Abdominal muscle activation of elite male golfers with chronic low back pain

Ultrasound Biofeedback Increases Abdominal Muscle Activation in Golfers With a History of Low Back Pain

OBJECTIVES

To compare activation ratios of the transverse abdominis (TrA) during an abdominal draw-in maneuver (ADIM) and abdominal obliques during a golf swing, with and without ultrasound biofeedback, and to determine intrarater reliability of these ultrasound thickness measures.

DESIGN

Single-session crossover study.

SETTING

Laboratory.

PARTICIPANTS

Sixteen adult golfers with 2 or more episodes of low back pain (LBP) in the past year.

INTERVENTIONS

Verbal cueing alone and verbal cueing with ultrasound biofeedback.

MAIN OUTCOME MEASURES

Bilateral TrA activation ratios were calculated during an ADIM with and without ultrasound biofeedback. Activation ratios of the abdominal obliques were calculated bilaterally during golf swings with and without ultrasound biofeedback. Intraclass correlation coefficients (ICCs) were calculated for average thickness across all muscles and conditions for the nonbiofeedback trials.

RESULTS

Transverse abdominis activation ratios were significantly higher when ultrasound biofeedback was provided bilaterally ( P < 0.001). Abdominal oblique activation ratios during the golf swing were also significantly higher with ultrasound biofeedback for the lead ( P = 0.014) and trail ( P < 0.001) sides. Intraclass correlation coefficient values ranged from 0.92 to 0.97 ( P < 0.001).

CONCLUSIONS

Ultrasound biofeedback can increase activation ratios of the TrA during a supine ADIM in adult golfers with a history of LBP. Postswing ultrasound biofeedback increases activation of the abdominal obliques during a golf swing in golfers with a history of LBP. Ultrasound thickness measures of the TrA and obliques have excellent intrarater reliability.

Biomechanical parameters of the golf swing associated with lower back pain: A systematic review

Low back pain (LBP) is the most common injury in golfers of all abilities. The primary aim of this review was to improve understanding of human golf swing biomechanics associated with LBP. A systematic review using the PRISMA guidelines was performed. Nine studies satisfying inclusion criteria and dually reporting golf swing biomechanics and LBP were identified. Human golf swing biomechanics potentially associated with LBP include: reduced lumbar flexion velocity; reduced transition phase length; reduced lumbar torsional load; earlier onset of erector spinae contraction; increased lumbar lateral flexion velocity; reduced or greater erector spinae activity; and earlier onset of external oblique contraction. These potential associations were undermined by a very limited and conflicting quality of evidence, study designs which introduced a severe potential for bias and a lack of prospective study design. There is no conclusive evidence to support the commonly held belief that LBP is associated with "poor" golf swing technique. The potential associations identified should be further investigated by prospective studies of robust design, recruiting participants of both sexes and dexterities. Once firm associations have been identified, further research is required to establish how this knowledge can be best integrated into injury prevention and rehabilitation.

Is average club head speed a risk factor for lower back injuries in professional golfers? A retrospective case control study

BACKGROUND

Our hypothesis was that higher average club head speed is correlated with lower back injuries in professional golfers.

METHODS

This was a retrospective case control study of male professional golfers who suffered lower back injuries while playing golf. The injured group was composed of 14 Professional Golfers' Association (PGA) golfers who withdrew from a PGA tour event due to a back injury during the years 2017-2019. The case-control matching procedure was used to randomly match cases and controls with a 2:1 allocation ratio, respectively, based on age. Variables were chosen based on currently proposed risk factors. Data was statistically analyzed using SPSS 25.

RESULTS

There were 14 PGA golfers who suffered lower back injuries during the years 2017-2019 who were included in this study. There was no significant difference in age, height, weight or BMI between the injured and control group. The injured group had a higher mean club head speed than the control group (P < 0.01).

CONCLUSION

This study found that average club head speed was significantly higher in PGA golfers who suffered back injuries while golfing during a two-year period (2017-2019) when compared with age-matched controls.

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.

The relationship between shot velocity and physical characteristics of lacrosse players

BACKGROUND

This study was designed to quantify the relationship between the velocity at which lacrosse players can shoot a lacrosse ball (shot velocity) with a lacrosse stick and a variety of physical strength attributes.

METHODS

Twenty lacrosse athletes were recruited to participate in the study. We measured shot velocity with a microwave, speed-measuring apparatus.

RESULTS

Shot velocity showed significant and moderate correlations with the distance a player can throw a medicine ball (r=0.58-0.66), the height at which a player could jump vertically from a crouching position (r=0.44-0.46), a player's hand grip strength (r=0.33-0.46), and the isokinetic concentric strength of player knees (r=0.20-0.45). The thrown distance of a medicine ball was significantly and moderately correlated with vertical jump height (r=0.32-0.47) and hand grip strength (r=0.33-0.53), respectively.

CONCLUSIONS

Strength and conditioning coaches should train lacrosse players in strengthening their core, lower extremities and in movements that link their arms with the lower part of the body. The muscular strength of trunk rotation, which relies on the strength of the arms and lower limbs, greatly enhances a player's ability to shoot a lacrosse ball at high velocities.

