British Journal of Sports Medicine

Published by BMJ

Online ISSN: 1473-0480


Print ISSN: 0306-3674


  • Article

July 1989


75 Reads

P N Sperryn

Table 3 Mucosal immune concentrations (IgA and IgA1) measured in saliva at baseline and after each of the experimental treatments 
Table 4 Changes in whole-blood cytokine concentrations between L fermentum and placebo treatments 
Oral administration of the probiotic Lactobacillus fermentum VRI-003 and mucosal immunity in endurance athletes
  • Article
  • Full-text available

March 2008


1,481 Reads

To evaluate the ability of a probiotic Lactobacillus fermentum VRI-003 (PCC) to enhance the mucosal immune system of elite athletes. A double-blind, placebo-controlled, crossover trial was conducted over a 4-month period of winter training. PARTICIPANTS; 20 healthy elite male distance runners. PCC was given at a daily dose of 1.26 x 10(10) as a freeze-dried powder in gelatin capsules. Placebo capsules contained an inert excipient. Treadmill performance (monthly), mucosal and systemic immunity (monthly), training (daily) and illness (daily) were assessed. Serum cytokine levels, salivary IgA levels and incidence, duration and severity of respiratory tract infections were measured. Subjects reported less than half the number of days of respiratory symptoms during PCC treatment (30 days) compared with placebo (72 days, p<0.001). Illness severity was also lower for episodes occurring during the PCC treatment (p = 0.06). There were no significant differences in the mean change in salivary IgA and IgA1 levels, or in interleukin (IL)4 and IL12 levels, between treatments. However, PCC treatment elicited a twofold (p = 0.07) greater change in whole-blood culture interferon gamma (IFNgamma) compared with placebo. No substantial changes in running performance measures were seen over the study period. Prophylactic administration of PCC was associated with a substantial reduction in the number of days and severity of respiratory illness in a cohort of highly trained distance runners. Maintenance of IFNgamma levels may be one mechanism underpinning the positive clinical outcomes.

ACOG Committee Opinion. Exercise in pregnancy and the postpartum period. Number 267, January 2002 ACOG. American College of Obstetricians and Gynecologists Int J Gynecol Obstet 2002 77 79 81 10.1016/S0020-7292(02)80004-2

March 2003


2,885 Reads

Regular exercise is promoted for its over- all health benefits. Pregnancy is recog- nised as a unique time for behaviour modification and is no longer considered a condition for confinement. It is cur- rently recognised that habits adopted during pregnancy could affect a woman's health for the rest of her life.For the first time the recommendation suggests a possible role for exercise in the preven- tion and management of gestational diabetes. The recommendations also promote exercise for sedentary women and those with medical or obstetric complications, but only after medical evaluation and Sports Medicine (CDC-ACSM) have rec- ommended the accumulation of 30 min- utes or more of moderate intensity physical activity on most, and preferably all,days of the week. 4 Moderate intensity physical activity is defined as activity with an energy requirement of 3-5 metabolic equivalents (METS). For most healthy adults, this is equivalent to brisk walking at 3-4 mph. The CDC-ACSM statement also recognises that more intense exercise performed in 20-60 minute sessions on three to five days a week will result in higher levels of physi- cal fitness. Despite the fact that pregnancy is associated with profound anatomical and physiological changes, there are few instances that should preclude otherwise healthy,pregnant women from following the same recommendations.

Epidemiologic review of collegiate acl injury rates across 14 sports: National collegiate athletic association injury surveillance system data 2004-05 through 2011-12

