bluuebunny/crossref_metadata_2025 huggingface dataset:
Sagittal plane translation of the tibia in anterior cruciate ligament‐deficient knees during commonly used rehabilitation exercises
Authors: Lysholm M. , Messner K.
Published: July 2010

It may be assumed that exercises that provoke high sagittal plane knee translations also induce high stresses on an anterior cruciate ligament substitute and, therefore, these exercises should be limited during the first months after reconstruction. In 18 patients with unilateral anterior cruciate ligament deficiency, sagittal plane knee translations were measured with a goniometer linkage system during common activities. The largest translations were found during low‐speed isokinetic exercises. Further, isokinetic and isometric exercises on the Cybex‐II dynamometer provoked in more than 40% of the patients larger translations on the injured than on the healthy knee. However, isometric exercises without distally applied load only provoked small translation. During bicycling, translations increased with increasing resistance similarly in both limbs. Except for walking downstairs, load‐bearing exercises, such as sitting down and standing up from a chair and walking upstairs, only produced negligible amounts of tibial translation. In conclusion, during the early phase after anterior cruciate ligament reconstruction, activities such as bicycling and some weightbearing exercises seem to be more recommendable than low‐speed isokinetic exercises, isometric contractions at a low knee flexion angle with distally applied load or walking downstairs.
Do highly physically active females have a lowered basal metabolic rate?
Authors: Dahlström M. , Jansson E. , Ekman M. , Kaijser L.
Published: July 2010

In several studies estimated energy intake has been found to be low compared with estimated energy expenditure in female athletes. It has therefore been suggested that female athletes may have a depressed basal energy expenditure (BMR). The main purpose of the present study was to explore this possibility by measuring BMR in physically extremely active females. Eight female dancers and 7 controls with low physical activity, all musicians, were studied; the variables measured included body weight, height, skinfold thickness and total body potassium. BMR was measured by indirect calorimetry. In conclusion, the present study lends no support to the idea of a lowered basal metabolic rate in female athletes as an explanation of the general finding of a lower estimated energy intake than energy expenditure in this type of subjects.
Cardiovascular changes with age and exercise
Authors: Kasch F. W. , Boyer J. L. , Van Camp S. , Nettl F. , Verity L. S. , Wallace J. P.
Published: July 2010

Various studies report a 0–22% per decade decline in circulatory function (VO2max) with advancing age. Twelve exercising men (E) were followed for 28 years, mean age 43 and 71 years, initial to final measurement, while 12 dropouts (C) detrained for 21 years, with a mean age from first to last measurement of 48 and 69 years, respectively. VO2 max in E changed from 45.9 to 39.4 ml · min−1· kg−1, 5% per decade, whereas C declined from 36.0 to 21.4 ml min−1· kg−1, 19% per decade. Resting blood pressure was unchanged in E, 119/75 mmHg, whereas C rose from 128/85 to 149/90 mmHg. The data suggest that regular aerobic exercise forestalls the usual loss of circulatory function with increasing age.
Repair of Bankart lesions with a suture anchor in recurrent dislocation of the shoulder
Authors: Karlsson J. , Järvholm U. , Swärd L. , Lansinger O.
Published: July 2010

This study describes the 3‐year results of Bankart reconstruction in 50 consecutive patients with posttraumatic, recurrent, anterior instability of the shoulder. A modified procedure, using suture anchors was used in all patients, to simplify the soft‐tissue attachment to the glenoid rim. Forty‐seven of 50 (94%) patients regained normal stability. Two recurrent dislocations and one subluxation occurred. The functional results according to the Rowe scoring system were satisfactory in 43 of 50 (86%) of the patients, and unsatisfactory in 7 of 50 (14%). Of the patients with unsatisfactoy results, 3 had recurrent instability and 4 had not regained normal range of shoulder motion. The suture anchors were found to simplify the procedure, and no specific complications as a result of the modified technique were seen.
Mechanical efficiency in athletes during running
Authors: Kyröläinen H. , Komi P. V. , Belli A.
Published: July 2010

The purpose of this study was to compare the external mechanical efficiency (ME) between power‐trained athletes (n= 5) and endurance‐trained athletes (n= 5). The relationships between biomechanical variables and metabolic cost were also investigated. The subjects ran at 3 different speeds (2.50 m · s−1, 3.25 m · s−1 and 4.00 m · s−1) both on the treadmill and on the track. The external work of the subjects was determined by a kinematic arm, and energy expenditure was determined by measuring oxygen consumption and respiratory exchange ratio. Biomechanical parameters included ground reaction forces, angular displacements of the knee and ankle joints and electromyography (EMG) of the selected muscles. The mean ME (±SD) values during running on treadmill were as follows: 49.6±8.9%, 60.1±9.6% and 61.2±10.4% for the endurance group, and 47.1±3.7%, 52.0±4.3% and 57.4±5.5% for the power group. In running on the track the respective values were 57.5±11.9%, 51.5±6.1% and 62.2±9.2% for the endurance group, and 47.0±8.3%, 45.3±10.2% and 60.0±5.9% for the power group. The subject groups did not differ significantly in ME due to high interindividual variance among both subject groups. The metabolic responses such as heart rate, pulmonary ventilation and oxygen uptake differed clearly between the athletic groups but this was not the case for the most of the biomechanical variables (such as EMG, step length and vertical displacement of the centre of the gravity). In conclusion, physiological and biomechanical variables appear to affect ME in a very complex way. In other words, efficiency is related individually to the sum of many variables.
Morphology, enzyme activities and buffer capacity in leg muscles of Kenyan and Scandinavian runners
Authors: Saltin B. , Kim C. K. , Terrados N. , Larsen H. , Svedenhag J. , Rolf C. J.
Published: July 2010

