bluuebunny/crossref_metadata_2025 huggingface dataset:
The estimation of body density in rugby union football players.
Authors: Bell W
Published: December 2008

The general regression equation of Durnin and Womersley for estimating body density from skinfold thicknesses in young men, was examined by comparing the estimated density from this equation, with the measured density of a group of 45 rugby union players of similar age. Body density was measured by hydrostatic weighing with simultaneous measurement of residual volume. Additional measurements included stature, body mass and skinfold thicknesses at the biceps, triceps, subscapular and suprailiac sites. The estimated density was significantly different from the measured density (P < 0.001), equivalent to a mean overestimation of relative fat of approximately 4%. A new set of prediction equations for estimating density was formulated from linear regression using the logarithm of single and sums of skinfold thicknesses. Equations were derived from a validation sample (n = 22) and tested on a crossvalidation sample (n = 23). The standard error of the estimate (s.e.e.) of the equations ranged from 0.0058 to 0.0062 g ml-1. The derived equations were successfully crossvalidated. Differences between measured and estimated densities were not significant (P > 0.05), total errors ranging from 0.0067 to 0.0092 g ml-1. An exploratory assessment was also made of the effect of fatness and aerobic fitness on the prediction equations. The equations should be applied to players of similar age and playing ability, and for the purpose of identifying group characteristics. Application of the equations to individuals may give rise to errors of between -3.9% to +2.5% total body fat in two-thirds of cases.
Implications of health and safety legislation for the professional sportsperson.
Authors: Fuller C W
Published: December 2008

There are a large number of injuries in most professional sports every year, and research interest has usually centred around the medical aspects of these injuries. However, health and safety legislation also applies to professional sport, and it is important, as with any other occupation, to understand the underlying causes of the incidents leading to the injuries and to take steps to minimize future injuries. The introduction of the Management of Health and Safety at Work Regulations 1992 formalized a risk assessment approach to health and safety issues; an approach that has always been implicit in the Health and Safety at Work etc. Act 1974. This review assesses how the relevant UK health and safety legislation impacts on the professional sportsperson.
Validity of conventional anthropometric techniques for predicting body composition in healthy Chinese adults.
Authors: Eston R G , Fu F , Fung L
Published: December 2008

There is little information on the application of generalized prediction equations to ethnic groups other than Europeans and groups of European descent. The purpose of this study was to crossvalidate conventional equations on a group of 56 Chinese adults. Body density was assessed by underwater weighing and also predicted by equations which use a combination of selected skinfolds-biceps, triceps, pectoral, subscapular, abdominal, suprailiac, thigh and calf. There were significant correlations (P < 0.01) between the various methods of predicting percentage fat. However, analysis of variance revealed significant differences (P < 0.01) between mean values. In the men, the Jackson and Pollock equation underestimated, and the Durnin and Womersley equation overestimated, the percentage fat predicted by underwater weighing. The best predictor site in this group was the medial calf skinfold (r = 0.81), which is not included in either equation. In the women, the best predictor sites were the triceps, suprailiac and thigh. As these sites are also used in the Jackson et al. equation, it is not surprising that there was no difference between the prediction of percentage fat by this equation and underwent weight. It is concluded that the Durnin and Womersley and Jackson and Pollock equations tend to overestimate and underestimate, respectively, the percentage fat in Chinese men. Alternative equations which use the calf skinfold may be more appropriate for this ethnic group. In Chinese women, there appears to be good agreement between Jackson and Pollock and hydrodensitometric estimations of percentage fat.
Leucocyte and erythrocyte counts during a multi-stage cycling race ('the Milk Race').
Authors: Keen P , McCarthy D A , Passfield L , Shaker H A , Wade A J
Published: December 2008

Venous blood samples were taken from eight competitors in mid-evening after a racing day, and in the early morning before the next day's race, three times during the course of the Milk Race, 1992. These were used to gather information about the changes in circulating leucocyte levels in response to the exceptionally high sustained daily workload required during a major multi-stage race. The primary objective was to provide knowledge of 'normal' values against which future clinical judgements of abnormality might be made in these unusual circumstances. During the race, estimated energy output was about 25 MJ (6000 kCal)/day. The mean total circulating leucocyte numbers (per litre of blood), and those of individual leucocyte classes (neutrophil, lymphocyte, monocyte, eosinophil and basophil) were all inside the normal range both in the morning and in the evening. Evening counts were, however, 30-50% higher than morning counts, for all classes except eosinophils. We conclude that individual clinical decisions about leucocyte levels can best be made using normal (sedentary man) values if a morning sample is taken.
Reproducibility of cardiorespiratory measurements during submaximal and maximal running in children.
Authors: Unnithan V B , Murray L A , Timmons J A , Buchanan D , Paton J Y
Published: December 2008