April 2014


151 Reads

Extensive effort has been put into awareness and prevention programs to decrease the overall rate of injury and the difference between sexes. The objective of this review is to document the rate of ACL injury in 14 collegiate sports over an eight year period and compare it to an earlier 16 year review. Descriptive Epidemiology. Universities in the U.S. NCAA athletes. There was no intervention. The primary outcome chosen apriori is injury. The majority of ACL injuries to women occurred by a non-contact mechanism of injury while the majority of ACL injuries to men occurred by a contact mechanism. The highest rates of ACL injury for men were found in American football (0.17 per 1000 A-E and wrestling (0.16 per 1000 A-E). The highest rates of ACL injury for women were found in basketball and lacrosse (0.23 per 1000 A-E). Within the 8 year study period men's and women's ice hockey showed the greatest increase over time with an average annual rate of change of 105% and 136% respectively. Mens' baseball and women's lacrosse showed the greatest decrease in average annual rate of change (16.9% and 17% respectively).When comparing the current 8 years of data to previously reported 16 years of data baseball and women's basketball, showed no change, men's basketball, lacrosse, and wrestling along with field hockey showed an increase and American football, men's and women's ice hockey and soccer, women's lacrosse, softball, and volleyball showed a decrease in overall injury rate. Despite focused scientific efforts and prevention programs ACL injuries remain a significant injury in collegiate sports. Women continue to sustain ACL injuries at higher rates than men in the comparable sports of soccer, basketball, and lacrosse.

Table 1 Data on the sporting disciplines of the athletes 
Figure 1 Electrocardiograph changes in an elite soccer player from a British Premier League club showing sinus bradycardia, sinus arrhythmia, and Sokolow voltage criterion for left ventricular hypertrophy typical of that seen in most of the athletes in this study. In addition, there is right axis deviation and tall T waves. 4 by 2.5s + 1 rhythm ld 10.0 mm/mV 25.0 mm/s 
Table 2 Electrocardiographic results 
Electrocardiographic changes in 1000 highly trained junior elite athletes

November 1999


312 Reads



Elliott PM




To evaluate the spectrum of electrocardiographic (ECG) changes in 1000 junior (18 or under) elite athletes. A total of 1000 (73% male) junior elite athletes (mean (SD) age 15.7 (1.4) years (range 14-18); mean (SD) body surface area 1.73 (0.17) m2 (range 1.09-2.25)) and 300 non-athletic controls matched for gender, age, and body surface area had a 12 lead ECG examination. Athletes had a significantly higher prevalence of sinus bradycardia (80% v 19%; p<0.0001) and sinus arrhythmia (52% v 9%; p<0.0001) than non-athletes. The PR interval, QRS, and QT duration were more prolonged in athletes than non-athletes (153 (20) v 140 (18) milliseconds (p<0.0001), 92 (12) v 89 (7) milliseconds (p<0.0001), and 391 (27) v 379 (29) milliseconds (p = 0.002) respectively). The Sokolow voltage criterion for left ventricular hypertrophy (LVH) and the Romhilt-Estes points score for LVH was more common in athletes (45% v 23% (p<0.0001) and 10% v 0% (p<0.0001) respectively), as were criteria for left and right atrial enlargement (14% v 1.2% and 16% v 2% respectively). None of the athletes with voltage criteria for LVH had left axis deviation, ST segment depression, deep T wave inversion, or pathological Q waves. ST segment elevation was more common in athletes than non-athletes (43% v 24%; p<0.0001). Minor T wave inversion (less than -0.2 mV) in V2 and V3 was present in 4% of athletes and non-athletes. Minor T wave inversion elsewhere was absent in non-athletes and present in 0.4% of athletes. ECG changes in junior elite athletes are not dissimilar to those in senior athletes. Isolated Sokolow voltage criterion for LVH is common; however, associated abnormalities that indicate pathological hypertrophy are absent. Minor T wave inversions in leads other than V2 and V3 may be present in athletes and non-athletes less than 16 but should be an indication for further investigation in older athletes.

Protocol for the dano-run study: a 1-year observational follow up study on running related injuries in 1000 novice runners

April 2011


190 Reads

Background The knowledge on the relation between running patterns and Running Related Injuries (RRIs) is sparse. Studies have tried to document a relationship. However, no firm conclusions can be made. Still it is necessary to identify which running exposures increase the risk of injuries and which exposures might be considered safe. Objective The purpose of this study is to investigate the link between the running volume and the development of RRIs. Design Observational prospective follow up study. Setting Clinical setting on novice and recreational athletes. Participants Healthy individuals (N=1000) who have not been running the past 1 year is included. All participants receive a global positioning system (GPS) watch (Garmin FR 110) and a pair of neutral running shoes (Adidas Glide 2). They are instructed to start running as much as they want, two times a week as a minimum. They must wear their GPS watch at each training session and upload data to an internet based database. All participants are followed for 1 year. Assessment of risk factors Running volume measured as absolute number of kilometres and the graduation in kilometres pr. week over a period of 3 weeks. Main outcome measurement RRI is defined as any musculoskeletal complaint of the lower extremity or back causing a restriction of running for at least 1 week. Results Time to RRI is compared between groups with different absolute running volumes. In a similar way time to injury is compared between individuals with different weekly training graduations. Conclusion This study may be the first study to adequately measure running patterns reliably in a large sample. The exposure is quantified by GPS, which is not affected by subject recall and is therefore a clear methodological improvement compared to previous studies. If absolute volume or running graduation over time seems to lead to injury, the study findings and methodology create a solid foundation for future randomised controlled trials in this field.