The study comprises data on 12 Scandinavian runners who had either trained for two weeks in Kenya (n= 6; ∼2000 meters above sea level (m.a.s.l.)) or in Portugal (n= 6; sea level (s.l.)) and on 13 Kenyan runners (9 junior and 4 senior) living and training at ∼2000 m.a.s.l. Muscle biopsies were taken before and after the training camps in the Scandinavian runners and once on the Kenyan runners from the vastus lateralis (v.l.) and the gastrocnemius muscles. Muscle fiber size and composition were similar in the various groups (4.6–5.1 × 103μm2; ST ∼60–70%; FTa 30–40%; FTb < 6.0%) with a tendency for some more (∼5%) FTa fibers in the gastrocnemius muscle. Mean number of capillaries in v.l. varies between 405–493 cap · (mm2)−1, 2.0–2.7 cap · fiber−1, and 4.4–6.2 cap around the various fiber types, with the Kenyan seniors having the highest and the Kenyan juniors the lowest values. All runners had 10–20% more capillaries in their gastrocnemius muscle. Similar levels for citrate synthase (CS) activity were found in the v.l. of the Kenyan seniors and Scandinavian runners, whereas the Kenyan juniors were 10–15% lower. The 3‐hydroxyacyl‐CoA‐dehydrogenase (HAD) activity was 20% higher in the Kenyan than in the Scandinavian runners. In the gastrocnemius muscle, both enzyme activities were 20–50% higher in Scandinavian and Kenyan runners. The ratio for lactate dehydrogenase (LDH) isoform1–2 and isoform4–5 was increased when training at altitude due to a lowering of LDH4–5 and became close to what was observed in the Kenyan runners. Also muscle buffer capacity became increased in the altitude training groups. It is concluded that muscle morphology is quite similar in Scandinavian and Kenyan runners with no effect of training at altitude. Mitochondrial enzyme activities are also unaltered at altitude, but the Kenyan runners have markedly higher HAD activity. Muscle buffer capacity is elevated in the Scandinavian runners training at altitude, and it appears to be an effect of altitude, as no change was observed in the Scandinavian runners training at s.l., which was also the case for the LDH1–2: LDH4–5 ratio as a result of a lowering of LDH4–5 activity.
Salbutamol and high‐intensity treadmill running in nonasthmatic highly conditioned athletes
Authors: Heir T. , Stemshaug H.
Published: July 2010

Salbutamol is a widely used drug among elite athletes. We wanted to provide more information on the effects of salbutamol in nonasthmatic athletes. Seventeen highly conditioned male athletes (Vo2max > 70 ml · kg−1· min−1) participated in a randomized, double‐blind and placebo‐controlled cross‐over study. Nebulized salbutamol (0.05 mg/kg) or placebo was inhaled prior to a high intensity (110% of Vo2max) treadmill run to exhaustion. The measured variables included endurance time, oxygen uptake, ventilation, breathing rate, heart rate, and oxygen saturation. Lung function was measured as forced expiratory volume in the first second (FEV1) before and after medication, and during the recovery from the run. The high intensity runs led to total exhaustion after 4–10 min. A close‐to‐significant shortening in endurance time was found when salbutamol was given. During the running (0–4 min) the oxygen uptake was slightly lower and the heart rate was slightly higher when salbutamol was given. No differences were found in peak oxygen uptake, peak heart rate, ventilation, breathing rate or oxygen saturation. FEV1 reflected an increase in airway caliber after the inhalation of salbutamol. These changes were still present in the recovery from the test run with the exception of the measurement immediately after the exercise. Although evidence for β‐adrenergic stimulation was found, it was concluded that a therapeutic dose of nebulized salbutamol does not improve performance in highly trained athletes during a high‐intensity run to exhaustion.
Patellofemoral pain syndrome in young women
Authors: Thomeé R. , Renström P. , Karlsson J. , Grimby G.
Published: July 2010

Clinical alignment, pain variables, common symptoms and functional activity level associated with patellofemoral pain syndrome (PFPS) were evaluated in 40 women with PFPS and 20 healthy controls. No significant difference could be found neither between the patients' most symptomatic knee and least symptomatic knee, nor between the patients and controls regarding clinical lower extremity alignment, such as Q‐angle and leg‐heel alignment measurements. There were no radiographic signs of malalignment. The patients were significantly more involved competitively in sports but had a significantly lower pain free activity level than the controls. Pain was associated with increased activity. It is suggested that chronic overloading and temporary overuse of the patellofemoral joint, rather than malalignment, contribute to patellofemoral pain.
Salivary and blood lactate after supramaximal exercise in sprinters and long‐distance runners
Authors: Ohkuwa T. , Itoh H. , Yamazaki Y. , Sato Y.
Published: July 2010