Systematic review of musculoskeletal injuries in professional golfers

OBJECTIVE

The distribution of injuries affecting professional golfers is yet to be fully understood. We performed a systematic review of the clinical literature to establish the epidemiology of musculoskeletal injuries affecting professional golfers.

DESIGN

Systematic review.

DATA SOURCES

Searched databases in July 2018 were PubMed, SPORTDiscus and Embase.

ELIGIBILITY CRITERIA

Published observational research articles relating to the incidence or prevalence of musculoskeletal injuries in professional golfers, which were written in the English language and not restricted by age or gender.

RESULTS

Of the 1863 studies identified on the initial search, 5 studies were found to satisfy the inclusion criteria for analysis. The mean age of the golfers in these studies was 34.8 (±3.6) years. The gender of patients in included studies compromised 72% males and 28% females. Four studies reported that lumbar spine injuries were the most common (range 22%-34%). Excluding injuries to the spine (lumbar, thoracic and cervical), the hand/wrist was the next most common region of injury (range 6%-37%). The quality of the studies was relatively poor with no study satisfying >50% of the quality assessment tool questions and only one study giving a clear definition of how they defined injury.

CONCLUSION

There is a paucity of well-designed epidemiological studies evaluating musculoskeletal injuries affecting professional golfers. Injuries to the spine are the most frequently affected region, followed by the hand/wrist. This study has identified targeted areas of future research that aims to improve the management of injuries among professional golfers.

Risk Factors Associated With Low Back Pain in Golfers: A Systematic Review and Meta-analysis

Context:

Low back pain is common in golfers. The risk factors for golf-related low back pain are unclear but may include individual demographic, anthropometric, and practice factors as well as movement characteristics of the golf swing.

Objective:

The aims of this systematic review were to summarize and synthesize evidence for factors associated with low back pain in recreational and professional golfers.

Data Sources:

A systematic literature search was conducted using the PubMed, CINAHL, and SPORTDiscus electronic databases through September 2017.

Study Selection:

Studies were included if they quantified demographic, anthropometric, biomechanical, or practice variables in individuals with and without golf-related low back pain.

Study Design:

Systematic review and meta-analysis.

Level of Evidence:

Level 3.

Data Extraction:

Studies were independently reviewed for inclusion by 2 authors, and the following data were extracted: characterization of low back pain, participant demographics, anthropometrics, biomechanics, strength/flexibility, and practice characteristics. The methodological quality of studies was appraised by 3 authors using a previously published checklist. Where possible, individual and pooled effect sizes of select variables of interest were calculated for differences between golfers with and without pain.

Results:

The search retrieved 73 articles, 19 of which met the inclusion criteria (12 case-control studies, 5 cross-sectional studies, and 2 prospective longitudinal studies). Methodological quality scores ranged from 12.5% to 100.0%. Pooled analyses demonstrated a significant association between increased age and body mass and golf-related low back pain in cross-sectional/case-control studies. Prospective data indicated that previous history of back pain predicts future episodes of pain.

Conclusion:

Individual demographic and anthropometric characteristics may be associated with low back pain, but this does not support a relationship between swing characteristics and the development of golf-related pain. Additional high-quality prospective studies are needed to clarify risk factors for back pain in golfers.

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.

Electromyographic analyses of the erector spinae muscles during golf swings using four different clubs

The purpose of this study was to compare the electromyography (EMG) patterns of the thoracic and lumbar regions of the erector spinae (ES) muscle during the golf swing whilst using four different golf clubs. Fifteen right-handed male golfers performed a total of twenty swings in random order using the driver, 4-iron, 7-iron and pitching-wedge. Surface EMG was recorded from the lead and trail sides of the thoracic and lumbar regions of the ES muscle (T8, L1 and L5 lateral to the spinous-process). Three-dimensional high-speed video analysis was used to identify the backswing, forward swing, acceleration, early and late follow-through phases of the golf swing. No significant differences in muscle-activation levels from the lead and trail sides of the thoracic and lumbar regions of the ES muscle were displayed between the driver, 4-iron, 7-iron and pitching-wedge (P > 0.05). The highest mean thoracic and lumbar ES muscle-activation levels were displayed in the forward swing (67-99% MVC) and acceleration (83-106% MVC) phases of the swing for all clubs tested. The findings from this study show that there were no significant statistical differences between the driver, 4-iron, 7-iron and pitching-wedge when examining muscle activity from the thoracic and lumbar regions of the ES muscle.

Comparison of Thoracic and Lumbar Erector Spinae Muscle Activation Before and After a Golf Practice Session

Lower back pain is commonly associated with golfers. The study aimed: to determine whether thoracic- and lumbar-erector-spinae muscle display signs of muscular fatigue after completing a golf practice session, and to examine the effect of the completed practice session on club head speed, ball speed and absolute carry distance performance variables. Fourteen right-handed male golfers participated in the laboratory-based-study. Surface electromyography (EMG) data was collected from the lead and trail sides of the thoracic- and lumbar-erector-spinae muscle. Normalized root mean squared (RMS) EMG activation levels and performance variables for the golf swings were compared before and after the session. Fatigue was assessed using median frequency (MDF) and RMS during the maximum voluntary contraction (MVC) performed before and after the session. No significant differences were observed in RMS thoracic- and lumbar-erector-spinae muscle activation levels during the five phases of the golf swing and performance variables before and after the session (p > .05). Significant changes were displayed in MDF and RMS when comparing the MVC performed before and after the session (p < .05). Fatigue was evident in the trail side of the erector-spinae muscle after the session.

