

Clubhead speed (CHS) is a commonly assessed golf performance measure and has been demonstrated to increase in response to physical training. Knowledge of the physical attributes that correlate with CHS will aid in developing effective testing and training protocols for golfers. Thus, the purpose of this review was to identify studies that evaluated the correlation between physical attributes and CHS and synthesise the correlation coefficients using three-level meta-analytic methods. Physical attributes were categorised first by general physical attribute categories. Pooled correlations were also estimated for specific attributes (e.g. jump height, body mass) that were evaluated across three or more studies. The results suggested that CHS had the strongest correlations with measures of upper body power/explosiveness (r = 0.51, 95% confidence interval [95CI]: 0.34, 0.67), lower body strength (r = 0.46; 95CI: 0.27, 0.66), upper body strength (r = 0.41; 95CI: 0.18, 0.63), and lower body power/explosiveness (r = 0.38; 95CI: 0.23, 0.53). Muscle endurance (r = 0.18; 95CI: 0.07, 0.28) and anthropometrics (r = 0.27; 95CI: 0.12, 0.42) had small, but significant correlations, while flexibility (r = 0.03; 95CI: -0.08, 0.14) had a trivial correlation. Several specific assessments such as squat strength, estimated jump power, and medicine ball throw outcomes had large pooled correlations with CHS (r = 0.55-0.63). Overall, the results suggest that measures of muscle strength and power/explosiveness have moderate-large correlations with CHS. Flexibility measures did not have significant associations with CHS, but this may be a result of the specific measures used within the literature.

Three Dimensional Upper Limb Joint Kinetics of a Golf Swing with Measured Internal Grip Force

The biomechanics of a golf swing have been of interest to golfers, instructors, and biomechanists. In addition to the complexity of the three-dimensional (3D) dynamics of multi-segments of body, the closed-chain body posture as a result of both hands holding a club together makes it difficult to fully analyze the 3D kinetics of a golf swing. To identify the hand-grip joint force and torque applied by each hand, we directly measured the 3D internal grip force of nine registered professional golfers using an instrumented grip. A six-axis force-torque sensor was connected to a custom-made axially separated grip, which was then connected to a driver shaft using a manufactured screw thread. Subjects participated in two sessions of data collection featuring five driver swings with both a regular and customized sensor-embedded grip, respectively. Internal grip force measurement and upper limb kinematics were used to calculate the joint force and torque of the nine-linkage closed-chain of the upper limb and club using 3D inverse dynamics. Direct measurement of internal grip forces revealed a threefold greater right-hand torque application compared to the left hand, and counterforce by both hands was also found. The joint force and torque of the left arm tended to precede that of the right arm, the majority of which had peaks around the impact and showed a larger magnitude than that of the left arm. Due to the practical challenge of measuring internal force, heuristic estimation methods based on club kinematics showed fair approximation. Our results suggest that measuring the internal forces of the closed-chain posture could identify redundant joint kinetics and further propose a heuristic approximation.

The Relationship between Isometric Force-Time Characteristics and Dynamic Performance: A Systematic Review

The purpose of this article was to review the data on the relationship between multi-joint isometric strength test (IsoTest) force-time characteristics (peak force, rate of force development and impulse) and dynamic performance that is available in the current literature. Four electronic databases were searched using search terms related to IsoTest. Studies were considered eligible if they were original research studies that investigated the relationships between multi-joint IsoTest and performance of dynamic movements; published in peer-reviewed journals; had participants who were athletes or active individuals who participate in recreational sports or resistance training, with no restriction on sex; and had full text available. A total of 47 studies were selected. These studies showed significant small to large correlations between isometric bench press (IBP) force-time variables and upper body dynamic performances (r² = 0.221 to 0.608, p < 0.05) and significant small to very large correlation between isometric squat (ISqT) (r² = 0.085 to 0.746, p < 0.05) and isometric mid-thigh pull (IMTP) (r² = 0.120 to 0.941, p < 0.05) force-time variables with lower body dynamic performances. IsoTest force-time characteristics were shown to have small to very large correlations with dynamic performances of the upper and lower limbs as well as performance of sporting movements (r² = 0.118 to 0.700, p < 0.05). These data suggest that IsoTest force-time characteristics provide insights into the force production capability of athletes which give insight into dynamic performance capabilities.