This investigation examined the reproducibility of salivary lactate measurement in long‐distance runners following a 3000‐m run and compared the salivary and blood lactate concentrations in sprinters and long‐distance runners following a 400‐m run. There was no significant difference in salivary and blood lactate between the first and second 3000‐m run test. The peak salivary and blood lactate following a 400‐m run was higher in sprinters than in long‐distance runners. There was a significant relationship between the peak lactate of saliva and that of blood following a 400‐m run. The results showed that the salivary lactate following exercise was reproducible and the salivary lactate concentration may serve as a relevant indicator in determining which have a higher lactate production.
Effects of function and weight‐bearing on the healing of full‐thickness cartilage defects in rats
Authors: Grundnes O. , Relkerås O.
Published: July 2010

The effects of different degrees of active motion were studied in 30 male Wistar rats. In all rats a full‐thickness cartilage defect of 1.0 mm in diameter was made in the medial condyle of both femurs. The rats were then allocated to the following three groups; i) exercising group which followed a 4‐week training program of moderate intensity, ii) a non‐weight‐bearing group in which unilateral achilles tenotomy was made to reduce weight‐bearing and iii) control rats which were allowed normal cage activity. Healing of the defect was evaluated by planimetric analysis and histologic evaluation. Effects of the training program was confirmed by a lesser weight increase in the exercise group. Planimetric analysis revealed no differences between the groups in the area of the original defect at the end of the experiment. There were no differences in healing ratio (area of healing/area of original defect) between the exercise and control groups, whereas the healing ratio was increased in the non‐weight‐bearing limbs compared with control and exercised rats. The favorable effect of non‐weight‐bearing was further indicated by differences in healing ratio between the two limbs in the non‐weight‐bearing group. Histological evaluation showed that the defect was repaired by a fibrocartilage substance along the periphery of the original defect and fibrovascular granulation tissue centrally. Evaluated by microscopic appearance, there were no qualitative differences between the three groups. We conclude that in the initial repair process by fibrocartilage non‐weight‐bearing is conductive to healing of full‐thickness cartilage defects. The short‐term effects revealed no differences on qualitative healing. Increased activity does not seem to prolong the initial fibrocartilage healing compared with normal activity with full weight‐bearing.
Patellar tendinitis—a case report of elongation and ossification of the inferior pole of the patella
Authors: Grossfeld S. L. , Engebretsen L.
Published: July 2010

Patellar tendinitis is a condition that occurs in patients who are involved in repetitive use of the extension mechanism. The most common symptoms are pain at the inferior pole of the patella, and radiographic changes may also occur. This case report demonstrates an extreme example of elongation of the inferior pole of the patellar tendon. The ossification caused the patient pain, which was resolved with surgical removal of the bone.
Physical activity and physical fitness as protection against premature disease or death
Authors: Andersen L. B.
Published: July 2010

It is known from prospective studies that the incidence of coronary heart disease (CHD) is lower in the physically active compared with the sedentary part of the population, and the rate of CHD is lower with higher fitness level. In studies where both physical activity (PA) and fitness are assessed, only fitness, and not PA, appear to be an independent predictor of mortality from CHD. It is unclear whether other fitness components than maximal oxygen uptake (Vo2max) have a beneficial effect on the rate of CHD. Further, it seems likely that there is an upper threshold of fitness (Vo2max) above which no further improvement in risk factors for CHD is found. However, most middle‐aged people have fitness levels below this threshold. There is no doubt that the middle‐aged sedentary person benefits from physical activity regardless of type and intensity, and it may be easier to motivate a sedentary person to carry out moderate physical activity. However, it is likely that the best effect is achieved by performing physical activity of a type and intensity sufficient to improve the fitness level. Still, recommendations of type, frequency, duration and intensity are matters of debate.
Effect of goal orientation on achievement beliefs, cognition and strategies in team sport
Authors: Roberts G. C. , Ommundsen Y.
Published: July 2010

Nicholls' motivation conceptual framework pertaining to achievement goals was used to study the relationship between two implicit goal orientations (task and ego) and achievement cognitions and beliefs about the competitive team sport experience. The study examined the relationship between the goal orientations and purposes of team sport, motivational climate, satisfaction, sources of satisfaction, achievement strategies, and perception of ability in team sport. The subjects were 148 students experienced in team sport at a Norwegian university. The scales were translated specifically for the study and factor analyses used to determine the factor structure of the scales. Seventeen factors along the 6 dimensions emerged, and canonical analysis determined that predominantly task‐oriented subjects focused on health‐related activities within purposes, preferred mastery climates and focused on mastery‐oriented criteria to determine satisfaction and other achievement‐related beliefs. In contrast, predominantly ego‐oriented subjects focused on status enhancement for purpose, preferred performance‐oriented climates and focused on ego‐oriented criteria to determine satisfaction and other achievement beliefs.
Pseudoarthrosis between a patellar tendon ossicle and the tibial tuberosity in Osgood‐Schlatter's disease
Authors: Robertsen K. , Kristensen O. , Sommer J.
Published: July 2010