The Biomechanics of the Modern Golf Swing: Implications for Lower Back Injuries

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.

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.

Electromyographic Analysis of the Lower Limb Muscles in Low- and High-Handicap Golfers

PURPOSE

The aim of this study was to compare the electromyographic patterns of the lower limb muscles during a golf swing performed by low- and high-handicap golfers.

METHOD

Ten golfers (5 low- and 5 high-handicap) performed 8 swings using a 7-iron. Surface electromyography (EMG) was recorded for the following lower limb muscles on both sides: biceps femoris, semitendinosus, gluteus maximus, vastus medialis and lateralis, rectus femoris, tibialis anterior, peroneus longus, and gastrocnemius medialis and lateralis. The golf-swing phases were determined by 3-dimensional high-speed video analysis.

RESULTS

Compared with the high-handicap golfers, the low-handicap golfers performed the forward swing with a shorter duration of the swing phases, with the exception of the late follow-through, where they exhibited longer duration. Considering the EMG patterns, the low-handicap golfers showed a tendency for the studied muscles to reach an activation peak earlier and presented statistically significant higher muscle activity in some of the lower limb muscles, mainly from the left side.

CONCLUSION

Differences between low- and high-handicap golfers were found in the average duration of swing phases and in the activation level of the lower limbs, with more evidence on muscles from the left side.

Comparison of Muscle Onset Activation Sequences between a Golf or Tennis Swing and Common Training Exercises Using Surface Electromyography: A Pilot Study

Aim. The purpose of this pilot study is to use surface electromyography to determine an individual athlete's typical muscle onset activation sequence when performing a golf or tennis forward swing and to use the method to assess to what degree the sequence is reproduced with common conditioning exercises and a machine designed for this purpose. Methods. Data for 18 healthy male subjects were collected for 15 muscles of the trunk and lower extremities. Data were filtered and processed to determine the average onset of muscle activation for each motion. A Spearman correlation estimated congruence of activation order between the swing and each exercise. Correlations of each group were pooled with 95% confidence intervals using a random effects meta-analytic strategy. Results. The averaged sequences differed among each athlete tested, but pooled correlations demonstrated a positive association between each exercise and the participants' natural muscle onset activation sequence. Conclusion. The selected training exercises and Turning Point™ device all partially reproduced our athletes' averaged muscle onset activation sequences for both sports. The results support consideration of a larger, adequately powered study using this method to quantify to what degree each of the selected exercises is appropriate for use in both golf and tennis.

An electromyographic study of the effect of hand grip sizes on forearm muscle activity and golf performance

The study describes the differences in surface electromyography (EMG) activity of two forearm muscles in the lead and trail arm at specific phases of the golf swing using a 7-iron with three different grip sizes among amateur and professional golfers. Fifteen right-handed male golfers performed five golf swings using golf clubs with three different grip sizes. Surface EMG was used to measure muscle activity of the extensor carpi radialis brevis (ECRB) and flexor digitorum superficialis (FDS) on both forearms. There were no significant differences in forearm muscle activity when using the three golf grips within the group of 15 golfers (p > 0.05). When using the undersize grip, club head speed significantly increased (p = 0.044). During the backswing and downswing phases, amateurs produced significantly greater forearm muscle activity with all three grip sizes (p < 0.05). In conclusion, forearm muscle activity is not affected by grip sizes. However, club head speed increases when using undersize grips.

Inter-joint coordination between hips and trunk during downswings: Effects on the clubhead speed

Understanding of the inter-joint coordination between rotational movement of each hip and trunk in golf would provide basic knowledge regarding how the neuromuscular system organises the related joints to perform a successful swing motion. In this study, we evaluated the inter-joint coordination characteristics between rotational movement of the hips and trunk during golf downswings. Twenty-one right-handed male professional golfers were recruited for this study. Infrared cameras were installed to capture the swing motion. The axial rotation angle, angular velocity and inter-joint coordination were calculated by the Euler angle, numerical difference method and continuous relative phase, respectively. A more typical inter-joint coordination demonstrated in the leading hip/trunk than trailing hip/trunk. Three coordination characteristics of the leading hip/trunk reported a significant relationship with clubhead speed at impact (r < -0.5) in male professional golfers. The increased rotation difference between the leading hip and trunk in the overall downswing phase as well as the faster rotation of the leading hip compared to that of the trunk in the early downswing play important roles in increasing clubhead speed. These novel inter-joint coordination strategies have the great potential to use a biomechanical guideline to improve the golf swing performance of unskilled golfers.