Low back pain and golf: A review of biomechanical risk factors

Golf is an international sport played by a variety of age groups and fitness levels, and although golf has a low to moderate aerobic intensity level, injuries are common among professional and amateur golfers. High amounts of force experienced during the golf swing can lead to injury when golfers lack appropriate strength or technique with the lower back most commonly injured. Research has indicated that trunk muscle activation, hip strength and mobility, and pelvis and trunk rotation are associated with low back pain (LBP). Based on anecdotal evidence, golf practitioners specifically address issues in weight shift, lumbar positioning, and pelvis sequencing for golfers with LBP. This review aims to elucidate the effects of proper and improper golf swing technique on LBP and to help golf practitioners understand how to approach the alleviation of LBP in their clientele.

Differences in kinematics and driver performance in elite female and male golfers

The aim of this study was to compare swing kinematic differences between women and men and investigate which variables predict clubhead speed (CHS) and carry distance (CD) whilst accounting for individual variation.

METHODS

Swing kinematics and driver performance data were collected on 20 (10 women) elite golfers (HCP 0.7 ± 1.4). We used Bayesian T-test for between sex comparison of swing kinematics and Bayesian Analysis of covariance (ANCOVA) to produce general linear models for CHS and carry distance for elite female and male golfers separately.

RESULTS

There was strong evidence that the driver performance variables CHS and CD were decreased in women compared to men, and two kinematic variables; time to arm peak speed downswing and angular wrist peak speed were slower in women. The ANCOVAs identified very strong to overwhelming evidence that participant as a fixed factor was a determinant of CHS for both women and men but was not a determinant of CD.

CONCLUSION

when looking to enhance driver performance among high-level golfers, coaches should be aware that variables that determine CHS and CD differ among women and men and if the aim is to improve CHS coaches should not forget the importance of individual swing characteristics.

The effect of alterations in foot centre of pressure on lower body kinematics during the five-iron golf swing

The research aimed to evaluate the effects of an intervention aimed at altering pressure towards the medial aspect of the foot relating to stability mechanisms associated with the golf swing. We hypothesised that by altering the position of the foot pressure, the lower body stabilisation would improve which in turn would enhance weight distribution and underpinning lower body joint kinematics. Eight professional golf association (PGA) golf coaches performed five golf swings, recorded using a nine-camera motion analysis system synchronised with two force platforms. Following verbal intervention, they performed further five swings. One participant returned following a one-year intervention programme and performed five additional golf swings to provide a longitudinal case study analysis. Golf performance was unchanged evidenced by the velocity and angle of the club at ball impact (BI), although the one-year intervention significantly changed the percentage of weight experienced at each foot in the final 9% of downswing, which provided an even weight distribution at BI. This is a highly relevant finding as it indicates that the foot centre of pressure was central to the base of support and in-line with the centre of mass (CoM), indicating significantly increased stability when the CoM is near maximal acceleration.

Kinematic determinants of performance parameters during golf swing

In golf, the trunk and pelvis kinematic variables are often related to measures of performance due to the highly complex and multi-joint movements involved in swings. However, it is unclear how specific body segments or joints contributed to the golf performance parameters. Therefore, the purpose of this study was to identify the key joints, including those of the upper and lower trunk, that are associated with golf performance parameters, such as X-Factor and pelvis motion. A motion capture system was used to obtain three-dimensional kinematics of golf swings performed by 10 low handicap male golfers. Based on regression analysis, right knee adduction, right shoulder external rotation and left elbow extension in ball address to top of the backswing and left knee adduction and lower trunk right bending with left rotation in top of the backswing to end of follow-through were presented as predictor variables for the X-Factor. For pelvis movement, a greater number of joint angles were associated with pelvis posterior tilt during backswing and pelvis motion to target with right rotation during downswing/follow-through. This study provides fundamental details of the movement mechanisms of major joints, as well as their relationships with performance parameters. Such understanding can be combined with training to improve the golfing skill and prevent possible injuries.