A journey of 1000 miles begins with a single step

September 2002


101 Reads

In my peregrinations from the ACSM meeting in St Louis to England, Norway, and Canada recently, I found myself desperately searching the airport bookshops for something distracting to while away the hours of travel and came across an absolute cracker of a sports medicine book. No, I don't mean yet another soccer book, although I do note that the quality of the books has improved out of sight in recent years. It makes a pleasant change given that many sports books are written for fans that follow the text with their fingers! No, this book is about muscles. It is called Prime mover: a natural …

Complete inclusion of adaptive rowing only 1000m ahead

August 2013


95 Reads

Adaptive rowing (AR) at the Paralympic level is accessible for rowers with physical disability. AR was included for the first time in the Beijing 2008 Paralympic Games. Racing distance for all AR events is currently 1000 m, which impedes public recognition of this sport and leads to many organisational challenges during the inclusive World Rowing Championships. The aim of this report was to discuss the feasibility of increasing AR race distance to 2000 m from a sports injury and athletic health perspective. As limited data on injury and illness risks exist in AR, knowledge and experiences had to be taken from other Paralympic sports. The anticipated duration of 2000 m AR competitions is either comparable or considerably lower than that of the other Paralympic disciplines with similar characteristics. AR has inherent injury and health risks especially within thorax, shoulders and low back region, but they are not expected to be significantly modified by increased racing times. Specific considerations need to be taken into account for athletes with a spinal cord injury, like in other sport disciplines. There are no distinctive contra-indications for AR events of 2000 m based on the current literature review and a 10-year experience in this sport. Long-term follow-ups are needed to understand fully the injury and health risk associated with AR and to develop appropriate prevention strategies.

Changes in blood glucose levels during a 1005-km running race: A case study

April 1992


42 Reads

The blood glucose response of a male ultramarathon runner was monitored throughout a 1005-km race. Before the race the runner had a fasting blood glucose concentration of 5.1 mM. At no stage during the race were his mean blood glucose levels less than 5.8 mM. This was partially attributed to the eating patterns of the athlete, the times at which blood samples were taken, the glycaemic index of food ingested and hyperglycaemia. While there was no evidence of glucosuria, ketones were present in the urine on one day of the event. There were other signs suggesting that at various stages of the event the runner had a metabolic acidosis. Possible reasons for this are discussed.

Figure 1 Serum concentrations of the biochemical markers of brain damage S-100B (A) and neurone specific enolase (NSE) (B) before and after a competitive game of soccer. Symbols corresponding to each player are connected with a line.  
Serum concentrations of two biochemical markers of brain tissue damage S-100B and neurone specific enolase are increased in elite female soccer players after a competitive game

April 2006


125 Reads

It is a matter of debate whether or not ordinary heading of the ball in soccer causes injury to brain tissue. To analyse concentrations of the biochemical markers of brain tissue damage S-100B and neurone specific enolase (NSE) in serum of female elite soccer players in association with a competitive game. Venous blood samples were obtained from 44 female soccer players before and after a competitive game for analysis. The number of headers and trauma events (falls, collisions, etc) was assessed from videotape recordings for each player. Concentrations of both brain damage markers were increased after the game (S-100B, 0.18 (0.11) v 0.11 (0.05) microg/l (p = 0.000); NSE, 10.14 (1.74) v 9.05 (1.59) microg/l (p = 0.001)). There was a significant correlation between changes in S-100B concentrations and both the number of headers (r = 0.430, p = 0.004) and the number of other trauma events (r = 0.517, p < 0.001). The concentrations of both S-100B and NSE were increased by game associated activities and events. The increases in S-100B concentration were significantly related to the number of headers and other trauma events, which indicates that both these factors may have contributed to these increases.

