Introducing a new method to record injuries during military training: a prospective study among 296 young Norwegian conscripts

INTRODUCTION

Most epidemiological studies in the field of military medicine have been based on data from medical records and registries. The aims of this study were to test a self-reporting injury surveillance system commonly used in sports medicine in a military setting, and to describe the injury pattern among Norwegian army conscripts during a period of military training.

METHOD

A total of 296 conscripts in His Majesty the King's Guard were asked to report all injuries each week for 12 weeks, using a modification of the Oslo Sports Trauma Research Center Questionnaire on Health Problems (OSTRC-H2). We recorded all injuries irrespective of their need for medical attention or consequences for military participation. In addition, we retrieved data on injuries recorded by military physicians in the medical record from the Norwegian Armed Forces Health Register.

RESULTS

The mean weekly response rate was 74%. A total of 357 injuries were recorded, of which 82% were only captured through the OSTRC-H2 and 3% only in the medical records. The average weekly prevalence of injury was 28% (95% CI: 25% to 31%), and 10% (95% CI: 8% to 12%) experienced injuries with a substantial negative impact on training and performance. The greatest injury burden was caused by lower limb injuries, with knee and foot injuries as the predominant injury locations.

CONCLUSION

The OSTRC-H2 is suitable for use in a military setting and records substantially more injuries than the standard medical record. The prevalence of injuries among conscripts is high and comparable with many elite sports.

#ReadyToplay: hamstring injuries in women's football - a two-season prospective cohort study in the Norwegian women's premier league

In this two-season prospective cohort study (2020-2021), we aimed to describe the characteristics, clinical findings and magnetic resonance imaging (MRI) findings of hamstring injuries in the Norwegian women's premier league. Hamstring injuries were examined by team physiotherapists using a standardised clinical examination and injury form. Injury location and severity (modified Peetrons classification) were graded based on MRI by two independent radiologists. Fifty-three hamstring injuries were clinically examined, 31 of these with MRI. Hamstring injuries caused 8 days (median) lost from football (interquartile range: 3-15 days, range: 0-188 days), most were non-contact and occurred during sprinting. Gradual-onset (53%) and sudden-onset injuries (47%) were evenly distributed. The injuries examined with MRI were classified as grade 0 (52%), grade 1 (16%) or grade 2 (29%). One proximal tendinopathy case was not graded. Grade 2 injuries caused more time loss than grade 0 (19 ± 8 vs. 7 ± 7 days, p = 0.002). Of injuries with MRI changes, 60% were in the m. biceps femoris, mainly the muscle-tendon junction, and 40% in the m. semimembranosus, most in the proximal tendon. Compared to previous findings from men's football, a higher proportion of hamstring injuries in women's football had a gradual onset and involved the m. semimembranosus, particularly its proximal tendon.

Characteristics of functional movement screening testing in elite handball players: Indicative data from the 9

OBJECTIVES

To test 9 + screening batterie's intra-rater reliability, to provide indicative data of elite handball players, and to analyze difference between age, playing positions and level of play.

DESIGN

Descriptive study.

SETTING

Icelandic elite male handball players.

PARTICIPANTS

182 elite male handball players.

MAIN OUTCOME MEASURES

Nine + screening battery.

RESULTS

Reliability test: Intra-class correlation for the total score was 0.95. The correlation of each of the test factors varied from 0.63 to 0.91. The mean total score was 22.3 ± 2.9 (95%CI 16.7-28.1), with no difference in total score comparing players age or level of play. Goalkeepers displayed a higher total score than other players (F_3,151 = 5.75, p = 0.001). Junior players had a lower score than senior players in tests measuring abdominal strength and core stability; Test 5; │²(3, 182) = 41.5, p < 0.0001, Test 6; │²(3, 182) = 55.7, p < 0.0001, Test 7; │²(3, 182) = 11.8, p < 0.005, but higher scores in tests measuring trunk and shoulder mobility Test 8; │²(3, 182) = 18.2, p < 0.0001, Test 9; │²(3, 182) = 22.2, p = 0.006.

CONCLUSIONS

The 9+ intra-rater reliability was acceptable for the total score and individual tests. Age-related differences were provided in many individual tests.

