Effects of the golfer–ground interaction on clubhead speed in skilled male golfers

The relationship between skill and ground reaction force variability in amateur golfers

It is accepted that highly skilled golfers are more consistent in their clubhead presentation and shot outcomes than their lesser skilled counterparts. However, the relationships between movement variability, outcome variability and skill in golf are not particularly well understood. This study examined the ground reaction force variability of one-hundred and four amateur golfers for shots with drivers and 5-irons. Principal component analysis was used as a data reduction technique and allowed all three components of ground reaction force to be considered together. There were statistically significant trends for the higher skilled golfers to display lower variability in two of the five principal components (driver) and four of the five principal components (5-iron). A similar trend was also observed in the other principal components, but these trends were not statistically significant. Intra-individual variability was much lower than inter-individual variability across all golfers; the golfers were each relatively consistent in maintaining their own ground reaction force patterns. Lower variability in ground reaction forces may partly explain how highly skilled golfers maintain lower variability in shot outcomes.

Effects of two-step golf swing drills on rhythm and clubhead speed in competitive juniors

Vertical and horizontal rhythms are crucial aspects of a dynamic golf swing, and the two-step swing drills (TSSD) were specifically designed to promote rhythmic unloading and loading of the legs. The purpose of this study was to evaluate the effects of a TSSD training session on the swing rhythm and clubhead speed (CHS) among competitive junior golfers (3.1 ± 4.4 hcp). The driver swings (7 swings each) of 10 competitive junior golfers (aged 15-18) were captured before and after a TSSD session consisting of four stages (lasting less than 45 minutes). Post-TSSD training, there were significant increases in CHS (p < .001), maximum unweighting (p = .006), the trail-side push (p = .009), the horizontal motion ranges of the body and pelvis (p = .005-.031), the upward/downward motion range of the body in the backswing (p = .042/.024), and the backswing/downswing angular velocity peaks of the axle-chain system (p < .033). The stepping-like leg actions primarily facilitated horizontal motion rhythm over vertical motion and unweighting over push in terms of ground interaction. These findings suggest that TSSD can serve as an effective method for developing a rhythmic and dynamic motion pattern while increasing CHS.

Kinematic, Kinetic, and Temporal Metrics Associated With Golf Proficiency

ABSTRACT

McHugh, MP, O'Mahoney, CA, Orishimo, KF, Kremenic, IJ, and Nicholas, SJ. Kinematic, kinetic, and temporal metrics associated with golf proficiency. J Strength Cond Res 38(3): 599-606, 2024-The biomechanics of the golf swing have been studied extensively, but the literature is unclear on which metrics are indicative of proficiency. The purpose of this study was to determine which metrics identified golf proficiency. It was hypothesized that discrete kinematic, kinetic, and temporal metrics would vary depending on proficiency and that combinations of metrics from each category would explain specific proficiency metrics. Kinematic, kinetic, and temporal metrics and their sequencing were collected for shots performed with a driver in 33 male golfers categorized as proficient, average, or unskilled (based on a combination of handicap, ball velocity, and driving distance). Kinematic data were collected with high-speed motion analysis, and ground reaction forces (GRF) were collected from dual force plates. Proficient golfers had greater x-factor at ball impact and greater trunk deceleration before ball impact compared with average ( p < 0.05) and unskilled ( p < 0.01) golfers. Unskilled golfers had lower x-factor at the top of the back swing and lower peak x-factor, and they took longer to reach peak trunk velocity and peak lead foot GRF compared with average ( p < 0.05) and proficient ( p < 0.05) golfers. A combination of 2 kinematic metrics (x-factor at ball impact and peak pelvis velocity), 1 kinetic metric (peak lead foot GRF), and 2 timing metrics (the timing of peak trunk and arm velocity) explained 85% of the variability in ball velocity. The finding that x-factor at ball impact and trunk deceleration identified golf proficiency points to the potential for axial trunk rotation training to improve performance.

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.