Low Back Pain in Athletes Is Associated with General and Sport Specific Risk Factors: A Comprehensive Review of Longitudinal Studies

We aimed to examine systematically the available evidence on risk factors of low back pain (LBP) in athletes. We performed search without language restriction in PubMed, Ovid, Google Scholar, Scopus, and CINAHL. Longitudinal studies that examined possible risk factors of LBP in athletes were included in this systematic review. Based on methodological quality of studies, a best-evidence synthesis was conducted. Seven longitudinal studies were included, four of which had high methodological quality. Results showed that previous LBP, decreased lumbar flexion, and decreased lumbar extension are positively associated with LBP. There was moderate evidence for hip flexor tightness and high body weight as a risk factor. We found insufficient evidence for association between forward bending, previous injury, and amount of training per week, active years, age, and sex with LBP. In conclusion this study would provide a list of risk factors for LBP in athletes, though it showed a strong evidence for only a few including decrease lumbar flexion or extension, previous LBP, and high body weight. This review indicated a high heterogeneity of study characteristics including assessed risk factors and statistical techniques might limit the quality of evidence.

Recurrence quantification analysis and support vector machines for golf handicap and low back pain EMG classification

The quantification of non-linear characteristics of electromyography (EMG) must contain information allowing to discriminate neuromuscular strategies during dynamic skills. There are a lack of studies about muscle coordination under motor constrains during dynamic contractions. In golf, both handicap (Hc) and low back pain (LBP) are the main factors associated with the occurrence of injuries. The aim of this study was to analyze the accuracy of support vector machines SVM on EMG-based classification to discriminate Hc (low and high handicap) and LBP (with and without LPB) in the main phases of golf swing. For this purpose recurrence quantification analysis (RQA) features of the trunk and the lower limb muscles were used to feed a SVM classifier. Recurrence rate (RR) and the ratio between determinism (DET) and RR showed a high discriminant power. The Hc accuracy for the swing, backswing, and downswing were 94.4±2.7%, 97.1±2.3%, and 95.3±2.6%, respectively. For LBP, the accuracy was 96.9±3.8% for the swing, and 99.7±0.4% in the backswing. External oblique (EO), biceps femoris (BF), semitendinosus (ST) and rectus femoris (RF) showed high accuracy depending on the laterality within the phase. RQA features and SVM showed a high muscle discriminant capacity within swing phases by Hc and by LBP. Low back pain golfers showed different neuromuscular coordination strategies when compared with asymptomatic.

Golf-related low back pain: a review of causative factors and prevention strategies

Golf is a popular sport with both perceived and real health benefits. However, certain injury risks are also prevalent, particularly to the lower back. Epidemiological studies have shown that lower back pain (LBP) from golf account for between 18% and 54% of all documented ailments, leading many researchers to regard the condition as the most common golf injury.

The purpose of this review was to examine the scientific literature to ascertain the risk factors associated with the development of LBP from playing golf and suggest methods to modify or limit these factors. Results of the review indicate that the high frequency of LBP appears multi-factorial although the asymmetrical and forceful nature of the swing along with excessive play and practice, particularly amongst elite players, appear to be common factors. Other factors include swing flaws leading to excessive side-bend and over-rotation of the spine, abnormal muscle recruitment, poor trunk endurance, restricted lead hip internal rotation and the use of unnecessarily stressful club transportation methods. Methods to help control or eliminate excessive stress on the lower back would include reducing the amount spent playing or practicing, seeking professional assistance to assess and adjust swing mechanics, improve trunk and hip flexibility, increase the strength and endurance of the trunk musculature, consider different footwear options and avoid carrying the golf bag. Adopting some or all of these recommendations should allow players to continue to enjoy the sport of golf well into their senior years.

Frequency-effect of playing screen golf on body composition and golf performance in middle-aged men

There are many studies showing that physical training improves body composition including bone mineral density (BMD) in almost all subjects. However, the frequency-dependent effect of playing golf on body composition is still not clearly comprehended. Moreover, the effect of screen golf in relations with exercise-frequency on body composition and golf performance has not been documented. Forty year old men participated and were classified into 4 groups: Control group (n= 10), BMD1 group (n= 10) played screen golf less than 1 day per a week, BMD2–3 group (n= 10) played screen golf 2–3 days per a week, and BMD5 group (n= 10) played screen golf 5 days per week. Dual-energy X-ray absorptiometry (DXA) was performed on 30 male recreational golfers and 10 sedentary individuals. The data gained through DXA were fat mass, lean mass, regional (head, rib, arm, leg, pelvis, spine and trunk) BMD level, and total BMD level summed by regional scores. The club speeds were measured using the Golfzon Vision machine and the handicap points were measured using a simple questionnaire. The present results suggest that the long-frequency of playing screen golf does not improve bone mineral density, lean mass, and handicap point yet improves fat mass and club speed in the middle-aged men.