Interseason variability in isokinetic strength and poor correlation with Nordic hamstring eccentric strength in football players

In elite sport, the use of strength testing to establish muscle function and performance is common. Traditionally, isokinetic strength tests have been used, measuring torque during concentric and eccentric muscle action. A device that measures eccentric hamstring muscle strength while performing the Nordic hamstring exercise is now also frequently used. The study aimed to investigate the variability of isokinetic muscle strength over time, for example, between seasons, and the relationship between isokinetic testing and the new Nordic hamstring exercise device. All teams (n = 18) eligible to compete in the premier football league in Qatar underwent a comprehensive strength assessment during their periodic health evaluation at Aspetar Orthopaedic and Sports Medicine Hospital in Qatar. Isokinetic strength was investigated for measurement error, and correlated to Nordic hamstring exercise strength. Of the 529 players included, 288 players had repeated tests with 1/2 seasons between test occasions. Variability (measurement error) between test occasions was substantial, as demonstrated by the measurement error (approximately 25 Nm, 15%), whether separated by 1 or 2 seasons. Considering hamstring injuries, the same pattern was observed among injured (n = 60) and uninjured (n = 228) players. A poor correlation (r = .35) was observed between peak isokinetic hamstring eccentric torque and Nordic hamstring exercise peak force. The strength imbalance between limbs calculated for both test modes was not correlated (r = .037). There is substantial intraindividual variability in all isokinetic test measures, whether separated by 1 or 2 seasons, irrespective of injury. Also, eccentric hamstring strength and limb-to-limb imbalance were poorly correlated between the isokinetic and Nordic hamstring exercise tests.

Magnetic Resonance Imaging of Experimental Tendonitis in Sheep

Experimental tendonitis in sheep is used to demonstrate the advantages of magnetic resonance imaging: three-dimensional imaging ability, high image resolution and the ability to detect alteration in tissue composition that occurs in pathological states.

A valid and reliable method to measure jump-specific training and competition load in elite volleyball players

Use of a commercially available wearable device to monitor jump load with elite volleyball players has become common practice. The purpose of this study was to evaluate the validity and reliability of this device, the Vert, to count jumps and measure jump height with professional volleyball players. Jump count accuracy was determined by comparing jumps recorded by the device to jumps observed through systematic video analysis of three practice sessions and two league matches performed by a men's professional volleyball team. Jumps performed by 14 players were each coded for time and jump type and individually matched to device recorded jumps. Jump height validity of the device was examined against reference standards as participants performed countermovement jumps on a force plate and volleyball-specific jumps with a Vertec. The Vert device accurately counted 99.3% of the 3637 jumps performed during practice and match play. The device showed excellent jump height interdevice reliability for two devices placed in the same pouch during volleyball jumps (r = .99, 95% CI 0.98-0.99). The device had a minimum detectable change (MDC) of 9.7 cm and overestimated jump height by an average of 5.5 cm (95% CI 4.5-6.5) across all volleyball jumps. The Vert device demonstrates excellent accuracy counting volleyball-specific jumps during training and competition. While the device is not recommended to measure maximal jumping ability when precision is needed, it provides an acceptable measure of on-court jump height that can be used to monitor athlete jump load.

Knee function among elite handball and football players 1-6 years after anterior cruciate ligament injury

The aim of the study was to describe objective and self-reported knee function for athletes who have returned to elite handball and football play after an ACL injury, comparing these to non-injured players at the same level. A total of 414 handball and 444 football players completed baseline tests from 2007 through 2014, examining lower extremity strength, dynamic balance, knee laxity, and knee function (KOOS questionnaire). Measures were compared between injured and non-injured legs and between injured legs and legs of controls. Eighty (9.3%) of the 858 players reported a previous ACL injury, 1-6 years post-injury (3.5±2.5 years), 49 handball (61.3%) and 31 football players (38.7%). We found no difference in strength or dynamic balance between previously ACL-injured (N=80) and non-injured players legs (N=1556). However, lower quadriceps (6.3%, 95% CI: 3.2-9.2) and hamstrings muscle strength (6.1%, 95% CI: 3.3-8.1) were observed in previously ACL-injured legs compared to the non-injured contralateral side (N=80). ACL-injured knees displayed greater joint laxity than the contralateral knee (N=80, 17%, 95% CI: 8-26) and healthy knees (N=1556, 23%, 95% CI: 14-33). KOOS scores were significantly lower for injured knees compared to knees of non-injured players. ACL-injured players who have successfully returned to elite sport have comparable strength and balance measures as their non-injured teammates. Subjective perception of knee function is strongly affected by injury history, with clinically relevant lower scores for the KOOS subscores Pain, Function, Sport, and Quality Of Life.

