References

Exercise, the menstrual cycle, and reproduction. Infertility ReprodMed ClinicsN Am 1998 9 667-87. 2 Warren MP, Shangold MM. Sports Gynecology Problems and Care of the Athletic Female. Cambridge, MA Blackwell Science, 1997. 3 Constantini NW, Warren MP. Physical activity, fitness, and reproductive health in women clinical observations. In Bouchard C, Shephard RJ, Stephens T, eds. Physical Activity, Fitness and Health International Proceedings and Consensus Statement....

Cardiovascular disease

Over the last five decades cardiovascular disease (CVD) has been the most common cause of death in the Western world. Inside the EU, 44 of all deaths are attributed to CVD and this is almost twice as many as all cancers put together 2 . CVD rates have decreased during the last few decades in Western countries especially in men below the age of 75 years 3,4 . This development is in contrast to the Eastern European countries, where CVD rates have increased. The positive trend in the Northern...

Prevention of cardiovascular disease

The Bogalusa heart study has shown that atherosclerosis begins early in life 13 . The following risk factors were identified as predictors of fatty streaks and fibrous plaques in the coronary arteries and aorta of young individuals 13 body mass index, systolic and diastolic blood pressure, serum concentrations of total cholesterol, triglycerides, low-density lipoprotein cholesterol and smoking habits. A large number of studies has been performed to assess the effects of increased PA on the...

Congenital heart disease and arrhythmia

There are several different congenital heart defects and arrhythmias, most of which may be subdivided according to their severity. Furthermore, surgical corrections and individual factors may further influence hemodynamics at rest and during exercise. In the 1960s and 1970s, a restriction in physical activities and sports participation was implemented in almost every child with a suspected or proven congenital heart disease or arrhythmia. The discussion and guidelines over the recent years,...

Exercise after acute myocardial infarction

In the 18th century William Heberden and Caleb H. Parry recommended physical activity for patients with angina pectoris 13,14 . Other views soon became dominant and for almost 200 years rest was a major part in the treatment of angina pectoris and in myocardial infarction. In the 1950s the bed rest period after a my-ocardial infarction was shortened and it was reported that the patients having shorter bed rest after a myocar-dial infarction returned to normal activities sooner. It was shown...

Physical inactivity and the burden of cardiovascular disease in type 2 diabetes

Patients with type 2 diabetes have a two- to four-fold increased mortality from cardiovascular disease 6 . The ultimate goal of all therapies in type 2 diabetes is to reduce this burden. In the Aerobic Center Longitudinal Study discussed above 7 , the association between low cardiorespiratory fitness and physical inactivity and total mortality in 1263 men with type 2 diabetes was also studied. After adjustment for age, preexisting and family history of cardiovascular disease, fasting glucose...

Prevalence of eating disorders among athletes

The epidemiology of eating disorders poses a particular challenge to investigators due to problems with case definition, and the tendency of eating-disordered subjects to conceal their illness and avoid professional help. Estimates of the prevalence of the symptoms of eating disorders and clinical eating disorders among female athletes range from less than 1 to as high as 75 108,118,119 . The prevalence of anorexia nervosa (2.2 ), bulimia nervosa (7.2 ) and subclinical eating disorders (10 )...

Multiple choice questions

For each question, please indicate which of the statements a-e is correct. 1 Exercise-induced chest pain and heartburn a are more common in weight lifters and swimmers than runners c require adequate evaluation to exclude a cardiac d occur more often fasting than after meals e are best treated with anticholinergic or sedative 2 Exercise-associated abdominal pain a is generally worse during training than competition b may be associated with diarrhea or a strong urge to have a bowel movement c...

Acute myotendinous groin injuries

The iliopsoas can be strained by a forceful flexion against resistance as occurs when the ground is mistakenly kicked instead of the ball, or in eccentric contraction, e.g. when the thigh is forced into extension. The adductor muscles are usually strained in eccentric contraction, e.g. in a forceful abduction, often with some degree of hip joint rotation, as in a sliding tackle in soccer. The injury usually occurs in the myotendinous junction but can also occur in the tendon itself or at the...

Adaptability of older people to exercise Crosssectional perspective

In Fig. 3.3.3 the decline in sports performance that occurs with increasing age was described in terms of changes in world record performances. These athletes represent a highly elite population of individuals, some of whom have continued in competition since adulthood, whilst others are those who have come into a sport as a master or veteran competitor. Physiologic analysis in the laboratory of these athletes reveals that as a general rule, and as with their performance or competition data,...

Anatomy

The pelvic region is an essential part of the functional anatomy in most sports activities. The pelvis needs to be stable and well controlled for the athlete to perform with skill. The pelvis is the turning point between the upper and the lower part of the body. Multiple muscles and ligaments originate from and or insert onto the pelvis, and to control and stabilize the pelvis a delicate balance exists between these structures to coordinate the movements passing through this region. Two of the...

Ankle joint injuries Ankle arthroscopy

Ankle arthroscopy is a valuable tool in the diagnosis and treatment of various intra-articular ankle disorders. Visualization of intra-articular pathology without arthrotomy is possible, thus reducing the risk of surgical complications. Indications for ankle arthroscopy are osteochondral fractures, chondral lesions, soft tissue impingement, bony impingement, post-traumatic osteoarthritis and loose bodies. Chronic pain at the anterior aspect of the ankle joint is rather frequent in athletes,...