With the increased use of oxygen consumption measurements in clinical and sporting studies, measurement variability has become more important to both the paediatric clinician and the sports scientist. In this study we assessed the reproducibility of cardiorespiratory measurements during submaximal and maximal running in children. Ten healthy, physically active boys (mean(s.d.) age 10.7(0.71) years) performed two submaximal and two maximal running tests within a 4 week period. The submaximal protocol consisted of three 6 minute runs at 7.2, 8.0 and 8.8 km/h. Every attempt was made to minimize the sources of non-biological variability at each testing session. During submaximal exercise, oxygen consumption (VO2), heart rate (HR) and fractional utilization appeared to be the most reliable measures accounting for over two-thirds of the total variation (coefficients of reliability (CR) of 68%, 94% and 82% respectively). Ventilation (Ve) and respiratory exchange ratio (RER) proved to be only moderately reliable accounting for less than half of the total variation (CR 50% and 45% respectively). At maximal exercise, VO2, Ve and time to exhaustion were most reliable, accounting for approximately two-thirds of the total variation (CR 65%, 63% and 63% respectively). Within this test environment, a two visit submaximal assessment was capable of estimating VO2 with a standard error of +/- 1.25 ml/kg/min. Similarly, for maximal testing a two visit assessment estimated peak VO2 with a standard error of +/- 2.28 ml/kg/min. On the evidence of these results a two visit assessment for submaximal and maximal exercise testing seems adequate to estimate the stability of submaximal cardiorespiratory measures and peak VO2 in healthy, normally active boys.
Chronic ankle instability: the value of talar tilt under general anaesthesia.
Authors: McCaskie A W , Gale D W , Finlay D , Allen M J
Published: December 2008

Ankle inversion injuries are the most common injury in sport and yet treatment is controversial. One result is chronic ankle instability, an injury for which criteria for surgical intervention are unclear. This prospective study of 14 patients showed that a large proportion of patients had no detectable abnormality on preoperative investigation, but were subsequently shown to have an abnormality under general anaesthesia. This suggests that a good history of chronic instability is more sensitive an indicator than conventional investigations. Stress views under anaesthesia may confirm the problem.
Bilateral isokinetic variables of the shoulder: a prediction model for young men.
Authors: So R C , Siu O T , Chin M K , Chan K M
Published: December 2008

Clinicians frequently want to know the pre-injury strength of an uninjured limb. The purpose of this study was to delineate the differences in bilateral isokinetic peak torque (PT) at 60 degrees and 240 degrees, and torque acceleration energy (TAE), average power (AP) and total work (TW) at 240 degrees during shoulder extension and flexion movements, and to develop a method to determine the expected maximal isokinetic variables of the dominant shoulder based upon isokinetic measurements from the non-dominant shoulder. Shoulder isokinetic measurements were obtained from 30 normal young male adults. While bilateral correlation was significant (P < 0.01), results also suggest significant bilateral differences P < 0.01). Thus, it is inappropriate to use the uninjured extremity to predict the pre-injured strength of the injured side without adjustment. In this investigation models were developed relating the expected maximal isokinetic measurement of the dominant shoulder to the non-dominant shoulder measurements.
The mathematical relationship between the number of events in which people are injured and the number of people injured.
Authors: Uitenbroek D G
Published: December 2008

In this paper the mathematical relationship between the number of times people sustained injuries and the number of people injured is discussed. The number of injury-causing events in a population will be larger than the number of people injured as people can be injured on more than one occasion. The Poisson distribution is used as a way to study the relationship between the two different sets of numbers. A practical example is given of injuries sustained while running. From this it seems that injury proneness needs to be considered in studying those who were injured on more than one occasion while running during the past year.
A new gas dilution method for measuring body volume.
Authors: Nagao N , Tamaki K , Kuchiki T , Nagao M
Published: December 2008

This study was designed to examine the validity of a new gas dilution method (GD) for measuring human body volume and to compare its accuracy with the results obtained by the underwater weighing method (UW). We measured the volume of plastic bottles and 16 subjects (including two females), aged 18-42 years with each method. For the bottles, the volume measured by hydrostatic weighing was correlated highly (r = 1.000) with that measured by the new gas dilution method. For the subjects, the body volume determined by the two methods was significantly correlated (r = 0.998). However, the subject's volume measured by the gas dilution method was significantly larger than that by underwater weighing method. There was significant correlation (r = 0.806) between GD volume-UW volume and the body mass index (BMI), so that UW volume could be predicted from GD volume and BMI. It can be concluded that the new gas dilution method offers promising possibilities for future research in the population who cannot submerge underwater.
Surgical repair of traumatic medial disruption of the elbow in competitive athletes.
Authors: Inoue G , Kuwahata Y
Published: December 2008

Five active athletes with acute medial elbow rupture were treated with muscle-ligamentous repair and a spiked washer. All patients regained full strength as well as stability of the elbow, and resumed previous sporting activities within 3 months of surgery. Early surgical repair of the ligament and flexor mass should be considered for active athletes who exhibit gross instability of the elbow on a valgus stress test without anaesthesia.
Traumatic carotid and vertebral artery dissection in a professional jockey: a cautionary tale.
Authors: Fletcher J , Davies P T , Lewis T , Campbell M J
Published: December 2008