Experimental Investigation of the Collective Raman Scattering of Multiple Laser Beams in Inhomogeneous Plasmas

Experiments have been performed evidencing significant stimulated Raman sidescattering (SRS) at large angles from the density gradient. This was achieved in long scale-length high-temperature plasmas in which two beams couple to the same scattered electromagnetic wave further demonstrating for the first time this multiple-beam collective SRS interaction. The collective nature of the coupling and the amplification at large angles from the density gradient increase the global SRS losses and produce light scattered in novel directions out of the planes of incidence of the beams. These findings obtained in plasmas conditions relevant of inertial confinement fusion experiments similarly apply to the more complex geometry of these experiments where anomalously large levels of SRS were measured.

Interseason variability of a functional movement test, the 9+ screening battery, in professional male football players

BACKGROUND

The Nine Plus screening battery test (9+) is a functional movement test intended to identify limitations in fundamental movement patterns predisposing athletes to injury. However, the interseason variability is unknown.

AIM

To examine the variability of the 9+ test between 2 consecutive seasons in professional male football players.

METHODS

Asymptomatic Qatar Star League players (n=220) completed the 9+ at the beginning of the 2013 and 2014 seasons. Time-loss injuries in training and matches were obtained from the Aspetar Injury and Illness Surveillance Program. No intervention was initiated between test occasions.

RESULTS

A significant increase in the mean total score of 1.6 points (95% CI 1.0 to 2.2, p<0.001) was found from season 1 (22.2±4.1 (SD)) to season 2 (23.8±3.3). The variability was large, as shown by an intraclass correlation coefficient (ICC) of 0.24 (95% CI 0.11 to 0.36) and a minimal detectable change (MDC) of 8.7 points. Of the 220 players, 136 (61.8%) suffered a time-loss injury between the 2 tests. There was an improvement in mean total scores in the injured (+2.0±0.4 (SE), p<0.001) group but not in the uninjured group (+0.9±0.5, p=0.089). The variability from season 1 to season 2 was large both in the injured (ICC 0.25, 0.09 to 0.40, MDC 8.3) and uninjured (ICC 0.24, 0.02 to 0.43, MDC 9.1) groups.

CONCLUSIONS

The 9+ demonstrated substantial intraindividual variability in the total score between 2 consecutive seasons, irrespective of injury. A change above 8 points is necessary to represent a real change in the 9+ test between seasons.

Experimental Evidence of the Collective Brillouin Scattering of Multiple Laser Beams Sharing Acoustic Waves

The indirect-drive scheme to inertial confinement fusion uses a large number of laser beams arranged in a symmetric angular distribution. Collective laser plasma instabilities can therefore develop that couple all the incident laser waves located in a cone to the daughter wave growing along the cone symmetry axis [D. F. DuBois et al., Phys. Fluids B 4, 241 (1992)]. With complementary diagnostics of Thomson scattering and of the scattered light, we demonstrate the occurrence of collective stimulated Brillouin sidescattering driving collective acoustic waves in indirect-drive experiments.

Injury rate and injury pattern among elite World Cup snowboarders: a 6-year cohort study

BACKGROUND

There is limited knowledge on the injury rate and injury pattern in the different disciplines among elite snowboarders.

OBJECTIVE

The aim of this study was to describe and compare the injury rate and injury pattern among the different International Ski Federation (Fédération Internationale de Ski, FIS) World Cup (WC) snowboard disciplines.

METHODS

We conducted retrospective interviews with FIS WC snowboard athletes at the end of each season in the period 2007-2012, to register all acute injuries sustained during training or competition during the competitive season requiring attention by medical personnel. To calculate the exposure, we obtained information from result lists from the FIS competition database for all WC competitions for each of the interviewed athletes.