Table 1 Genes associated with soft-tissue injuries 
Genetic risk factors for soft-tissue injuries 101: A practical summary to help clinicians understand the role of genetics and 'personalised medicine'

July 2009


480 Reads

Acute and chronic (overuse) musculoskeletal soft tissues injuries are common as a result of sports and occupational related physical activities. These injuries have no single cause -- instead, they result from a complex interaction of intrinsic and extrinsic factors which include genetic factors. Specific genetic elements have been identified for certain soft tissue injuries and I will summarise those in this editorial. I also explore the possible clinical implications of including genetic risk factors in multifactorial models developed to understand the molecular mechanisms of musculoskeletal soft tissue injuries.

Table 1. Mean (SD) of demographic characteristics of all the respondents and of the respondents within each gender. 
Table 2. Median (IQR) or % of characteristics of the training routine among all the respondents and among the respondents within each gender. 
Musculoskeletal pain in recreational runners prior to race participation: a cross-sectional survey in 1049 runners

April 2011


263 Reads

Background We know that high-performance sports place high stress in the musculoskeletal system, often resulting in injury, pain, or other complaints. It is not unusual for athletes to decide to participate in important competitions, despite an ongoing disability or injury. However, we are unaware of any study that has presented any clear information about this issue in recreational runners. Objective The aims of this study were to calculate the prevalence of presence of musculoskeletal pain in amateur runners immediately before a race and to identify possible factors that could be associated with presence of musculoskeletal pain in this population. Design This is a cross-sectional survey study. Setting These runners were recreational athletes that participated in different races in São Paulo (Brazil), the distance of these races ranged from 5.000/10.000 meters. Participants A convenience sample of 1049 runners, 24.1% women (n=253) and 75.9% men (n=796). Assessment of risk factors This questionnaire contained information on presence of musculoskeletal pain, demographic characteristics, weight, body mass index, running experience, running mileage/week, number of training sessions/week, predominant training surface and coaching utilisation. We used logistic regression analysis to indentify associations between possible factors and presence of musculoskeletal pain (p<0.05). The data were collected 1-2 h prior to the races. Main outcome measurements Presence of musculoskeletal pain. Results The prevalence of presence of musculoskeletal pain was 20% and 26.9% for men and women respectively. Running experience (OR=2.97, 95% CI 1.59 to 5.56) and weekly running distance (OR=1.88, 95% CI 1.02 to 3.48) were associated with presence of musculoskeletal pain in men prior to the race. Conclusion The prevalence of presence of musculoskeletal pain in amateur runners prior to the race was high. We have observed higher experience in running (ie, more than 10 years) and high training volumes (ie, more than 50 Km/week) were associated with presence of musculoskeletal pain.

Parachuting from fixed objects: Descriptive study of 106 fatal events in BASE jumping 1981-2006

June 2008


121 Reads

To analyse the characteristics of fatal incidents in fixed object sport parachuting (building, antenna, span, earth (BASE) jumping) and create a basis for prevention. Descriptive epidemiological study. Data on reported fatal injury events (n = 106) worldwide in 1981-2006 retrieved from the BASE fatality list. Assessment of risk factors: Human, equipment and environmental factors. Main outcome measurements: Identification of typical fatal incident and injury mechanisms for each of the four fixed object types of BASE jumping (building, antenna, span, earth). Human factors included parachutist free fall instability (loss of body control before parachute deployment), free fall acrobatics and deployment failure by the parachutist. Equipment factors included pilot chute malfunction and parachute malfunction. In cliff jumping (BASE object type E), parachute opening towards the object jumped was the most frequent equipment factor. Environmental factors included poor visibility, strong or turbulent winds, cold and water. The overall annual fatality risk for all object types during the year 2002 was estimated at about one fatality per 60 participants. Participants in BASE jumping should target risk factors with training and technical interventions. The mechanisms described in this study should be used by rescue units to improve the management of incidents.