Biomechanical effect of altered lumbar lordosis on intervertebral lumbar joints during the golf swing: a simulation study

Although the lumbar spine region is the most common site of injury in golfers, little research has been done on intervertebral loads in relation to the anatomical-morphological differences in the region. This study aimed to examine the biomechanical effects of anatomical-morphological differences in the lumbar lordosis on the lumbar spinal joints during a golf swing. The golf swing motions of ten professional golfers were analyzed. Using a subject-specific 3D musculoskeletal system model, inverse dynamic analyses were performed to compare the intervertebral load, the load on the lumbar spine, and the load in each swing phase. In the intervertebral load, the value was the highest at the L5-S1 and gradually decreased toward the T12. In each lumbar spine model, the load value was the greatest on the kypholordosis (KPL) followed by normal lordosis (NRL), hypolordosis (HPL), and excessive lordosis (EXL) before the impact phase. However, results after the follow-through (FT) phase were shown in reverse order. Finally, the load in each swing phase was greatest during the FT phase in all the lumbar spine models. The findings can be utilized in the training and rehabilitation of golfers to help reduce the risk of injury by considering individual anatomical-morphological characteristics.

The crunch factor's role in golf-related low back pain

BACKGROUND CONTEXT

The golf swing exposes the spine to complex torsional, compressive, and shearing loads that increase a player's risk of injury. The crunch factor (CF) has been described as a measure to evaluate the risk of low back injuries in golfers and is based on the notion that lateral flexion and axial trunk rotation jointly contribute to spinal degeneration. However, few studies have evaluated the appropriateness of this measure in golfers with low back pain (LBP).

PURPOSE

To objectively examine the usefulness of the CF as a measure for assessing the risk of low back injury in golfers.

STUDY DESIGN

Field-based research using a cross-sectional design.

METHODS

This research used three-dimensional motion analysis to assess the golf swings of 12 golfers with LBP and 15 asymptomatic controls. Three-dimensional kinematics were derived using Vicon Motus, and the CF was calculated as the instantaneous product of axial trunk rotation velocity and lateral trunk flexion angle.

RESULTS

Maximum CFs and their timings were not significantly different between the symptomatic and asymptomatic groups. Furthermore, for those golfers who produced higher CFs (irrespective of the group), the increased magnitude could not be attributed to an increased axial angular trunk velocity or lateral flexion angle, but rather to a concomitant increase in both of these variables.

CONCLUSIONS

The findings suggested that although the fundamental concepts that underpin the CF seem sensible, this measure does not appear to be sensitive enough to distinguish golfers with LBP from the asymptomatic players.

A methodological approach for the biomechanical cause analysis of golf-related lumbar spine injuries

A new methodological approach employing mechanical work (MW) determination and relative portion of its elemental analysis was applied to investigate the biomechanical causes of golf-related lumbar spine injuries. Kinematic and kinetic parameters at the lumbar and lower limb joints were measured during downswing in 18 golfers. The MW at the lumbar joint (LJ) was smaller than at the right hip but larger than the MWs at other joints. The contribution of joint angular velocity (JAV) to MW was much greater than that of net muscle moment (NMM) at the LJ, whereas the contribution of NMM to MW was greater rather than or similar to that of JAV at other joints. Thus, the contribution of JAV to MW is likely more critical in terms of the probability of golf-related injury than that of NMM. The MW-based golf-related injury index (MWGII), proposed as the ratio of the contribution of JAV to MW to that of NMM, at the LJ (1.55) was significantly greater than those at other joints ( < 1.05). This generally corresponds to the most frequent occurrence of golf-related injuries around the lumbar spine. Therefore, both MW and MWGII should be considered when investigating the biomechanical causes of lumbar spine injuries.

Minimizing injuries and enhancing performance in golf through training programs

Context:

Golf is a popular sport, particularly in older populations. Regardless of age and skill level, golfers risk injury to the back, shoulder, wrist and hand, elbow, and knee. Because of the unique compressive, shear, rotational, and lateral bending forces created in the lumbar region during the golf swing, the primary sport-related malady experienced by amateurs and professionals is low back pain. Extrinsic and intrinsic injury risk factors have been reported in the literature. A growing body of evidence supports the prescription of strength training routines to enhance performance and reduce the risk of injury.

Evidence Acquisition:

Relevant studies were reviewed on golf injuries, swing mechanics, training routines, and general training program design. The following electronic databases were used to identify research relevant to this report: MEDLINE (from 1950–November 2009), CINAHL (1982–November 2009), and SPORTDiscus (1830–November 2009).

Results:

Injuries may be associated with lack of warm-up, poor trunk flexibility and strength, faulty swing technique, and overuse.

Conclusions:

Implementing a training program that includes flexibility, strength, and power training with correction of faulty swing mechanics will help the golfer reduce the likelihood of injury and improve overall performance.

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.

Lower back pain in golfers: a review of the literature

OBJECTIVE

To review the epidemiological literature on low back pain in golfers and to review the golf swing and relate the literature on the mechanics of the swing to the lower back.

METHODS

A computer search was conducted of Index Medicus (1966 to 2004), MANTIS (1880 to present) and CINAHL (1982 to 2004) for literature on the following key words: low back, golf, injury. A manual search for relevant references in review papers on the subject was also conducted. The results were collated and literature fitting the criteria were collected and evaluated for suitability.