Relationships between Challenge Tour golfers' clubhead velocity and force producing capabilities during a countermovement jump and isometric mid-thigh pull

A number of field-based investigations have evidenced practically significant relationships between clubhead velocity (CHV), vertical jump performance and maximum strength. Unfortunately, whilst these investigations provide a great deal of external validity, they are unable to ascertain vertical ground reaction force (vGRF) variables that may relate to golfers' CHVs. This investigation aimed to assess if the variance in European Challenge Tour golfers' CHVs could be predicted by countermovement jump (CMJ) positive impulse (PI), isometric mid-thigh pull (IMTP) peak force (PF) and rate of force development (RFD) from 0-50 ms, 0-100 ms, 0-150 ms and 0-200 ms. Thirty-one elite level European Challenge Tour golfers performed a CMJ and IMTP on dual force plates at a tournament venue, with CHV measured on a driving range. Hierarchical multiple regression results indicated that the variance in CHV was significantly predicted by all four models (model one R² = 0.379; model two R² = 0.392, model three R² = 0.422, model four R² = 0.480), with Akaike's information criterion indicating that model one was the best fit. Individual standardised beta coefficients revealed that CMJ PI was the only significant variable, accounting for 37.9% of the variance in European Challenge Tour Golfers' CHVs.

Examination of the neuromechanical factors contributing to golf swing performance

This study investigated the relationship between a range of neuromechanical variables in the lower- and upper-body, and golf performance. Participants were assessed for individual muscle stiffness, vertical stiffness (Kvert), flexibility, power and maximal isometric strength. Furthermore, golf performance was determined by handicap and club head speed. Pearson's correlations quantified the relationships between neuromechanical variables and performance measures. Participants were also separated into relatively high club head speed (HC) and low club head speed (LC) groups and compared for physical characteristics. Club head speed showed positive relationships with Kvert and power and a negative relationship with hip mobility. The HC group exhibited superior Kvert and power, while strength and flexibility measures were not related to performance. Higher levels of lower-body stiffness, rate of force development and power output appear to be beneficial for generating superior club head speed. A stiffer system may reduce the time needed to remove the "slack" from the series elastic component therefore, reducing electromechanical delay and enhancing rate of force development. The large positive association with rate of force development suggests that increasing this component, along with power production may be superior focal components for training in golfers due to the short duration of the downswing.

The development of a tournament preparation framework for competitive golf: A Delphi study

Tournament preparation in golf is used by players to increase course knowledge, develop strategy, optimise playing conditions and facilitate self-regulation. It is not known whether specific behaviours in tournament preparation should be given priority in education and practice at different stages of competition. This study aimed to achieve consensus on the importance of specific tournament preparation behaviours or "items" to players of five competitive levels. A two-round Delphi study was used, including an expert panel of 36 coaches, high-performance staff, players and academics. Participants were asked to score the relative importance of 48 items to players using a 5-point Likert-type scale. For an item to achieve consensus, 67% agreement was required in two adjacent score categories. Consensus was reached for 46 items and these were used to develop a ranked framework for each competitive level. The developed framework provides consensus-based guidelines of the behaviours that are perceived as important in tournament preparation. This framework could be used by national sport organisations to guide the development of more comprehensive learning environments for players and coaches. It could also direct future studies examining the critical behaviours for golfers across different competitive levels.

The role of pelvis-thorax coupling in controlling within-golf club swing speed

Pelvis-thorax coordination has been recognised to be associated with swing speed. Increasing angular separation between the pelvis and thorax has been thought to initiate the stretch shortening cycle and lead to increased clubhead speed. The purpose of this study was to determine whether pelvis-thorax coupling played a significant role in regulating clubhead speed, in a group of low-handicap golfers (mean handicap = 4.1). Sixteen participants played shots to target distances determined based on their typical 5- and 6-iron shot distances. Half the difference between median 5- and 6-iron distance for each participant was used to create three swing effort conditions: "minus", "norm", and "plus". Ten shots were played under each swing effort condition using both the 5-iron and 6-iron, resulting in six shot categories and 60 shots per participant. No significant differences were found for X-factor for club or swing effort. X-factor stretch showed significant differences for club and swing effort. Continuous relative phase (CRP) results mainly showed evidence of the stretch shortening cycle in the downswing and that it was more pronounced late in the downswing as swing effort increased. Substantial inter-individual CRP variability demonstrated the need for individual analyses when investigating coordination in the golf swing.

Development of a golf-specific load monitoring tool: Content validity and feasibility

Athletes often record details of their training and competitions, supported by information such as environmental conditions, travel, as well as how they felt. However, it is not known how prevalent these practices are in golfers, or how valuable this process is perceived. The purpose of this study was to develop a golf-specific load monitoring tool (GLMT), and establish the content validity and feasibility of this tool amongst high-level golfers. In the first phase of development, 21 experts were surveyed to determine the suitability of items for inclusion in the GLMT. Of the 36 items, 21 received >78% agreement, a requirement to establish content validity and for inclusion in the GLMT. Total duration was the preferred metric for golf-specific activities, whilst rating of perceived exertion (RPE) was preferred for measuring physical training. In the second phase, feasibility of the tool was assessed by surveying 13 high-level male golfers following 28-days of daily GLMT use. All items included in the GLMT were deemed feasible to record, with all players participating in the feasibility study providing high to very high ratings. Golfers responded that they would consider using a load monitoring tool of this nature long term, provided it can be completed in less than five minutes per day.