Lower extremity kinematic and kinetic factors associated with bat speed at ball contact during the baseball swing

The purpose of this study was to determine which biomechanical variables measured during the baseball swing are associated with linear bat speed at ball contact (bat speed). Twenty collegiate baseball players hit a baseball from a tee into a net. Kinematics were recorded with a motion capture system sampling at 500 Hz and kinetics were measured by force plates under each foot sampling at 1000 Hz. Associations between bat speed, individual joint and segment kinematics, joint moments and ground reaction forces (GRF) were assessed using Pearson correlations and stepwise linear regression. Average bat speed was 30 ± 2 m/s. Lead foot peak vertical (159 ± 29% BW, r = 0.622, P = 0.001), posterior (-57 ± 12% BW, r = -0.574, P = 0.008) and resultant (170 ± 30% BW, r = 0.662, P = 0.001) GRF were all correlated with bat speed. No combination of factors strengthened the relationship to bat speed beyond these individual variables. These results illustrate the role of the lead leg in generating and transferring ground reaction forces through the kinetic chain in order to accelerate the bat. Training to improve bat speed should include both general lower extremity strengthening exercises and sport-specific hitting drills to improve lower extremity force production following lead foot contact.

Lower Body Joint Moments during the Golf Swing in Older Adults: Comparison to Other Activities of Daily Living

Golf participation has increased dramatically in the last several years. With this increase in participation, clinicians need better evidenced based strategies to advise those golfers with different pathologies when it is safe to return to the game. Golf teaching professionals also need to understand how to alter golf mechanics to protect injured and/or diseased joints in golfers to allow them to play pain free and avoid further injury. This study used a 3-dimensional link segment model to calculate the net joint moments on the large lower limb joints (knee and hip) during golf (lead and trail leg) and two commonly studied activities of daily living (gait and sit-to-stand) in 22 males, healthy, adult golfers. It also examined the correlations between these knee and hip joint loads and club head speed. The external valgus knee moment and the internal hip adduction moment were greater in the lead leg in golf than in the other activities and were also correlated with club head speed. This indicates a strategy of using the frontal plane GRF moment during the swing. The internal hip extension and knee flexion moment were also greater in the golf swing as compared with the other activities and the hip extension moment was also correlated with club head speed. This emphasizes the importance of hip extensor (i.e., gluteus maximus and hamstring) muscle function in golfers, especially in those emphasizing the use of anterior-posterior ground reaction forces (i.e., the pivoting moment). The golf swing places some loads on the knee and the hip that are much different than the loads during gait and sit-to-stand tasks. Knowledge of these golf swing loads can help both the clinician and golf professional provide better evidence-based advice to golfers in order to keep them healthy and avoid future pain/injury.

Influence of muscle strength, power, and rapid force capacity on maximal club head speed in male national level golfers

This study investigated the relationships between maximal club head speed (CHS) and physiological and anthropometric parameters in 21 national-level male golfers (age: 21.9 ± 3.9 years; handicap: +1.1 ± 1.7). Maximal isometric strength (MVC) was measured during isometric mid-thigh pull and bench press, while MVC and rate of force development (RFD) were measured during isometric leg press. Power, lower limb stiffness, positive impulse, jump height and RFDdyn were measured during countermovement jump (CMJ). Moreover, rotational trunk power, active range of motion (AROM) and anthropometrics were determined. Comparisons were made between participants with high (FTG) and low (STG) CHS, respectively. FTG demonstrated greater isometric mid-thigh pull and isometric bench press MVC, leg press RFD, rotational trunk power, and CMJ parameters (except RFDdyn) as well as reduced hip AROM compared to STG (P < 0.01). CHS was positively correlated to isometric mid-thigh pull and isometric bench press MVC, leg press RFD, rotational trunk power and CMJ parameters (P < 0.01). In conclusion, strong positive correlations were observed between maximal CHS and maximal strength and power parameters. Consequently, improving maximal neuromuscular strength and power may be considered of importance for golfers, as greater CHS and accompanying driving distance may lead to competitive advantages.

Centre of pressure golf swing movement strategies are better defined using a continuous approach than by segregated styles

The relationships between movement style and golf performance have been well researched, but the premise of segregated movement styles has not been fully examined. The purpose of this investigation was to examine the postulation that centre of pressure data are not best described by segregated styles but instead by a continuum and to determine relationships between centre of pressure, handicap and clubhead speed using a continuous approach. Centre of pressure paths of driver and 5-iron shots from 104 amateur golfers were analysed using discrete and continuous methods. Discrete methods used different cluster evaluation criteria which result in two-cluster and twenty-cluster solutions being considered "optimum". The two-cluster solution showed the characteristics of "front-foot" and "reverse" centre of pressure styles. However, a continuous principal component analysis method revealed that the clusters were not well separated and provided support for a multidimensional continuum. The principal components had a high correlation with handicap and clubhead speed. Lower handicap and higher swing speed golfers tended to display a centre of pressure with a "front-foot" style and a fast transition towards the front foot at the start of the downswing. A continuous characterisation of centre of pressure styles has more utility than the segregated styles previously described.