RESULTS

The lower back is a common site of golf-related injury and has resulted in much research being conducted on the forces produced by the 'modern' swing in the low back. An analysis of the 'modern' swing when compared to the 'classic' golf swing, demonstrates lower rotational forces on the low back in the 'classic' swing. However, no studies exist to compare the different types of swing.

CONCLUSION

The back is an area of the body that undergoes significant movement and muscular activity during the golf swing. It is likely that the significant activity and repetitive nature of the swing are associated with the high rate of injury in golfers. Modification of the golf swing has been hypothesized to reduce the incidence of low back injury in golf. Further research needs to be conducted on the various golf swings to evaluate if different swings change low back injury rates in golfers.

The myth of core stability

The principle of core stability has gained wide acceptance in training for the prevention of injury and as a treatment modality for rehabilitation of various musculoskeletal conditions in particular of the lower back. There has been surprisingly little criticism of this approach up to date. This article re-examines the original findings and the principles of core stability/spinal stabilisation approaches and how well they fare within the wider knowledge of motor control, prevention of injury and rehabilitation of neuromuscular and musculoskeletal systems following injury.

The relationship between hip rotation range of movement and low back pain prevalence in amateur golfers: an observational study

OBJECTIVE

To investigate whether amateur golfers with self-reported low back pain have reduced hip rotation compared to asymptomatic controls.

DESIGN

Observational case-control study.

SETTING

Data collection took place at 2 amateur golf clubs in southern England.

PARTICIPANTS

On initial contact, all participants completed a screening questionnaire used to allocate participants into LBP (n=28) and control groups (n=36). LBP group were found to be heavier than controls (t=2.242, 95% CI 0.763-13.332) but were matched for age, height, handedness, handicap, rounds played per week and years of play.

MAIN OUTCOME MEASURES

Primary outcome measures were lead and non-lead hip medial and lateral rotation in 0 degrees of flexion as measured by inclinometer. Secondary measures included inter and intra-rater reliability.

RESULTS

The LBP group had significantly reduced lead hip passive (LBP 21.14+/-10.17 degrees; controls 31.06+/-8.06 degrees, t=-4.228, 95% CI -14.621--5.205) and lead hip active medial rotation (LBP 21.46+/-10.01; controls 28.06+/-7.49 degrees, t=-2.908, 95% CI -11.147--2.036) compared to controls. No between group differences were found in non-lead hips or any passive or active lateral rotation measures.

CONCLUSION

Although there is lack of causality between LBP and hip rotation, the deficit in lead leg medial hip rotation in amateur golfers who suffer LBP may be relevant for screening or treatment selection.

The lumbar spine and low back pain in golf: a literature review of swing biomechanics and injury prevention

BACKGROUND CONTEXT

The golf swing imparts significant stress on the lumbar spine. Not surprisingly, low back pain (LBP) is one of the most common musculoskeletal complaints among golfers.

PURPOSE

This article provides a review of lumbar spine forces during the golf swing and other research available on swing biomechanics and muscle activity during trunk rotation.

STUDY DESIGN

The role of "modern" and "classic" swing styles in golf-associated LBP, as well as LBP causation theories, treatment, and prevention strategies, are reviewed.

METHODS

A PubMed literature search was performed using various permutations of the following keywords: lumbar, spine, low, back, therapy, pain, prevention, injuries, golf, swing, trunk, rotation, and biomechanics. Articles were screened and selected for relevance to injuries in golf, swing mechanics, and biomechanics of the trunk and lumbar spine. Articles addressing treatment of LBP with discussions on trunk rotation or golf were also selected. Primary references were included from the initial selection of articles where appropriate. General web searches were performed to identify articles for background information on the sport of golf and postsurgical return to play.

RESULTS

Prospective, randomized studies have shown that focus on the transversus abdominus (TA) and multifidi (MF) muscles is a necessary part of physical therapy for LBP. Some studies also suggest that the coaching of a "classic" golf swing and increasing trunk flexibility may provide additional benefit.

CONCLUSIONS

There is a notable lack of studies separating the effects of swing modification from physical rehabilitation, and controlled trials are necessary to identify the true effectiveness of specific swing modifications for reducing LBP in golf. Although the establishment of a commonly used regimen to address all golf-associated LBP would be ideal, it may be more practical to apply basic principles mentioned in this article to the tailoring of a unique regimen for the patient. Guidelines for returning to golf after spine surgery are also discussed.

Trunk muscle onset and cessation in golfers with and without low back pain

The knowledge of the onset and cessation timing of the paraspinal muscles that surround the lumbar spine is an important area of research for the understanding of low back pain. This study examined the timing of the erector spinae and external oblique muscle activity in a group of golfers with and without low back pain. The study compared the results of surface electromyography measurements for two groups of golfers. Twelve male golfers who had reported a mild or greater level of pain in the lower back that was experienced while playing golf were examined. A further fifteen male golfers who had reported no history of lower back pain in the previous 12 months were recruited as controls. The results showed that the low-back-pain golfers switched on their erector spinae muscle significantly in advance of the start of the backswing. This finding was not evident in the group who did not have low back pain symptoms. Low-back-pain golfers, therefore, may use the erector spinae muscle as a primary spinal stabiliser instead of the stronger deeper muscles such as transversus abdominis and multifidus. These results may have important implications for conditioning programmes for golfers with low back pain.