Jockeys accept bony fractures and soft tissue injuries as occupational hazards. An average National Hunt jockey falls once in ten races with an injury rate of 4.25%. Head injury is a common cause of morbidity and the benefit of helmets is well recognized. Neck injuries are also common and usually musculoskeletal. Although rare, trauma to the neck arteries may go unnoticed yet have catastrophic consequences. Internal tears can allow arterial blood to dissect the layers of the arterial wall and obstruct the lumen. Severe obstruction may lead to cerebral ischaemia and infarction. An appreciation of the early clinical signs caused by this process may allow effective intervention. We report a case which illustrates these points.
Blood lactate levels of decathletes during competition.
Authors: Beaulieu P , Ottoz H , Grange C , Thomas J , Bensch C
Published: December 2008

There are many detailed physiological profiles of athletes who participate in a wide variety of sporting activities but few data have been obtained on decathletes. This study defines some physiological characteristics of these athletes and measures capillary lactate concentrations [La(b)] during a laboratory test of progressive maximal exhaustion and the different events during competition. The treadmill test is similar to the 100 m, 400 m and 1500 m in terms of [La(b)] accumulation but only similar to the 1500 m in terms of velocity. The 400 m is the most demanding event with the greatest blood lactate accumulation (mean(s.d.) 16.38(2.36) mmol l-1). The [La(b)] at the end of the 110 m hurdles is significantly lower than in any other racing events (mean(s.d.) 6.96(1.32) mmol l-1) compared with mean(s.d.) 12.14(2.87) and mean(s.d.) 11.44(2.16) for the 100 m and 1500 m respectively. The [La(b)] after the long jump, the high jump and the pole vault are not significantly different (mean(s.d.) 5.30(2.23), 4.64(1.39) and 5.36(1.34) mmol l-1) respectively).
Effect of exercise training programme on bone mineral density in novice college rowers.
Authors: Cohen B , Millett P J , Mist B , Laskey M A , Rushton N
Published: December 2008

Exercise has important effects on skeletal mineralization. Changes in bone mineral density (BMD) and bone mineral content (BMC) as measured by dual energy X-ray absorptiometry were investigated in a group of 17 male novice college oarsmen over a 7-month period and were compared with eight age-matched controls. The rowing training programme consisted of approximately 8 h rowing, 1 h weight training, and 1 h running per week. After 7 months training the mean BMD of the lumbar spine (L1-L4) had increased significantly by 2.9% (P < 0.001) and the mean BMC had increased by 4.2% (P < 0.001). There was no significant change in the control group. Neither group showed a significant change in BMD or BMC in the femoral neck, greater trochanter or Ward's triangle. This study provides further evidence that exercise plays an important role in bone mineral formation.
Cardiorespiratory strain of a five day jogging relay.
Authors: Oksa J , Rissanen S , Martikkala V
Published: December 2008

The heart rates of 14 voluntary subjects (seven male and seven females) participating in a 5 d jogging relay were recorded. The jogging speed was controlled at 3.0 m.s-1 on average. The heart rate measurements were related to cardiorespiratory responses obtained during VO2max test on a treadmill. The mean (s.d.) VO2max values were 53(2) and 48(2) ml.kg-1.min-1 and the anaerobic threshold was 42(1) and 38(2) ml.kg-1.min-1 for male and female subjects respectively. During the relay the mean(s.d) heart rate values of male and female subjects were 150(1), and 167(3) beats.min-1 (P < 0.001), corresponding to 68(1) and 76(2)% VO2max (P < 0.01) as calculated from the individual HR/VO2 regression equations. The jogging time above anaerobic threshold heart rate level was 9(3)% for the males and 43(7)% for the females (P < 0.001) of the total jogging time. The results indicate that even in a leisure oriented jogging event, cardiorespiratory strain can be rather high and that the strain can be significantly higher for female than for male subjects. The determination of the anaerobic threshold as well as VO2max is important when quantifying the level of cardiorespiratory strain of exercise.
A quantifiable approach in the comparison of isokinetic assessment data--new correlation equations for the Johnson antishear device and standard shin pad in the isokinetic assessment of the knee.
Authors: Li C K , Chan K M , Hsu Y S , Chien P , Wong W N
Published: December 2008

The rehabilitation of the knee with a deficient anterior cruciate ligament (ACL) always presents a great challenge. Isokinetic assessment allows muscle performance to be quantified. The antishear device, introduced by Johnson, has the distinct advantage of minimizing the anterior translation force during isokinetic exercise. In a previous report, there was a significant difference between the Johnson double pad antishear device and the standard single pad device in knee extension. The main purpose of this study was to define a correlation equation such that data generated in the use of the two different devices can be compared for assessment. Ten subjects were tested with the Cybex isokinetic dynamometer with a randomly selected sequence of test speeds. Correlation coefficient (r), regression analysis and paired t tests (P) were performed to estimate the correlation and difference between the two devices. It is concluded that a significant difference in the data generated between the two devices indicated that a single device should be selected to carry out a series of comparisons on a particular subject. However, if the two devices are used in a series of testings, a set of correlation equations has been defined to facilitate such comparison. The findings in this study will widen the application of comparison of isokinetic data in the quantitative approach of rehabilitation of the knee with a deficient anterior cruciate ligament.
A field study of the ventilatory response to ambient temperature and pressure in sport diving.
Authors: Muller F L
Published: December 2008