A kinetic analysis of the judo osoto-gari technique: relationship to sweeping leg velocity

The present study characterised supporting leg kinetics (sweeping and pivot legs) during osoto-gari and investigated the relationship between kinetic variables and sweeping leg velocity at sweep contact. Fifteen black belt judoka performed osoto-gari. Motion data were recorded using a Mac3D motion analysis system (250 Hz), and ground reaction force (GRF) data were collected using four force plates (1,000 Hz). During the swing phase, the peak anterior (r = -0.535, p = 0.040) and upward (r = -0.693, p = 0.005) GRFs generated by the sweeping leg and the peak plantar flexion moment (r = 0.548, p = 0.034) and power (r = -0.700, p < 0.005) of the sweeping leg ankle joint significantly correlated with the sweeping leg velocity at sweep contact. During the throwing phase, the peak clockwise moment (r = -0.604, p = 0.017) correlated with the peak sweeping leg velocity. The peak knee extension moment (r = 0.602, p = 0.018), hip flexion moment (r = -0.589, p = 0.021) and knee power (r = -0.618, p = 0.016) of the pivot leg also correlated with the sweeping leg velocity at sweep contact. The results indicated that exertion of the sweeping leg ankle plantar flexors positively contributed to the sweeping velocity. Increasing whole-body rotation by contracting the pivot leg knee extensors is a crucial biomechanical factor in accelerating the sweeping leg at sweep contact.

Changes in dynamic balance control in adults with obesity across walking speeds

Adults with obesity have gait instability, leading to increased fall risks and decreased physical activity. Whole-body angular momentum (WBAM) is regulated over a gait cycle, essential to avoid a fall. However, how obese adults regulate WBAM during walking is unknown. The current study investigated changes in WBAM about the body's center of mass (COM) during walking in obese and non-obese adults across different walking speeds. Twenty-eight young adults with obesity and normal weight walked barefoot at a fixed walking speed (FWS, 1.25 m/s) and at five different speeds based on their preferred walking speed (PWS): 50, 75, 100, 125, and 150 % of PWS. Adults with obesity walked slower with shorter step length, wider step width, and longer double support time (p < 0.01). The ranges of frontal- and transverse-plane WBAM were greater in obese adults (p < 0.01). We also found that the range of frontal-plane WBAM did not significantly change with walking speed (p > 0.05), while the range of transverse-plane WBAM increased with walking speed (p < 0.01). The ranges of frontal- and transverse-plane WBAM increased with the mediolateral ground reaction force and mediolateral moment arm (p < 0.01), which may be most affected by lateral foot placement relative to the body's COM. Our findings suggest that controlling mediolateral stability during walking is more challenging in obese adults, independent of their slow walking speed. Understanding whole-body rotational dynamics observed in obese walking provides an insight into the biomechanical link between obesity and gait instability, which may help find a way to reduce fall risks and increase physical activity.

The effect of obesity on whole-body angular momentum during steady-state walking

BACKGROUND

Individuals with obesity demonstrate deficits in postural stability, leading to increased fall risks. Controlling whole-body angular momentum is essential for maintaining postural stability during walking and preventing falls. However, it is unknown how obesity impacts whole-body angular momentum during walking.

RESEARCH PURPOSE

To investigate the change in angular momentum about the body's COM during walking in individuals with different degrees of obesity.

METHODS

Thirty-eight young adults with different body mass index (BMI) scores walked barefoot at their preferred speed on a treadmill for 2 min. The whole-body angular momentum has been quantified from ground reaction force and moment data to capture the rotational behavior of walking in individuals with obesity without relying solely on placing markers on anatomical landmarks.

