bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative analysis of patellar tracking for screening of lateral patellar instability in adolescent population
Authors: Tsuda E , Ishibashi Y , Yamamoto Y , Maeda S , Kimura Y , Sasaki S
Published: March 2011

Background

The incidence of lateral patellar dislocation becomes higher with increased participation in sports activities in adolescence. A screening test to diagnose asymptomatic lateral patellar instability could be useful for prevention of the sports-related patellar dislocation, however, has not been established.

Objective

To quantitatively analyze patellar tracking in the adolescent population using a video system.

Design

Cross-sectional study.

Setting

Healthy students participating sports activities in 2nd year junior high school.

Participants

38 female and 49 male students with no past traumatic history or complaints of the knees.

Assessment of risk factors

The subject was seated on a testing table with reflective markers placed on the medial and lateral femoral condyles (knee markers). To identify the medial and lateral edge of patella, the examiner pinched the patella with the thumb and index finger with reflective markers attached to the finger tips (patellar markers). The subject actively extended the knee from 90° to full extension, and the examiner followed the patella. A frontal view of knee joint was recorded with a digital video camera.

Main outcome measurements

The patella position was defined as patellar lateral index (PLI), which was a percentage of the distance from the medial knee marker to the midpoint of the medial and lateral patellar markers divide by the distance between the medial and lateral knee markers. The PLI at 0% and 80% of extension phase (approximately 90° and 20° of flexion) was determined.

Results

The average PLI was 57.0 ± 2.8% and 55.7 ± 4.1% at 0% and 80% of extension phase, respectively. Four students showed patellar lateral shift with more than 5% increase in PLI according to the extension.

Conclusion

The excessive increase in PLI at the knee extension might be a risk factor for the patellar dislocation. Follow-up study is required to determine the relationship between PLI and the clinical presence of patellar instability.
Compliance with an injury prevention program in dutch adult male amateur soccer
Authors: van Beijsterveldt A , Krist M , van de Port I , Backx F
Published: March 2011

Background

Compliance with and attitudes towards injury prevention programs, like ‘The11’ (from FIFA), can influence the effectiveness of such programs.

Objective

The aim of this study is to monitor the use of the ‘The11’ during practice sessions in one season and to determine opinions of coaches and players concerning this program.

Design

This study is part of a cluster-randomised controlled trial on the effectiveness and cost-effectiveness of ‘The11’.

Setting

First class amateur teams from one district in the Netherlands participated in this study. They all had practice sessions 2–3 times a week.

Participants

Male players aged 18–40 years were eligible for inclusion in the study. 10 teams, including 212 players, participated and were followed for one season (September 2009–June 2010).

Intervention

The participating teams were instructed to perform ‘The11’, during each practice session throughout the season.

Main outcome measurements

Compliance of all players was registered each session by the coaches. At the end of the season coaches as well as players were asked to fill in a questionnaire to assess their attitudes towards ‘The11’ and injury prevention in general.

Results

Preliminary results show that teams completed ‘The11’ in 81% of all practice sessions and players in 84% of the sessions they attended.

All the coaches (n=12) stated that including injury prevention in the practice sessions is important. 53% of the players returned their questionnaire (n=110). Of them 54.8% was moderately to highly motivate to perform ‘The11’ during each practice session. On average a third of the players mentioned every exercise as ‘boring’. Coaches and players believed that ‘bench’, ‘sideways bench’ and ‘hamstrings’ are the most important three (from 10) exercises to prevent soccer injuries.

Conclusion

More extensive results of this study are expected in February 2011. Also the correlations between compliance, attitudes and injuries can be presented in Monaco.
Epidemiology of illness during the super 14 rugby tournament – a prospective cohort study
Authors: Schwellnus M , Derman W , Lambert M , Redhead C , Page T
Published: March 2011

Background

There is some evidence suggesting that medical illness can account for a significant proportion of consultations by a team physician travelling with a group of elite athletes. The Super 14 Rugby tournament is conducted over a 3 months period and involves intercontinental travel.

Objective

The purpose of this study was to determine the incidence of medical illness in rugby players participating in the 2010 Super 14 Rugby tournament.

Setting

2010 Super 14 Rugby tournament.

Participants

A cohort of elite rugby players from eight Super 14 rugby teams (average squad size of 30 players) was recruited.

Assessment

All players completed a pre-competition questionnaire pertaining to personal details, training history, personal general medical history and medication. Players were then followed daily over the 3 month competition period (total of 20 836 player days). Team physicians completed a daily medical illness and treatment log using a newly developed illness coding system based on the ICD10 codes (100% compliance). Information included the daily squad size and illness details (system affected, final diagnosis, symptoms, treatment and training/match days lost).

Main outcome measurement

Incidence of illness (illness per 1000 player days).

Results

The overall incidence of illness in the cohort was 21.4 per 1000 player days. The highest incidence (per 1000 player days) of illness by system was in the respiratory system (6.6), gastro-intestinal system (5.9) and the dermatological system (4.7). Respiratory tract illness accounted for 31% of all illness followed by the gastro-intestinal system (28%) and the dermatological system (22%).

Conclusion

Medical illness is common in elite rugby players participating in an international tournament over a 3-month period. Respiratory tract, gastro-intestinal tract and dermatological illness accounted for over 80% of these illnesses.
Kinematics of lumbar spine motion in rowing during a fatiguing protocol: a comparison of ergometer and boat rowing
Authors: Wilson F , Simms C , Gormley J , Gissane C
Published: March 2011

Background

The incidence of lumbar spine injury is high. Ergometer rowing and fatigue have been cited as risk factors for this injury.