Effects of nine weeks isokinetic training on power, golf kinematics, and driver performance in pre-elite golfers

Background

It has previously been shown that isotonic strength training can improve driver performance among golfers, though few studies have investigated effects of strength training on swing kinematics together with driver performance. In this study we investigated whether isokinetic rotational training could improve driver performance and swing kinematic variables amongst elite golfers.

Methods

Twenty competitive pre-elite golfers (handicap better than -3.0), 13 men and 7 women, were split into two groups, one group received the isokinetic power training (IK) alongside their normal isotonic pre-season strength-training and the other group continued with their normal isotonic pre-season strength-training regime (IT). The IK group completed 12 sessions of isokinetic power training on a standing rotation exercise (10% body weight at 1 m/s) and barbell squat (25 kg plus 10% body weight at 0.5 m/s). The IT group continued with their normal isotonic pre-season strength-training regime. Participants were tested for rotational power, lower body power, golf swing kinematics, and driver performance before and after a nine-week training period.

Results

After the nine-week training period both the IK and the IT groups increased their dominant side rotational force and power (effect sizes between 0.50-0.96) and magnitude based inference indicated that IK had a likely (> 80%) more beneficial increase in dominant side rotational force and power. For swing kinematics, IK had a likely (> 80%) more beneficial improvement in lead arm speed and acceleration compared to the IT group. For driver performance, IK had a possible (65%) beneficial effect on ball speed and likely (78%) beneficial effect on carry distance when compared to IT, whereas neither of the groups improved club head speed.

Conclusion

In the present study on pre-elite golfers we found that 9 weeks of isokinetic training increased seated rotational force and power, peak arm speed and arm acceleration, ball speed, and carry distance more compared to isotonic training. Even though isokinetic training did not increase CHS, it did result in greater carry distance.

How to quantify the transition phase during golf swing performance: Torsional load affects low back complaints during the transition phase

The transition phase of a golf swing is considered to be a decisive instant required for a powerful swing. However, at the same time, the low back torsional loads during this phase can have a considerable effect on golf-related low back pain (LBP). Previous efforts to quantify the transition phase were hampered by problems with accuracy due to methodological limitations. In this study, vector-coding technique (VCT) method was proposed as a comprehensive methodology to quantify the precise transition phase and examine low back torsional load. Towards this end, transition phases were assessed using three different methods (VCT, lead hand speed and X-factor stretch) and compared; then, low back torsional load during the transition phase was examined. As a result, the importance of accurate transition phase quantification has been documented. The largest torsional loads were observed in healthy professional golfers (10.23 ± 1.69 N · kg^-1), followed by professional golfers with a history of LBP (7.93 ± 1.79 N · kg^-1), healthy amateur golfers (1.79 ± 1.05 N · kg^-1) and amateur golfers with a history of LBP (0.99 ± 0.87 N · kg^-1), which order was equal to that of the transition phase magnitudes of each group. These results indicate the relationship between the transition phase and LBP history and the dependency of the torsional load magnitude on the transition phase.

Improving performance in golf: current research and implications from a clinical perspective

Golf, a global sport enjoyed by people of all ages and abilities, involves relatively long periods of low intensity exercise interspersed with short bursts of high intensity activity. To meet the physical demands of full swing shots and the mental and physical demands of putting and walking the course, it is frequently recommended that golfers undertake golf-specific exercise programs. Biomechanics, motor learning, and motor control research has increased the understanding of the physical requirements of the game, and using this knowledge, exercise programs aimed at improving golf performance have been developed. However, while it is generally accepted that an exercise program can improve a golfer's physical measurements and some golf performance variables, translating the findings from research into clinical practice to optimise an individual golfer's performance remains challenging. This paper discusses how biomechanical and motor control research has informed current practice and discusses how emerging sophisticated tools and research designs may better assist golfers improve their performance.