Table 1 Population characteristics 
Table 4 Athletes with a new cardiac diagnosis: clinical characteristics 
history, physical examination and ECG in the study population and test required for each abnormality 
Costs and yield of a 15-month preparticipation cardiovascular examination with ECG in 1070 young athletes in Switzerland: Implications for routine ECG screening

February 2014


330 Reads

The usefulness and modalities of cardiovascular screening in young athletes remain controversial, particularly concerning the role of 12-lead ECG. One of the reasons refers to the presumed false-positive ECGs requiring additional examinations and higher costs. Our study aimed to assess the total costs and yield of a preparticipation cardiovascular examination with ECG in young athletes in Switzerland. Athletes aged 14-35 years were examined according to the 2005 European Society of Cardiology (ESC) protocol. ECGs were interpreted based on the 2010 ESC-adapted recommendations. The costs of the overall screening programme until diagnosis were calculated according to Swiss medical rates. A total of 1070 athletes were examined (75% men, 19.7±6.3 years) over a 15-month period. Among them, 67 (6.3%) required further examinations: 14 (1.3%) due to medical history, 15 (1.4%) due to physical examination and 42 (3.9%) because of abnormal ECG findings. A previously unknown cardiac abnormality was established in 11 athletes (1.0%). In four athletes (0.4%), the abnormality may potentially lead to sudden cardiac death and all of them were identified by ECG alone. The cost was 157 464 Swiss francs (CHF) for the overall programme, CHF147 per athlete and CHF14 315 per finding. Cardiovascular preparticipation examination in young athletes using modern and athlete-specific criteria for interpreting ECG is feasible in Switzerland at reasonable cost. ECG alone is used to detect all potentially lethal cardiac diseases. The results of our study support the inclusion of ECG in routine preparticipation screening.

Hyponatraemic encephalopathy despite a modest rate of fluid intake during a 109 km cycle race * Commentary

November 2005


80 Reads

To report a case of exertional hyponatraemic encephalopathy that occurred despite a modest rate of fluid intake during a 109 km cycling race. Men and women cyclists were weighed before and after the race. All subjects were interviewed and their water bottles measured to quantify fluid ingestion. A blood sample was drawn after the race for the measurement of serum Na(+) concentration. From the full set of data (n = 196), one athlete was found to have hyponatraemic encephalopathy (serum [Na(+)] 129 mmol/l). She was studied subsequently in the laboratory for measurement of sweat [Na(+)] and sweat rate. Despite a modest rate of fluid intake (735 ml/h) and minimal predicted sweat Na(+) losses, this female athlete developed hyponatraemic encephalopathy. The rate of fluid intake is well below the rate currently prescribed as optimum. Drinking to thirst and not to a set hourly rate would appear to be the more appropriate behaviour.

Changes in plasma arginine vasopressin concentrations in cyclists participating in a 109-km cycle race

June 2010


29 Reads

To evaluate the osmotic and non-osmotic regulation of arginine vasopressin (AVP) during endurance cycling. Design: Observational study. Setting 109 km cycle race. 33 Cyclists. None. Plasma sodium concentration ([Na(+)]), plasma volume (PV) and plasma arginine vasopressin (AVP) concentration ([AVP](p)). A fourfold increase in [AVP](p) occurred despite a 2-mmol l(-1) decrease in plasma [Na(+)] combined with only modest (5%) PV contraction. A significant inverse correlation was noted between [AVP](p) Delta and urine osmolality Delta (r = -0.41, p<0.05), whereas non-significant inverse correlations were noted between [AVP](p) and both plasma [Na(+)] Delta and % PV Delta. Four cyclists finished the race with asymptomatic hyponatraemia. The only significant difference between the entire cohort with this subset of athletes was postrace plasma [Na(+)] (137.7 vs 133.5 mmol l(-1), p<0.001) and plasma [Na(+)] Delta (-1.9 vs -5.1 mmol l(-1), p<0.05). The mean prerace [AVP](p) of these four cyclists was just below the minimum detectable limit (0.3 pg ml(-1)) and increased marginally (0.4 pg ml(-1)) despite the decline in plasma [Na(+)]. The osmotic regulation of [AVP](p) during competitive cycling was overshadowed by non-osmotic AVP secretion. The modest decrease in PV was not the primary non-osmotic stimulus to AVP. Partial suppression of AVP occurred in four (12%) cyclists who developed hyponatraemia during 5 h of riding. Therefore, these results confirm that non-osmotic AVP secretion and exercise-associated hyponatraemia does, in fact, occur in cyclists participating in a 109 km cycle race. However, the stimuli to AVP is likely different between cycling and running.