Objective

Compare the kinematics of the lumbar spine in rowers on an ergometer and a sculling boat during a fatiguing protocol.

Design

Lumbar spine kinematics were assessed in the sagittal plane using a twin axis electrogoniometer.

Setting

A laboratory and field based study of elite level rowing.

Participants

19 male rowers, mean age 24.2 (3.7) years, mean weight 82.5 (8.4) kg and height 1.88 (0.05) m.

Assessment of risk factors

Maximum range of lumbar flexion was measured before each test. Sagittal plane lumbar spine angular kinematics were measured during an ergometer rowing trial which comprised of an incremental ‘step test’ on a Concept 2 ergometer. The trial was repeated in a sculling boat on the water.

Main outcome measurements

Pre-test maximum flexion and maximum lumbar flexion during each test were compared. Mean sagittal flexion in the lumbar spine during the first and last stage of the step test was compared. The findings of ergometer and boat rowing were compared.

Results

Maximum sagittal flexion was 113% (15.2) of pre-test range during ergometer rowing and 104.1% (10.2) during boat rowing. Lumbar flexion increased over the course of testing. Increase in lumbar flexion was significantly greater on the ergometer (mean change+4.4°(0.85)) compared with the boat (mean change+1.3°(1.1)), (mean difference 3.1, 95% CI 0.3 to 5.9, t=2.28, p=0.035).

Conclusion

Rowers experience a very high level of lumbar spine flexion which increases over the course of a rowing trial. Ergometer rowing results in significantly greater increases in sagittal motion in the lumbar spine compared to boat rowing.
Determination of the prevalence of bronchial asthma (BA) and development of an effective protocol to detect BA in japanese elite athletes
Authors: Dohi M , Komatsu Y , Yamasawa F , Akama T , Watanabe K , Hasegawa A , Hirashima M , Fujita Y , Ota K , Kawahara T
Published: March 2011

Background

The prevalence of bronchial asthma (BA) including exercise-induced bronchoconstriction (EIB) and airway hyperresponsivenss (AHR) is increasing not only among normal population but also among athletes and prevention of these attacks are just as life saving and crucial for the athlete. The negative impact on athletic performance and the effect of inhaled corticosteroids and ƒÀ2-agonists are factors to providing prevention strategies in these athletes.

Objective

To determine the prevalence of BA (including silent BA) and develop an effective protocol to detect BA and provide preventive measures in elite athletes.

Methods

Asthma questionnaires and spirometry were conducted for all regardless of their clinical history. Bronchodilator tests were administered to those who met our criteria of past history, suspicious symptoms, values of FEV1%, and concave shape of flow-volume curves. Bronchial provocation tests were held to detect EIB and AHR in some athletes with suspicious symptom. IOC-criteria were used to consider those tests to be positive. Diagnosis of BA was made by consideration of all factors.

Participants

347 male and 305 female Japanese elite athletes participating at the Beijing Olympic Games 2009 and the Vancouver Olympic Games 2010.

Main outcome measurements

Detecting BA and silent BA is important to prevent BA attacks and begin early intervention strategies in elite athletes in view of their performance and doping violence.

Results

21 athletes met IOC criteria in bronchodilator test. The provocation test was positive for asthma in four cases. The prevalence of BA among Japanese elite athletes was 12.1%. Number of Asymptomatic athletes diagnosed as BA reached to 2.9%.

Conclusion

The prevalence of BA among Japanese elite athletes is similar to prevalence of athletes reported and our protocol can sufficiently detect BA and silent BA as well.
Are kinetic chain rowing exercises relevant in shoulder and trunk injury prevention training?
Authors: De Mey K , Danneels L , Cagnie B , Cools A
Published: March 2011

Background

Recent guidelines emphasise the importance of functional kinetic chain exercises during injury prevention training. Knowledge of muscle activation levels during various unilateral rowing exercises is lacking.

Objective

To describe and compare the activation levels of scapulothoracic and lumbopelvic muscle parts during eight variations of the high rowing exercise.

Design

Descriptive study. Exercise performance was standardised and individualised based on height, age and body weight.

Setting

Controlled laboratory study at Ghent University (Belgium).

Participants

30 young healthy volunteers with a history of being active in sports and able to perform the exercises correctly.

Interventions

Activation levels of the upper trapezius (UT) and lower trapezius (LT) muscles of the dominant shoulder, and multifidus (MF) and erector spinae (ES) muscles at both sides of the trunk were investigated. Exercises were performed in front of a pulley apparatus.

Main outcome measurements

Individual muscle activation levels captured by surface Electromyography.

Results

Shoulder muscle activation was characterised by superior LT (>12.5% MVIC) over UT (<7.12% MVIC) muscle activation across exercises. Rowing in a static unipedal squat position revealed highest LT muscle activation (18.33% MVIC). Upright exercises (squatted or lunged) showed generally higher trunk muscle activation levels compared to a sitting or standing execution. Superior MF (>21% MVIC) over ES (<30.13% MVIC) muscle activation was found during all upright exercises, except during static bipedal squatting. Highest MF muscle activation was found heterolateral to arm movement during the dynamic single leg squat version of the exercise (33.26% MVIC; p<0.05).