Anterior posttraumatic instability

This is the most common type of shoulder instability. It is the result of a shoulder trauma which causes Table 6.6.4 Pathoanatomic conditions leading to laxity. Abnormal version of either the glenoid or Fraying secondary to hyperelasticity of the deformation Avulsion from glenoid or humeral head Generalized joint laxity Loss of proprioceptive feedback Tendon rupture,SLAP lesion Cumulative microtrauma Paresis due to nerve damage Fig. 6.6.26 Classification of recurrent shoulder instability. Fig....

Anterior tibial compartment syndrome

Anterior tibial syndrome exists in both an acute and a chronic form, both caused by overuse 6 . The acute anterior tibial syndrome is an exertional pain syndrome with dramatic symptoms including pain and major swelling and should be treated by early fasciotomy. Ischemia and muscle necrosis may develop if the diagnosis is missed and treatment is delayed. The subcutaneous fasciotomy should not be used, in order to avoid the tourniquet effect by intact skin in the distal leg and ankle. Chronic...

Avulsion fractures

Avulsion fractures about the pelvis occur almost exclusively in the adolescent population. The apophyses make a relatively weak connection to the central bony skeleton through the zone of provisional calcification of the growth plate. Powerful muscle contractions from the muscles around the hip and pelvis are occasionally able to overpower the stability of the growth plate and cause avulsion fractures. There are three typical locations for avulsion fractures of the pelvis (i) anterior superior...

Basic examination

The general impression of the shoulder contours gives valuable information Is this a muscular or a slight individual Is there atrophy on the affected side of the deltoid (as in axillary nerve palsy), the supraspinatus (as in rotator cuff rupture) or the infraspinatus muscles (as in suprascapular nerve palsy in volleyball players) Is the humeral head in joint (An epulet shoulder is characteristic of acute dislocation.) Is the acromioclavicu-lar joint intact or is the clavicle protruding Ask the...

Bursitis

There are at least 13 permanent bursae present in the hip region, and they are often localized between tendons and muscles and over bony prominences. The pathologic conditions involving the bursae can be divided into traumatic and inflammatory conditions. Traumatic bursitis can be called hemorrhagic bursitis, or hemobursa. The most common cause of hemorrhagic bursitis is either a direct trauma, e.g. a fall against the bursa, or an indirect trauma through a strain in a passing tendon with...

Carbohydrate

The focus with regard to athletes' diets has been on carbohydrate intake in particular, since the body's glycogen stores are very limited. Although glycogen content is increased about two-fold in a well-trained Table 2.4.6 Size of glycogen stores on different diets. From 25 . athlete compared with a sedentary person (Table 2.4.6), the glycogen stores are still a limiting factor for exercise endurance and intensity (see Chapter 1.2). Compared with the fat stores, glycogen stores can supply...

Cardiac structure

The increase in maximal cardiac output (Qmax) following endurance training results from a larger cardiac stroke volume (SV), whereas maximal heart rate (HRmax) is unchanged or even slightly reduced. While heart size is a function of total body size as well as genetic factors, the higher SV achieved by endurance training is attributed to enlargement of cardiac chamber size and to expansion of total blood volume 12 . On the basis of cross-sectional studies in both female and male...

Case story 241 Energy in long distance biking might be obtained by sport drinks and carbohydrate loading

62-year-old, non-athlete male body weight 82 kg, height 187 cm, BMI 23.4 kg m2, body fat 22 , calculated BMR 6673 kJ, Vb2max 3.42L min or 41.7 mL kg min. He participates in one of the classic Swedish sporting events (Vattern-rundan), a noncompetitive endurance biking race with no exact completion times or publication of results. The300-km Vatternrundan is a physically taxing event, as it will take the ordinary participant 15-20 h of cycling to complete. Most cyclists start in the evening and...

Case story 631

A male football (soccer) player, 27 years old, has played at elite level for 9 months. He is suffering from pain in the right groin and remembers one painful episode of hyperextension of the right hip during a match 3 months ago. The physiotherapist in the club has treated him with ultrasound, stretching, massage and some abdominal and back exercises. Six weeks after the groin pain started, he was examined at our sports medicine center. Clinical signs of adductor-related pain, iliopsoas-related...

Case story 651

The patient is a 32-year-old semiprofessional soccer goalkeeper. He has previously been treated for a complicated fracture of the distal phalanx of the right thumb and minor finger injuries, had resected an exostosis of the lateral region of the right distal femur and glenoid labral lesions in both shoulders, and has had surgical treatment of both Achilles tendons because of tendinopathy. He has played i20 compulsory matches in a row without missing one single match because of injury. During...

Case story 662

A 27-year-old weight lifter gradually developed anterior pain in his left shoulder, extending out anterolateral in the arm. He had pain when weight-lifting, but also in his daily life, lifting shopping bags, during sleep, or working with the arm above horizontal. There were few degrees reduction in flexion, but otherwise normal movements of the shoulder. He had good power in all rotator cuff muscles, but pain when abducting with power against resistance. Neer's and Hawkins' tests were positive,...

Classical reference

Knee joint changes after meniscectomy. J Bone Joint Surg 1948 30B 664-670. This paper records an investigation of changes found in the knee joint at intervals ranging from 3 months to 14 years after meniscectomy. Radiologic study. After excluding all cases with definite osteoarthritis, a comparison was made between the preoperative and postoperative X-ray films in 107 cases of meniscectomy. Owing to difficulty in securing identical views on separate occasions, the changes...