This study reports on the relationship between minute ventilation (VE) and environmental variables of temperature (T) and pressure (P) during open water diving. The author conducted a total of 38 dives involving either a light (20 dives) or a moderate (18 dives) level of physical activity. Within each of these groups, P and T taken together accounted for about two thirds of the variance in the VE data. A very significant increase in VE was observed as T decreased (1 < T(degrees C) < 22), and the magnitude of this increase at a given pressure level was similar in the 'light' and the 'moderate' data sets. A second order observation, particularly notable at lower temperature, was the decrease in VE with increasing pressure under conditions of light work. Empirical functions of the from VE = A+B/P n[1 + exp(T - 8)/10], where A, B, and n are adjustable variables, could accommodate both data sets over the whole range of T and P. These results are the first obtained under actual diving conditions to provide evidence for interactions between P, T, and VE. Understanding the physiological mechanisms by which these interactions occur would assist in appreciation of the limitations imposed on scuba divers by the environmental conditions as they affect their ventilatory responses.
Wild water rapid burns.
Authors: Wright J B
Published: December 2008

Swimming pool water slides are becoming increasingly long and adventurous. This case report and survey suggest that they may carry with them a notable risk of friction burns.
Ankle taping improves proprioception before and after exercise in young men.
Authors: Robbins S , Waked E , Rappel R
Published: December 2008

Ankle sprains are common sports injuries. Inadequate foot position awareness is thought to be the fundamental cause of these injuries. Ankle taping may decrease risk of injury through improving foot position awareness. The benefit of taping is thought to decrease with duration of exercise because of poor tape adherence to human skin. This study was a randomized, crossover, controlled comparison experiment that tested the hypothesis that ankle taping improves foot position awareness before and after exercise. A sample of 24 healthy young blindfolded volunteers, wearing their own athletic shoes, indicated perceived slope direction and estimated slope amplitude when bearing full body weight and standing on a series of blocks. The top slope of the blocks varied between 0 degree and 25 degrees, in 2.5 degrees increments, to orient the plantar surface with respect to the leg toward pronation, supination, plantarflexion, and dorsiflexion, relative to its position on a flat surface. Foot position awareness, which was considered the reciprocal of surface slope estimate error, varied with testing condition, particularly when surface slope was greater than 10 degrees, presumably the most important range considering ankle injuries. In this higher range absolute position error was 4.23 degrees taped, and 5.53 degrees untaped (P < 0.001). Following exercise, in the higher range absolute position error was 2.5% worse when taped and 35.5% worse when untaped (P < 0.001). These data support the hypothesis that ankle taping improves proprioception before and after exercise. They also indicate that foot position awareness declines with exercise. Compared to barefoot data (position error 1.97 degrees), foot position error was 107.5% poorer with athletic footwear when untaped (absolute position error 4.11 degrees), and 58.1% worse when taped (position error 3.13 degrees). This suggests that ankle taping partly corrects impaired proprioception caused by modern athletic footwear and exercise. Footwear could be optimized to reduce the incidence of these injuries.
Precompetition injury and subsequent tournament performance in full-contact taekwondo.
Authors: Feehan M , Waller A E
Published: December 2008

OBJECTIVE: To determine the pattern of injuries sustained by taekwondo competitors, and how previous injury affects performance in sporting competition. METHODS: Competitors at a major New Zealand full-contact taekwondo tournament were given a comprehensive questionnaire immediately before competition. Self reports of injuries sustained through taekwondo in the previous 12 months were determined. RESULTS: No significant sex differences were found. The injury prevalence was high, but comparatively less than reported for other contact sports such as rugby football. However, one in 20 injuries was a closed head injury. No significant associations between prior injury and tournament outcome were found. CONCLUSIONS: Taekwondo can be a source of disabling injury. However, the fact that prior injury did not appear to be associated with impaired competition performance may militate against acceptance of control and regulation by competitors and coaches.
The New Zealand rugby injury and performance project. III. Anthropometric and physical performance characteristics of players.
Authors: Quarrie K L , Handcock P , Waller A E , Chalmers D J , Toomey M J , Wilson B D
Published: December 2008