Conclusion

High rowing exercises recruit posterior shoulder and trunk muscles relevant in injury prevention training. Unilateral rowing during a single leg squat position or movement seems most favourable for athletic injury prevention training purposes.
Spondylolysis decreases sports performance in sumo wrestlers – radiological changes of lumbar spine in high school and collegiate sumo wrestlers
Authors: Nakagawa Y , Mukai S , Hattori Y , Nakamura T
Published: March 2011

Background

Sumo has long been a traditional sport in Japan, and recently is becoming a popular sport that is rapidly attracting enthusiasts abroad. With the aim of having the sport included in the Olympics, World Women Sumo Championships as well as World Sumo Championship have also been held since 1999. In October 2010, these Championships will be held in Poland.

Objectives

The purpose of this study was to examine the radiological changes in the lumbar spine in freshman collegiate and high school sumo wrestlers and the relationship between the radiological changes and the lumbar spine symptoms.

Design

Epidemiology.

Setting

High school league and elite division.

Participants

We examined 78 freshman collegiate and 16 high school sumo wrestlers who belonged to the Japanese Sumo Federation. They were high level players.

Interventions

They underwent routine radiographic examination of their lumbar spine and questionnaire of their lumbar symptoms as a medical check.

Results

Their mean height was 175.3 cm, weight was 113.8 kg, body mass index (BMI) was 37.0 kg/m2, and sumo career was 7.9 years in college. High school sumo wrestlers were significantly smaller than collegiate ones in weight, BMI and sumo career. 10 high school wrestlers (62.5%) and 43 collegiate ones (55.1%) had some lumbar symptoms. Seven high school wrestlers (43.8%) and 25 collegiate ones (32.1%) had deformities of lumbar spine. No significant difference existed during two groups in the above phenomena. However, the occurrence rate of spondylolysis in high school wrestlers (31.3%) was significantly larger than collegiate ones (11.5%). The correlation between spondylolysis and lumbar symptoms was significant. Therefore, it may be indicated that sumo wrestlers give up to continue this sport because of symptomatic spondylolysis.

Conclusion

Early detection and treatment of spondylolysis is needed because it may decrease sports performance in sumo wrestlers.
The relationship between physical game demands and injury rehabilitation in international rugby union: a global positioning system analysis
Authors: Coughlan G , Green B , Pook P , Toolan E , O'Connor S
Published: March 2011

Background

Over the past 10 years the methodologies and technology of recording professional rugby union game data has greatly improved with global positioning system (GPS) now the gold standard.

Objective

The aims of the present study were to evaluate the physical demands of the game at an international rugby union level using a GPS and establish the potential of the system in providing feedback to the management (sports medicine and coaching) team in relation to the mechanism/prevention of injury, as well as rehabilitation and exercise load prior to return to play.

Setting

International rugby union team.

Patients

Two international rugby union players were recruited to participate in this investigation.

Interventions

GPS data generated by the two players (one forward and one back) in an international test match were analysed,

Main outcome measurements

Specifically speed zones and bodyload sustained in tackles and scrum activities.

Results

The back covered a greater overall distance compared to the forward. The forward had a higher number of entries into the low speed zones of standing/non-purposeful movements and walking with fewer entries into the high-intensity running and maximal speed running. Work-to-rest ratios were identical for both players over the course of the game. The forward player sustained a significantly higher number of impacts and total bodyload. Total and average bodyload in tackles made were larger for the back, with this trend reversed for tackles against.

Conclusion

GPS data provides important performance indicators, assists in the development of conditioning and training protocols, as well as injury management and return to play criteria for players. This information should be utilised to identify injury prevention strategies and game characteristics, as well as improving player welfare.
Prevalence of jumper's knee among non-elite athletes from different sports; a cross-sectional survey
Authors: Zwerver J , Bredeweg SW , van den Akker-Scheek I
Published: March 2011

Background

The jumper's knee (JK) is a difficult-to-treat overuse injury of the patellar and quadriceps tendon with a very negative impact on the careers of many athletes. The prevalence of JK among non-elite athletes from different sports and its aetiology are unknown.

Objective

To determine the prevalence of JK in non-elite athletes from different sports and to determine potential risk factors for JK.

Design

Cross-sectional survey.

Setting

Male and female non-elite athletes.

Participants

We interviewed 891 male and female non-elite athletes from seven popular sports in the Netherlands: basketball, volleyball, handball, korfball, soccer, field hockey and athletics.

Assessment

Using a specially developed questionnaire, information was obtained about individual characteristics (age, height and weight), training background, previous and actual knee problems and the VISA-P score.

Results

The overall prevalence of current JK was 8.5% (78 out of 891 athletes), showing a significant difference between sports with different loading characteristics and playing surfaces. Prevalence was highest among volleyball players (14.4%) and lowest among soccer players (2.5%); it was significantly higher among male athletes (51 out of 502, 10.2%) than female athletes (25 out of 389, 6.4%) (÷2=3.91, p=0.048). Mean duration of symptoms was 18.9 months (SD 21.6; range 2.0–59.8). The mean VISA-P score of the athletes with JK was 71.4 (SD 13.8). Age, height and weight were significantly different between athletes with JK and those without.