We report a case of pseudoarthrosis between a patellar tendon ossicle and the tibial tuberosity. A man, 18 years of age, had persistent symptoms of Osgood‐Schlatter's disease from the left knee for 3 years. Conservative treatment was without effect. Excision of the ossicle resulted in complete relief of symptoms. Histologic examination showed a pseudoarthrosis covered with cartilage and no sign of inflammation. Persistent symptoms of Osgood‐Schlatter's disease for more than 2 years indicate exploration.
Physcial exercise and low back pain
Authors: Campello M. , Nordin M. , Weiser S.
Published: July 2010

Health care providers often prescribe exercises as treatment for nonspecific low back pain. However, the effectiveness of this treatment is poorly documented in the literature. While the evidence suggests that exercise in general is beneficial, there is a lack of knowledge about the types, frequency and duration of exercises that should be prescribed and at what stage of injury they are most helpful. In addition, few studies have dealt with exercise treatment alone rather than in combination with other treatments, making it hard to decipher the unique contribution of exercise. Inadequate study designs also make conclusions difficult. Conversely, the literature clearly shows that inactivity has detrimental effects (i.e. delayed return to normal activity, and negative physiological and psychological effects) for low back pain patients.
Clinical benefit of intensive dynamic exercises for low back pain
Authors: Manniche C. , Manniche Claus
Published: July 2010

Over the years there has been an apparent contradiction between the widely utilized treatment of low back pain through exercise, and the often apparently disappointing results reported in the scientific literature. Recently published studies have shown that the most important factor regarding the training effects of chronic low back patients is the administration of a high training stimulus (number of repetitions of the exercise, exercise resistance, and the total number of sessions). This would explain why several of the previously published studies regarding training show insignificant results. Simply stated, in many low‐dosage or short‐time studies, the positive effects of training have not had adequate opportunity to take hold in the chronic low back pain patient. The patient group which has been operated on for disc prolapse often exhibits considerable functional deteriorations post‐operatively. Rehabilitation studies have shown that many of these patients also benefit from post‐operative rehabilitation including high dosage exercise programs. Exercise programs are generally free of side‐effects.
Nontraumatic glenohumeral instability and coracoacromial impingement in swimmers
Authors: Bak K.
Published: July 2010

Competitive swimming is one of the most demanding and time‐consuming sports. Swimmers at elite level practice 20–30 h per week. During 1 year's practice, the average top level swimmer performs more than 500,000 stroke revolutions per arm. These innumerable repetitions over many years of hard training together with an increasing muscular imbalance around the shoulder girdle seem to be the main etiological factors in the development of the overuse syndrome swimmer's shoulder. Shoulder pain in swimmers has in general been regarded as synonymous with coracoacromial impingement, i.e. anterior shoulder pain due to rotator cuff tendinitis, but new knowledge suggests that a concomitant glenohumeral instability plays an additional role. The diagnostic complexity of the problem is as challenging as the search for the gold standard of treatment. The condition should ideally be diagnosed as early as possible, and intensive functional rehabilitation of the shoulder girdle including the scapular muscles should be started in order to restore muscle balance. The surgical possibilities include subacromial decompression in cases of purely mechanical impingement. If a painful glenohumeral instability persists after intensive functional rehabilitation, anterior capsulolabral reconstruction can be performed. Still, however, short‐ and long‐term results show that surgery is less successful in elite athletes involved in overhead sports. Prevention protocols include education of coaches in primary injury prophylaxis and the institution of resistance strength training in prepubescent swimmers. Emphasis should be made to improve muscular balance around the glenohumeral and scapulothoracic joints.
The sportsman's hernia ‐ fact or fiction?
Authors: Fredberg U. , Kissmeyer‐Nielsen P.
Published: July 2010

This review is based on the results of 308 operations for unexplained, chronic groin pain suspected to be caused by an imminent, but not demonstrable, inguinal hernia: the ‘sportsman's hernia’ (SH). No differences in perioperative findings between cured and non‐cured athletes were found. However, there was a remarkable difference between the various perioperative findings in the studies. It was characteristic that further clinical investigation of the noncured, operated athletes gave an alternative and treatable diagnosis in more than 80% of cases. Herniography was used consistently in the diagnostic process in all the studies on SH. However, in 49% of cases hernias were also demonstrated on the opposite, asymptomatic groin side. In conclusion, the final diagnosis (and treatment) often reflects the speciality of the doctor and the present literature does not supply proper evidence to the theory that SH constitutes a credible explanation for chronic groin pain.
Calf muscle strength in former elite distance runners
Authors: Trappe S. W. , Costill D. L. , Goodpaster B. H. , Pearson D. R.
Published: July 2010