OBJECTIVE: To investigate the anthropometric and physical performance characteristics of New Zealand rugby players of different ages and both sexes. METHODS: 356 rugby players (264 male, 92 female) took part in the study during a single season. Playing grade ranged from schoolboys and schoolgirls to senior men and women. Assessment of height, weight, neck circumference, and somatotype was performed before the competitive rugby season. A battery of six physical performance assessments was completed after the anthropometry. Analysis of variance was used to examine differences in these variables between field positions and grades. RESULTS: Significant differences between forwards and backs on anthropometric and physical performance variables were apparent at all grades assessed. In terms of anthropometric characteristics, forwards of a given grade were generally taller, possessed greater body mass, and were more endomorphic and less ectomorphic than backs of the same grade. The backs tended to perform better on physical performance measures than forwards, being more aerobically fit, faster, more agile, and possessing a higher degree of muscular endurance. Differences in anthropometry and physical performance attributes were also apparent between players from the various grades. The players at higher levels were generally larger, and performed better on tests of physical performance than the players at lower levels. These differences were found in both sexes. CONCLUSIONS: The greater body mass of the forwards allows them to obtain greater momentum than the backs when sprinting. The ability to obtain greater momentum is important in the body contact phases of the game. Forwards may compromise their aerobic fitness and speed to some extent in order to maintain a high body mass. The anthropometric and physical performance characteristics of players appear to reflect the demands placed on them by the sport.
Relation of speed of a mile run, maximum energy cost of running, and maximum oxygen consumption: a field study.
Authors: Das S K , Dutta A
Published: December 2008

OBJECTIVE: To compare the maximum energy cost of running (MECR) estimated from the speed of a mile run and the maximum oxygen consumption (VO2max) with a field step test. METHODS: MECR was defined as the maximum VO2, derived from the equation VO2 = 5.3 mph + 3.9 (ml.min-1.kg-1), when the subject performs a maximal, exhausting run and attains maximum speed. The equation is based on a straight line relation between speed and VO2. In this study MECR was obtained from a mile run and was compared with VO2max by extrapolation using a step test. Both tests were performed in the field. RESULTS AND CONCLUSIONS: The variation in the MECR with VO2max was within +/- 10%. It therefore appears that the speed of a mile run is a good criterion of VO2max or estimated MECR for the measurement of physical fitness, and for the selection, recruitment, and assignment of an individual in field sports.
Spontaneous rupture of the anterior cruciate ligament after anabolic steroids.
Authors: Freeman B J , Rooker G D
Published: December 2008

Anabolic steroids remain popular among body builders and power athletes despite numerous warning about their side effects. A case of spontaneous rupture of the anterior cruciate ligament is reported in a bodybuilder taking steroids. While there are many published reports of tendon rupture associated with steroid intake, the authors could find no report relating to ligament disruption.
Evaluation of iron metabolism indices and their relation with physical work capacity in athletes.
Authors: Karamizrak S O , Işlegen C , Varol S R , Taşkiran Y , Yaman C , Mutaf I , Akgün N
Published: December 2008

OBJECTIVE--To evaluate the relation between iron status and physical working capacity, and to assess the effect of oral iron treatment on these variables, in athletes with borderline iron status. METHODS--Blood haemoglobin (Hb), packed cell volume (PCV), red blood cell count (RBC), serum iron, total iron binding capacity (TIBC), and ferritin determinations were compared in 71 male and 18 female athletes participating in various sports and in matched male (n = 11) and female (n = 8) controls. The first aim was to assess the relations between these variables and performance in a physical work capacity test (PWC170). Oral iron treatment (175-350 mg ferrous fumarate daily) was provided for three weeks to six male and five female athletes with borderline Hb concentrations, to determine the effects of such treatment on both iron status and performance. RESULTS--Among females, handball players had the lowest serum ferritin concentrations (P < 0.05), the highest TIBC values, and lowest PWC170 scores (P < 0.01); runners had the highest ferritin concentrations and PWC170 scores (P < 0.01). There were significant correlations (P < 0.01) between PWC170 and PCV, serum ferritin, and transferrin saturation of female athletes. Hb, serum iron, serum ferritin, and transferrin saturation increased with iron treatment in both males (P < 0.01) and females (P < 0.05). CONCLUSIONS--Serum ferritin determination may prove a valuable addition to the screening of athletes and may indicate the need for iron treatment, even though a causal effect on improvement of work capacity may not be present.
Use of radionuclide imaging to determine gastric emptying of carbohydrate solutions during exercise.
Authors: MacLaren D , Miles A , O'Neill I , Critchley M , Grime S , Stockdale H
Published: December 2008

OBJECTIVE--To investigate the repeatability of continual assessment of the gastric emptying rates of carbohydrate solutions in exercising subjects using 99mtechnetium labelling. METHODS--Gastric emptying of a 5% glucose solution and an iso-osmotic maltodextrin solution was measured using 3 MBq of 99mtechnetium labelled diethylene triamine penta-acetic acid (DTPA) and continuous gamma camera imaging in five male subjects. The subjects performed four 1 h trials at 70% VO2 peak on a cycle ergometer. After 15 min, 200 ml of a radiolabelled solution of glucose or maltodextrin were ingested in a blind crossover protocol. The two solutions were each ingested on separate occasions (trial 1 and trial 2) to establish repeatability. RESULTS--Statistical analysis showed no differences between trial 1 and trial 2 for both solutions. There were no significant differences for the emptying rates between the two test solutions. CONCLUSIONS--Posterior imaging using a computer linked gamma camera following the ingestion of 99mtechnetium labelled DTPA mixed with carbohydrate solutions provides a repeatable method of assessing gastric emptying characteristics in exercising subjects. This technique showed no significant differences between the emptying rates of a single dose of iso-osmotic glucose or maltodextrin solution.
Vibromyographic recording from human muscles with known fibre composition differences.
Authors: Mealing D , Long G , McCarthy P W
Published: December 2008