Conclusion

Prevalence of JK is high among non-elite athletes and varies between 14.4% and 2.5% for different sports. JK is almost twice as common among male non-elite athletes compared to female athletes. Different sport-specific loading characteristics of the knee extensor apparatus, playing surface, age, height and weight seem to be risk factors associated with patellar tendinopathy.
Epidemiology of patellar tendon injury in elite male soccer players
Authors: Hägglund M , Waldén M , Zwerver J , Ekstrand J
Published: March 2011

Background

Patellar tendon injuries are common in jumping sports. The epidemiology in soccer is not well described.

Objective

To study the epidemiology of patellar tendon injury in elite male soccer players and evaluate potential risk factors.

Design

Prospective cohort study.

Setting

Men's professional soccer.

Participants

51 European elite soccer clubs (2229 players) from three different cohorts; Swedish First League and Union of European Football Associations (UEFA) Champions League cohorts playing at home grounds with natural grass, and UEFA Artificial Turf cohort playing on third generation artificial turfs, were followed between 2001 and 2009 over a varying number of seasons.

Assessment of risk factors

Internal (age, stature, body mass) and external (total exposure, training/match exposure ratio, team home surface, seasonal distribution, playing position) risk factors were investigated using multivariate logistic regression.

Main outcome measurements

Patellar tendon injury (insidious onset tendinopathy or acute partial rupture) leading to time-loss from soccer.

Results

139 patellar tendon injuries were recorded (1.5% of all injuries) with an incidence of 0.12 injuries/1000 h and a season prevalence of 2.4%. Most injuries (60%) were minimal to mild (<8 days absence), and 19% were recurrent complaints. No difference in season prevalence (OR 0.96, 95% CI 0.62 to 1.48) or incidence (RR 1.22, 95% CI 0.84 to 1.77) was observed between teams playing on artificial turf and natural grass. Multivariate logistic regression showed that high total exposure hours (OR 1.02 per 10 h increase; 95% CI 1.00 to 1.04) and increased body mass (OR 1.16 per 5 kg increase; 95% CI 1.00 to 1.34) were significant risk factors for patellar tendon injury.

Conclusion

Although mainly mild in nature, patellar tendon injuries are fairly common in elite soccer and the recurrence rate is high. Exposure to artificial turf did not increase the risk of injury. Increased body mass and high total amount of exposure were identified as risk factors for patellar tendon injury.
Sidestep cutting technique affects knee valgus loading
Authors: Kristianslund E , Krosshaug T
Published: March 2011

Background

Anterior cruciate ligament (ACL) injuries pose serious short and long term consequences for athletes in team sports worldwide. Modifying technique is an important part of effective prevention programs, but the understanding of which technique that reduces potentially harmful joint loadings is limited. Prevention can likely be improved with better knowledge of technique effects.

Objective

Study the effect of sidestep cutting technique on knee valgus moments.

Design

Cross-sectional.

Setting

Three sidestep cutting manoeuvres to each side in a 240 Hz motion analysis lab.

Participants

131 female elite handball back and wing players (22.4±4.0 years, 173±6 cm, 69±7 kg). Two excluded due to technical problems.

Assessment of risk factor

Initial contact (IC) knee flexion, knee valgus, hip abduction, ankle pronation, torso lateral flexion, torso rotation, speed of torso rotation, inward rotation of foot relative to direction of motion and lateral distance from centre of mass of the body to the centre of pressure of the foot, as well as length of contact phase, cutting angle and approach speed.

Main outcome

Maximum knee valgus moment during first 50 ms of contact phase.

Results

Average maximum valgus moment was 1.54 ± 0.64 Nm/kg. Six variables had a pronounced effect in the linear regression model. An increase of knee valgus angle at IC of one SD gave a 0.20 Nm/kg (13%) increase in maximum valgus moment. Corresponding effect sizes was 0.14 Nm/kg (9%) for hip abduction, 0.22 Nm/kg (14%) for ankle pronation, 0.12 Nm/kg (8%) for cut width, 0.16 Nm/kg (10%) for cutting angle and 0.21 Nm/kg (14%) for approach speed.

Conclusion

We have identified potentially harmful sidestep cutting technique components. ACL injury prevention programs should continue to focus on cutting techniques with small knee valgus angles, low ankle pronation and narrow stance, particularly for cuts that are performed with high approach speed and sharp direction changes.
Soccer and futsal injuries in the netherlands
Authors: van Hespen A , Stege J P , Stubbe J H
Published: March 2011

Background

Participation in sports has beneficial effects on health. Unfortunately there are also negative effects due to sports injuries. The number of sports injuries in the Netherlands is about 3.6 million every year. A lot of those injuries occur during soccer. TNO developed a web-Based Injury information System (BIS) to study sports injuries.

Objective

To study the incidence, location, severity and risk factors of professional soccer and futsal injuries.

Design

In soccer a prospective cohort study was carried out by means of web-based information gathering. Data on background, injuries and recovery were registered during the season by the medical staff. A retrospective cohort study was carried out in futsal. Same data were collected by means of a self-administered questionnaire for the players.

Setting

Three cohorts of players were followed during one season: professional male soccer (2007), professional female soccer (2007–2008) and premier league male futsal (2009–2010).

Participants

1.039 elite male soccer players, 118 elite female soccer players and 77 elite male futsal players.

Outcome measurements

Incidence, location, type, re-injury, overuse/trauma, duration of injuries. An injury was defined as physical complaints caused by soccer/futsal and resulting in a time loss from soccer/futsal of at least 1 day.

