Medial epicondylitis. An electromyographic analysis and an investigation of intervention strategies

What differences exist between the lead and trail wrist in extensor carpi ulnaris activity and golf swing joint kinematics in sub-elite golfers?

This study assessed the lead and trail arm peak and average extensor carpi ulnaris (ECU) muscle activity in association with tri-planar angular velocities of the lead and trail wrists during the golf swing. Fifteen sub-elite, male right-handed golfers (Mage = 34.7 years ±13.3, Mhandicap = 1.5 ± 2.2) were recruited to execute five shots each with their pitching wedge, 7-iron and driver clubs in an indoor golf simulator. Surface electromyography (EMG) sensors were placed over the ECU muscle belly and inertial measurement unit sensors were placed bi-laterally on the distal forearm and dorsum of the hand. There was a statistically greater recruitment of the trail ECU muscle during the downswing (p < 0.001) for all clubs. The lead ECU muscle was recruited more during the backswing (p < 0.001) and follow through (p < 0.024) phases. There were statistically different tri-planar movement patterns between the lead and trail wrist throughout all three phases of the golf swing. No significant relationships were found between downswing EMG data and clubhead kinematics at impact. In conclusion, differing wrist kinematics and associated muscle activity may contribute to the asymmetrical injury pattern seen clinically.

Upper Body Injuries in Golfers

PURPOSE OF REVIEW

Golf is a sport that can be played by an athlete of any age, which enhances its popularity. Each golfer's swing is unique, and there is no "right" way to swing the golf club; however, the professional golfer often has more of a consistent swing as opposed to an amateur golfer. A collaborative, team approach involving the golfer with a swing coach, physical therapist, and physician often can be informative on how to prevent golf injury, but also how to treat golf injury if it occurs.

RECENT FINDINGS

As a rotational sport, the golfer needs to be trained and treated with respect for how the body works as a linkage system or kinetic chain. A warm-up is recommended for every golfer before practicing or playing, and this warm-up should account for every segment of the linkage system. Though it has been thought of as a relatively safe sport, injuries can be seen with golfers of any age or skill level, and upper body injuries involving the cervical and thoracic spine, shoulder, elbow, and wrist are common. A narrative review is provided here of the epidemiology of golf injury and common injuries involving each of these upper body regions. In addition, treatment and injury prevention recommendations are discussed.

Golf Swing Segmentation from a Single IMU Using Machine Learning

Golf swing segmentation with inertial measurement units (IMUs) is an essential process for swing analysis using wearables. However, no attempt has been made to apply machine learning models to estimate and divide golf swing phases. In this study, we proposed and verified two methods using machine learning models to segment the full golf swing into five major phases, including before and after the swing, from every single IMU attached to a body part. Proposed bidirectional long short-term memory-based and convolutional neural network-based methods rely on characteristics that automatically learn time-series features, including sequential body motion during a golf swing. Nine professional and eleven skilled male golfers participated in the experiment to collect swing data for training and verifying the methods. We verified the proposed methods using leave-one-out cross-validation. The results revealed average segmentation errors of 5–92 ms from each IMU attached to the head, wrist, and waist, accurate compared to the heuristic method in this study. In addition, both proposed methods could segment all the swing phases using only the acceleration data, bringing advantage in terms of power consumption. This implies that swing-segmentation methods using machine learning could be applied to various motion-analysis environments by dividing motion phases with less restriction on IMU placement.

