Painful conditions in the Achilles tendon region in elite badminton players
Author: The American Journal of Sports Medicine - Volume 30, Issue 1
Date: 07 Jul 2002
Category: Articles
Badminton is a sport that makes heavy demands on the player. The physical work is intermittent, involving high-intensity activity interspersed with short rest pauses. The game involves abrupt jerking movements and staccato footwork. (15) In badminton, overuse injuries are the most frequent injury occurrence, (8) but there is also a relatively high incidence of acute Achilles tendon ruptures. (3, 5, 11, 13)
The cause of Achilles tendon ruptures is considered to be multifactorial and is still largely unknown. Most etiologic theories are based on mechanical, degenerative, and inflammatory factors. About 75% of total Achilles tendon ruptures and the majority of partial ruptures are related to sports activities, usually those involving abrupt repetitive jumping and sprinting movements. (12) Studies have shown that 15% to 21% of athletes with acute Achilles tendon ruptures reported previous Achilles tendon pain. (2, 4, 6, 9, 10, 14) The occurrence of Achilles tendon injuries in athletes increases with age; most of the badminton players in the aforementioned studies were recreational players in the age group between 30 and 40 years. (4, 10)
Not all Achilles tendon injuries in badminton players are total or partial ruptures. There are other injuries, most often associated with pain, in the Achilles tendon region. In some studies in Denmark, investigators have reported that 7.5% of all badminton injuries were classified as Achillodynia (pain in the Achilles region), with the frequency being similar in elite and recreational players. (7, 8) Thus, the problem of painful conditions in the Achilles tendon region in badminton players seems relatively widespread, but little is known about the type and severity of such injuries. The purpose of this investigation was to describe the prevalence and characteristics of painful conditions in the Achilles tendon region in Swedish elite badminton players.
MATERIALS AND METHODS
During the badminton midseason in February 1998, after study approval by the Committee on Ethics at the Faculty of Medicine, University of Umea, a letter was sent to all eight teams in the Swedish elite division (highest level) in badminton asking the players to complete and return a questionnaire. The questionnaire included questions about basic player characteristics, injuries, and diseases. The players were asked to describe the amount and type of training and the amount of competition during the actual season and during the previous 5 years. The players were also asked about current and previous (last 5 years) symptoms in the Achilles tendon region. There were also questions, when applicable, about any diagnoses and treatment regimens. In some cases data were completed by telephone calls to the players. Mean values [+ or -] standard deviations and independent samples t-tests were calculated by the computerized SPSS system (version 7.5, SPSS Inc., Chicago, Illinois).
RESULTS
Sixty-six players from seven teams answered and returned the questionnaires, a response rate of 88%. The 66 players included 41 men (62%) and 25 women (38%) with mean ages of 24.4 and 21.9 years, respectively. Basic characteristics of the players are given in Table 1. Sixty players (91%) were right-handed. One male player had diabetes mellitus for which he took insulin treatment. All other players were healthy and were not taking any medication. None of the players were smokers, but 14 (21%) were using snuff regularly or occasionally.
The amount of weekly training (total) of the players at the time they answered the questionnaire was 11.7 [+ or -] 5.5 hours, and during the previous 5 years the amount of weekly training was 11.5 [+ or -] 4.8 hours. The amount of training, divided into specific types of training, and the number of competitions at the time of the questionnaire and during the previous 5 years are shown in Table 2.
Twenty-one of the players (32%) reported current pain or pain during the previous 5 years in the Achilles tendon region. Eleven of the players (17%) had pain in the Achilles tendon region on the day they completed the questionnaire. Twenty of the 21 players with a painful condition classified their pain as being continuous (5 players) or as intermittent or correlated with certain movements (15 players). Twelve of the players described their pain as being located in the midportion of the Achilles tendon. Not one of these players had ruptured their Achilles tendon during the 5-year period. The painful conditions in the Achilles tendon region of these 21 badminton players are detailed in Table 3.
The frequency of Achilles tendon pain was higher in men (37%, 15 of 41) than in women (24%, 6 of 25), but the difference was not statistically significant. There were no significant differences in body mass index and age between players with and without Achilles tendon pain, and Achilles tendon pain was found in players of all ages (range, 18 to 34 years). There was no significant difference in the frequency of Achilles tendon pain between the different badminton teams represented in this study. Seven of the 21 players with pain had symptoms on the right side, 8 had symptoms on the left side, and 6 had bilateral symptoms. There was no significant difference in frequency or side of the painful conditions between right- and left-handed players.
There were differences in the amount of training between the players with and without symptoms, as shown in Table 4. The players who had a painful condition reported a higher weekly training load, with significant differences in the number of hours of total training, badminton training, endurance training, and strength training.
DISCUSSION
In this report we have investigated the prevalence and characteristics of painful conditions in the Achilles tendon region in elite badminton players in Sweden. The investigation revealed that about one-third of the players (32%) reported the occurrence of a painful condition in the Achilles tendon region during the previous 5 years, and that approximately one in every six players (17%) had an ongoing painful condition. A majority of the painful conditions were described as occurring in the midportion of the Achilles tendon. However, despite the Achilles tendon pain, the players were able to take part in training and playing sessions. We also found that the training load for all players had been on the same level for the last 5 years and that the training load was significantly higher in players with symptoms.
The cause of painful conditions in the Achilles tendon region is unknown, but Kvist (12) has described several possible etiologic factors associated with injuries and painful conditions in the Achilles tendon. Among these, the most common error with training is stated to be "too much too soon." (12) In our investigation, a high weekly training load was the only factor that correlated with pain in the Achilles tendon region. We found no association between Achilles tendon pain and body mass index, age, or sex. From our investigation we would tend to conclude that the most common error is "too much all the time." In accordance with a Danish study, (8) our findings show that the badminton players in our investigation were training and playing even though they had symptoms. Furthermore, in our study, the players with symptoms also had a significantly higher training load compared with the players without symptoms.
Studies have shown that athletes with acute Achilles tendon ruptures report previous Achilles tendon pain in 15% to 21% of cases. (2,4,6,9,10,14) In our investigation of elite badminton players we found a relatively high prevalence of Achilles tendon pain, although there had been no case of an acute Achilles tendon rupture among these 66 elite badminton players during the previous 5 years. Whether this is a coincidence, or whether it is possible that elite badminton players are better trained than recreational players and thus their tendons are less susceptible to a total rupture is impossible to answer. Logically, however, the training that these elite badminton players have engaged in for many years ought to have resulted in a stronger calf muscle-tendon unit with a high capacity to absorb energy. Eccentric loadings are very common during badminton play and should result in high eccentric calf muscle strength, which could possibly protect against the eccentric forces associated with total Achilles tendon ruptures. We theorize that the relatively high incidence of total Achilles tendon ruptures seen among recreational badminton players (4,10) might be caused, at least in part, by some players having insufficient eccentric calf muscle strength to withstand the eccentric forces placed on the tendon.