The effect of oral motor activity on the athletic performance of professional golfers

Human motor control is based on complex sensorimotor processes. Recent research has shown that neuromuscular activity of the craniomandibular system (CMS) might affect human motor control. In particular, improvements in postural stability and muscle strength have been observed as a result of voluntary jaw clenching. Potential benefits of jaw aligning appliances on muscle strength and golf performance have also been described. These reports are highly contradictory, however, and the oral motor task performed is often unclear. The purpose of our study was, therefore, to investigate the effect of submaximum biting on golf performance via shot precision and shot length over three different distances. Participants were 14 male professional golfers - seven with sleep bruxism and seven without - randomly performing golf shots over 60m, 160m, or driving distance while either biting on an oral splint or biting on their teeth; habitual jaw position served as the control condition. Statistical analysis revealed that oral motor activity did not systematically affect golf performance in respect of shot precision or shot length for 60m, 160 m, or driving distance. These findings were reinforced by impact variables such as club head speed and ball speed, which were also not indicative of significant effects. The results thus showed that the strength improvements and stabilizing effects described previously are, apparently, not transferable to such coordination-demanding sports as golf. This could be due to the divergent motor demands associated with postural control and muscle strength on the one hand and the complex coordination of a golf swing on the other. Interestingly, subjects without sleep bruxism performed significantly better at the short distance (60 m) than those with bruxism. Because of the multifactorial etiology of parafunctional CMS activity, conclusions about the need for dental treatment to improve sports performance are, however, completely unwarranted.

Validity of the X-factor computation methods and relationship between the X-factor parameters and clubhead velocity in skilled golfers

The purpose of this study was to assess the validity of the X-factor computation methods and to examine whether direct relationships exist between the X-factor parameters and the clubhead velocity in a group of skilled male golfers (n = 18, handicap = -0.6 +/- 2.1). Five driver trials were captured from each golfer using an optical motion capture system (250 Hz). Two plane-based methods (conventional vs. functional swing plane-based) and one Cardan rotation-based method (relative orientation) were used to compute select X-factor (end of pelvis rotation, top of backswing, ball impact (BI), and maximum), X-factor stretch (stretch and maximum stretch), and X-factor velocity (BI and maximum) parameters. The maximum clubhead velocity was extracted and normalized to golfer's body height to eliminate the effect of body size. A one-way repeated MANOVA revealed that the computation methods generated significantly different X-factor parameter values (p < 0.001). The conventional method provided substantially larger X-factor values than the other methods in the untwisting phase and the meaningfulness of select X-factor parameters generated by this method was deemed questionable. The correlation analysis revealed that the X-factor parameters were not directly related to the maximum clubhead velocity (both unnormalized and normalized).

Development and validation of the Approach-Iron Skill Test for use in golf

The primary aim of this study was to develop and validate a golf-specific approach-iron test for use with elite and high-level amateur golfers. Elite (n=26) and high-level amateur (n=23) golfers were recruited for this study. The 'Approach-Iron Skill Test' requires players to hit a total of 27 shots. Specifically, three shots are hit at each of nine targets on a specially constructed driving range in a randomised order. A real-time launch monitor positioned behind the player, measured the carry distance for each of these shots. A scoring system was developed based on the percentage error index of each shot, meaning that 81 points was the maximum score possible (with a maximum of three points per shot). Two rounds of the test were performed. For both rounds of the test, elite-level golfers scored significantly higher than their high-level amateur counterparts (56.3 ± 5.6 and 58.5 ± 4.6 points versus 46.0 ± 6.3 and 46.1 ± 6.7 points, respectively) (P<0.05). For both elite and high-level players, 95% limits of agreement statistics also indicated that the test showed good test-retest reliability (2.1 ± 7.9 and 0.2 ± 10.8, respectively). Due to the clinimetric properties of the test, we conclude that the Approach-Iron Skill Test is suitable for further examination with the players examined in this study.

Evidence for biomechanics and motor learning research improving golf performance

The aim of this review was to determine how the findings of biomechanics and motor control/learning research may be used to improve golf performance. To be eligible, the biomechanics and motor learning studies had to use direct (ball displacement and shot accuracy) or indirect (clubhead velocity and clubface angle) golf performance outcome measures. Biomechanical studies suggested that reducing the radius path of the hands during the downswing, increasing wrist torque and/or range of motion, delaying wrist motion to late in the downswing, increasing downswing amplitude, improving sequential acceleration of body parts, improving weight transfer, and utilising X-factor stretch and physical conditioning programmes can improve clubhead velocity. Motor learning studies suggested that golf performance improved more when golfers focused on swing outcome or clubhead movement rather than specific body movements. A distributed practice approach involving multiple sessions per week of blocked, errorless practice may be best for improving putting accuracy of novice golfers, although variable practice may be better for skilled golfers. Video, verbal, or a combination of video and verbal feedback can increase mid-short iron distance in novice to mid-handicap (hcp) golfers. Coaches should not only continue to critique swing technique but also consider how the focus, structure, and types of feedback for practice may alter learning for different groups of golfers.