Classification systems

When taking part in competitions, classifications of the disabled athletes may be necessary for the competition to be fair. This is comparable to weight classes in various able-bodied sports. You don't match flyweight with heavy weight. Likewise you don't match slightly disabled with severely disabled in one-to-one competitions. Still one has to remember that we all are more or less different in character and physical possibilities, disabled or not. Therefore no one can expect any...

Compartment syndrome

The muscle groups in the forearm are surrounded by fasciae, which are inelastic. A rapid increase in the content of the fasciae, either hematoma, edema or hypertrophy of the musculature, therefore leads to increased compartmental pressure. With small or intermittent increases, a reversible ischemia of the muscle occurs, but the pressure may be so high that it leads to irreversible ischemia and necrosis of the muscle. A compartment pressure of 30 mmHg or more for more than 8 h leads to muscle...

Definitions

Eating disorders are characterized by disturbances in eating behavior, body image, emotions and relationships. Athletes constitute a unique population, and special diagnostic considerations should be made when working with this group 105,115,116 . Despite similar symptoms subclinical cases in athletes are easier to identify than in non-athletes 108 . Since athletes, particularly at the elite level, are evaluated by their coach every day, changes in behavior and physical symptoms may be...

Differential diagnosis

Dyspnea in relation to strenuous exercise is common and there is always a risk of interpreting this as asthma. A carefully taken history is mandatory and an exercise challenge test to confirm the presence of EIB should be performed (Fig. 4.5.3). Typically, subjects with EIB report symptoms such as dyspnea and wheeze within the first 5-10 min after the start of the first bout of exercise. Some subjects are able to run through their symptoms, and after 20-30 min seem to attain a 'second wind' and...

Direct in vivo tendon forces during normal locomotion

Normal locomotion and or muscle function usually refers to stretch-shortening cycles 2 , where the active muscle is first stretched (eccentric action) prior to shortening (concentric action). The purpose of SSC is to make the performance more efficient as compared to isolated forms of either isometric or concentric actions. Figure 1.5.23 is a typical example of how the buckle transducer technique, which can be used to characterize the loading of the triceps surae muscle-tendon complex, is...

Distribution of sonographic tendon changes

With ultrasound two distinct findings are seen, depending on whether the proximal two-thirds or the distal third of the Achilles tendon is involved. In tendons exhibiting proximal middle-third Achilles tendinosis with subtotal tendon cross-section involvement, over 90 exhibit changes in the medial segment, and isolated changes in the lateral segment are never seen. The medial distribution suggests that the tendinosis at least in part reflects increased tensile forces over the medial side of the...

Doping

The prevalence of doping in children is difficult to assess. Figures are obtained most often by self-reporting, a method that carries an inherited bias. In a meta-analysis of i6 studies of children and adolescents between 6 and 19 years of age, frequencies between 0.6 and 15 were found 65 . Misuse of anabolic steroids was most often reported. However, both human growth hormone and stimulants were also mentioned. Males in the highest age group had the highest prevalence of doping in accordance...

Doping and boosting

People with a disability may be taking medications for control of a disease process or specific symptoms, or both. Advising doctors should be aware of drugs that, if used, may be on the International Olympic Committee (IOC) list of doping substances, and in particular of certain products sold over the counter as remedies for the common cold, cough, pain, indigestion, etc., which may contain banned substances. During the Barcelona Paralympic Games in i992, 2i7 tests were performed and three were...

Editors and Contributors

Per Aagaard Team Denmark Test Center, Sports Medicine Research Unit, University of Copenhagen, Bispebjerg Hospital, Copenhagen, DK-2400N, Denmark Steven Abramowitch Musculoskeletal Research Center, Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA Lars Bo Anderson Institute of Exercise andSports Science, University of Copenhagen, DK-2200N, Denmark Arne Astrup Research Department of Human Nutrition, Royal Veterinarian and Agricultural...

Effects of mechanical strain on bone turnover and bone remodeling

Bone remodeling is also affected by mechanical strain. The general trend is decreased bone degradation, possibly caused by reduced osteoclast recruitment as mentioned above. Young recruits subjected to military training display increased bone mass at the heel of 3 , but at the same time bone formation and resorption markers go down by 10-12 37 . The impact of physical activity on bone turnover may, however, depend on the kind of exercise performed. In dogs immobilization increases bone...

Endocrine system

Aging is associated with many changes in endocrine function and a number of these changes are important with regard to physical activity. During growth and development an important role is played by growth hormone (GH) which is secreted by the anterior pituitary gland. The secretion of this hormone falls with increasing age. The fall in growth hormone secretion is particularly marked around 40 years and occurs at approximately 14 per decade 40 . The decrement in growth hormone secretion has...

Energy sources at rest

At rest, under postabsorptive conditions, fatty acids constitute the primary energy source, accounting for approximately 60 of energy requirements, leaving about 20 for carbohydrates and proteins, respectively. Postabsorptive conditions are said to be present when no nutrients are entering the blood from the intestinal tract. The energy liberated per gram of nutrient combusted is 17 kJ for carbohydrates and proteins and 39 kJ for fat. Therefore, the demand for fat combustion at rest can be...

Energy sources during exercise in the postabsorptive state

During exercise, the energy consumption may be increased by 20-fold. The primary factor determining whether carbohydrates or fat are preferentially used during exercise is the exercise intensity, the proportion of energy derived from carbohydrates growing progressively larger with increasing intensity. At a moderate exercise level of 100 W, demanding an oxygen uptake of around 1.5 L min, equalling an energy expenditure of 1800 kJ h, the proportions might typically change to 60 carbohydrates and...

