Tennis elbow: survey among 839 tennis players with ...

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Abstract. Background: Lateral epicondylitis, which is more commonly known as tennis elbow, is prevalent in the world of sports; however this injury still.
Original research Rogerio Teixeira Silva and Marcelo Bannwart Santos Med Sci Tennis 2008;13(1):36-41

Tennis elbow: survey among 839 tennis players with and without injury Photography: Henk Koster

Abstract Background: Lateral epicondylitis, which is more commonly known as tennis elbow, is prevalent in the world of sports; however this injury still causes confusion among doctors and other healthcare professionals. Numerous studies have evaluated treatment options and prognosis, but few have taken into consideration the extent to which tennis players, themselves, understand this ailment. Objective: To determine to what level Brazilian tennis players understand the aetiology and courses of treatment for tennis elbow. Subjects: 839 tennis players who had been playing tennis for a mean age of 11 years. Methods: A simple, multi-choice questionnaire was made available on an internet site dedicated to tennis enthusiasts. Results: Among the players enrolled in this study, 41.8 % reported being affected by this injury. Despite the fact that nearly half of all tennis players had been affected, most players were unaware of the causes of tennis elbow. Even among those who had been affected by tennis elbow, only 39.3 % believed that the cause of the lesion was the backhand stroke, and almost all (94.9 %) had undergone some form of treatment before seeking advice from a physician. Conclusions: We believe that this study demonstrates the need to properly educate players, coaches, and physicians so that they can better understand the clinical management of tennis elbow. Without such an understanding, tennis players tend to treat themselves and only seek medical advice during the chronic phase of the injury, when the prognosis is worse. Keywords: tennis elbow, tennis, injury, epidemiology

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Drawing Frans Bosch

Introduction The term tennis elbow is commonly used to describe an injury, lateral epicondylitis, which occurs on the lateral face of the elbow. Despite the fact that tennis elbow is highly prevalent among recreational tennis players - nearly half will suffer this injury - a large percentage of tennis elbow studies have focused on individuals who do not participate in sports.1-6 These studies however, fail to address the differences in tennis elbow aetiology and injury characteristics between athletes and non-athletes. Therefore, it is important to understand this injury with regard to its aetiology among tennis players. While the clinical diagnosis of tennis elbow is simple, there appears to be a lack of consensus on the clinical characteristics and aetiology of the injury as well as the effectiveness of various treatments.3,7 There is currently no uniform treatment for this injury among tennis players and several recent studies have reported a lack of evidence for justifying the various treatments that are currently prescribed.8-10 It is well established that tennis elbow incidence correlates with improper stroke technique, particularly improperly executed backhand strokes performed with one hand.5,11,12 Although these findings are well understood within the scientific community, many tennis players are unaware of these characteristics of tennis elbow, which leads a large number of players to treat this injury without seeking medical assistance, most often with rest or using homemade therapies. Since recreational tennis players are largely unaware of the aetiology and courses of treatment for tennis elbow, we attempted to determine to what level Brazilian tennis players understood this injury. The principal objective of this study was to determine the opinions of recreational Brazilian tennis players regarding their understanding of tennis elbow, taking into account that this term is common to recreational tennis athletes. The results of this survey will contribute to the establishment of policies to properly educate coaches, players, and physicians on the management and prevention of this injury.

Methods We developed a simple, multiple-choice questionnaire in order to analyze Brazilian tennis players’ knowledge of the aetiology and available courses of treatment for tennis elbow. This survey was available on an internet website specializing in tennis news. Participation by the responding tennis players was voluntary and those who completed the questionnaire consented to the use of the collected data for the purposes of scientific research including statistical analysis and publication. The research ethics committee of our sector gave its approval for the work to be performed, and the methods used in this study followed the norms for research involving living beings that are in force in our country. In the questionnaire general data, including the respondent’s age, sex, years playing recreational tennis, and whether they had ever suffered from tennis elbow diagnosed by a doctor which required treatment were collected. Subjective questions, with a single correct answer, were then asked about these injuries and the tennis player’s method(s) of treatment. The questions and possible responses for the questionnaire are shown in Table 1. Table 1. Questions and possible responses for the questionnaire relating to the aetiology of tennis elbow. 1. In your opinion, what is the meaning of tennis elbow? a. Any kind of pain that the tennis player feels in the elbow region, because of tennis practice b. It is a pain on the external (lateral) side of the elbow c. It is a pain on the internal (medial) side of the elbow d. It is a kind of arthrosis of the elbow in tennis players 2. In your opinion, what type of movement is the main cause of the injury? a. Backhand b. Forehand c. Serve d. All of them e. The injury is unrelated to inadequate technique in a specific stroke >> 37

