Effects of Olympic-style taekwondo kicks on an instrumented head-form and resultant injury measures

Headguard use in combat sports: position statement of the Association of Ringside Physicians

Headguard use is appropriate during some combat sports activities where the risks of injury to the face and ears are elevated. Headguards are highly effective in reducing the incidence of facial lacerations in studies of amateur boxers and are just as effective in other striking sports. They should be used in scenarios - especially sparring prior to competitions - where avoidance of laceration and subsequent exposure to potential blood-borne pathogens is important. Headguards are appropriate where avoidance of auricular injury is deemed important; limited data show a marked reduction in incidence of auricular injury in wrestlers wearing headguards.Headguards should not be relied upon to reduce the risk of concussion or other traumatic brain injury. They have not been shown to prevent these types of injuries in combat sports or other sports, and human studies on the effect of headguards on concussive injury are lacking. While biomechanical studies suggest they reduce linear and rotational acceleration of the cranium, changes in athlete behavior to more risk-taking when wearing headguards may offset any risk reduction. In the absence of high-quality studies on headguard use, the Association of Ringside Physicians recommends that further research be conducted to clarify the role of headguards in all combat sports, at all ages of participation. Furthermore, in the absence of data on gender differences, policies should be standardized for men and women.

Sports Injury and Illness after Implementation of the Web-Based Surveillance System in World Taekwondo

CONTEXT

There is a shortage of Taekwondo epidemiology studies since the rule changes introduced by World Taekwondo in 2017.

OBJECTIVE

To describe injury and illness patterns at the Muju 2017 World Taekwondo Championships (WTC) following the implementation of the web-based surveillance system by World Taekwondo.

DESIGN

Prospective cohort study.

SETTING

All injuries and illnesses were recorded during the 2017 WTC using a web-based system developed by the International Olympic Committee.

PATIENTS OR OTHER PARTICIPANTS

971 athletes who participated in the 2017 WTC.

MAIN OUTCOME MEASURE(S)

A profiles and mechanisms of injury and illness in the 2017 WTC.

RESULTS

We analyzed total 131 injuries and 26 illnesses, corresponding to an overall clinical incidence of 13.5 ((95% confidence interval (CI): 11.2-15.8)) injuries and 2.7 (95% CI: 1.6-3.7) illnesses per 100 athletes, and an overall incidence rate of 19.3 (95% CI: 16.0-22.6) injuries and 3.8 (95% CI: 2.4-5.3) illnesses per 1,000 athlete-days, respectively. Most injuries occurred in the lower extremities (46.6%, n=61), of which knee injuries were most frequent (19.8%, n=26). Among the head and trunk injuries (29.8%, n=39), face injuries (22.1%, n=29) were most frequent, whereas among upper extremity injuries (23.7%, n=31), finger injuries (6.1%, n=8) were most frequent. Contusions (33.6%, n=44) were the most frequent injury type, followed by fractures and ligament ruptures/sprains. The most common injury mechanism was in contact with another athlete (74.0%, n=97), whereas the least common was concussions (n=5). The major affected system was the respiratory system (30.8%, n=8), with major symptoms being pain (42.3%, n=11) and fever (26.9%, n=7). Environmental factors were the most common cause of illness (57.7%, n=15).

CONCLUSION

The web-based surveillance system used at the 2017 WTC revealed that 13.5/100 athletes (77.8/1,000 athlete-exposures, 13.9/1000 minute-exposures) had new or recurrent injuries, whereas 2.7/100 athletes became ill.

Injury and Illness in World Taekwondo Junior Athletes: An Epidemiological Study

Taekwondo has been reported to be one of the most injurious sports in the summer Olympics, however, there is a dearth of data about injury profiles for junior athletes. Therefore, we aimed to identify the incidence and profiles of the injuries and illnesses that occurred during the 2018 World Taekwondo Junior Championships and recorded using an online system. Among the 889 athletes, 67 injuries and four illnesses were reported, corresponding to an overall clinical incidence of 7.5 injuries (95% confidence interval [CI]: 5.7-9.3) and 0.5 illnesses (0.1-0.9) per 100 athletes. The most frequent injuries were lower extremity injuries (n = 33, 3.71% of all athletes), mostly in the foot/toe (n = 11, 1.2% of athletes), followed by head and trunk injuries, mostly in the face (n = 14, 1.6% of athletes), and upper extremity injuries, mostly in the fingers (n = 6, 0.7% of athlete). Contusions (n = 37, 4.2% of athlete) were the most frequent injury type, followed by ligament ruptures/sprains and laceration. The most common injury mechanism was contact during an opponent attack (n = 51, 5.7% of athlete). Three mild concussions none resulted in time loss (none required hospital transfer or had prolonged recovery). The respiratory system was the most affected by illness, with pain and fever as symptoms. Environmental factors were the most common cause of illness. This study shows that 7.5 per 100 athletes (38.5/1000 athlete-exposures and 6.9/1000 min-exposures) had new or recurrent injuries, whereas 0.5 per 100 athletes experienced illness. In conclusion, the data shows male athletes reported more injuries than females and the most common cause of injury was due to contact between athletes. Contusions, ligament rupture/sprains, laceration and fractures to the lower extremities, head, and trunk were the most common injury. Knowing these injury profiles of junior taekwondo athletes can help taekwondo stakeholders, especially medical staff to prepare accordingly to ensure the safety of the athletes.

