It might seem a little overboard, but some of these papers are hiding great little gems!
Trying to perfect your swinging, putting, and chipping? Research comes to the rescue
Abstract: This study analyzes muscle activity, recorded in an eight-channel electromyographic (EMG) signal stream, during the golf swing using a 7-iron club and exploits information extracted from EMG dynamics to predict the success of the resulting shot. Muscles of the arm and shoulder on both the left and right sides, namely flexor carpi radialis, extensor digitorum communis, rhomboideus and trapezius, are considered for 15 golf players (∼5 shots each). The method using Gaussian filtering is outlined for EMG onset time estimation in each channel and activation sequence profiling. Shots of each player revealed a persistent pattern of muscle activation. Profiles were plotted and insights with respect to player effectiveness were provided. Inspection of EMG dynamics revealed a pair of highest peaks in each channel as the hallmark of golf swing, and a custom application of peak detection for automatic extraction of swing segment was introduced. Various EMG features, encompassing 22 feature sets, were constructed. Feature sets were used individually and also in decision-level fusion for the prediction of shot effectiveness. The prediction of the target attribute, such as club head speed or ball carry distance, was investigated using random forest as the learner in detection and regression tasks. Detection evaluates the personal effectiveness of a shot with respect to the player-specific average, whereas regression estimates the value of target attribute, using EMG features as predictors. Fusion after decision optimization provided the best results: the equal error rate in detection was 24.3% for the speed and 31.7% for the distance; the mean absolute percentage error in regression was 3.2% for the speed and 6.4% for the distance. Proposed EMG feature sets were found to be useful, especially when used in combination. Rankings of feature sets indicated statistics for muscle activity in both the left and right body sides, correlation-based analysis of EMG dynamics and features derived from the properties of two highest peaks as important predictors of personal shot effectiveness. Activation sequence profiles helped in analyzing muscle orchestration during golf shot, exposing a specific avalanche pattern, but data from more players are needed for stronger conclusions. Results demonstrate that information arising from an EMG signal stream is useful for predicting golf shot success, in terms of club head speed and ball carry distance, with acceptable accuracy. Surface EMG data, collected with a goal to automatically evaluate golf player's performance, enables wearable computing in the field of ambient intelligence and has potential to enhance exercising of a long carry distance drive.
Pub.: 28 Apr '16, Pinned: 14 Jul '16
Abstract: The purpose of this study was to compare kinetic, kinematic, and performance variables associated with full and shortened modern backswings in a skilled group of modern swing (one-plane) golfers. Shortening the modern golf backswing is proposed to reduce vertebral spine stress, but supporting evidence is lacking and performance implications are unknown. Thirteen male golfers performed ten swings of each swing type using their own 7-iron club. Biomechanical-dependent variables included the X-Factor kinematic data and spine kinetics. Performance-related dependent variables included club head velocity (CHV), shot distance, and accuracy (distance from the target line). Data were analysed with repeated measures ANOVA with an a priori alpha of 0.05 (SPSS 22.0, IBM, Armonk, NY, USA). We found significant reductions for the X-Factor (p < 0.05) between the full and shortened swings. The shortened swing condition ameliorated vertebral compression force from 7.6 ± 1.4 to 7.0 ± 1.7 N (normalised to body weight, p = 0.01) and significantly reduced CHV (p < 0.05) by ~2 m/s with concomitant shot distance diminution by ~10 m (p < 0.05). Further research is necessary to examine the applicability of a shortened swing for golfers with low back pain.
Pub.: 12 Apr '16, Pinned: 14 Jul '16
Abstract: We test hypotheses regarding risk taking behavior of competitors in settings characterized by one-on-one, single elimination tournaments. We draw data from 579 professional golf matches and over 18,000 holes from 2003 to 2013 in tournaments where match-play scoring is used rather than stroke-play. Because of the uniqueness of the data, we are able to provide clean empirical tests of how risk taking is affected by horizon effects (holes remaining), peer effects arising from heterogeneity in player abilities, match status (whether behind or ahead), and the difficulty of the task/project (hole). The findings are applicable to corporate settings where only a few rivals compete for a prize, such as a winning bid, a promotion, market share dominance, and patents. Other applications include litigation contests and political elections.