3. In your opinion, what is the most important cause that leads to tennis elbow? a. Inadequate stroke technique b. A stronger racquet for playing tennis c. High string tension d. None of these 4. Do you think that all elbow pains should lead tennis players to seek immediate medical assessments? a. Yes b. No 5. Have you ever used treatments without medical guidance when you had elbow pains resulting from tennis? a. Yes b. No The correct responses for questions 1, 2 and 3 were: B, A and A, respectively. The other responses to these questions were considered to be incorrect for the purposes of statistical power analysis. The responses A and B were compared for the purposes of statistical analysis in questions four and five. Statistical analysis The qualitative variables were represented by absolute and relative frequencies (%) while the quantitative variables were represented by the means, standard deviations (sd), minimums and maximums. The mean age and length of time playing tennis for each group was compared using the Student’s t test for independent samples. The presence of association between qualitative variables was calculated using a chi-squared test. The significance level of 0.05 (α = 5%) was adopted, and described values lower than this were considered to be significant. The statistical power of the analysis performed in this study was calculated for each question using a confidence interval of 95%, a beta error of 20% (power of 0.80), and alpha error of 0.05 (5%).13 To calculate the statistical power in questions 1, 2, and 3, we compared correct (single answer) and incorrect responses (all three alternative answers together). The subjective questions relating to treatment (questions four and five) were analyzed according to the responses given and compared in a two-tailed model with the hypothesis that the responses given by the group reporting injuries would be different from the responses given by the uninjured group. Results Demographic data A total of 839 tennis players responded to the questionnaire and sent it for our evaluation. Of the respondents, 762 (90.8%) were Age (years) n (%) male and 77 (9.2%) were female. 10 to 19 96 (11.4) The tennis players’ ages ranged from 10 to 78 years, with a mean 20 to 29 128 (15.3) age of 37.2 years and a standard 30 to 39 202 (24.1) deviation of 12.4 years. The distribution of these players by age 40 to 49 279 (33.3) groups is presented in Table 2.

Table 2. Distribution of the tennis players by age groups

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50 to 59

116 (13.8)

60 to 69

16 (1.9)

70 to 79

2 (0.2)

The tennis players included in this study had played tennis for a mean of 145.5 months, with a minimum of three and a maximum of 792 months. Out of the total number of players, 351 (41.8%) had been afflicted with a tennis elbow injury while the remaining 488 (58.2%) reported that they had not had tennis elbow in the past. Questions relating to the aetiology of this tennis injury When asked about the characteristics of tennis elbow, the majority of responding tennis players (446 or 53.2%) believed correctly that the injury was a pain on the external side of the elbow. The remaining respondents were incorrect in believing that tennis elbow was described as any elbow pain (156/839 or 18.6%) , pain on the internal face of the elbow (148/839 or 17.6%), or a type of joint arthrosis (89/ 839 or 10.6%). Respondent were less clear when asked about which movement caused the injury. Two hundred and eighty nine (34.1 %) of the responding tennis players correctly indicated that the backhand stroke was responsible; however, 269 (32.1 %), a statistically equivalent number, indicated that all strokes were responsible. Of the remaining one-third of respondents, ninety-six tennis players (11.4%) thought the injury was caused by the forehand, 93 (11.1%) thought it was the serve, and 95 (11.3%) believed it was unrelated to any specific stroke. When asked what was the most important cause of tennis elbow among players, a majority (553 or 65.9%) responded that it was due to playing incorrectly. The remaining players responded incorrectly; 17.6% (148/839) believed that high string tension was the main cause of the injury, 7.3% (61/839) believed that racquet weight was the problem, and 9.2% (77/839) believed that none of these reasons adequately expressed what caused the injury. Questions relating to care and treatment for the symptoms The majority of the responding tennis players believed that they should seek medical advice from a physician when they had elbow pain resulting from tennis. Out of the total respondents, 70.4% (591/839) answered yes to question 4 of the questionnaire while the remaining 29.6% (248/839) believed that medical care should not be sought for the first episode. When asked about treatments, 67.3% (565/839) reported that they had used homemade treatments or undergone treatment without seeking medical advice when they had an episode of elbow pain.