An improved method for obtaining rotational accelerations from instrumented headforms

The following compares the effect of differentiation methods used to acquire angular acceleration from three types of un-helmeted headform impact tests. The differentiation methods considered were the commonly used 5-point stencil method and a total variation regularization method. Both methods were used to obtain angular acceleration by differentiating angular velocity measured by three angular rate sensors (gyroscopes), and a reference angular acceleration signal was obtained from an array of nine linear accelerometers (that do not require differentiation to obtain angular acceleration). For each impact, three injury criteria that use angular acceleration as an input were calculated from the three angular acceleration signals. The effect of the differentiation methods were considered by comparing the criteria values obtained from gyroscope data to those obtained from the reference signal. Agreement with reference values was observed to be greater for the TV method when a user-defined tuning parameter was optimized for the impact test and cutoff frequency of each condition, particularly at higher cutoff frequencies. In this case, mean absolute error of the five-point stencil ranged from 1.0 (the same) to 11.4 times larger than that associated with the TV method. When a constant tuning parameter value was used across all impacts and cutoff frequencies considered in this study, the TV method still provided a significant improvement over the 5-point stencil method, achieving mean absolute errors as low as one-tenth that observed for the five-point stencil method.

Inertial Sensors for Performance Analysis in Combat Sports: A Systematic Review

The integration of technology into training and competition sport settings is becoming more commonplace. Inertial sensors are one technology being used for performance monitoring. Within combat sports, there is an emerging trend to use this type of technology; however, the use and selection of this technology for combat sports has not been reviewed. To address this gap, a systematic literature review for combat sport athlete performance analysis was conducted. A total of 36 records were included for review, demonstrating that inertial measurements were predominately used for measuring strike quality. The methodology for both selecting and implementing technology appeared ad-hoc, with no guidelines for appropriately analysing the results. This review summarises a framework of best practice for selecting and implementing inertial sensor technology for evaluating combat sport performance. It is envisaged that this review will act as a guide for future research into applying technology to combat sport.

Injuries in taekwando: systematic review

OBJECTIVES

Assess rates/1000athletic encounters(AE) in Taekwondo of injuries/age/gender/type/location.

METHODS

Searches in 17 electronic, 7 grey-literature databases. Two researchers independently assessed Abstracts/titles and abstracted data. Risk-of-bias assessed with Newcastle-Ottawa scale. Rates/1000AE computed, weighted by study sizes.

RESULTS

Eighteen studies included 3 Olympic, 4 world, 1 European, 13 national, 10 provincial and one national school competition. Seventeen studies provided an injury definition and recorded injuries on forms. Rates are average rate/1000AE, weighted by study size. For ten studies which provided rates by gender, rate for males(n = 9,286) was 58/1000AE and females(n = 3,720) 52.7/1000AE. For six studies which provided data on injuries/1000minutes/exposure by gender rate for males(n = 6,885) was 10.7/1000minutes/exposure and for females(n = 2,539) 10.4. For two studies which provided data by age and gender, rate for males 11-13 years(n = 949) was 29.6, 14-17(n = 512) 53.1 and ≥18(n = 711) 40.7, and for females 11-13 years(n = 472) 30.5, 14-17(n = 338) 72 and ≥18(n = 240) 37.5. For eight studies which provided injury location rates by gender rate for all ages for males(n = 5,856) for head/neck injuries was 13.3, torso 4.2, upper-extremity 9.4 and lower-extremity 21.7 and females(n = 2,126) for head/neck injuries was 14.2, torso 3.1, upper-extremity 7.3 and lower-extremity 26.6. For nine studies which provided injury type rates by gender, rate for all ages for males(n = 7,509) for abrasions/contusions/lacerations was 37.5, for sprains/strains 10.3 and fractures 5.9, and for females(n = 2,852) for abrasions/contusions/lacerations 27.9, for sprains/strains 8.7 and fractures 3.8. For concussions for eight studies for males(n = 9,078) rate was 13.3 and females(n = 3628) 11.4. The majority of injuries occurred to the lower extremities, and in defence (61%).