Pub.: 14 May '14, Pinned: 14 Jul '16
Abstract: This study aimed to examine the effect of the impact point on the golf ball on the horizontal launch angle and side spin during putting with a mechanical putting arm and human participants. Putts of 3.2 m were completed with a mechanical putting arm (four putter-ball combinations, total of 160 trials) and human participants (two putter-ball combinations, total of 337 trials). The centre of the dimple pattern (centroid) was located and the following variables were measured: distance and angle of the impact point from the centroid and surface area of the impact zone. Multiple regression analysis was conducted to identify whether impact variables had significant associations with ball roll variables, horizontal launch angle and side spin. Significant associations were identified between impact variables and horizontal launch angle with the mechanical putting arm but this was not replicated with human participants. The variability caused by "dimple error" was minimal with the mechanical putting arm and not evident with human participants. Differences between the mechanical putting arm and human participants may be due to the way impulse is imparted on the ball. Therefore it is concluded that variability of impact point on the golf ball has a minimal effect on putting performance.
Pub.: 17 Mar '16, Pinned: 14 Jul '16
Abstract: The purpose of this study was to investigate the influence of shaft stiffness on grip and clubhead kinematics. Two driver shafts with disparate levels of stiffness, but very similar inertial properties, were tested by 33 golfers representing a range of abilities. Shaft deflection data as well as grip and clubhead kinematics were collected from 14 swings, with each shaft, for each golfer using an optical motion capture system. The more flexible shaft (R-Flex) demonstrated a higher contribution to clubhead speed from shaft deflection dynamics (P < .001), but was also associated with significantly less grip angular velocity at impact (P = .001), resulting in no significant difference in clubhead speed (P = .14). However, at the individual level, half of the participants demonstrated a significant difference in clubhead speed between shafts. The more flexible shaft was also associated with significantly different magnitudes of head rotation relative to the grip. More specifically, both bend loft (P < .001) and bend lie (P < .001) were greater for the R-Flex shaft, while bend close (P = .017) was greater for the stiffer (X-Flex) shaft. However, changes in grip orientation resulted in no significant differences in face orientation, between the shafts, at impact.
Pub.: 12 Mar '16, Pinned: 14 Jul '16
Abstract: Our aim was to determine how skilled players regulate linear and angular impulse while maintaining balance during the golf swing. Eleven highly skilled golf players performed swings with a 6-iron and driver. Components contributing to linear and angular impulse generated by the rear and target legs (resultant horizontal reaction force (RFh), RFh-angle, and moment arm) were quantified and compared across the group and within a player (α = .05). Net angular impulse generated by both the rear and target legs was greater for the driver than the 6-iron. Mechanisms used to regulate angular impulse generation between clubs varied across players and required coordination between the legs. Increases in net angular impulse with a driver involved increases in target leg RFh. Rear leg RFh-angle was maintained between clubs whereas target leg RFh became more aligned with the target line. Net linear impulse perpendicular to the target line remained near zero preserving balance while net linear impulse along the target line decreased in magnitude. These results indicate that the net angular impulse was regulated between clubs by coordinating force generation of the rear and target legs while sustaining balance throughout the task.
Pub.: 10 Mar '16, Pinned: 14 Jul '16
Abstract: The use of multi-segment trunk models to investigate the crunch factor in golf may be warranted. The first aim of the study was to investigate the relationship between the trunk and lower trunk for crunch factor-related variables (trunk lateral bending and trunk axial rotation velocity). The second aim was to determine the level of association between crunch factor-related variables with swing (clubhead velocity) and launch (launch angle). Thirty-five high-level amateur male golfers (Mean ± SD: age = 23.8 ± 2.1 years, registered golfing handicap = 5 ± 1.9) without low back pain had kinematic data collected from their golf swing using a 10-camera motion analysis system operating at 500 Hz. Clubhead velocity and launch angle were collected using a validated real-time launch monitor. A positive relationship was found between the trunk and lower trunk for axial rotation velocity (r(35) = .47, P < .01). Cross-correlation analysis revealed a strong coupling relationship for the crunch factor (R(2) = 0.98) between the trunk and lower trunk. Using generalised linear model analysis, it was evident that faster clubhead velocities and lower launch angles of the golf ball were related to reduced lateral bending of the lower trunk.