Swing kinematics in skilled male golfers following putting practice

STUDY DESIGN

Control laboratory study consisting of preintervention and postintervention measurements.

OBJECTIVE

To determine the effects of a putting practice session on the kinematics of full golf swings made by skilled male golfers.

BACKGROUND

Skilled golfers perform putting practice for prolonged periods. The combination of sustained trunk flexion with minimal trunk motion may affect the endurance capacity of the trunk extensor muscles. Because of their important role in the golf swing, any impairment of the trunk extensors may negatively influence full-swing kinematics, but this has not been previously evaluated.

METHODS AND MEASURES

Three-dimensional swing kinematics and holding time on the Biering-Sørensen test of isometric trunk extensor endurance were evaluated in 29 skilled male golfers before and after performing a 40-minute putting task.

RESULTS

After the intervention, peak segmental speeds were reduced and total swing duration increased (mean +/- SD, 36 +/- 55 milliseconds). There were reductions in the magnitude of pelvis and torso axial rotation during the downswing (mean +/- SD, -2.3 degrees +/- 2.6 degrees and -2.3 degrees +/- 4.7 degrees , respectively). The peak difference between torso rotation and pelvis rotation during early downswing was also significantly reduced by 0.9 degrees +/- 2.0 degrees (P<.05). The effects on pelvis and torso rotation were smallest for golfers with higher body mass index (BMI). Holding time on the Biering-Sørensen test after putting practice was significantly reduced by 25.7 +/- 23.8 seconds (P = .01).

CONCLUSION

Changes in swing kinematics observed following 40 minutes of putting practice might have resulted from fatigue-related impairment of the trunk extensor muscles, a view supported by the poorer performance on the postintervention Biering-Sørensen test. Results showed that swing kinematics of golfers with high BMI were least affected by the putting practice.

LEVEL OF EVIDENCE

Harm, level 5.

Interaction between playing golf and HRT on vertebral bone properties in post-menopausal women measured by QCT

We investigated the effect of playing regular golf and HRT on lumbar and thoracic vertebral bone parameters (measured by QCT) in 72 post-menopausal women. The main finding of this study was that there was positive interaction between golf and HRT on vertebral body CSA and BMC at the thoracic 12 and lumbar 2 vertebra but not the third and seventh thoracic vertebras.

INTRODUCTION

Identifying specific exercises that load the spine sufficiently to be osteogenic is an important component of primary osteoporosis prevention. The aim of this study was to determine if in postmenopausal women regular participation in golf resulted in greater paravertebral muscle mass and improved vertebral bone strength.

METHODS

Forty-seven postmenopausal women who played golf regularly were compared to 25 controls. Bone parameters at the mid-vertebral body were determined by QCT at spinal levels T3, T7, T12 and L2 (cross-sectional area (CSA), total volumetric BMD (vBMD), trabecular vBMD of the central 50% of total CSA, BMC and cortical rim thickness). At T7 and L2, CSA of trunk muscles was determined.

RESULTS

There was a positive interaction between golf and HRT for vertebral CSA and BMC at T12 and L2, but not at T3 or T7 (p ranging < 0.02 to 0.07). Current HRT use was associated with a 10-15% greater total and trabecular vBMD at all measured vertebral levels. Paravertebral muscle CSA did not differ between groups. Vertebral CSA was the bone parameter significantly related to muscle CSA.

CONCLUSION

These findings provide preliminary evidence that playing golf may improve lower spine bone strength in postmenopausal women who are using HRT.

The role of upper torso and pelvis rotation in driving performance during the golf swing

While the role of the upper torso and pelvis in driving performance is anecdotally appreciated by golf instructors, their actual biomechanical role is unclear. The aims of this study were to describe upper torso and pelvis rotation and velocity during the golf swing and determine their role in ball velocity. One hundred recreational golfers underwent a biomechanical golf swing analysis using their own driver. Upper torso and pelvic rotation and velocity, and torso-pelvic separation and velocity, were measured for each swing. Ball velocity was assessed with a golf launch monitor. Group differences (groups based on ball velocity) and moderate relationships (r > or = 0.50; P < 0.001) were observed between an increase in ball velocity and the following variables: increased torso-pelvic separation at the top of the swing, maximum torso-pelvic separation, maximum upper torso rotation velocity, upper torso rotational velocity at lead arm parallel and last 40 ms before impact, maximum torso-pelvic separation velocity and torso-pelvic separation velocity at both lead arm parallel and at the last 40 ms before impact. Torso-pelvic separation contributes to greater upper torso rotation velocity and torso-pelvic separation velocity during the downswing, ultimately contributing to greater ball velocity. Golf instructors can consider increasing ball velocity by maximizing separation between the upper torso and pelvis at the top of and initiation of the downswing.