RESULTS

We found that adults with higher BMI scores walked slower with shorter step length, wider step width, and longer double support time (ps<.01). Ranges of the frontal- and transverse-plane angular momentum were greater in adults with higher BMI scores (ps<.01), while no difference was observed between BMI groups in the total sum of changes in whole-body angular momentum in any plane (ps>.05).

SIGNIFICANCE

Obesity not only decreased walking speed but also limited the ability to control mediolateral stability during walking. Investigating how obesity affects whole-body angular momentum may help better understand why adults with obesity have atypical gait with poor balance, address fall risk factors, and facilitate participation in physical activities.

Is Golf a Contact Sport? Protection of the Spine and Return to Play After Lumbar Surgery

STUDY DESIGN

Narrative review.

OBJECTIVE

To address the gap in the literature on specific return to play protocols and rehabilitation regimens for golfers undergoing lumbar spine surgery with a high impact swing.

METHODS

This review did not involve patient care or any clinical prospective or retrospective review of patient information and thus did not warrant institutional review board approval. The available literature of PubMed, Medline, and OVID was utilized to review the existing literature.

RESULTS

Studies have shown that the forces through the lumbar spine in the modern-era golf swing are like other contact sports. Methods of protecting the lumbar spine include proper swing mechanics, abdominal and paraspinal musculature strengthening and flexibility as well as physical fitness. There are a variety of treatment options available to treat lumbar spine pathology each with a different return to play recommendations from doctors in the field.

CONCLUSIONS

With the introduction of a high impact, modern-era swing to the game of golf, the pathology is seen in the lumbar spine of both young, old, professional, and amateur golfers with low back pain are similar to other athletes in contact sports. Surgery is effective in returning athletes to a similar level of play even though no protocols exist for an effective and safe return. There have been many studies conducted to determine appropriate treatment and return to play for these injuries, but there is a gap in the literature on specific return to play protocols and rehabilitation regimens for golfers undergoing lumbar spine surgery with a high impact swing. As return to competitive play is important, especially with professional golfers, studies combining the use of swing mechanics changes, rehabilitation regimens and the type of surgery performed would be able to provide some insight into this topic now that golf may begin to be considered a contact sport.

Relationships between highly skilled golfers' clubhead velocity and kinetic variables during a countermovement jump

Previous research has sought to establish the relationship countermovement jump (CMJ) performance has with clubhead velocity (CHV). However, these investigations either assessed lower skilled golfers, or utilised field-based protocols, which are unable to assess a number of biomechanical variables. Fifty highly skilled golfers performed CMJs on Kistler force platforms in laboratory conditions. The CMJ variables included positive impulse, net impulse, average power, peak power, peak force, force at zero velocity and jump height. Clubhead velocity was measured using a TrackMan 3e launch monitor at a driving range. A Pearsons correlation was employed to measure the strength and direction of the relationships between CHV and CMJ derived performance variables. Results indicated strong positive relationships (all p's <0.001) between CHV and positive impulse (r = 0.695), net impulse (r = 0.689), average power (r = 0.645), peak power (r = 0.656), peak force (r = 0.517) and force at zero velocity (r = 0.528) with no significant relationship with jump height. However, if investigators only have access to field-based protocols, it is recommended that they measure jump height and utilise inverse dynamics to calculate take-off velocity. By multiplying take-off velocity by mass, this allows the attainment of net impulse.

Foot Insole Pressure Distribution during the Golf Swing in Professionals and Amateur Players

There are numerous articles that study the ground reaction forces during the golf swing, among which only a few analyze the pressure pattern distributed on the entire surface of the foot. The current study compares the pressure patterns on the foot insoles of fifty-five golfers, from three different performance levels, playing swings with driver and 5-iron clubs in the driving range. Five swings were selected for each club. During each swing, ultra-thin insole sensors (4 sensors/cm2) measure foot pressure at the frequency of 100 Hz. To perform statistical analysis, insole sensors are clustered to form seven areas, with the normalized pressure of each area being our dependent variable. A video camera was used to label the five key instants of the swing. Statistical analysis demonstrates a significant difference between the pressure distribution pattern of the left and right feet for both driver and 5-iron. However, the pressure distribution pattern remains almost the same when switching the club type from 5-iron to driver. We have also observed that there are significant differences between the pattern of professionals and players with medium and high handicap. The obtained pattern agrees with the principle of weight transfer with a different behavior between the medial and lateral areas of the foot.

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.