The purpose of this investigation was to examine calf muscle strength and cross‐sectional area in 29 middle‐aged men (current mean=48.4±3.1 years) who had significant differences in their physical activity levels. These men were initially evaluated to determine the physiological requirements for successful distance running in the late 1960s at a time when they were all considered elite distance runners. Based on their training regimens in the interim between testing, subjects were described as highly trained (HI; n=10), fitness trained (FIT; n=12), or untrained (UT; n=7). In addition, an aged‐matched sedentary group (CON; n=7) was tested. Each subject was evaluated for Vo2max plantar flexion calf muscle strength and cross‐sectional area (CSA) of the lower leg (gastrocnemius and soleus). Muscle CSA was determined by computed tomography, whereas calf strength measurements were made using a specially designed leg restraint system and an isokinetic dynamometer. There were no significant differences in plantar flexion strength (at 60 and 180°/s) or CSA of the gastrocnemius and soleus muscles among the groups. Calf muscle strength per CSA was also similar at both test velocities for all groups. These data demonstrate that middle‐aged distance runners who have continued to run at a relatively high level for 20–25 years have similar calf muscle CSA and strength compared with aged‐matched males who run significantly less or not at all.
Injuries in elite volleyball
Authors: Aagaard H. , Jørgensen U.
Published: July 2010

During the 1993–1994 volleyball season, injuries to players in the two Danish elite divisions were registered by means of a questionnaire survey. Eighty per cent of the players returned the questionnaire. A total of 70 female players reported 79 injuries and 67 male players reported 98 injuries, representing an overall incidence of 3.8 injuries per player per 1000 volleyball hours played. The injury incidence was the same for female and male players. Most injuries occurred in spiking (32%) and in blocking (28%). The injuries were predominantly either acute injuries to fingers (21%) and ankles (18%) or overuse injuries to shoulders (15%) and knees (16%). Shoulder injuries seemed to be a more serious problem in females. During the past 10 years the rate of overuse injuries has increased from 16% to 47% in male elite volleyball, corresponding to a significant increase in the incidence of these injuries from 0.5 to 1.8 injuries per player per 1000 played hours (P<0.001). A possible explanation for this could be a 50% increase in training activity during this period.
Viscoelastic stress relaxation during static stretch in human skeletal muscle in the absence of EMG activity
Authors: Magnusson S. P. , Simonsen E. B. , Dyhre‐Poulsen P. , Aagaard P. , Mohr T. , Kjaer M.
Published: July 2010

The present study sought to investigate the role of EMG activity during passive static stretch. EMG and passive resistance were measured during static stretching of human skeletal muscle in eight neurologically intact control subjects and six spinal cord‐injured (SCI) subjects with complete motor loss. Resistance to stretch offered by the hamstring muscles during passive knee extension was defined as passive torque (Nm). The knee was passively extended at 5o/s to a predetermined final position, where it remained stationary for 90 s (static phase) while force and integrated EMG of the hamstring muscle were recorded. EMG was sampled for frequency domain analysis in a second stretch maneuver in five control and three SCI subjects. There was a decline in passive torque in the 90‐s static phase for both control and SCI subjects, P<0.05. Although peak passive torque was greater in control subjects, P<0.05, there was no difference in time‐dependent passive torque response between control (33%) and SCI (38%) subjects. Initial and final 5‐s IEMG ranged from 1.8 to 3.4 μ V.s and did not change during a stretch or differ between control and SCI subjects. Frequency domain analysis yielded similar results in both groups, with an equal energy distribution in all harmonics, indicative of ‘white noise’. The present data demonstrate that no measurable EMG activity was detected in either group during the static stretch maneuver. Therefore, the decline in resistance to static stretch was a viscoelastic stress relaxation response.
High prevalence of elbow problems among goalkeepers in European team handball ‐ ‘handball goalie's elbow’
Authors: Tyrdal S. , Bahr R.
Published: July 2010

The aim of this study was to describe elbow problems among goalkeepers in team handball. A questionnaire was sent to the coaches of 449 senior and 32 junior teams in Norway in 1992. Of these, 304 coaches responded (63%) and their teams were included in the study. A total of 329 out of 729 goalkeepers (45±1.8%) and 166 out of 4120 court players (4.0±0.3%) were reported by their coaches to have current or previous symptoms from one or both elbows when playing handball. In response to a second questionnaire sent to all the goalkeepers (729; response rate 81%), 41±2.0% reported current elbow problems and an additional 34±2.0% reported previous problems. During a 2‐year observation period from 1992 to 1994, 8.6±1.8% of the goalkeepers with previously healthy elbows experienced elbow problems. The typical complaint was recurrent pain and disability episodes, each with an acute onset, but with varying duration. The mechanism of injury for the goalkeepers appears to be repeated hyperextension traumas. We conclude that elbow pain and disability is a significant problem for a large number of goalkeepers in team handball. These problems may be described as a syndrome called ‘handball goalie's elbow’.
Low LDL oxidation in veteran endurance athletes
Authors: Kujala U. M. , Ahotupa M. , Vasankari T. , Kaprio J. , Tikkanen M.J.
Published: July 2010