Energy sources during exercise in the trained state

One factor counteracting the low fat combustion at high exercise intensities is the effect of training. It has been convincingly shown that, at a certain exercise intensity, a trained individual uses more fat than an untrained individual. This effect is quite strong and occurs after relatively short periods of training. One group of subjects was studied after 5 and 31 days of training for 2 h daily at a moderately high exercise intensity (60 of the pretraining Vo2max) 48 . Following 5 days of...

Epidemiologic evidence

Following the results of a survey by an expert group 5 of the global prevalence of obesity, the WHO has now declared obesity to be one of the major international health problems. The situation continues to worsen for example, the prevalence of overweight and obesity in England has doubled over the past 10-15 years 5 . In this same period energy consumption, estimated on a national level, has been seen to be decreasing. This must mean that energy expenditure by physical exercise has diminished...

Epidemiology

The incidence of lateral epicondylitis is about 50 in recreational tennis players over 30 years of age i . It is rarer in younger persons, probably because their tissue is stronger and more elastic, and in elite players, who in many cases have a better technique than recreational players. Besides racquet sports, lateral epicondylitis is also seen in squash and table tennis. The male female ratio is nearly i. The most important factors for development of lateral epicondylitis in tennis players...

Exercise Calculate your own BMR

Table 2.4.2 Calculation of basal metabolic rate based on age, sex and body weight (W). From 1 . Table 2.4.2 Calculation of basal metabolic rate based on age, sex and body weight (W). From 1 . been established in order to calculate BMR with reasonable accuracy based on anthropometric data (weight, length, age and sex) 1 . It has been postulated that for survival, 24-h energy turnover represents about 1.27 times BMR, and for a sedentary lifestyle total energy turnover represents about 1.55 times...

Exercise in patients with stable heart failure

In congestive heart failure exercise tolerance is severely limited the peak pulmonary oxygen uptake may be less than 10 mL O2 kg min. This is due to central factors like attenuated myocardial function (the cardiac ejection fraction is often less than 20 ), decreased inotropic response and increased diastolic pressures, and peripheral factors such as reduced vasodilator response, increased activity of sympathetic afferents and impaired muscle function. Exercise training programs, for example...

Extensor carpi ulnaris tenosynovitis

Extensor carpi ulnaris (ECU) tenosynovitis is an uncommon condition seen typically in racquet sports 62,69 . The ECU is notable because of its distinct sheath which crosses the wrist (Fig. 6.7.12) 70 . The ECU is believed to contribute to the stability of the wrist. Patients with ECU tenosynovitis typically present with dorsal ulnar wrist pain and swelling. Examination demonstrates tenderness over the ECU at the wrist with pain provoked by ulnar deviation of the wrist and restricted...

Extensor insertional tenosynovitis

2nd Dorsal Compartment Injection

Extensor insertional tenosynovitis can occur in any of the extensor tendons. Pain along the tendon is the presenting complaint. The second dorsal compartment (extensor carpi radialis longus and brevis) is the most common of the extensor tendons to be affected. It may be associated with bony thickening at the insertion site which is referred to as carpal bossing 66-68 . This condition should be distinguished from a dorsal wrist ganglion where the mass is more proximal and transilluminates....

F

Fig. 5.1.9 (a) Medial elbow pain in a competitive throwing athlete. Coronal MR image discloses a non-acute high-grade tear at the ulnar attachment of the anterior band of the medial collateral ligament (arrow). Note the poor tissue remodeling, with residual signal hyperintensity. (b) Axial fast spin echo sequence in the same patient discloses an osteophyte (curved arrow) off the posteromedial margin of the elbow joint. Note the thinning of cartilage over the posterior margin of the trochlea...

Fiber types

Within the individual motor units muscle fibers with specific characteristics exist with regard to contractile, histochemical and metabolic activity. Furthermore, muscle fibers from a given motor unit are known to be located over a relatively large area of the cross- sectional area of the muscle (up to 25 ), indicating that within a given small muscle region all fibers represented in the muscle will be present. Two main categories of motor unit exist, one of which possesses a relatively slow...

Foot pressure transducers

Force platforms as described above can be used to measure both static and dynamic plantar forces provided that the platform is capable of producing independent measures of both vertical and shear forces. In many applications, both clinical and athletic, it is desirable to have a continuous recording of the pressure distribution under the foot. Forces acting under the foot in various foot pathologies such as diabetic neuropathy, leprosies, injury and deformation are naturally different from...

Fractures of the phalanges and metacarpals

Fractures in the hand encountered in sports are often a result of low-energy injuries and are frequently stable 89 . Diagnosis is often easily made by an X-ray. On physical examination it is important to assess rotation of the ray by asking the patient to flex the fingertips and touch the palm (Fig. 6.7.17). Fractures of the distal phalanx may be divided into tuft, shaft and base or physeal fractures in children 90 . Most closed shaft and tuft fractures are stable and these may be associated...

Glycogen resynthesis

During the postexercise period, restoration of muscle glycogen reserves is crucial for recovery of exercise capacity 22,23 . Glucose is the major precursor for glycogenesis and must be supplied in the postexercise period to facilitate muscle glycogen resynthesis. The lowering of muscle glycogen levels during exercise results in activation of the enzyme glycogen synthase 24 and the more extensive the glycogen depletion, the greater the activation of glycogen synthase and glyco-gen storage 25 ....