Physical Determinants of Golf Swing Performance: A Review

Sheehan, WB, Bower, RG, and Watsford, ML. Physical determinants of golf swing performance: A review. J Strength Cond Res XX(X): 000-000, 2019-Traditionally, golf practice has primarily focused on the mental, technical, and skill aspects as the primary means to improve performance. Only recently has a greater emphasis been placed on the physical components with balance, muscular strength, power, and specific muscle-tendon properties demonstrating positive associations with club head speed and carry distance. Accordingly, this review will explore the influence of these physical components on measures of golf swing performance. Superior balance may allow players to effectively deal with the need to shift weight during the swing as well as different stance positions, whereas superior lower-body muscular strength, power, and stiffness may allow more mechanical work to be performed on the club during the swing per unit of time, consequently increasing club head speed. Alternatively, flexibility may also contribute to enhanced force production with a greater range of motion, particularly when generating the "X-factor," allowing for a longer backswing and more time to produce higher angular velocities and forces. Furthermore, training intervention studies focusing on the aforementioned components have demonstrated enhancements in swing performance. Targeting multiple muscle groups, including those implicated via electromyography activation, and utilizing multiple modalities have proven effective at increasing club head speed. However, such multifaceted programs have made it difficult to determine the mechanisms that specifically contribute to performance gains. Despite these limitations, strength, power, and musculotendinous stiffness, particularly in the lower body, seem to be stronger determinants of club head speed and carry distance than flexibility. Furthermore, acute improvements can be induced using resistance-orientated warm-ups.

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.

Commercial golf glove effects on golf performance and forearm muscle activity

The study aimed to determine whether or not commercial golf gloves influence performance variables and forearm muscle activity during golf play. Fifteen golfers participated in the laboratory based study, each performing 8 golf swings with a Driver and 7-iron whilst wearing a glove and 8 without wearing the glove. Club head speed, ball speed and absolute carry distance performance variables were calculated. Surface electromyography was recorded from the flexor digitorum superficialis and extensor carpi radialis brevis on both forearm muscles. Club head speed, ball speed and absolute carry distance was significantly higher when using the Driver with the glove in comparison to the Driver without the glove (p < 0.05). No significant differences were evident when using the 7-iron and no significant differences were displayed in muscle activity in either of the conditions. Findings from this study suggest that driving performance is improved when wearing a glove.

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.

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.

Effects of core and non-dominant arm strength training on drive distance in elite golfers

BACKGROUND

Various training schemes have sought to improve golf-related athletic ability. In the golf swing motion, the muscle strengths of the core and arms play important roles, where a difference typically exists in the power of arm muscles between the dominant and non-dominant sides. The purposes of this study were to determine the effects of exercises strengthening the core and non-dominant arm muscles of elite golf players (handicap < 3) on the increase in drive distance, and to present a corresponding training scheme aimed at improving golf performance ability.

METHODS

Sixty elite golfers were randomized into the control group (CG, n = 20), core exercise group (CEG, n = 20), and group receiving a combination of muscle strengthening exercises of the non-dominant arm and the core (NCEG, n = 20). The 3 groups conducted the corresponding exercises for 8 weeks, after which the changes in drive distances and isokinetic strength were measured.

RESULTS

Significant differences in the overall improvement of drive distance were observed among the groups (p < 0.001). Enhancement of the drive distance of NCEG was greater than both CG (p < 0.001) and CEG (p = 0.001). Except for trunk flexion, all variables of the measurements of isokinetic strength for NCEG also showed the highest values compared to the other groups. Examination of the correlation between drive distance and isokinetic strength revealed significant correlations of all variables except trunk flexion, wrist extension, and elbow extension.

CONCLUSION

The combination of core and non-dominant arm strength exercises can provide a more effective specialized training program than core alone training for golfers to increase their drive distances.

Changes in pain, dysfunction, and grip strength of patients with acute lateral epicondylitis caused by frequency of physical therapy: a randomized controlled trial

[Purpose] The purpose of this study was to investigate the changes in pain, dysfunction, and grip strength of patients with acute lateral epicondylitis and to suggest the appropriate treatment frequency and period. [Subjects] The subjects were divided into three: 2 days per week group (n=12), 3 days per week group (n=15), and 6 days per week group (n=13). [Methods] All groups received conventional physical therapy for 40 minutes and therapeutic exercises for 20 minutes per session during 6 weeks. The outcome measurements were the visual analogue scale (VAS), Patient-Rated Tennis Elbow Evaluation (PRTEE), and grip strength. [Results] The results of this study were as follows: at 3 weeks, there were no significant differences in VAS and PRTEE in the 3 groups, but at 6 weeks, 6 days per week group significantly decreased these two outcomes. Grip strength was significantly increased in 3 and 6 days per week groups at 6 weeks. [Conclusion] In conclusion, physical therapy is needed 3 days per week for 3 weeks in patients with acute lateral epicondylitis. After 3 weeks, 6 days per week is the most effective treatment frequency.