The ‘oxidation hypothesis’ states that oxidative modification of low‐density lipoprotein (LDL) is important in the pathogenesis of the atherosclerotic lesion. Physical exercise has been reported to reduce clinical manifestations of atherosclerosis. We compared the effects of aerobic physical exercise history on oxidation characteristics of plasma LDL at rest in non‐smoking male veteran endurance athletes (n= 15) and control subjects (n= 16). As an indicator of LDL oxidation we used a method which provides an estimate of LDL diene conjugation in vivo. The athletes had lower plasma LDL cholesterol diene conjugation (P= 0.003). They also had lower cholesterol, lower LDL and higher high‐density lipoprotein (HDL) cholesterol. Intensive physical exercise energy expenditure correlated inversely with LDL diene conjugation (r=−0.41, P= 0.021). We conclude that participation in intensive physical exercise training is associated with reduced plasma LDL fraction oxidation as reflected by LDL diene conjugation. This finding may have relevance for studies aiming to explain the variation in occurrence of ischemic heart disease.
Function and biomechanics of tendons
Authors: Kirkendall D. T. , Garrett W. E.
Published: July 2010

Tendon is a highly organized connective tissue joining muscle to bone, capable of resisting high tensile forces while transmitting forces from muscle to bone. The dense, regularly arranged collagenous tissue is made up of fibers, cells of various shapes and ground substance. The mechanical and physiological characteristics of collagen (nearly 85% of the dry weight of tendon) dictate the qualities of tendon. In addition, tendon is flexible so that it can bend at joints, as well as acting as a damping tissue to absorb shock and limit potential damage to muscle (1). Tendon also shows a degree of extensibility. If the strain used to stretch a tendon could be recovered, a beneficial elastic effect would be achieved. Muscles lengthen and shorten in a cyclical manner. During the lengthening period, elastic energy can be stored and used as elastic recoil. For example, the Achilles tendon is stretched late in the stance phase as the triceps surae muscles contract and the ankle dorsiflexes. Prior to plantarflexion, muscle activation ceases and stored energy helps to initiate planter flexion.
Etiology and pathophysiology of chronic tendon disorders in sports
Authors: Kannus P.
Published: July 2010

In sports medicine, a chronic overuse injury is defined as a long‐standing or recurring orthopedic problem and pain in the musculoskeletal system, which started during exertion due to repetitive tissue microtrauma (1). Repetitive microtrauma, which is basically repeated exposure of the musculoskeletal tissue to low‐magnitude forces, results in injury at the microscopic level, and no single acute trauma is normally involved in the pathogenesis of an overuse injury. In chronic tendon disorders, ‘overuse’implies that the tendon has been strained repeatedly to 44% strain until unable to endure further tension, whereupon injury occurs (2). The structure of the tendon is disrupted micro‐ or macroscopically by this repetitivestrain, i.e. collagen fibers begin to slide past one another, causing breakage of their cross‐linked structure, and denaturate; inflammation, edema and pain result. Thus, tendinitis, peritendinitis, tenosynovitis, insertion tendinitis, tendinous bursitis or apophysitis is the earliest clinically recognizable manifestation of overuse tendon injury (3).
Etiology and pathophysiology of tendon ruptures in sports
Authors: Kannus P. , Natri A.
Published: July 2010

Of all spontaneous tendon ruptures, complete Achilles tendon tears are most closely associated with sports activities (1–3). Schönbauer (3) reported that 75% of all ruptures of the Achilles tendon are related to sports. In Plecko & Passl (2) the number was 60%. In our material of 430 cases, the number of sports‐related Achilles ruptures was very similar (62%), while only 2% of ruptures of other tendons were sports‐related (P<0.001) (1). Also, the majority of Achilles reruptures occurred in sports. The ruptures occurred most often in soccer (34%), track and field (16%) and basketball (14%). The distribution of Achilles ruptures according to different sports varies considerably from country to country, according to the national sport traditions. For example, in northern and middle Europe, soccer, tennis, track and field, indoor ball games, downhill skiing, and gymnastics are the most common; and in North America, football, basketball, baseball, tennis and downhill skiing dominate the statistics (1, 2, 4). In sports, some Achilles ruptures are not spontaneous or degeneration‐induced but may occur as a consequence of the remarkably high forces that are involved in the performance (2). Ruptures in the high jump or triple jump are good examples. In such cases, failure in the neuromuscular protective mechanisms due to fatigue or disturbed co‐ordination can frequently be found. The spontaneous complete rupture of the supraspinatus tendon of the rotator cuff does not occur very frequently in sports. Those sports that include high‐energy throwing movements, such as American and Finnish baseball, American football, rugby and discus and javelin throwing, may, however, produce this injury. Partial tears and inflammations of the rotator cuff complex are much more frequent in throwing sports. The complete rupture of the proximal long head of the biceps brachii tendon is rare among competitive and recreational athletes. In our material, under 2% of these ruptures were associated with sports activities (5). The rupture (avulsion) of the distal tendon of the biceps muscle is rare. In sports, gymnastics, body building and weight lifting have been said to be able to produce this injury (6). In general, complete ruptures of the quadriceps tendon and the patellar tendon occur most often in older individuals. In our study, the mean age of these patients was 65 years (5). However, these injuries do also occur in younger age groups, especially in athletes. In athletes, the rupture most frequently occurs in high‐power sports events, such as high jump, basketball and weight lifting, at the age of 15‐30 years. A chronic patellar apicitis (jumper's knee) may predispose rupture of the tendon (7). As is the case with the rotator cuff complex, overuse inflammation and partial tears of the quadriceps and patellar tendons are one of the most characteristic athletic injuries. Complete spontaneous ruptures of other tendons in sports are rare, although the literature does provide case studies from almost every tendon the human body possesses (8–18).
Histopathological findings in spontaneous tendon ruptures
Authors: Józsa L. , Kannus P.
Published: July 2010