Heat loss

In cold environments radiation and convection are the main avenues for heat loss. In winter sports convection dominates the heat transfer, since warm layers of air around the body are rapidly conveyed away from the skin by the air movement produced by the ongoing activity. The so-called wind chill index (WCI) has been constructed in which the combined effects of environmental temperature and wind are converted to a hypothetical temperature in still air, which has the same cooling effect as the...

History and physical examination

A thorough and detailed physical examination of the knee is more useful than any other diagnostic test to aid the examining physician in determining the etiology of a patient's presenting complaints. The presenting complaints for the majority of knee injuries are fairly specific in the majority of cases and a clinician should have a general idea of what to expect on physical examination after reviewing a thorough history on a patient. The initial part of the history should start with the...

Hormonal regulation of fat metabolism during exercise

The mobilization of free fatty acids from the adipose tissue during exercise is stimulated by cate-cholamines, mainly norepinephrine synthetized from sympathetic nerves, and inhibited by insulin. In adipose tissue, degradation of triglycerides into glycerol and free fatty acids is to some degree balanced by reesterification of fatty acids, using acyl-CoA and glycolysis-derived glycerol-3-phosphate. This re-esterification has been found to be 20 of the lipolytic rate at rest, but only 12 during...

How is inflammation involved in muscle injury

It has been shown that after a bout of eccentric exercise, muscle maximum force generation continues to decline for several days. These data suggest that the initial mechanical events of exercise trigger subsequent events which result in further muscle injury. Tidball summarized in an excellent review the events following muscle injury cells 5 . Mononucleated cells are activated by injury, and then provide the chemotac-tic signal to circulating inflammatory cells. Three subsequent stages of...

Imaging

Plain radiographs are usually the first choice in most conditions involving the pelvis and the hip joints (Fig. 6.3.4). When osseous involvement is suspected a stan- Fig. 6.3.4 X-ray of a female long-distance runner with groin pain. The X-ray shows a stress fracture in the pubic bone (arrows). Fig. 6.3.4 X-ray of a female long-distance runner with groin pain. The X-ray shows a stress fracture in the pubic bone (arrows). dard radiologic examination should include an antero-posterior projection...

Imaging of specific injuries

MR imaging has been shown to be accurate in depiction of meniscal and ligament tears of the knee 6,7 . Meniscal tears are classified by an intrameniscal grading system for internal signal 8 or by the presence of abnormal meniscal pathology, in which the diagnosis of a radial split, displaced fragment or bucket-handle tear may be seen (Fig. 5.1.6). An awareness of normal meniscal vascularity is essential in order to aid in preoperative planning for potential meniscal repair. While a high...

Immune system

During both moderate and vigorous physical activity leukocytes in the blood increase, which is a strengthening of the defence system. However, after prolonged intensive exercise with a duration of more than an hour at above 75 of aerobic capacity, a weakening of the immune system is found hours to days afterwards. Experimental research in animals support this hypothesis 96 , but in humans the risk of infections has been studied in epidemiologic studies. About 10 studies have reported on upper...

In vivo tendon and ligament force measurements in humans

Information on the forces produced by individual skeletal muscles, tendons and ligaments is important to the understanding of muscle mechanics, muscle physiology, musculoskeletal mechanics, neurophysiol-ogy and motor control. The methods applied to produce these forces have been both direct and indirect. Indirect estimation can refer to such methods as the mathematical solution of the actual muscle force in the indeterminate musculoskeletal system. Electromyography (EMG) has been used as an...

Increased fat oxidation

The effect of exercise on substrate utilization may exert an impact on appetite regulation and energy intake, independent of the effect of exercise on energy expenditure. The contribution of fat oxidation to energy expenditure changes from nearly 100 at rest and during low-intensity exercise to very low levels during high-intensity exercise. However, the absolute oxidation of fat may be higher during high-intensity exercise than low-intensity exercise, because of the difference in total energy...

Introduction

A physically active lifestyle and active participation in sports and physical activity is important for all age groups. Reasons to participate in sports and physical activity are many, such as pleasure and relaxation, competition, socialization, and maintenance and improvement of fitness and health. However, sports participation also entails a risk for overuse injuries as well as acute injuries, which may even lead to death or permanent disability. In the following chapters the health benefits...

Knee injuries and osteoarthritis

Experimental models of joint degeneration show that mechanical instability created by transection of the anterior cruciate ligament (ACL) and meniscectomy often leads to progressive joint degeneration. Joint instability combined with loss of sensory innervation greatly increases the susceptibility of the articular cartilage to damage 28 . The association between primary knee OA and female gender is well known 3,4 , but in OA induced by an injury no such association has yet been shown 5,14,18,51...

Lateral and posterolateral rotatory instability

The symptoms of lateral and posterolateral rotatory instability are not typical. They vary according to the degree of instability. Redislocations are rare. Most commonly complaints are vague diffuse elbow pain, clicking, catching, locking and snapping during activity. Posterolateral rotatory instability most often shows as episodes of apprehension when the arm is supinated in extension, or during supination in slight flexion when valgus stress is applied to the arm 18,51 . Demonstration of...

Lateral peroneal compartment syndrome

Isolated chronic compartment syndrome in the peroneal muscles is rarely seen. But several authors state that when there is an anterior compartment syndrome, the lateral peroneal compartment is simultaneously affected. Therefore standard surgery has been fas-ciotomy of both the anterior and lateral compartments of the leg 6 . The necessity of the strategy has been questioned, and one study 15 has shown that the results after fasciotomy of the anterior compartment alone were as good as when...