CONCLUSIONS

There are published data on 20,210 Taekweondo competitors. Only 8/18 studies reported prior injuries. Longitudinal studies are needed of injuries, ascertainment of causes, identify participants with higher rates, measure the results of preventive measures, rule change to exclude head kicks, and encourage non-contact Taekwondo especially for participants with high injury rates.

Biomechanical head impact characteristics during sparring practice sessions in high school taekwondo athletes

OBJECTIVE The purpose of this study was to monitor head impact magnitude and characteristics, such as impact location and frequency, at high school taekwondo sparring sessions. METHODS Eight male high school taekwondo athletes participated in this study. The head impact characteristics were recorded by X-Patch, a wireless accelerometer and gyroscope, during 6 taekwondo sparring sessions. The outcome measures were the peak linear acceleration ( g = 9.81 msec²), peak rotational acceleration, rotational velocity, and Head Injury Criterion. RESULTS A total of 689 impacts occurred over 6 sessions involving the 8 athletes. There was an average of 24 impacts per 100 minutes, and there were significant differences in the frequency of impacts among both the sessions and individual athletes. In order of frequency, the most commonly hit locations were the side (38.2%), back (35.7%), and front (23.8%) of the head. CONCLUSIONS The data indicate that there is a relatively high number of head impacts experienced by taekwondo athletes during sparring practice. According to the rotational acceleration predicting impact severity published in previous research, 17.1% of the impacts were deemed to be a moderate and 15.5% were deemed to be severe.

Youth Participation and Injury Risk in Martial Arts

The martial arts can provide children and adolescents with vigorous levels of physical exercise that can improve overall physical fitness. The various types of martial arts encompass noncontact basic forms and techniques that may have a lower relative risk of injury. Contact-based sparring with competitive training and bouts have a higher risk of injury. This clinical report describes important techniques and movement patterns in several types of martial arts and reviews frequently reported injuries encountered in each discipline, with focused discussions of higher risk activities. Some of these higher risk activities include blows to the head and choking or submission movements that may cause concussions or significant head injuries. The roles of rule changes, documented benefits of protective equipment, and changes in training recommendations in attempts to reduce injury are critically assessed. This information is intended to help pediatric health care providers counsel patients and families in encouraging safe participation in martial arts.

Resultant linear acceleration of an instrumented head form does not differ between junior and collegiate taekwondo athletes' kicks

OBJECTIVE

The purpose of this study was to compare the effects of various taekwondo kicks and age (school level) in absolute terms and relative body mass on the resultant linear acceleration (RLA) of an instrumented head form.

METHODS

Forty-eight male (middle school: 16; high school: 16; university: 16) taekwondo athletes were recruited for this study. Subjects performed 10 turning, 10 jump spinning hook, and 10 jump back kicks on a Hybrid II head mounted on a height-adjustable frame.

RESULTS

A 2-way (School × Kick) MANOVA was used to determine the differences in RLA between schools (age groups) by type of kick. There was no univariate School main effect for absolute RLA (η ² = 0.06) and RLA relative to body mass (η ² = 0.06). No univariate Kick main effects were found for absolute (η ² = 0.06) and relative RLA (η ² = 0.06).

CONCLUSION

It is of concern that RLA did not significantly differ between school levels, implying that young taekwondo athletes generate similar forces to their adult counterparts, possibly exposing young athletes to an increased risk for head injuries.

Biomechanics of head injury in olympic taekwondo and boxing

Objective

The purpose was to examine differences between taekwondo kicks and boxing punches in resultant linear head acceleration (RLA), head injury criterion (HIC15), peak head velocity, and peak foot and fist velocities. Data from two existing publications on boxing punches and taekwondo kicks were compared.

Methods

For taekwondo head impacts a Hybrid II Crash Dummy (Hybrid II) head was instrumented with a tri-axial accelerometer mounted inside the Hybrid II head. The Hybrid II was fixed to a height-adjustable frame and fitted with a protective taekwondo helmet. For boxing testing, a Hybrid III Crash Dummy head was instrumented with an array of tri-axial accelerometers mounted at the head centre of gravity.

Results

Differences in RLA between the roundhouse kick (130.11±51.67 g) and hook punch (71.23±32.19 g, d = 1.39) and in HIC15 (clench axe kick: 162.63±104.10; uppercut: 24.10±12.54, d = 2.29) were observed.

Conclusions

Taekwondo kicks demonstrated significantly larger magnitudes than boxing punches for both RLA and HIC.