A spontaneous rupture of a tendon may be definied as a rupture that occurs during movement and activity, that should not and usually does not damage the involved musculotendinous units (1). Spontaneous tendon ruptures were uncommon before the 1950s. Böhler found only 25 Achilles tendon ruptures in Wien between 1925 and 1948 (2). Mösender & Klatnek treated 20 Achilles tendon ruptures between 1953 and 1956, but 105 ruptures between 1964 and 1967 (3). Lawrence et al. found only 31 Achilles tendon ruptures in Boston during a period of 55 years (1900‐1954) (4). During the recent decades tendon ruptures have, however, become relatively common in developed countries, especially in Europe and North America. A high incidence of tendon ruptures has been reported in Austria, Denmark, Finland, Germany, Hungary, Sweden, Switzerland and the USA; somewhat lower incidences have been reported in Canada, France, Great Britain and Spain. On the other hand, Greece, Japan, the Netherlands and Portugal have reported a clearly lower incidence. Interestingly, Achilles tendon ruptures are a rarity in developing countries, ecpecially in Africa and East‐Asia (5). In many developed countries, the increases in the rupture incidence have been dramatic. In the National Institute of Traumatology in Budapest, Hungary, the number of patients with an Achilles tendon rupture increased 285% in men and 500% in women between two successive 7‐year periods, 1972‐1978 and 1979–1985(5).
Immediate external compression in the management of an acute muscle injury
Authors: Thorsson O. , Lilja B. , Nilsson P. , Westlin N.
Published: July 2010

In a prospective, non‐randomized study 40 athletes with contusion or distension injuries to the thigh or the calf muscle were followed with tests of range of motion (ROM) of knee or ankle joint, test of serum creatine kinase (CK) and ultrasonography of the injury until completely recovered. An experimental group of 19 injuries where subjects received treatment with application of a maximum compression bandage within 5 min (mean=2 min) of the injury was compared to a control group of 21 injuries where subjects were treated with rest and elevation only, and in some cases non‐maximum compression after 10–30 min. No significant differences were noted with respect to time to complete subjective recovery, ultrasonic size of the injury or time to normal findings on ultrasound between treatment and control groups. Strain injuries, although showing a tendency to be smaller in size, took a longer time to complete recovery than contusion injuries (mean±SD=26±22 days and 19±9 days, respectively, P=0.02). Diagnostic CK values and reductions in ROM were not correlated to the severity of the trauma, while ROM showed weak correlation to the sonographically measured size of the hematoma (r=0.42; P<0.01). Injuries displaying a circumscript anechoic, low‐echogenic or mixed lesion at the diagnostic ultrasound investigation normalized more slowly (P=0.001) and took longer to complete recovery (P=0.001) than injuries with diffuse hyperechogenic lesions. We conclude that in this study the application of a maximum compression bandage within 5 min of a muscle trauma did not significantly reduce the size of the hematoma nor significantly shorten the time to complete subjective recovery compared with no immediate treatment. The diagnostic ultrasound investigation was valuable in predicting the severity of the trauma.
Muscle phosphocreatine repletion following single and repeated short sprint efforts
Authors: Dawson B. , Goodman C. , Lawrence S. , Preen D. , Polglaze T. , Fitzsimons M. , Fournier P.
Published: July 2010

Phosphocreatine (PCr) repletion following either single (1x6 s, n=7) or repeated (5x6 s, departing every 30 s, n=8) maximal short sprint cycling efforts was measured in separate groups of trained subjects. Muscle biopsies (vastus lateralis) were taken pre‐exercise before warming up, and then at 10 s, 30 s and 3 min post‐exercise. After the 1 × 6 s sprint PCr concentration was respectively, 55% (10 s; P<0.01), 69% (30 s; P<0.01) and 90% (3 min; NS) of the pre‐exercise value (mean±SD) (81.1±7.4 mmol · kg−1 DM), whereas after the 5 × 6 s sprints, PCr concentration was, respectively, 27% (10 s; P<0.01), 45% (30 s; P<0.01) and 84% (3 min; P<0.01) of the pre‐exercise value (77.1±4.9 mmol · kg−1 DM). PCr concentration was correlated with muscle lactate at 30 s (r=−0.82; P<0.05) and 3 min of recovery (r=−0.94; P<0.01) for the 1 × 6 s sprint, but not for the 5 × 6 s sprints. The extent of PCr repletion was significantly greater after the 5 × 6 s sprints than the 1 × 6 s sprint between both 10 s and 30 s and 30 s and 3 min, despite lower PCr levels at 10 s, 30 s and 3 min following the 5 × 6 s sprints. Full repletion of PCr is likely to take longer after repeated sprints than single short sprints because of a greater degree of PCr depletion, such that replenishment must commence from lower PCr levels rather than because of slower rates of repletion.
Radial epicondylalgia (‘tennis elbow'): treatment with stretching or forearm band. A prospective study with long‐term follow‐up including range‐of‐motion measurements
Authors: Sölveborn S.‐A.
Published: July 2010