Pub.: 02 Mar '16, Pinned: 14 Jul '16
Abstract: Sensorimotor rhythm (SMR) activity has been related to automaticity during skilled action execution. However, few studies have bridged the causal link between SMR activity and sports performance. This study investigated the effect of SMR neurofeedback training (SMR NFT) on golf putting performance. We hypothesized that preelite golfers would exhibit enhanced putting performance after SMR NFT. Sixteen preelite golfers were recruited and randomly assigned into either an SMR or a control group. Participants were asked to perform putting while electroencephalogram (EEG) was recorded, both before and after intervention. Our results showed that the SMR group performed more accurately when putting and exhibited greater SMR power than the control group after 8 intervention sessions. This study concludes that SMR NFT is effective for increasing SMR during action preparation and for enhancing golf putting performance. Moreover, greater SMR activity might be an EEG signature of improved attention processing, which induces superior putting performance.
Pub.: 13 Feb '16, Pinned: 14 Jul '16
Abstract: Variability and control structure are under-represented areas of golf swing research. This study investigated the use of the abundant degrees of freedom in the golf swing of high and intermediate skilled golfers using uncontrolled manifold (UCM) analysis. The variance parallel to (VUCM) and orthogonal to (VOrth) the UCM with respect to the orientation and location of the clubhead were calculated. The higher skilled golfers had proportionally higher values of VUCM than lower skilled players for all measured outcome variables. Motor synergy was found in the control of the orientation of the clubhead and the combined outcome variables but not for clubhead location. Clubhead location variance zeroed-in on impact as has been previously shown, whereas clubhead orientation variance increased near impact. Both skill levels increased their control over the clubhead location leading up to impact, with more control exerted over the clubhead orientation in the early downswing. The results suggest that to achieve higher skill levels in golf may not lie simply in optimal technique, but may lie more in developing control over the abundant degrees of freedom in the body.
Pub.: 20 Jan '16, Pinned: 14 Jul '16
Abstract: Participation in specific activities requires complex ranges of knee movements and activity-dependent kinematics. The purpose of this study was to investigate dynamic knee kinematics during squat and golf swing using image-matching techniques.Five healthy males performed squats and golf swings under periodic X-ray images at 10 frames per second. We analyzed the in vivo three-dimensional kinematic parameters of subjects' knees, namely the tibiofemoral flexion angle, anteroposterior (AP) translation, and internal-external rotation, using serial X-ray images and computed tomography-derived, digitally reconstructed radiographs.During squat from 0° to 140° of flexion, the femur moved about 25mm posteriorly and rotated 19° externally relative to the tibia. Screw-home movement near extension, bicondylar rollback between 20° and 120° of flexion, and medial pivot motion at further flexion were observed. During golf swing, the leading and trailing knees (the left and right knees respectively in the right-handed golfer) showed approximately five millimeters and four millimeters of AP translation with 18° and 26° of axial rotation, respectively. A central pivot motion from set-up to top of the backswing, lateral pivot motion from top to ball impact, and medial pivot motion from impact to the end of follow-through were observed.The medial pivot motion was not always recognized during both activities, but a large range of axial rotation with bilateral condylar AP translations occurs during golf swing. This finding has important implications regarding the amount of acceptable AP translation and axial rotation at low flexion in replaced knees.IV.
Pub.: 20 Jan '16, Pinned: 14 Jul '16
Abstract: The modern golf swing is a complex and asymmetrical movement that places an emphasis on restricting pelvic turn while increasing thorax rotation during the backswing to generate higher clubhead speeds at impact. Increasing thorax rotation relative to pelvic rotation preloads the trunk muscles by accentuating their length and allowing them to use the energy stored in their elastic elements to produce more power. As the thorax and pelvis turn back towards the ball during the downswing, more skilled golfers are known to laterally slide their pelvis toward the target, which further contributes to final clubhead speed. However, despite the apparent performance benefits associated with these sequences, it has been argued that the lumbar spine is incapable of safely accommodating the forces they produce. This notion supports a link between the repeated performance of the golf swing and the development of golf-related low back injuries. Of the complaints reported by golfers, low back injuries continue to be the most prevalent, but the mechanism of these injuries is still poorly understood. This review highlights that there is a paucity of research directly evaluating the apparent link between the modern golf swing and golf-related low back pain. Furthermore, there has been a general lack of consensus within the literature with respect to the methods used to objectively assess the golf swing and the methods used to derived common outcome measures. Future research would benefit from a clear set of guidelines to help reduce the variability between studies.
Pub.: 26 Nov '15, Pinned: 14 Jul '16
Abstract: 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.
Pub.: 06 Nov '15, Pinned: 14 Jul '16