Ligament dynamization

The glenohumeral ligaments and capsule are relatively lax in the midranges of joint rotation and seem to function only at the end ranges to limit excessive translations and prevent further rotation of the humerus with respect to the scapula 18,26,33,37 . Studies have demonstrated that the rotator cuff tendons attach directly to the various capsuloligamentous components 38 . Therefore, it is possible that the glenohumeral capsule and ligaments may be loaded during contraction of the rotator cuff...

Loading models

Two tools that have been used to study cartilage response to load are in vitro models of cartilage explant loading and in vivo models of cartilage impact loading. In this section, work in these two areas will be reviewed. These two tools address several issues related to cartilage function. First is the question of what loads are required for healthy cartilage. Too small a load can lead to atrophy, an excessive load can lead to cartilage damage and future degeneration. Second is the question of...

Meniscal injuries

Injuries to the menisci are common in sports, with an incidence between 6 and 10 10000 per year 50 . They are frequently the culprits for keeping athletes out of activity and for creating early osteoarthritis. The menisci are known to serve a crucial role in the complex biomechanics of knee joint function. The fact that meniscal injury and meniscectomy may result in early osteoarthritis of the knee serves as an impetus to advance our knowledge of this structure with regard to basic...

Mental health

Epidemiologic studies have shown associations between physical activity and symptoms of depression 98-101 , clinical depression 102 and general well-being. Most studies have used self-report questions for the assessment of both physical activity and mental health. These questions are useful to identify persons with perceived mental stress, but there is a poor relationship between questionnaire variables and clinical diagnoses of stress and depression 103 . Subjects with mood disturbances have...

Minerals

Minerals and trace elements constitute about 4 of the body. The dominant part is calcium phosphate in the skeleton, representing almost 2-3 of body mass, while the trace elements constitute less than 0.02 . As the latter play an essential role in the metabolic function of the body, trace elements represent essential nutrients which must be consumed regularly, albeit in small amounts. Today 21 minerals and trace elements have been identified as essential, but recommended daily allowances (RDA)...

Musculocutaneous nerve overload

The nerve can be compressed between the lateral border of the biceps aponeurosis and the brachial fascia during repetitive elbow extension combined with forearm pronation. Symptoms are burning hyperesthesia in the lateral forearm, and tenderness and weakness of the biceps muscle. Examination reveals atrophy of biceps and reduced sensation on the lateral forearm. Treatment consists of rest and with persisting symptoms decompression with resection of a wedge of the biceps aponeurosis 56 .

Myocarditis

One reason why clinicians advise against performing vigorous exercise during acute infections is the potential for supervening myocarditis 7,8 . Acute exercise during ongoing viral myocarditis causes increased viral replication, inflammation and necrosis in the myocardium. Thus, swimming during the initial phase of coxsackie virus B3 infection in immunologically immature (2-week-old suckling) mice increased mortality 9 . Many of the affected mice died of congestive heart failure while swimming,...

Optimal fluid intake

During physical activity fluid is lost at a rate dependent on the degree of work intensity, temperature and humidity of the surroundings. Often athletes have a water loss due to sweating of 1-2L h. For elite runners this may amount to 3.5-4L in warm surroundings. Studies have shown a tendency to drink too little (involuntary dehydration) since increased thirst during physical activity does not appear until the subjects dehydrate about 1 of their body weight. This should be viewed in light of...

Osteoporosis and related fractures

Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone tissue. These changes lead to enhanced bone fragility and increased risk of fractures. Osteoporosis as such without fracture is usually symptomless and the diagnostic criterion is bone mass. The most commonly used indicator of bone mass is areal bone mineral density (BMD, g m2), which can be measured accurately by dual-energy X-ray absorptiometry (DXA). Bone density accounts for 75-85 of the variance in...

Osteoporosis Introduction

The effects of exercise on the skeleton are generally thought to be positive, and numerous studies have indicated that physical activity increases bone mass in humans. Particularly for women, physical activity is recommended for preventing the development of osteoporosis, and regular, vigorous, weight-bearing activity of 1 h or more each week is associated with an increase in bone mineral density (BMD) within a normal population 38 . However, research also indicates that too much physical...

Overload injuries and degenerative changes

Athletes who include a large portion of weight-lifting in their strengthening exercises may trigger pain in the AC joint. This type of pain and AC problem appears under various names weight lifter's shoulder, lateral osteolysis of the clavicle and AC arthritis (Fig. 6.6.35). Overload problems in the AC joint have been described by several authors and not only in weight lifters 147 150 . When athletes other than lifters suffer from AC arthritis, this could simply be due to overambitious training...

Overuse injuries Introduction

Tendon overuse injury, often called tendinitis, is a common problem in both sports and industry. Data from the Bureau of Labor Statistics (1988) indicate that tendon overuse injuries account for 48 of reported occupational illness. Also, in a large European sports clinic, a quarter of all athletes treated for knee disorders were diagnosed with tendon overuse injury 83 . Clinically, the treatment of tendon disease has been largely empirical. Typical treatment protocols include combination of...

Pathophysiology

In secondary impingement, there is nothing 'in the way' in the subacromial space, nothing that the humeral head naturally can collide with. The humeral head is brought into a position where it can collide with the acromion because of hypermobility of the head. The pathogenesis of secondary impingement seems to be glenohumeral instability with insufficiency of both the passive and dynamic stabilizers (lengthening of the glenohumeral ligaments and the anterior capsule, and dyscoordination and...