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.

Electromyographic analysis of forearm muscles in professional and amateur golfers

BACKGROUND

No fine-wire electromyography studies have been performed to compare the activity of forearm muscles in professional golfers versus amateur golfers.

HYPOTHESIS

The fine-wire electromyographic activity of forearm muscles differs between professional and amateur golfers during the different phases of the golf swing.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten male right-handed amateur golfers and 10 male right-handed professional golfers without history of elbow symptoms were tested with fine-wire electromyographic electrodes inserted into the flexor carpi radialis, pronator teres, flexor carpi ulnaris, and extensor carpi radialis brevis muscles of both forearms. Electromyographic data were synchronized with video data, and the muscle activity was expressed as a percentage of maximum manual muscle test activity for each phase of the golf swing.

RESULTS

Compared with professional golfers, amateur golfers had more muscle activity in the pronator teres of the trail arm (right arm in a right-handed golfer) in the forward swing phase (120.9% maximum manual muscle test vs 57.4% maximum manual muscle test; P = .04) and a trend toward increased activity in the acceleration phase (104.8% maximum manual muscle test vs 53.1% maximum manual muscle test; P = .08). In contrast, professional golfers had more muscle activity in the pronator teres of the lead arm (left arm in a right-handed golfer) in the acceleration phase (88.1% maximum manual muscle test vs 36.3% maximum manual muscle test; P = .03) and a trend toward increased activity in the early follow-through phase (58.1% maximum manual muscle test vs 28.8% maximum manual muscle test; P = .06).

CONCLUSION

Pronator teres muscle activity in the golf swing differs significantly between professional and amateur golfers.

CLINICAL RELEVANCE

Exercises with an emphasis on stretching and strengthening of the pronator teres may be useful in treating and/or preventing medial epicondylitis in amateur golfers.

Golf injuries: a review of the literature

Golf is one of a few activities that people of all ages and skill level can play. Injury as with all sports can occur. The low back is the most common injury sustained whilst playing golf, and the dynamic action of the golf swing is a major contributing factor to injury. The golf swing is a complex movement that utilises the whole body in a coordinated fashion and when repeated frequently can result in injury. Injury can be overuse or traumatic in nature. Overuse injuries predominate in the professional golfer, and amateur golfer injury tends to occur secondary to an incorrect golf swing. Upper limb injuries are also common due to their role in linking the fast moving golf club with the power-generating torso. Fortunately, injury from a club or ball strike is rare. More common are the overuse injuries associated with the back, neck and shoulder. Most golf injury data have been collected retrospectively and further epidemiological study of a prospective nature is required to determine injury incidence and factor relating to the onset of injury.

Muscle activity during the golf swing

In the right hands, the golf swing is a motion that inspires looks of awe from the public. It is a complex movement of the whole body to generate power to a golf ball to propel the ball great distances with accuracy. This movement relies on the coordinated sequence of muscle activation to produce a fluid and reproducible movement. This paper reviews the literature on golf swing related muscle activity. The phases of this activity are discussed with a view to assisting the practitioner in understanding the swing. Such understanding may help in the management of the injured golfer.

Golf and upper limb injuries: a summary and review of the literature

BACKGROUND

Golf is a popular past time that provides exercise with social interaction. However, as with all sports and activities, injury may occur. Many golf-related injuries occur in the upper limb, yet little research on the potential mechanisms of these injuries has been conducted.