Results

Male soccer: 965 injuries, incidence 5.9, knee 20%, sprain/ligament 20%, 15% re-injury, 67% trauma, average duration 34 days.

Female soccer: 125 injuries, incidence unknown, knee 22%, sprain/ligament 32%, 16% reinjury, 73% trauma, average duration 21 days.

Male futsal: 58 injuries, incidence 3.1, ankle 38%, sprain/ligament 38%, 41% re-injury, 74% trauma, duration: 27% more than 4 weeks.

Conclusions

The rate of injuries among professional (fe)male soccer and premier league male futsal is high. Results for male and female soccer are in general comparable but different from results for futsal. BIS provides sports leagues with information that might help to improve their prevention management.
Practice injury rates in collegiate sports
Authors: Agel J , Schisel J
Published: March 2011

Background

Published data has demonstrated that collegiate athletes sustain significantly higher game than practice injury rates (13.8 vs 4.0 injuries per 1000 A-Es). Review of this data demonstrates disparities within the practice injury rates with pre-season practice injury rates being significantly higher than in-season and post-season practice rates.

Objective

Our a priori primary hypothesis was that Fall sports would show the largest differential in pre-season compared to in-season practice injury rates. Our secondary hypothesis was that Division I would report higher rates of pre-season practice injury rates compared to Divisions II and III.

Setting

National Collegiate Athletic Association (NCAA).

Participants

250 NCAA Injury Surveillance System participating schools with 182 000 injuries with 1 300 000 exposures.

Assessment of risk factors

The dependent variables are sport, season and division.

Main outcome measure

The independent variable is injury; defined as time loss of 1 day or more from a scheduled athletic activity.

Results

Pre-season practice consistently resulted in the highest injury rates across all Divisions regardless of season. Men's football (Fall) had the highest rate ratio of pre-season to in-season practice injury (3.47 (3.40, 3.54)). Men's and Women's soccer (Fall) were next (3.28 (3.11, 3.45), 3.27 (3.09, 3.45). Women's Division 1 soccer, had the greatest differential between pre-season and in-season practice injury as well as the highest pre-season practice injury rate for all sports except Division 1 men's wrestling (Winter). There was no consistent injury pattern demonstrated across season when sports were analyzed by Division.

Conclusion

Pre-season practices are responsible for a disproportionate share of practice injuries. Fall sports demonstrate the highest within sport practice injury rates. Attention should be paid to this finding in order to ensure that practices are conducted in a safe manner for the athletes and all potential injury prevention options taken advantage of.
Cost-effectiveness of an injury prevention program in dutch male amateur soccer
Authors: van Beijsterveldt A , Krist M , van de Port I , Backx F
Published: March 2011

Background

Approximately 16% of all sports injuries in the Netherlands are the result of playing outdoor soccer.

Objective

The aim of this intervention study is to investigate the cost-effectiveness of an injury prevention program (‘The11’ from FIFA) in male amateur soccer players. The hypothesis is that the ‘The11’ exercises have a beneficial effect on injury incidence, injury severity, medical costs and/or absenteeism.

Design

The study is a two-armed cluster randomised controlled trial. Randomisation has taken place on a cluster level: the regional competitions.

Setting

First class amateur teams, in two separated districts in the Netherlands, participate in this study. All participating teams have practice sessions 2–3 times a week.

Participants

Male players aged 18–40 years were eligible for inclusion in the study. 22 teams participated in this study, resulting in 460 players performing an intake at the start of the intervention season (intervention group 214 players, control group 246 players).

Intervention

The teams in the intervention group were instructed to perform ‘The11’, during each practice session throughout the 2009–2010 season (September–June). All teams of the control group were asked to continue their practice sessions as usual.

Main outcome measurements

The primary outcomes of the study include injury incidence, healthcare use and absenteeism. These outcomes were registered online during the competitive season 2009–2010.

Results

Preliminary results show that the proportion of injured players was almost equal for both groups (58.9% vs 57.7%). The injury risk for both research groups was the same (0.92). The sports absenteeism was on average 1 day longer in the intervention group (30.3 vs 29.3 days).

Conclusions

First impression is that there are no significant differences between the two research groups. However, more extensive results of this study, particularly focused on possible confounders and cost-effectiveness, are expected in January 2011 and can be presented in Monaco.
Measurement of activity return after injury
Authors: Agel J , Harvey E
Published: March 2011

Background

Injury results in a limitation of activity participation. Treatment of injury is designed to return the patient to as a high level of activity as desired.

Objective

To design an activity measure that allows clinicians to:

Determine patients' pre-injury preferred activities, level of participation, intensity, and frequency of participation.

Determine patients' recovery level of participation, intensity, and frequency of participation in the pre-injury preferred activities.

Determine if the patients' lack of full return to activity is due to the injury or to other reasons external to the injury.

Setting

Orthopaedic community based clinics.

Participants

Patients with musculoskeletal complaints.

Intervention

Treatment of injury.

Main outcome measure

The composite of the patients' current activity participation, level of limitation, and reason for limitation.

Results

Favourite/Most Important Activity

Q1 What is this activity?

Prior to Your Injury

Q2 Prior to your injury:

A How long would you normally participate in this activity?

|__|__| Hours per Time

B On average how many days a week would you participate in this activity?

|__| Days per Week

Current Time

Q3 Do you still engage in this sport or activity?