Pathways involved in the spreading of the mechanical signal to neighboring cells

Mechanical strain causes membrane perturbations, stimulation of integrin clustering resulting in increased secretion of growth factors (Fig. 1.8.2). The most important growth factors associated with cellular responses to mechanical stimuli are transforming growth factor b (TGF-b), insulin-like growth factors (IGFs), fibroblast growth factor (FGF) and EGF. TGF-b, basic FGF, and IGF-I are present in high concentrations during distraction osteogenesis and localized to osteoblastic and a small...

Physical activity and bone mass

Physical activity can influence bone mass by causing compressive or bending loads on bone. If these are sufficiently strong, they can cause a temporary deformation, strain, in bone. As a result, primary and secondary responses occur that stimulate bone formation. The purpose of the increased bone formation can be thought to act as part of a homeostatic mechanism that aims to keep deformation of bone due to mechanical loading within narrow limits in order to avoid damage of the bone structure....

Physiologic agents

There are two possible strategies for revealing doping with an agent which naturally occurs or may occur in some physiologic conditions in the human body. The more laborious way to find the solution is to make quantitative determinations of the agent itself, e.g. growth hormone (GH), and of a number of potential 'markers' of its effects. In the case of GH such markers could be e.g. insulin-like growth factor (IGF-I) and IGF binding proteins. Measurements should be made in the blood and urine....

Physiologic mechanisms linking physical activity and energy balance

Increased physical activity and less physical inactivity raises total energy expenditure, allowing individuals to consume more calories without gaining weight. There are several lines of evidence to indicate that individuals with 'a low energy output syndrome' are at an increased risk of weight gain and obesity, irrespective of whether this is caused by a genetically determined low resting metabolic rate 9 , by low levels of fidgeting or by an environmentally determined low level of physical...

Posterior compartment syndrome

This pain syndrome is mainly seen in middle-distance and endurance runners as well as in orienteers. Symptoms appear during and after running and may progress to a chronic compartment syndrome located at the gastrocnemius-soleus muscle complex. Intracompartmental pressure measurements can confirm the diagnosis, and in case of elevated pressure, fasciotomy is the ultimate treatment. The common crural fascia can be opened posteriorly at one or both sides. In some cases pain of the posterior...

Ultrasound

The term ultrasound refers to mechanical vibrations whose frequencies are above the limit of human audible perception. Medical ultrasonography utilizes frequencies in the range of 2-10 MHz. A central component of any ultrasound instrument is the transducer, which contains a small piezoelectric crystal. It serves as both the transmitter of sound waves into the body and the receiver of the returning echoes. When a brief alternating current is applied to the crystal, it vibrates at a...

Prevention of osteoporosis and fractures later in life

PA, and especially exercise which poses high strain on the bones, is associated with an elevation in bone mass and bone mineral density during childhood and adolescence 22,23 . It has been estimated that a level of PA achievable by a large proportion of children and adolescents may increase peak bone mass by approximately 7-8 24 . If the activity-related increase of bone mineral density during adolescence is maintained through adulthood, this increase might be sufficient to prevent premature...

Questions

For the following statements, please answer true (a) or false (b). 1 Physical activity can prevent type 2 diabetes and reduce the burden ofcardiovascular disease. 2 Resistive training increases capillary density in skeletal muscle. 3 An intact insulin signaling cascade is necessary for exercise to stimulate glucose uptake in type 2 diabetes. 4 Physical training improves glycemic control in type 1 diabetes. 5 Physical training improves insulin sensitivity and induces potentially antiatherogenic...

Selenium

Selenium functions as an antioxidant alone in the detoxification of heavy metals in the body and as a cofactor of the antioxidant enzyme glutathione per-oxidase. Dietary selenium deficiency increases tissue oxidative damage and it seems that selenium has a sparing effect on tissue levels of vitamin E. However in experimental studies selenium deficiency does not impair endurance capacity in rats and supplementation in humans has no effect on physical performance 82 . Selenium has also been shown...

Shoulder impingement

Basically there are three forms of impingement in the shoulder 1 primary impingement, in which the subacromial space is overcrowded and there is too little space for the supraspinatus and biceps tendons 2 secondary impingement, in which the rotator cuff is subject to microtrauma or overuse during motion, because of glenohumeral instability and 3 internal impingement, in which the undersurface of the rotator cuff collides with the superior rim of the glenoid. This is...

Skeletal muscle

Skeletal muscle is the largest organ in the body and has numerous functions most of which are impaired as a result of the aging process. Its prime role is to produce force and generate movement. It generates power during movement and also acts to brake movement. The force-generating ability of a muscle is primarily determined by its physiologic cross-sectional area. Measures of muscle strength made under isometric (static) conditions have shown that in both large and small muscles, in both men...

SLAP lesions

In the late 1980s and early 1990s, Synder and cowork-ers began to describe a lesion of the superior labral complex that included the biceps tendon 6 . This pathologic finding was called a SLAP (superior labrum anterior to posterior) lesion. Following review of over 700 shoulder arthroscopies, 20 patients had varying degrees of this SLAP lesion. The most common mechanism of injury was a fall on an outstretched arm that was forward and elevated, similar to the injury mechanism in posterior...