OBJECTIVE--To determine the relation between the vibromyographic (VMG) frequency characteristics and fibre composition in postural and non-postural human muscle undergoing a standardised voluntary contraction. METHODS--Two human muscles with different fibre compositions [soleus: postural, mainly type I (slow) fibres; biceps brachii: non-postural, mixed type I and II (fast) fibres] were recorded from 18 healthy males isometrically contracting at 50% of their maximum voluntary contraction (MVC). Muscle vibrations were recorded using a contact microphone and the frequency content of the signals calculated using fast fourier transform algorithms. RESULTS--The non-postural biceps brachii showed predominantly bimodal power spectra with significantly increased power in the 10-30 Hz bands (P < 0.01), as compared with soleus recordings which tended to be unimodal, with the majority of power below 10 Hz. CONCLUSIONS--Muscles with a large proportion of type I fibres generate VMG signals which contain an increased percentage of low frequencies as compared to muscles with a mixed population of type I and type II fibres. The VMG appears to be generated, in part at least, by the mechanical twitching of motor units within the muscle; frequency domain analysis of this signal may provide a non-invasive measure of muscle fibre composition.
Maternal rectal temperature and fetal heart rate responses to upright cycling in late pregnancy.
Authors: O'Neill M E
Published: December 2008

OBJECTIVE--To assess maternal rectal temperature and fetal heart rate responses to dynamic exercise. METHODS--11 healthy women with low risk pregnancies completed three separate upright cycling tests at 34 to 37 weeks gestation: 15 min at 62.5 W (mean maternal heart rate [MHR] 138 beats.min-1 (test A); 15 min at 87.5 W (MHR 156 beats.min-1) (test B); and 30 min at 62.5 W (MHR 142 beats.min-1) (test C). Rectal temperature and fetal heart rate were measured. RESULTS--Mean temperature increase after tests B and C [by 0.4(SD 0.1) degrees C] was greater than after test A [0.2(0.1) degrees C] (P < 0.001). Fetal heart rate, measured in the recovery period immediately after exercise, increased significantly only after tests B and C (P < 0.01). Exercise related changes in temperature and fetal heart rate weakly correlated in tests B (P < 0.02) and C (P < 0.01). CONCLUSIONS--Temperature and fetal heart rate changes were more marked after higher intensity (test B) or longer duration exercise (test C) compared with moderate exercise, but none of the tests caused adverse fetal heart rate changes (decrease in accelerations, bradycardia, or decelerations) or individual temperatures above 38 degrees C.
The Harstad injury prevention study: the epidemiology of sports injuries. An 8 year study.
Authors: Ytterstad B
Published: December 2008

OBJECTIVE--To describe the epidemiology of sports injuries occurring in a community during 8 years and to evaluate the outcome of an intervention implemented against injuries occurring in downhill skiing. METHODS--Hospital treated sports injuries occurring in Harstad, Norway (population 22 600) were recorded prospectively during an 8 year period. A prevention programme targeting downhill skiing injuries was evaluated. RESULTS--2234 sports injuries accounted for 17.2% of recorded unintentional injuries. Two out of three injuries occurred in team sports. Soccer accounted for 44.8% of all sports injuries. Downhill skiing injuries had higher mean score on the abbreviated injury scale than all other sports analysed combined (P < 0.01). Postintervention injury rates for downhill skiing were reduced by 15% when adjusting for exposure (P = 0.24). Further observations are needed for assessing the effectiveness of the downhill skiing safety programme. CONCLUSIONS--Strategies for future sports injury prevention include community involvement, particularly sports organisations. Local data analysis seems to justify some priorities, for example, promotion of helmet use in downhill skiing for young adolescents and prevention of lower limb fractures in male soccer players 15+ years old. Prospective hospital recording of injuries provides a tool for the design and outcome evaluation of sports injury intervention research.
Posterior sternoclavicular dislocation: an American football injury.
Authors: Marker L B , Klareskov B
Published: December 2008

Posterior dislocation of the sternoclavicular joint is uncommon, accounting for less than 0.1% of all dislocations. Since 1824 a little more than 100 cases have been reported, and the majority in the past 20 years. A review of published reports suggests that this injury is seen particularly in connection with American football. A typical case is described. The importance of this injury is that there is often a delay in diagnosis with potentially serious complications.
Complete avulsion of the hamstring tendons from the ischial tuberosity. A report of two cases sustained in judo.
Authors: Kurosawa H , Nakasita K , Nakasita H , Sasaki S , Takeda S
Published: December 2008

Rupture of the hamstring tendon is a rare injury. Two cases of complete rupture of the hamstring tendons sustained while playing judo are reported. The diagnosis of a rupture of the hamstring tendons was difficult from physical examination because of severe pain on knee or hip joint movement. Magnetic resonance imaging was non-invasive and showed the lesion clearly. In one of these two cases the less satisfactory results of non-operative treatment were clearly shown in both isokinetic muscle force evaluation and sports activities.
Changes in plasma enzyme activities in professional racing cyclists.
Authors: Mena P , Maynar M , Campillo J E
Published: December 2008