Electromyography of the trunk and abdominal muscles in golfers with and without low back pain

Twelve male golfers who experienced low back pain (LBP) whilst playing or practicing golf and 18 asymptomatic golfers were recruited and divided into handicap-specific groups; low-handicap golfers, with a handicap between 0 and 12 strokes; and high-handicap golfers, with a handicap of between 13 and 29 strokes. The myoelectric activity of the lumbar erector spinae (ES) and the external obliques (EO) was recorded via surface electromyography (EMG), whilst the golfers performed 20 drives. The root mean square (RMS) was calculated for each subject and the data for the ES and EO were normalised to the EMGs recorded whilst holding a mass equal to 5% of the subjects' body mass at arms length and whilst performing a double-leg raise, respectively. The results showed that the low-handicap LBP golfers tended to demonstrate reduced ES activity at the top of the backswing and at impact and greater EO activity throughout the swing. The high-handicap LBP golfers demonstrated considerably more ES activity compared with their asymptomatic counterparts, whilst EO activity tended to be similar between the high-handicap groups. The reduced ES activity demonstrated by the low-handicap LBP group may be associated with a reduced capacity to protect the spine and its surrounding structures at the top of the backswing and at impact, where the torsional loads are high. When considering this with the increased EO activity demonstrated by these golfers, it is reasonable to suggest that these golfers may be demonstrating characteristics/mechanisms that are responsible for or are a cause of LBP.

The role of biomechanics in maximising distance and accuracy of golf shots

Golf biomechanics applies the principles and technique of mechanics to the structure and function of the golfer in an effort to improve golf technique and performance. A common recommendation for technical correction is maintaining a single fixed centre hub of rotation with a two-lever one-hinge moment arm to impart force on the ball. The primary and secondary spinal angles are important for conservation of angular momentum using the kinetic link principle to generate high club-head velocity. When the golfer wants to maximise the distance of their drives, relatively large ground reaction forces (GRF) need to be produced. However, during the backswing, a greater proportion of the GRF will be observed on the back foot, with transfer of the GRF on to the front foot during the downswing/acceleration phase. Rapidly stretching hip, trunk and upper limb muscles during the backswing, maximising the X-factor early in the downswing, and uncocking the wrists when the lead arm is about 30 degrees below the horizontal will take advantage of the summation of force principle. This will help generate large angular velocity of the club head, and ultimately ball displacement. Physical conditioning will help to recruit the muscles in the correct sequence and to optimum effect. To maximise the accuracy of chipping and putting shots, the golfer should produce a lower grip on the club and a slower/shorter backswing. Consistent patterns of shoulder and wrist movements and temporal patterning result in successful chip shots. Qualitative and quantitative methods are used to biomechanically assess golf techniques. Two- and three-dimensional videography, force plate analysis and electromyography techniques have been employed. The common golf biomechanics principles necessary to understand golf technique are stability, Newton's laws of motion (inertia, acceleration, action reaction), lever arms, conservation of angular momentum, projectiles, the kinetic link principle and the stretch-shorten cycle. Biomechanics has a role in maximising the distance and accuracy of all golf shots (swing and putting) by providing both qualitative and quantitative evidence of body angles, joint forces and muscle activity patterns. The quantitative biomechanical data needs to be interpreted by the biomechanist and translated into coaching points for golf professionals and coaches. An understanding of correct technique will help the sports medicine practitioner provide sound technical advice and should help reduce the risk of golfing injury.

Lower back and elbow injuries in golf

Golf injuries to the lower back and elbow are common problems in both the professional and amateur player, and any information regarding the successful treatment of these injuries has important implications for the medical practitioner. This paper presents the successful management and outcome of two case studies associated with low back pain and lateral epicondylitis in golf. Exercise therapy and conditioning has been shown to be an effective treatment modality for these two types of injury. In particular, a dynamic exercise programme which incorporates golf functional rehabilitation, is a modern and accepted method by both the patient and the clinician. Effective programmes need to be golf-specific to maintain the interest of the participant and yet at the same time they need to be able to accommodate other factors such as age, gender and the level of the golfer. Furthermore, it is critical that the clinical practitioner has a fundamental knowledge of normal swing mechanics and a working knowledge of the musculoskeletal requirements needed to swing a golf club. In the case of the lower back injury, evaluation was based on detailed computer tomography and centred on the conditioning of the transversus abdominis muscle. Although this muscle is not considered to be paraspinal, it has particularly important implications in the maintenance of spinal stability so that other more specific golf functioning exercises and rehabilitation can be performed. For the case study of lateral epicondylitis detailed evaluation and consideration of neuropathy was an important factor in the diagnostic process. In part, it was necessary to deviate from conventional treatment to produce an effective outcome. A comprehensive resistance-strength-training programme and golf functional 'hitting' programme was used to treat the problem. The conformity by the patient to complete the exercise regimen has been an issue of concern for clinicians managing and treating golf-related problems. Many golfers are 'fanatical' and unless they can see that by continuing the programme their injury will be overcome, it is difficult trying to restrict their time on the golf course. The two case studies described in this article highlight how an extensive and dynamic golf functional programme could be used as an effective method for managing and preventing golf injuries.