Spinal stenosis

Encroachment of the spinal canal, usually by hyper-trophic bone, produces signs of neural claudication, and is particularly problematic in the elderly runner or orienteering athlete (> 60 years). Symptoms may present at an earlier age when associated with previous fracture or spinal surgery. Symptoms and signs. Leg aching and numbness with or without back pain and morning stiffness. Reduced walking or running distance. Pain is normally reduced by forward flexion. In patients with a central...

Spondylolysisspondylolisthesis

Spondylolysis is defined as a defect in the vertebral isthmus (lysis) or most commonly the pars inter-articularis. Multiple factors may be involved in its genesis. In athletes, a stress fracture is considered to cause the defect, predominately located at the L5 level. Biomechanically, torsion against resistance, hyperextension and rotation are possible causative movements. Previous studies have described that spondylolisthesis is found in about 80 of spondy-lolytic lesions, but the frequency...

Sports medicine kit

A list of the most essential equipment and supplies which should be available for assessment and treatment of injuries during training and games is found in the box below. A presence of a large number of the items mentioned for general treatment is not necessarily based on scientific evidence for their effect, but is based on practical experience from team doctors and physiotherapists. Current list of permitted and prohibited Local anesthetic, local glucocorticoid Strapping tape 12 mm, 25 mm,...

Stroke

There are two types of stroke, hemorrhagic and thrombotic, which only partly have the same etiology. A thrombotic stroke is caused by clot formation (atherosclerosis) and is therefore caused by the same risk factors as CHD. A hemorrhagic stroke is a bleeding event and one of the main risk factors for this is high blood pressure. Only few epidemiologic studies separate these two conditions even if risk factors partly differ and physical activity may act differently on these two types of stroke....

Summary

Biomechanics is an interdiscipline mostly concerned with movement analysis. The laws of physics are used to calculate strain applied to anatomic structures during movement. Movements are recorded by video cameras, and small markers or sensors are placed on the subject at anatomic landmarks. The video signals Fig. 1.5.28 Example of the two-dimensional ground reaction forces, plantar pressure distribution of the forefoot sensor (P14), and raw EMG signal of the gluteus maximus (GM) in the triple...

Surgical treatment of OA

For the patient in whom the treatment modalities discussed above do not provide sufficient pain relief, surgical treatment has to be considered. While the treatment methods used are the same as for any patient with OA, the often younger age of the patient with postinjury OA provides an important confounding factor in the decision. As mentioned, these patients often have expectations of a continued high level of physical activity and usually have a longer life expectancy than the average patient...

Sweating

The physiologic capacity for heat dissipation is closely linked to the ability to sweat. This depends on the size of the individual, on the physical fitness, and on the state of heat acclimatization. Maximal sweating rates may vary between 600 and 700 mL h for a sedentary person, to about 4L h in very well trained and heat-acclimatized individuals exercising in dry heat. The evaporation of 1L sweat removes approximately 2500 kJ (2430 kJ). However, in humid conditions the amount of sweat which...

The esophagus

Exercise has been reported to cause heartburn associated with gastroesophageal reflux (GER) 23,24 and chest pain of esophageal origin. However, chest pain, whenever it occurs in the setting of exertion, demands an evaluation for cardiac cause prior to specific esophageal evaluation. Esophageal motility changes occur with exercise. However, it is difficult to quantify physiologic manometric changes in the face of movement artifact induced by running and many studies have used a cycling model....

The frequency of lower leg injuries

Lower leg overuse injuries comprise approximately 10 of all overuse injuries in athletes. In younger athletes, the incidence is lower than in older. In runners, lower leg injuries account for approximately 20 of all injuries 2,3 . James et al. 4 evaluated 232 lower leg pain conditions in 180 runners, of which 13 were lower leg overuse injuries. Some of these (6 ) were stress fractures of the tibia and or fibula. The frequency of different pain syndromes of the lower leg varies according to...

The glycemic index

More recently, not only the amount but also the types of carbohydrate have been included in the dietary guidelines to athletes. The concept of glycemic index (GI) was introduced in 1981 in order to be able to classify carbohydrates according to the postprandial increase in blood glucose 32 GI blood glucose area of test food blood glucose area of white bread 100 According to the GI method, carbohydrates can be divided into high, medium and low GI foods. In general, GI is low for foods high in...

The inguinal canal and associated structures

A number of lower abdominal lesions giving rise to groin pain in connection with athletic activities have been described. They have been named sports hernia, sportsman's hernia, incipient hernia, Gilmore's groin, pubic pain, athletic pubalgia and others. The lesions seem to be non-specific and difficult to describe pathoanatomically. The pathologic findings at surgery have been described in subjective terms as 'loose-feeling inguinal floor', 'thinning of the fascia', 'tendency to bulge',...

The risk to the individual

The risks of deleterious effects of physical activity in an infected person vary considerably, depending both on the location, degree and cause of the infection and on the intensity and type of physical activity. Vigorous or prolonged physical activity as well as intensive mental stress can lower the defense against infection. Furthermore, a subclinical complication of infection, e.g. myocarditis, can be aggravated by physical exertion. The risk level is generally higher in a competing...

The snapping hip

This condition can be ascribed to a number of very different causes. The snapping sensation is audible but not always associated with pain. When the snapping is just associated with the sound of the snapping and no discomfort or pain is felt, the condition can usually be ignored and considered to be without any pathologic importance. The snapping can be located externally, that is on the lateral side of the hip, or internally on the medial side. The external snapping hip is normally easily...