OBJECTIVE: To reports changes in plasma levels in professional racing cyclists. METHODS: Plasma levels of the intracellular enzymes aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transpeptidase, lactate dehydrogenase, and alkaline phosphatase were measured resting and after exercise in professional cyclists participating in two road races: Vuelta Ciclista a Valencia (800 km, beginning of the cyclist season), and the top rank race Vuelta a España (2700 km, at the end of cyclist season). RESULTS: A significant increase in plasma aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase was observed at the end of the race over the corresponding paired start values (P < 0.05). The increase in plasma lactate dehydrogenase after the race was only statistically significant (P < 0.05) in the Vuelta a España. The longer the duration of the cycle tour race, the greater were the increases in aspartate aminotransferase and alanine aminotransferase levels. The high levels returned to their start values during the overnight resting period. CONCLUSIONS: The presence of these enzymes in the blood is probably due to mechanically damaged muscle cells leaking their contents into the interstitial fluid.
Low back pain and other overuse injuries in a group of Japanese triathletes.
Authors: Manninen J S , Kallinen M
Published: December 2008

OBJECTIVE: To document the incidence of low back pain and other overuse injuries in a group of triathletes, and to investigate any associations with various physical and triathlon related factors. METHODS: By means of a questionnaire, the physical characteristics, training habits, and the incidences of overuse injuries of 92 Japanese triathletes (70 males, 22 females) were documented. Student's t and chi 2 tests were used to determine the significance of any associations with injury incidence, as well as differences between subjects experiencing or not experiencing low back pain in the previous year. RESULTS: Low back pain was experienced by 32% of subjects in the previous year. The majority (54%) of low back pain episodes lasted under seven days, suggesting mainly soft tissue involvement, and 19% lasted over three months, suggesting involvement of the intervertebral discs. Weekly trunk flexor muscle training frequency was significantly greater (P = 0.035) for the low back pain subjects. Close to significant differences for average weekly cycling time, trunk flexor muscle training time, and low intensity aerobic training, as well near significant associations for weight training and average weekly triathlon training load, were also found. No other factors were significantly associated with low back pain. Low back injuries accounted for 28% of all injuries. Only the knee was a more common single site of injury (33%). CONCLUSIONS: The three most common injuries suffered by the triathletes were of the knee, back and shoulder. The low back pain suffered by many triathletes could be of a potentially serious nature. It is suggested that cycling is a major risk factor for low back pain in triathletes.
Eccentric and concentric isokinetic knee flexion and extension: a reliability study using the Cybex 6000 dynamometer.
Authors: Li R C , Wu Y , Maffulli N , Chan K M , Chan J L
Published: December 2008

OBJECTIVE: To determine the reliability of the Cybex 6000 isokinetic dynamometer in measuring the knee muscle performance concentrically and eccentrically. METHODS: 18 male and 12 female subjects with no previous knee injuries, who had not previously undergone any isokinetic testing, were studied. The flexor and extensor muscles groups of both knees were tested at 60 degrees s-1 and 120 degrees s-1 with the continuous concentric-eccentric cycle testing protocol. Variables studied included peak torque, total work, and average power. The interclass correlation coefficient (ICC 2,1) was used to determine the reliability with P < 0.05. RESULTS: Peak torque showed significantly greater ICC than the total work and average power, with test-retest reliability ranging from 0.82 to 0.91 for peak torque, from 0.76 to 0.89 for total work, and 0.71 to 0.88 for average power. Average variability for the three variables studied ranged from 9% to 14%. The ICCs for the three variables studied were significantly greater at 120 degrees s-1. The knee extensor muscle group showed greater test-retest reliability, and the results of isokinetic testing in the concentric contraction mode were more reproducible. CONCLUSIONS: The Cybex 6000 isokinetic dynamometer shows high reliability in measuring isokinetic concentric and eccentric variables. Some fluctuation should be allowed when evaluating variations of muscle performance between tests.
Risk assessment in professional football: an examination of accidents and incidents in the 1994 World Cup finals.
Authors: Hawkins R D , Fuller C W
Published: December 2008

OBJECTIVE: To assess the risks to footballers' health and safety during competitive international matches, with identification of the most common causes of injury. METHODS: Videos of 44 of the 52 matches played during the 1994 World Cup finals staged in the USA were analysed. During each match, several relevant variables were recorded, including the number of fouls, injuries, treatments, times of incidents, identity of players treated or injured, and the injury mechanism. Additional information on players' injuries was obtained from the extensive media coverage of the event. RESULTS: Only 29% of injuries resulted from foul play, whereas 71% of injuries to players occurred where no foul play was adjudged by the referee to have taken place (P < 0.01). Defenders were found to be proportionately subjected to a greater risk of injury than other players (P < 0.05). Fifteen per cent of all injuries were judged to be at least moderate, resulting in the player missing at least one match. Frequency of moderate injury was 1026 injuries per 100,000 hours played. CONCLUSIONS: The major causes of injuries during international football matches were not found to be associated with foul play, as judged by the referees. However, in those cases where injuries occurred without a foul being committed, almost 50% involved player to player contact. This gives some cause for concern and is worth further investigation.
The footballer's fracture
Authors: Cattermole H R , Hardy J R W , Gregg P J
Published: December 2008

Objective

To describe the typical tibial diaphyseal fracture (“footballer's fracture”) and to clarify the circumstances and mechanism of the injury.