Table 4. Data obtained from the 839 tennis players





p < 0.001 * / SP = 99%

Table 3. Characteristics of the tennis players with and without episodes of tennis elbow

Question 2

NO (n = 488)

YES (n = 351)

A

148 (30.3%)

138 (39.3%)

B

55 (11.3%)

41 (11.7%)

C

56 (11.5%)

37 (10.5%)

D

167 (34.2%)

102 (29.1%)

E

62 (12.7%)

33 (9.4%)

Variables

Tennis elbow injury

Years

No (n = 488)

Yes (n = 351)

Mean (sd)

32.7 (12.1)

43.6 (9.8)

Minimum – Maximum

9 – 73

15 – 78

Student’s t test

p < 0.001 *

Sex Female

51 (10.5%)

26 (7.4%)

Male

437 (89.5%)

325 (92.6%)

Chi-squared test

p = 0.132

Question 1

126.3 (113.0)

172.3 (125.5)

Minimum – Maximum

3 – 600

5 – 792

Student’s t test

p < 0.001 *

The two groups of respondents (those with and without episodes of tennis elbow) differed with regard to the percentage of responses that were considered correct for each question. However, the differences were only statistically significant (p>

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in which 41.8% of the players in our survey had already suffered tennis elbow requiring them to seek treatment. Collectively, these data demonstrate the importance of gaining a better understanding of this injury especially among recreational tennis players. Many biomechanical studies have been performed to study this injury among tennis players. Kelley et al.12 compared the electromyographic activity of arm muscles in players with and without lateral epicondylitis during a single-handed backhand tennis stroke. They concluded that the injured tennis players had significantly greater activity in the wrist extensors and pronator teres muscles during ball impact and early follow-through. They also reported that a leading elbow was a type of motion that could lead to such an injury. Furthermore, Roetert et al.5 described the importance of high muscle activity in the extensor carpi radialis brevis (ECRB) at ball contact during the one-handed backhand stroke. Collectively, these studies, together with findings reported by Riek et al.15, demonstrate that the main causes of tennis elbow among recreational tennis players are the movements associated with a one-handed backstroke and improper stroke technique. Therefore, we utilized the conclusions of these studies to design our questionnaire. In our study, the majority of tennis players believed that the term tennis elbow refers to a pain on the external side of the elbow. However, there was a highly significant difference (p < 0.001), with high statistical power (99%), between the responses of players who reportedly had never suffered this injury and those who had been injured. While the majority (61.8%) of previously injured players correctly defined tennis elbow, only 46.9% of uninjured players were able to do so. These results are especially disconcerting considering that even after suffering this injury, more than one third of patients (39.2%) did not fully understand their injury. In our view, this deserves attention because it suggests that, even when tennis players with such injuries are treated, they do not receive adequate guidance from doctors and physical therapists. Unfortunately, few healthcare professionals have studied biomechanical concepts specifically applied to tennis. In our opinion, this is necessary to adequately treat the injuries of tennis players and advise them on how to prevent re-injury. Although such advice is important, we agree with Nirschl and Ashman,16 who made it clear that tennis players themselves do not fully understand all aspects of this type of injury. It is unknown, for example, how to adequately determine the ideal racquet for each tennis player, and more studies in this field are necessary. In this study, slightly more of the previously injured players (39.3%) than uninjured players (30.5%) - a statistically insignificant difference (p=0.069) - responded that they believed that the backhand stroke was the main tennis movement responsible for tennis elbow. Consistent with the conclusions derived from our analysis of the first question in our survey, this finding further demonstrates that players do not have an adequate understanding of the causes of this injury. Therefore, they are unable to prevent these injuries from occurring or re-occurring. . When tennis players were asked to identify the most important for cause of tennis elbow, the majority of players, regardless of whether they had been previously afflicted with tennis elbow, correctly identified inadequate stroke technique as the major cause. However, significantly more players (p < 0.001) who had been previously injured correctly identified the cause. Again, these results illustrate the need to better educate tennis coaches and