RESULTS

We registered a total of 574 injuries among 1432 athletes, accounting for an overall injury rate of 40.1 injuries/100 athlete/season. A total of 171 injuries occurred during the FIS WC competitions, corresponding to 6.4 injuries/1000 runs. During competition, injury risk was highest in snowboard cross with 11.9/1000 runs, followed by 6.3 in halfpipe, 3.6 in big air and 2.8 in parallel giant slalom/parallel slalom (PGS/PSL). Snowboard cross also had the highest risk of severe injuries (>28 days absence). No differences in injury risk were detected between male and female snowboarders. The most commonly injured body part was the knee (17.8%), followed by the shoulder/clavicle (13.4%) and head/face (13.2%). The risk of knee injury (the most common injury type) and head injury was significantly higher in snowboard cross and halfpipe compared to PGS/PSL.

CONCLUSIONS

The risk of injuries was higher in snowboard cross than in halfpipe, big air and PGS/PSL. The most commonly injured body part was the knee. Prevention of snowboard injuries among elite snowboarders should focus on knee injuries, severe injuries and snowboard cross athletes.

Training volume and body composition as risk factors for developing jumper's knee among young elite volleyball players

Training volume and body composition have been suggested as risk factors for jumper's knee among athletic youth, but research is lacking. The aim of this 4-year prospective cohort study was to examine the relationship between training and competition load, body composition, and risk for developing jumper's knee. Participants are elite volleyball players, aged 16-18 years. Training and competition load was recorded continuously and body composition semiannually. Jumper's knee was diagnosed on a standardized clinical examination. We recruited 141 healthy students (69 males and 72 females), and 28 developed jumper's knee (22 boys and six girls). In a multivariate analyses, boys had three to four times higher risk compared with girls. Volleyball training had an odds ratio (OR) 1.72 (1.18-2.53) for every extra hour trained, and match exposure was the strongest sports-related predictor for developing jumper's knee with an OR of 3.88 (1.80-8.40) for every extra set played per week. We did not detect any significant differences between the groups in body composition at the time of inclusion or in the change of body composition during the study period. Conclusion, male gender, a high volume of volleyball training and match exposure were risk factors for developing jumper's knee.

Injuries of football referees: a representative survey of Swiss referees officiating at all levels of play

The purpose of this study was to investigate the frequency and characteristics of injury and musculo-skeletal complaints in Swiss football referees of all levels. A representative sample of 489 Swiss referees was interviewed regarding their socio-demographic characteristics, refereeing qualifications, time spent in training and in matches, history of injuries and musculo-skeletal complaints caused by training or refereeing, and other medical problems. A total of 110 referees (22.5%) reported having suffered at least one injury related to officiating, and 126 referees (25.8%) at least one refereeing-related musculo-skeletal complaint. Thigh strains and ankle sprains were the most frequent injuries, with the most frequent locations of complaints being the knee and lower back. The incidence of match injuries in the last 12 months was on average 2.06 per 1000 match hours; the incidence of training injuries was substantially lower (0.09 per 1000 training hours). The injury rates were similar for referees officiating at an adult level, but lower at a junior level. In comparison with elite football referees, the incidence of training injuries and the prevalence of musculo-skeletal complaints were lower in amateur referees. Nevertheless, preventive programs are indicated for referees at all levels, especially when considering the length of a referee's career.

Injectable agents derived from or targeting vascularity: has clinical acceptance in managing tendon disorders superseded scientific evidence?

OBJECTIVES

To report outcomes after sclerosing, platelet-rich plasma (PRP) and autologous blood injection therapies as a treatment for tendinopathy.

METHODS

We searched Pubmed for clinical trials on sclerosing, PRP and autologous blood injections for tendinopathy. We scored the quality of the studies using a modified Coleman Methodological Score (CMS) with 9 criteria, which results in a final score between 0 and 90.

RESULTS

We included 14 studies involving 328 tendons on sclerosing (mean CMS: 52; range 31-77), 6 studies involving 143 tendons on PRP (CMS: 57; 43-73) and 5 studies involving 160 tendons on autologous blood injections (CMS: 58, 50-68). Across treatments, the results appear promising, but as reflected by the low methodology scores, the majority of studies are non-randomized, retrospective, with small sample size or of short duration. Two of three RTCs on sclerosing injections reported better outcomes in the treatment group, while two RCTs on PRP injections show conflicting results. The only available RTC on autologous blood injections has only 8 weeks follow-up.

CONCLUSIONS

There is a need for large-scale RTCs with appropriate follow-up and study size to determine the efficacy of sclerosing, platelet-rich plasma and autologous blood injection therapies as a treatment for tendinopathy.