OBJECTIVE

To review the current literature on golf-related upper limb injuries and report on potential causes of injury as it relates to the golf swing.

DISCUSSION

An overview of the golf swing is described in terms of its potential to cause the frequently noted injuries. Most injuries occur at impact when the golf club hits the ball. This paper concludes that more research into golf-related upper limb injuries is required to develop a thorough understanding of how injuries occur. Types of research include epidemiology studies, kinematic swing analysis and electromyographic studies of the upper limb during golf. By conducting such research, preventative measures maybe developed to reduce golf related injury.

Elbow orthoses: a review of literature

The objective of this study is to review the available literature on elbow orthoses in patients with various diagnoses to assess the scientific base of the prescription of elbow orthoses. A search of literature in Medline, Embase, Cochrane and Recal was performed using the keyword "elbow" combined with "orthosis related keywords". Abstracts were read to select the papers dealing primarily with monoarticular elbow orthoses. References of the selected papers were also examined. A total of 57 papers were read of which 18 met the selection criteria. Both the quality and quantity of the studies appeared to be low, so in this study no definitive conctusions can be drawn about the efficacy of monoarticular elbow orthoses. Current prescriptions of elbow orthoses cannot be evidence based, because no scientific evidence on elbow orthoses is available.

MR imaging of tendon abnormalities of the elbow

Tendon injuries about the elbow are among the most commonly encountered pathology in this articulation. These injuries are often the result of chronic repetitive microtrauma but can be seen in the setting of acute trauma. This article focuses on the imaging diagnosis of tendon pathology in the elbow and the associated findings that can be seen with tendon injury. A detailed understanding of common pathology and patterns of injury can facilitate the ease and accuracy of imaging diagnosis.

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.

Managing golf injuries: technique and equipment changes that aid treatment

Proper golf technique and equipment and preventive measures can minimize golf-related injuries of the back, shoulders, elbows, and hands and wrists. Rotating the shoulder and hip a similar amount during the backswing and keeping the spine vertical during the follow-through can reduce lumbar spine strain. A rigid back support may lower the risk of vertebral compression fracture in osteoporotic patients. Shortening the backswing can decrease pressure on a degenerative acromioclavicular joint. Therapy for 'golfer's elbow' includes medial counterforce bracing, larger club grips, and graphite shafts. Treatments for wrist and hand disorders include proper swing and grip technique and larger, softer grips. Diagnosis of the easy-to-miss fracture of the hook of the hamate may require tomogram, CT, or MRI.

Etiology, diagnosis, and treatment of tendonitis: an analysis of the literature

Tendonitis is a common diagnosis in sports medicine. The traditional view of tendonitis is a tendon injury resulting from repetitive mechanical load with a subsequent inflammatory response. The English literature from 1966 to the present on the etiology, diagnosis, and treatment of tendonitis was evaluated. There is some scientific support in the literature for the diagnosis of tenosynovitis and tendinosis as a pathologic entity. Actual inflammation of tendon tissue consistent with tendonitis has not been seen clearly in patho-anatomic studies. Conclusive evidence confirming that repetitive mechanical load is a major etiologic factor could not be found. Similarly, strength deficits, inflexibility, and improper equipment have not been studied in a controlled prospective manner. Other factors such as age and tendon vascularity have been consistently correlated with these injuries although their overall importance remains difficult to assess. There are no controlled studies on treatment through physical therapy aimed at flexibility and/or strengthening. Treatment with anti-inflammatory drugs has been studied extensively. However, only nine of 32 studies are prospective and placebo controlled. Some pain relief was found in five of the nine controlled studies, but healing of the tendon problem was not studied in these short follow-up studies. Twenty-three studies on steroid injections were found. Eight were prospective and placebo controlled studies, with three showing beneficial effects of the injection at follow-up. It was concluded that much of the pathology and etiology of tendonitis remains unclear. The possibility must be considered that current treatment methods may not significantly affect the natural history.