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physicians in order to manage the rehabilitation of such patients. We propose that only through better education and training for tennis coaches will be possible to improve tennis players’ understanding of this injury. When we analyzed the data pertaining to the methods of treatment used by the survey respondents, we were surprised to learn the vast majority (94.9%) of the 351 tennis players who reported having had tennis elbow stated that they had undertaken some treatment on their own before seeking medical advice from a physician. Among the tennis players who reported that they had not had this injury, a nearly equivalent number sought treatment advice from a physician (52.5%) as underwent some treatment without medical guidance (47.5%). The difference between the two groups (with and without the injury) was highly significant (p < 0.001), with a statistical power of 100%. As commonly observed in our daily practice, different patients have different levels of pain tolerance and this partially dictates when they will seek a physician’s advice. During a patient’s first episode of elbow pain, most tennis players tend to treat their symptoms by using an analgesic cold gel after matches, by changing their racquet, or by limiting their play for a few weeks. Affected individuals tend to seek assistance only after the problem persists for some amount of time, often weeks or months. This may mean that they lose the opportunity for treatment during the acute phase of the injury, which has been shown to correlate with a better prognosis. Therefore, we believe that patients, especially tennis players, should be made aware of the advantages of receiving early treatment from a physician for lateral epicondylitis. Knudson and Blackwell11 used the term “leading elbow” to define the position of the elbow that may favor this injury. As predicted, when we question our patients suffering from tennis elbow, we observe that this technical error was frequently reported. Wei et al.17 recently proposed that control of the follow-through phase of the movements is a critical factor for reducing shock transmission and recommended that clinicians or trainers instruct beginner tennis players to quickly release the tightness of their grip after ball-to-racquet impact in order to reduce shock impact transmission to the wrist and elbow. Unfortunately, only anecdotal evidence exists to support the claim that altering one’s technique is sufficient to prevent injury or re-injury, therefore additiona studies will be required to examine this possibility.10, 17, 19 In the current study, no distinction was made between whether the tennis player performed backhand strokes with one or two hands. This may be of particular importance since Roetert et al.5 proposed that players who utilize the two-handed backhand stroke have a lower incidence of tennis elbow and may be the most effective backhand stroke for preventing lateral tennis elbow. This was not examined in our study since an individual’s sports technique often changes over time. When some tennis players have this injury, or feel elbow pain, they change their playing technique; for example changing from a one to a two handed backhand stroke. Since our evaluation did not involve a clinical examination of the players, we believe that this issue would be subject to error during an evaluation by questionnaire alone. The methods employed to collect data in this study were flawed only in that the survey was made available on an internet site dedicated to tennis enthusiasts. Therefore, individuals without access to the internet or who did not visit this particular website, due to lack of interest, were excluded from the study. Despite this,

a large sample of tennis players were surveyed (839), which made the sample a statistically relevant representation of the population. Due, in part to the large number of survey respondents, we were unable to examine each tennis players in person. However, with a greater number of tennis players responding, we were able to generate a larger volume of data and the survey was able to be more wide-ranging and representative. Since the term tennis elbow is well known among tennis players, it would not have been difficult for these players to report whether they had suffered this injury and had sought medical treatment. Krosshaug et al.20 have indicated that when an injury is well known in biomechanical terms and the injury mechanism is well established in the literature, a data survey by questionnaire alone is valid. Conclusions Unfortunately, no official data on recreational tennis players is available in Brazil, but it is believed that around one million people are regular recreational players. The fact that nearly half of these athletes, an estimated 500,000 individuals, will develop tennis elbow at some point demonstrates the importance of having more adequate player, coach, and physician educational programs in order to prevent this injury and enable athletes to have a better prognosis when this injury occurs. According to the data gathered in our survey, we determined that Brazilian tennis players are largely uniformed as to the causes and available treatments for tennis elbow, therefore current educational programs need to be enhanced. We believe that it may be possible to facilitate education programs through clubs, gyms and other organizations that give sports instruction to our tennis players. We believe that this study illustrates the inadequacies of the current programs in educating Brazilian tennis players to the risks of tennis elbow and hope that the results of this survey will contribute to the establishment of policies to properly educate coaches, players, and physicians on the management and prevention of this injury.