Heat stroke and 10K "fun runs": New safety measures are called for

November 2006


29 Reads

On Sunday 11 June 2006, 8000 people undertook a “fun run” in Hyde Park, the BUPA Capital 10K. During the course of the afternoon, St Mary’s Hospital emergency department received four, and another local hospital received three, collapsed adult runners. All collapsed at 7–10 km, were confused, and showed signs of severe heat stroke (with core temperatures of 40–41°C). Three patients required intubation, and three required sedation and high dependency unit care. One patient was admitted to the intensive care unit for 72 hours. Happily all survived, but there are some important lessons to be learnt for future similar events. No official temperatures were recorded at …

Anthropometric and training variables related to 10km running performance

January 1987


113 Reads

Sixty male distance athletes were divided into three equal groups according to their personal best time for the 10km run. The runners were measured anthropometrically and each runner completed a detailed questionnaire on his athletic status, training programme and performance. The runners in this study had similar anthropometric and training profiles to other distance runners of a similar standard. The most able runners were shorter and lighter than those in the other two groups and significantly smaller skinfold values (P less than 0.05). There were no significant differences between the groups for either bone widths or circumferences but the elite and good runners had significantly higher ponderal indices (P less than 0.05) than the average runners, indicating that they are more linear. Elite and good runners were also less endomorphic but more ectomorphic than the average runners. The elite runners trained more often, ran more miles per week and had been running longer (P less than 0.05) than good or average runners. A multiple regression and discriminant function analysis indicated that linearity, total skinfold, the type and frequency of training and the number of years running were the best predictors of running performance and success at the 10km distance.

Does Type 1 Diabetes Affect Achilles Tendon Response To A 10km Run?
Hyperglycaemia accelerates collagen cross-linking in tendons, which may manifest as an increased thickness or as an altered response to load. Type 1 diabetes mellitus (T1DM) is a unique population exhibiting hyperglycaemia independent of obesity and low physical activity. Ultrasound tissue characterisation (UTC) quantifies the structural integrity of a tendon based on the alignment of collagen, represented as echo-types (I-IV). To measure achilles tendon response to a 10km run among individuals with T1DM and controls. In this case-control study, UTC scans were taken at day 0, 2, 4 after a 10 km run. Analysis of UTC scans was performed in a blinded fashion. Social running club for people with T1DM. Individuals with T1DM (n=7) were diagnosed 13±12 years ago. Control participants (n=10) had no diagnosis or family history of T1DM. Participants all regularly ran ≥5 km in a recreational capacity with an average weekly distance of 18±3 km. VISA-A scores were 94±11 (T1DM) and 94±10 (control). The independent variable was diagnosis of T1DM (yes/no). HbA1c and blood glucose were also measured. Tendon response to a 10km run measured with UTC was defined as the key outcome variable before data collection. Baseline structure was the same in control and T1DM groups for all UTC four echo-types (I-IV) and for anteroposterior thickness (P>.05). Furthermore, no significant differences were observed within each group in response to the run. A novel finding that Achilles tendon baseline structure and response to a 10 km run over 4-days is the same in controls and T1DM. This suggests that T1DM individuals who are regularly physically active do not undergo the same structural changes to their Achilles tendon as previously demonstrated in the general diabetic population.

Table 1 Operational definitions used in the study
Figure 2 Seasonal variation in match injury rates among male professional football players.  
Figure 5 Seasonal variation in severe injury rates among male professional football players.  
Fewer ligament injuries but no preventive effect on muscle injuries and severe injuries: An 11-year follow-up of the UEFA Champions League injury study