1 □ Yes

2 □ No

Q4 How much is your ability to participate in this activity limited by your injury?

0 1 2 3 4 5 6 7 8 9 10

None Completely

If None (0) (Go to Q6 – top of next column)

If Limited (1–10) continue with Q5

Q5 What is the primary reason you are limited in this sport or activity anymore?

1 □ Your Injury

2 □ Other Reason –Describe:

Conclusion

This measure allows clinicians to track return to activity over time and understand if the decision to return to pre-injury activity is due to the injury or life events.
First time lateral patella dislocations: characterizing their readiness for return to activity
Authors: Arendt E , Agel J , Moore A
Published: March 2011

Background

There are no accepted objective criteria for return to activity after a first time lateral patella dislocation.

Objective

To define the characteristics of first time lateral patallofemoral dislocation (PFD) patients and their timeline for return to activity.

Design

Prospective observational.

Setting

University and private clinic.

Patients

31 patients were identified between Sept 2008 and 2010; confirmed by MRI (87%) or requiring reduction maneouver (13%). 23 agreed to non-operative treatment and structured physical therapy. Activity level was recorded.

Intervention

The independent variable was redislocation.

Results

There were 15 males and 16 females. Average age was 20. The majority of injuries occurred playing sports and were non-contact (70%).

The 23 patients all returned to full activity with no time off to nine months. 12 had no re-dislocations at 1 year. One re-dislocation occurred in a 15 year old male at 18 months. 10 patients had formal clearance for a full return to activity. Seven patients completed physical therapy.

KOOS data demonstrated minimal change between time of injury and month 3, and no change between 6 and 12 months.

Conclusion

All patients were on a structured physical therapy program with clearly defined functional parameters for return to activity. Most patients choose not to complete therapy and used self defined parameters for return to activities. Follow up indicates that most returned to previous level of function without known adverse sequelae.

This high rate of non-compliance with physical therapy and lack of physician clearance prior to return to activity is disconcerting. There is a disparity between the clinician's and patient's perceived seriousness and need for time off and rehabilitation.

KOOS outcome tool may not be capturing the disability associated with lateral PFD.

More attention is warranted to optimise management of this injury, to better understand the degree of impairment and timing of safe return.
A prospective study of injury in elite gaelic games
Authors: Blake C , Murphy J C , Gissane C , O'Malley E
Published: March 2011

Background

Gaelic football and hurling are the national sports of Ireland. They are both high velocity, multidirectional, contact field games. To date, prospective injury data for these has been of short duration.

Objective

To describe the incidence and nature of sport-related injuries in elite male Gaelic football and hurling players over a 3 year period.

Design

Prospective observational study.

Setting

Elite-level county representative teams.

Participants

16 male football and 16 hurling teams were tracked over the 2007–2009 seasons.

Assessment of risk factors

New injury diagnoses and classifications were recorded by the team physiotherapist or doctor onto the National GAA Injury Database, along with injury history and weekly team exposure to training and match hours.

Main outcome measures

Injury was defined as requiring 24 h time loss from training or match-play. Incidence rate was calculated as injuries/1000 h training and match-play.

Results

A total of 788 football and 671 hurling injuries were recorded. Incidence of injury/1000 h football training was 5.34 (2007), 3.67 (2008) and 3.37 (2009) and 5.13 (2007), 3.69 (2008) and 2.8 (2009) for hurling. Match-play injury rates were 97.0, 79.09 and 50.4/1000 h of football and 96.0, 87.4 and 46.5/1000 h of hurling. Lower limb injuries predominated (football: 74.2% to 76.7%; hurling: 68% to 70.5%). Hamstring injuries were the single most common injury overall (football: 17.4% to 25%, hurling: 15.7% to 16.5%). Upper limb injuries accounted for 9.2% to 14.7% of all football injuries and 16.6% to 24% of all hurling injuries. Muscle was the most frequently injured tissue (football: 38.3% to 45.8%; hurling: 35.5% to 42.2%) and fractures accounted for 3.3% to 5.3% football injuries and 6% to 7.9% hurling injuries.

Conclusion

These findings illustrate injury patterns in Gaelic football using a prospective methodology over consecutive seasons, thus providing a baseline from which injury prevention strategies can be evaluated.
Dutch elite athletes and anti-doping policies
Authors: de Hon O , Eijs I , Havenga A
Published: March 2011

Background and Objective

Anti-Doping Authority Netherlands, the official NADO of the Netherlands, evaluates periodically the knowledge, opinions, and attitudes of Dutch elite athletes on various anti-doping matters.

Design and participants

A total of 888 elite athletes, as acknowledged by National Olympic Committee NOC*NSF, were asked to fill out an anonymous, internet based, 83-item questionnaire. In addition, 453 professional football players (who have no traditional ties with the NOC) were selected from the database of the VVCS, the national representative organisation for professional soccer players. The study was conducted with the cooperation of NL Sporter, the independent association for elite athletes.

Results

A representative response of 38% for Olympic athletes was achieved; among soccer players the response was indicative at 21%.

The whereabouts-rule is the most controversial anti-doping rule for all athletes: 61% has experience with filing whereabouts data, but less than 20% finds it necessary to file such data in their own sport. One in three athletes regularly experiences problems with fulfilling their whereabouts requirements, undermining the support of this rule. Testing itself is less controversial: more than half of all athletes support the principle of Out-of-Competition testing. Of all athletes, 91% would feel guilty if they would use doping themselves. Athletes' knowledge about the Prohibited List and about doping regulations is good (7.1 to 8.8 on a scale of 0 tot 10). Athletes would favour better international harmonisation, more educational opportunities and more anti-doping training for their support personnel.