Methods

In an attempt to obtain a detailed analysis of the types of injury suffered, and thereby highlight areas for prevention, 100 consecutive adult football players with a tibial diaphyseal fracture were studied prospectively. Details of the circumstances and mechanism of injury were collected using a questionnaire (response rate 85%). Treatments depended on the Gustilo classification, displacement, and axial stability. Long term follow up was performed until clinical healing to define the overall prognosis.

Results

61% of players suffered a fracture of both the tibia and the fibula. Ninety five percent of the tibial fractures were transverse or short oblique and were caused by impact during a tackle. Radiographic evidence of bridging callus was better than a classification of the bony injury for predicting weeks to clinical healing. The delayed union and non-union incidence following this injury is low. One patient suffered symptomatic shortening. One patient suffered symptomatic angulation and two patients with non-union required bone grafting.

Conclusions

Tibial fracture is an expensive injury. It prevents a young population from being employed and takes up valuable NHS resources. As 85% of players were wearing shin guards, it is likely that improvements in shin guard design could reduce the rate of tibial fracture.
Getting started--a review of physical activity adoption studies.
Authors: Dunn A L
Published: December 2008

The aim of this paper has been to review methods that have been found to be effective in getting sedentary adults to adopt physical activity, to examine these methods within the multilevel framework conceptualised by Winett et al, and to provide recommendations for future research to test new methods and their effectiveness in leading to the adoption of physical activity in sedentary populations. Searches for relevant studies were conducted on the Medline computerised database. Additional studies were located in reference sections of these studies and other review papers. Surveys that specifically identified determinants of adoption of physical activity in adults were included. Reviewed articles were selected on the basis of quasi-experimental and experimental designs that specifically examined the question of how to get sedentary adults to adopt a programme of physical activity or exercise, had completely described methods, and evaluated the effectiveness of methods of increasing physical activity and/or exercise. While numerous reviews have been written on determinants on physical activity adoption and maintenance, only two prospective surveys have identified specifics of adoption of physical activity. Most of the evidence for techniques that help inactive people to adopt physical activity comes from quasi-experimental and experimental intervention studies examining various cognitive and behavioural strategies at the individual level. Fewer studies have examined techniques at the interpersonal, organisational, community, environmental, and policy level. More prospective observational studies aimed at homogeneous subgroups are needed to identify correlates of physical activity adoption to help tailor interventions. Continued clinical studies are needed to differentiate the necessary and sufficient strategies at the personal and interpersonal levels. Interventions aimed at environmental, institutional, and social levels remain largely unexplored and there is a need for more research that specifically targets inactive subgroups at these levels.
Effect of altered reproductive function and lowered testosterone levels on bone density in male endurance athletes
Authors: Bennell Kim L , Brukner Peter D , Malcolm Susan A
Published: December 2008

The effect of intense physical activity on female reproductive hormones is well recognised1–3and there is evidence that menstrual disturbances associated with hypo-oestrogenism adversely affect bone density especially at the lumbar spine.4 5Physical activity can also have a range of effects on male reproductive function depending upon the intensity and duration of the activity and the fitness of the individual.6In particular, endurance training may be associated with reductions in circulating testosterone levels. Since testosterone has important anabolic roles, alterations in reproductive hormone profiles may have detrimental skeletal consequences similar to those seen in females with menstrual disturbances. The aim of this brief review is to present the limited literature on the relation between bone density and testosterone levels in male endurance athletes.
Exercise therapy for osteoporosis: results of a randomised controlled trial.
Authors: Preisinger E , Alacamlioglu Y , Pils K , Bosina E , Metka M , Schneider B , Ernst E
Published: December 2008

OBJECTIVE: To define the effects of therapeutic exercise on bone density and back complaints. METHODS: A randomised controlled trial with parallel groups was conducted in an outpatient clinic, Medical School, University of Vienna. Ninety two sedentary post-menopausal women with back problems were randomly allocated to either exercise (groups 1 and 2) or control (group 3, no exercise, n = 31); the exercise group was retrospectively subdivided into compliant (group 1, n = 27) and not fully compliant patients (group 2, n = 34). Regular, initially supervised therapeutic exercise aimed at restoring biomechanical function was performed for four years. Bone density in the forearm was measured by single photon absorptiometry at entry and after four years; subjective back complaints were documented. RESULTS: A significant decrease in bone density was observed in groups 2 and 3; no change was noted in group 1; back complaints decreased in group 1 only. CONCLUSIONS: Sedentary postmenopausal women may benefit from regular long term therapeutic exercise in terms of subjective back complaints and slowed loss of bone mass.