June 2013


1,005 Reads

Limited information is available on the variation in injury rates over multiple seasons of professional football. To analyse time-trends in injury characteristics of male professional football players over 11 consecutive seasons. A total of 1743 players comprising 27 teams from 10 countries were followed prospectively between 2001 and 2012. Team medical staff recorded individual player exposure and time loss injuries. A total of 8029 time loss injuries were recorded. The match unavailability due to injury was 14% and constant over the study period. On average, a player sustained two injuries per season, resulting in approximately 50 injuries per team and season. The ligament injury rate decreased during the study period (R(2)=0.608, b=-0.040, 95% CI -0.065 to -0.016, p=0.005), whereas the rate of muscle injury (R(2)=0.228, b=-0.013, 95% CI -0.032 to 0.005, p=0.138) and severe injury (R(2)=0.141, b=0.015, 95% CI -0.013 to 0.043, p=0.255) did not change over the study period. In addition, no changes in injury rates over the 11-year period were found for either training (R(2)=0.000, b=0.000, 95% CI -0.035 to 0.034, p=0.988) or match play (R(2)=0.282, b=-0.015, 95% CI -0.032 to 0.003, p=0.093). The injury rate has decreased for ligament injuries over the last 11 years, but overall training, match injury rates and the rates of muscle injury and severe injury remain high.

Jump frequency may contribute to risk of jumper's knee: A study of interindividual and sex differences in a total of 11 943 jumps video recorded during training and matches in young elite volleyball players

April 2014


195 Reads

Male sex, total training volume (number of hours per week) and match exposure (number of sets played per week) are risk factors for jumper's knee among young elite volleyball players. However, it is not known whether jump frequency differs among players on the same squad. To examine interindividual and sex differences in jump frequency during training and matches in young elite volleyball players. Observational study. Norwegian elite volleyball boarding school training programme. Student-athletes (26 boys and 18 girls, 16-18 years). Individual jump counts were recorded based on visual analysis of video recordings obtained from 1 week of volleyball training (9 training sessions for boys and 10 for girls, 14.1 h and 17.8 h of training, respectively) and 10 matches (5.9 h for boys (16 sets) and 7.7 h for girls (21 sets). A total of 11 943 jumps were recorded, 4138 during matches and 7805 during training. As training attendance and jump frequency varied substantially between players, the total exposure in training ranged from 50 to 666 jumps/week among boys and from 11 to 251 jumps/week among girls. On average, this corresponded to 35.7 jumps/h for boys and 13.7 jumps/h for girls (Student t test, p=0.002). Total jump exposure during matches ranged between 1 and 339 jumps among boys and between 0 and 379 jumps among girls, corresponding to an average jump frequency of 62.2 jumps/h for boys and 41.9 jumps/h for girls (Student t test, p<0.039). The interindividual differences in jump frequency were substantially greater than any differences observed among player functions. Jump frequency has substantial interindividual and sex differences during training and matches in young elite volleyball players. Total jump volume may represent a more important risk factor for jumper's knee than total training volume, warranting further research attention.

Figure 1 
Table 1 Operational definitions used in the study
Figure 2 
Recurrence of Achilles tendon injuries in elite male football players is more common after early return to play: An 11-year follow-up of the UEFA Champions League injury study

June 2013


1,858 Reads

Background There is limited information about Achilles tendon disorders in professional football. Aims To investigate the incidence, injury circumstances, lay-off times and reinjury rates of Achilles tendon disorders in male professional football. Methods A total of 27 clubs from 10 countries and 1743 players have been followed prospectively during 11 seasons between 2001 and 2012. The team medical staff recorded individual player exposure and time-loss injuries. Results A total of 203 (2.5% of all injuries) Achilles tendon disorders were registered. A majority (96%) of the disorders were tendinopathies, and nine were partial or total ruptures. A higher injury rate was found during the preseason compared with the competitive season, 0.25 vs 0.18/1000 h (rate ratio (RR) 1.4, 95% CI 1.1 to 2.0; p=0.027). The mean lay-off time for Achilles tendinopathies was 23±37 (median=10, Q1=4 and Q3=24) days, while a rupture of the Achilles tendon, on average, caused 161±65 (median=169, Q1=110 and Q3=189) days of absence. Players with Achilles tendon disorders were significantly older than the rest of the cohort, with a mean age of 27.2±4 years vs 25.6±4.6 years (p<0.001). 27% of all Achilles tendinopathies were reinjuries. A higher reinjury risk was found after short recovery periods (31%) compared with longer recovery periods (13%) (RR 2.4, 95% CI 2.1 to 2.8; p<0.001). Conclusions Achilles tendon disorders account for 3.8% of the total lay-off time and are more common in older players. Recurrence is common after Achilles tendinopathies and the reinjury risk is higher after short recovery periods.

Top-cited authors