Conclusions

Technical improvements in whereabouts software are still necessary, and different ways should be explored to alleviate the burdens laid upon elite athletes without compromising the effectiveness of an out-of-competition testing programme. The knowledge on doping issues should be maintained, but more personal ways to accommodate for specific individual questions during educational meetings should be considered. Educational efforts for Football players should be strengthened.
New measurements of rearfoot, forefoot and shank-forefoot alignment in athletes
Authors: Mendonça L D , Bittencourt N F N , Amaral GM , Diniz L , Souza TR , Silva PL , Fonseca S T
Published: March 2011

Background

Foot misalignments may contribute to development of sports injuries. Some evaluation protocols of foot alignment are not practical, have poor reliability and doesn't reflect functional foot behaviour. We propose a new measurement procedure to solve these problems. We also introduce the measure of the alignment of shank relative to shank-forefoot alignment (SFA) that may be practical to assess the combined rearfoot and forefoot alignments.

Objective

to develop a practical and reliable foot alignment measure.

Design

observational cross-sectional.

Setting

all testing took place in the Minas Tênis Club and Sports Injury Prevention and Rehabilitation Laboratory – LAPREV in youth and elite sports.

Participants

75 females and 125 male (mean+SD age, 15.6+3.8; height, 151.1+62.8; body mass, 64.53+14.9) athletes were evaluated in this study (n=200). Participants with a history of congenital deformity or lower-extremity surgery in the previous 6 months were excluded.

Assessment: Shank bisection and four calcaneus marks were drawn according to the standardised parameters. A metal rod was fixed under the forefoot, the ankle was actively positioned at 90° of dorsiflexion and a picture was taken. SIMI motion 2D was used to measure the rearfoot (relative to shank), forefoot (relative to rearfoot) and SFA angles.

Main outcome measurements

rearfoot, forefoot and SFA angles.

Results

The Intraclass Correlation Coefficient (ICC) intratester was 0.89; 0.91 e 0.93 and intertester was 0.82; 0.91 e 0.90 (rearfoot, forefoot and SFA respectively). The means for each foot alignment were −1.83+3.3 (rearfoot), 16.25+8.9 (forefoot) and 13.9+2.6 (SFA). The agreement (ICC) of the sum of rearfoot and forefoot values with SFA was 0.98.

Conclusion

SFA reflects the sum of rearfoot and forefoot alignments, which supports the use of this measure. This protocol is reliable and it is possible to assess one athlete in proximally 5 min. Thus, these measures can be used in preseason assessments of injury risk factors in athletes.
PERPENDICULAR EXCHANGE-BIAS INDUCED BY A DISCONTINUOUS Ru LAYER IN Co90Fe10/Ru/Co90Fe10/FeMn MULTILAYERS
Authors: BAO JIN , XU XIAO-GUANG , LI XIAO-QI , ZHANG DE-LIN , JIANG YONG
Published: March 2011

A series of Co 90 Fe 10/ Ru/Co 90 Fe 10/ FeMn multilayers were fabricated by DC magnetron sputtering. Our results show that the in-plane and perpendicular exchange-bias fields H ex of the multilayers can be controlled by the continuity of the Ru layer. Increasing the continuity of the Ru layer increases the in-plane H ex and decreases the perpendicular one. When the thickness of the Ru layer is 0.5 nm, the perpendicular H ex reaches as high as 682 Oe. The perpendicular exchange-bias induced by a discontinuous underlayer may be applied in future perpendicular anisotropic spin valves or magnetic tunnel junctions.
STRUCTURAL EFFECTS OF SKS ACTIVE CARBON MODIFICATION WITH MELAMINE, STUDIED BY SEM, TEM, EDX AND QUANTUM-CHEMICAL SIMULATIONS
Authors: KHAVRYUCHENKO VOLODYMYR D. , KHAVRYUCHENKO OLEKSIY V. , SHKILNYY ANDRIY I. , LISNYAK VLADYSLAV V. , STRATIICHUK DENYS A.
Published: March 2011

SKS active carbon treated with melamine (SKS-N) was studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray microanalysis (EDX), and quantum-chemical (QC) simulations. The influence of mild oxidation in the structure of the SKS-N and the ways of melamine incorporation into the graphene system of carbon are demonstrated.
TOPOLOGICAL QUANTUM PHASE TRANSITION BETWEEN QUANTUM SPIN HALL STATE AND QUANTUM ANOMALOUS HALL STATE
Authors: LIU LAN-FENG , KOU SU-PENG
Published: March 2011

In this paper, starting from a lattice model of topological insulators, we study the quantum phase transitions among different quantum states, including quantum spin Hall state, quantum anomalous Hall state and normal band insulator state by calculating their topological properties (edge states, quantized spin Hall conductivities, and the number of zero mode on a π-flux). We find that at the topological quantum phase transitions (TQPTs), the topological "order parameter" — spin Chern number will jump. And since the masses of the nodal fermions will change sign, the third derivative of ground-state energy is nonanalytic. In addition, we discuss the finite temperature properties and the stability of the TQPTs.
DYADIC POLYGONS
Authors: MATCZAK K. , ROMANOWSKA A. B. , SMITH J. D. H.
Published: March 2011