The effects of mouthguards on the athletic ability of professional golfers

The purpose of this study was to determine the effect of stabilization splints and mouthguards on the athletic ability of professional golfers. For this study, eight professional golfers with a mean age of 20.5 were selected. These participants performed four trials of 10 driver swings and 10 putts with or without a stabilization splint (control group) or mouthguard. For the 4th trial, the splints were adjusted using a simple blind test so that the participants were unaware of the unilateral molar contact. The drive distance, club head speed, initial ball speed, and putting accuracy were compared and analyzed before and after the application of equal bilateral molar occlusion. When the bilateral molar occlusion was applied using a mouthguard or stabilization splint, the club head speed and driving distance in the presence of the oral appliances were significantly increased compared with those without the presence of either appliance (P < 0.05). Alternatively, the initial ball speed and putting accuracy in the presence of these appliances were increased compared with those without the presence of an appliance; however, this effect was not statistically significant. When the mouthguards or stabilization splints were adjusted to result in unilateral molar occlusion, the club head speed and driving distance in the presence of the appliances were significantly decreased compared with those that were obtained without these appliances (P < 0.05). The initial ball speed and the putting accuracy were not affected by the use of the appliances. No difference was observed in the effectiveness of the stabilization splint and mouthguard when bilateral molar occlusion was performed. The occlusion stability that results from stabilization splints and mouthguards is thought to increase the club head speed and driving distance in professional golf players.

Development of the Nine-Ball Skills Test to discriminate elite and high-level amateur golfers

Currently, there is a lack of appropriate skill assessments available for use in golf. The aim of this study was to examine the discriminative validity and the test-retest reliability of the newly developed "Nine-Ball Skills Test". Participants of two ability levels (elite, n = 14; high-level amateur, n = 16) each hit nine golf shots of differing combinations of trajectory (straight, fade, draw) and height (normal, high, low) at an individually determined target area. Each shot was scored on its percent error index from the target and whether it achieved the maximum height as required. Participants completed the test twice using a 5-iron club. The elite group scored significantly higher (P < 0.05) than the amateur group for both the first and second rounds of the test as well as the combined scores. The between-round test-retest reliability was deemed to be not acceptable, thus we propose that the test's protocol should include use of the two rounds as standard. Due to the importance of ball striking and flight control to performance in golf, the Nine-Ball Skills Test is appropriate for providing a measure of this skill component in elite and high-level amateur golfers.

Quiet eye training facilitates competitive putting performance in elite golfers

The aim of this study was to examine the effectiveness of a brief quiet eye (QE) training intervention aimed at optimizing visuomotor control and putting performance of elite golfers under pressure, and in real competition. Twenty-two elite golfers (mean handicap 2.7) recorded putting statistics over 10 rounds of competitive golf before attending training individually. Having been randomly assigned to either a QE training or Control group, participants were fitted with an Applied Science Laboratories Mobile Eye tracker and performed 20 baseline (pre-test) putts from 10 ft. Training consisted of video feedback of their gaze behavior while they completed 20 putts; however the QE-trained group received additional instructions related to maintaining a longer QE period. Participants then recorded their putting statistics over a further 10 competitive rounds and re-visited the laboratory for retention and pressure tests of their visuomotor control and putting performance. Overall, the results were supportive of the efficacy of the QE training intervention. QE duration predicted 43% of the variance in putting performance, underlying its critical role in the visuomotor control of putting. The QE-trained group maintained their optimal QE under pressure conditions, whereas the Control group experienced reductions in QE when anxious, with subsequent effects on performance. Although their performance was similar in the pre-test, the QE-trained group holed more putts and left the ball closer to the hole on missed putts than their Control group counterparts in the pressure test. Importantly, these advantages transferred to the golf course, where QE-trained golfers made 1.9 fewer putts per round, compared to pre-training, whereas the Control group showed no change in their putting statistics. These results reveal that QE training, incorporated into a pre-shot routine, is an effective intervention to help golfers maintain control when anxious.