9. Boyer MI, Hastings H 2nd. Lateral tennis elbow: “Is there any science out there?”. J Shoulder Elbow Surg 1999;8(5):481-91. 10. Alvarez-Nemegyei J, Canoso JJ. Evidence-based soft tissue rheumatology - epicondylitis and hand stenosing tendinopathy. J Clin Reumathol 2004;10:33-40. 11. Knudson D, Blackwell J. Upper extremity angular kinematics of the one-handed backhand drive in tennis players with and without tennis elbow. Int J Sports Med 1997;18(2):79-82. 12. Kelley JD, Lombardo SJ, Pink M, Perry J, Giangarra CE. Electromyographic and cinematographic analysis of elbow function in tennis players with lateral epicondylitis. Am J Sports Med 1994;22(3):359-63. 13. Eston RG, Rowlands AV. Stages in the development of a research project: putting the ideas together. Br J Sports Med 2000;34(1):54-69. 14. Mens JM, Stoeckart R, Snijders CJ, Verhaar JA, Stam HJ. Tennis elbow, natural course and relationship with physical activities: an inquiry among physicians. J Sports Med Phys Fitness. 1999;39(3):244-8. 15. Riek S, Chapman AE, Milner T. A simulation of muscle force and internal kinematics of extensor carpi radialis brevis during backhand tennis stroke: implications for injury. Clin Biomech 1999;14: 477–483. 16. Nirschl RP, Ashman ES. Elbow tendinopathy: tennis elbow. Clin Sports Med 2003;22:813-36. 17. Wei SH, Chiang JY, Shiang TY, Chang HY. Comparison of shock transmission and forearm electromyography between experienced and recreational tennis players during backhand strokes. Clin J Sport Med 2006;16(2):129-35. 18. Assendelft W, Green S, Buchbinder R, Struijs P, Smidt N. Extracts from concise clinical evidence: tennis elbow. Br Med J 2003;327:329. 19. Bisset L, Paungmali A, Vicenzino B, Beller E. A systematic review and metaanalysis of clinical trials on physical interventions for lateral epicondylalgia. Br J Sports Med 2005;39:411-22. 20. Krosshaug T, Andersen TE, Olsen O-EO, Myklebust G, Bahr R. Research approaches top describe the mechanism of injuries in sport: limitations and possibilities. Br J Sports Med 2005;39:330-9.

Acknowledgements We would like to acknowledge José Nilton Dalcim and Bruna Dalcim for their assistance in the online formatting of the questionnaire as well as PCE Company for their help with the English translation and revision of the manuscript. We would especially like to thank the tennis players who participated in this study.

1. Fedorczyk JM. Tennis elbow: blending basic science with clinical practice. J Hand Ther 2006;19(2):146-53. 2. Balk ML, Hagberg WC, Buterbaugh GA, Imbriglia JE. Outcome of surgery for lateral epicondylitis (tennis elbow): effect of worker’s compensation. Am J Orthop 2005;34(3):122-6. 3. Haahr JP, Andersen JH. Physical and psychosocial risk factors for lateral epicondylitis: a population based case-referent study. Occup Environ Med 2003;60(5):322-9. 4. Kamien M. A rational management of tennis elbow. Sports Med. 1990;9(3):173-91. 5. Roetert EP, Brody H, Dillman CJ, Groppel JL, Schultheis JM. The biomechanics of tennis elbow. An integrated approach. Clin Sports Med 1995;14(1):47-57. 6. Perkins RH, Davis D. Musculoskeletal injuries in tennis.. Phys Med Rehabil Clin N Am 2006;17(3):609-31. 7. Korthals-de Bos IBC, Smidt N, van Tulder MW, et al. Cost Effectiveness of Interventions for Lateral Epicondylitis Results from a Randomised Controlled Trial in Primary Care. Pharmacoeconomics 2004;22(3):185-95. 8. Hong QN, Durand MJ, Loisel P. Treatment of lateral epicondylitis: where is the evidence? Joint Bone Spine 2004;71(5):369-73.

Rogerio Teixeira Silva, MD, PhD, is an orthopedic surgeon with a special interest in shoulder and knee surgery. He is the Chairman of the South American Committee of the STMS, Vice-President of the Orthopedic Sports Medicine Committee of the Brazilian Orthopedic Society, and also acts as the Chief Medical Officer for the Brazilian Tennis Federation. He is responsible for the medical services of the Brazil Davis Cup and Fed Cup Teams. After completing his PhD he created the NEO – Orthopedic Sports Medicine Research Center, a private institute to promote research projects in the field of orthopedic sports medicine. The group is sponsored by Merck Sharp Dohme, Ache and Asics, and is working on projects for sports injuries prevention, advances in treatment of cartilage and tendon injuries, and pre-emptive analgesia for surgical procedures around the knee and shoulder. Address for correspondence: Rogerio Teixeira Silva, MD, PhD, Rua Carmelo Damato 40, São Paulo, SP, Brazil. Email: [email protected]

About the author

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Marcelo Bannwart Santos, PT, is Physical Therapist and Coordinator of the Sports Medicine Rehabilitation Section, at CETE - Federal University of Sao Paulo / and NEO - Orthopedic Sports Medicine Center. He is Director of the Brazilian Society of Sports Physical Therapy (SONAFE).

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