Stretching or upper forearm bands were used in the treatment of radial epicondylalgia (‘tennis elbow') in a prospective study of 185 patients. The two consecutive series did not differ with respect to, for example, age (median 43 years), gender (57% men), symptom duration (mean 12 months) and symptomatic elbow (68% right), and were examined before and after 1 month of treatment, then at 3 and 9 months, and at a longterm follow‐up (44/33 months). The 94 stretching‐treated patients were instructed to perform home exercises twice daily, but were also treated at six physiotherapist sessions the first month. The other 91 patients were told to use a prescribed proximal forearm band in daily activities as much as possible. Both treatments were successful with a continuous symptom reduction, but the outcome was statistically significant in favour of stretching at all follow‐ups, as assessed by subjective evaluation on a visual analogue pain scale, tabulated pain and condition alternatives on questionnaires, and objective findings such as palpation tenderness at the radial epicondyle, the (Mills') ‘tennis elbow pain test’, and range‐of‐motion. Practically all measured range‐of‐motions were restricted in both groups before treatment and did increase with stretching during the follow‐up period, while the various changes in the forearm band group were statistically non‐significant.
Registration of cruciate ligament injuries in Norwegian top level team handball. A prospective study covering two seasons
Authors: Myklebust G. , Maehlum S. , Engebretsen L. , Strand T. , Solheim E.
Published: July 2010

All cruciate ligament injuries in the three upper divisions for men and women (3392 players) in Norwegian team handball in the 1989‐90 and 1990–91 seasons were registered. A questionnaire was mailed to all injured players. Ninety‐three cruciate ligament injuries were registered; 87 in the anterior cruciate ligament (ACL), and six in the posterior cruciate ligament (PCL). Among women, 1.8% were injured compared with 1.0% of the men. In the first division, the risk of being injured was considerably higher: 4.5% of the players had a cruciate ligament injury. There were 0.97 cruciate ligament injuries per 1000 playing hours in the three divisions taken together. Seventy‐five per cent of the injuries occurred during games. Ninety‐five per cent involved no contact between players. Activities in which the friction between shoe and floor was significant caused 55% of the injuries. Injuries caused by running into another player contributed to only 5% of the injuries. No significant differences were observed in injury incidence during matches between different types of floors (parquet, Pulastic and other synthetic sufaces).
Injuries in young female players in European team handball
Authors: Wedderkopp N. , Kaltoft M. , Lundgaard B. , Rosendahl M. , Froberg K.
Published: July 2010

The purpose of this study was to examine the nature, extent and severity of sports injuries in young female players in European team handball and to identify the etiological factors involved in the injuries. Twenty‐two teams with 217 players, aged 16–18 years, participated in the study. A very high injury incidence during games was observed, with 40.7 injuries/1000 hours of game. Backplayers had the highest incidence (54.8/1000 hours), which is five times higher than any previously recorded injury incidence in players in European team handball. We found that 92.9% of injuries were traumatic and 7.1% were from overuse. One‐hundred and twenty‐four of the 211 injuries were traumatic injuries of the lower extremities. Of these 63 (51%) were without contact with an opponent. The study confirmed that European tesm handball is a sport that has a very high injury rate, especially regarding young female players. Field position and earlier injuries are major risk factors, with an earlier injury being the single highest risk factor and with backplayers having a significantly higher number of injuries than players in other field positions.
Passive properties of human skeletal muscle during stretch maneuvers
Authors: Magnusson S. P.
Published: July 2010

Despite limited scientific knowledge, stretching of human skeletal muscle to improve flexibility is a widespread practice among althletes. This article reviews recent findings regarding passive properties of the hamstring muscle group during stretch based on a model that was developed which could synchronously and continuously measure passive hamstring resistance and electromyographic activity, while the velocity and angle of stretch was controlled. Resistance to stretch was defined as passive torque (Nm) offered by the hamstring muscle group during passive knee extension using an isokinetic dynamometer with a modified thigh pad. To simulate a clinical static stretch, the knee was passively extended to a pre‐determined final position (0.0875 rad/s, dynamic phase) where it remained stationary for 90s (static phase). Alternatively, the knee was extended to the point of discomfort (stretch tolerance). From the torque‐angle curve of the dynamic phase of the static stretch, and in the stretch tolerance protocol, passive energy and stiffness were calculated. Torque decline in the static phase was considered to represent viscoelastis stress relaxation. Using the model, studies were conducted which demonstrated that a single static stretch resulted in a 30% viscoelastic stress relaxation. With repeated stretches muscle stiffness declined, but returned to baseline values within 1 h. Long‐term stretching (3 weeks) increased joint range of motion as a result of a change in stretch tolerance rather than in the passive properties. Strength training resulted in increased muscle stiffness, which was unaffected by daily stretching. The effectiveness of different stretching tecniques was attributed to a change in strech tolerance rather than passive properties. Inflexible and older subjects have increased muscle stiffness, but a lower stretch tolerance compared to subjects with normal flexiblity and younger subjects, respectively. Although far from all questions regarding the passive properties of humans skeletal muscle have been answered in these studies, the measurement technique permited skeletal muscle.