Dyadic rationals are rationals whose denominator is a power of 2. Dyadic triangles and dyadic polygons are, respectively, defined as the intersections with the dyadic plane of a triangle or polygon in the real plane whose vertices lie in the dyadic plane. The one-dimensional analogs are dyadic intervals. Algebraically, dyadic polygons carry the structure of a commutative, entropic and idempotent algebra under the binary operation of arithmetic mean. In this paper, dyadic intervals and triangles are classified to within affine or algebraic isomorphism, and dyadic polygons are shown to be finitely generated as algebras. The auxiliary results include a form of Pythagoras' theorem for dyadic affine geometry.
GROUP RINGS OF COUNTABLE NON-ABELIAN LOCALLY FREE GROUPS ARE PRIMITIVE
Authors: NISHINAKA TSUNEKAZU
Published: March 2011

We prove that every group ring of a non-abelian locally free group which is the union of an ascending sequence of free groups is primitive. In particular, every group ring of a countable non-abelian locally free group is primitive. In addition, by making use of the result, we give a necessary and sufficient condition for group rings of ascending HNN extensions of free groups to be primitive, which extends the main result in [Group rings of proper ascending HNN extensions of countably infinite free groups are primitive, J. Algebra317 (2007) 581–592] to the general cardinality case.
ON MODE REDUCTS OF SEMIMODULES
Authors: JABŁOŃSKI BARTOSZ M. , ROMANOWSKA ANNA B.
Published: March 2011

The problem of embedding modes as subreducts into semimodules over commutative semirings raises the question of characterizing those semimodules that may contain modes as subreducts. We initiate a study of such semimodules by providing certain classes of semimodules with this property. First we characterize mode reducts of commutative monoids, showing that they are equivalent to certain ternary algebras coming from the regularizations of varieties of integral affine spaces, and to some n-ary semilattices. Then we generalize these results, characterizing mode reducts of semimodules over commutative unital rings and semirings obtained from them by adding a new zero element.
BASS CYCLIC UNITS AS FACTORS IN A FREE GROUP IN INTEGRAL GROUP RING UNITS
Authors: GONÇALVES JAIRO Z. , RÍO ÁNGEL DEL
Published: March 2011

Marciniak and Sehgal showed that if u is a non-trivial bicyclic unit of an integral group ring then there is a bicyclic unit v such that u and v generate a non-abelian free group. A similar result does not hold for Bass cyclic units of infinite order based on non-central elements as some of them have finite order modulo the center. We prove a theorem that suggests that this is the only limitation to obtain a non-abelian free group from a given Bass cyclic unit. More precisely, we prove that if u is a Bass cyclic unit of an integral group ring ℤG of a solvable and finite group G, such that u has infinite order modulo the center of U(ℤG) and it is based on an element of prime order, then there is a non-abelian free group generated by a power of u and a power of a unit in ℤG which is either a Bass cyclic unit or a bicyclic unit.
APPLICATIONS OF p-DEFICIENCY AND p-LARGENESS
Authors: BUTTON J. O. , THILLAISUNDARAM A.
Published: March 2011

We use Schlage-Puchta's concept of p-deficiency and Lackenby's property of p-largeness to show that a group having a finite presentation with p-deficiency greater than 1 is large, which implies that Schlage-Puchta's infinite finitely generated p-groups are not finitely presented. We also show that for all primes p at least 7, any group having a presentation of p-deficiency greater than 1 is Golod–Shafarevich, and has a finite index subgroup which is Golod–Shafarevich for the remaining primes. We also generalize a result of Grigorchuk on Coxeter groups to odd primes.
MODIFIED HANOI TOWERS GROUPS AND LIMIT SPACES
Authors: MAKISUMI SHOTARO , STADNYK GRACE , STEINHURST BENJAMIN
Published: March 2011

We introduce the k-peg Hanoi automorphisms and Hanoi self-similar groups, a generalization of the Hanoi Towers groups, and give conditions for them to be contracting. We analyze the limit spaces of a particular family of contracting Hanoi groups, [Formula: see text], and show that these are the unique maximal contracting Hanoi groups under a suitable symmetry condition. Finally, we provide partial results on the contraction of Hanoi groups with weaker symmetry.
A CONJUGATION-FREE GEOMETRIC PRESENTATION OF FUNDAMENTAL GROUPS OF ARRANGEMENTS II: EXPANSION AND SOME PROPERTIES
Authors: ELIYAHU MEITAL , GARBER DAVID , TEICHER MINA
Published: March 2011

A conjugation-free geometric presentation of a fundamental group is a presentation with the natural topological generators x1,…,xn and the cyclic relations: [Formula: see text] with no conjugations on the generators.

We have already proved in [13] that if the graph of the arrangement is a disjoint union of cycles, then its fundamental group has a conjugation-free geometric presentation. In this paper, we extend this property to arrangements whose graphs are a disjoint union of cycle-tree graphs.

Moreover, we study some properties of this type of presentations for a fundamental group of a line arrangement's complement. We show that these presentations satisfy a completeness property in the sense of Dehornoy, if the corresponding graph of the arrangement is triangle-free. The completeness property is a powerful property which leads to many nice properties concerning the presentation (such as the left-cancellativity of the associated monoid and yields some simple criterion for the solvability of the word problem in the group).