Multiple choice questions

1 What is the response of cartilage explants to moderately increased cyclic loading a increased collagen synthesis b increased proteoglycan synthesis c increased collagen degradation d increased proteoglycan degradation. 2 What is the short-term consequence to cartilage of subfracture traumatic loading of a joint a degradation of proteoglycans and collagens b cell cloning, loss of proteoglycans c chondrocyte death, cracking of cartilage and sub-chondral bone, release of cytokines d cartilage...

Effects of running training

In dogs, light or moderate intensity level training improves the properties of articular cartilage while repetitive, intensive and strenuous training can cause injury to the cartilage. Response of the articular cartilage of young beagle knee (stifle) joint to running training has been studied with three different training programs. Running exercise of 4 km day on a treadmill, 5 days a week, for 15 weeks increases the thickness and PG content (16-26 ) in the femoral cartilage, whereas collagen...

Case study 481 GI bleeding

A 30-year-old elite woman runner was admitted to hospital following completion of a marathon 8 . She had developed crampy lower quadrant abdominal pain followed by several episodes of bloody diarrhea at the 4-mile mark. Her symptoms improved transiently during the race but worsened near the end. Following the marathon she began passing frank blood per rectum and presented to an emergency room. While her past GI history was unremarkable, she had noted abdominal pain and diarrhea during peak...

Acclimatization to cold

Practically no studies exist in which the effects of cold acclimatization on physical performance have been studied. We know from some studies that the unpleasantness of cold sensations becomes reduced or habituated after 1-4 daily cold exposures, and that increased sympathetic activity and shivering is attenuated within a week 12-14 . True cold acclimatization is difficult to induce in humans. Three types of adaptation to cold are described (i) metabolic, where a greater metabolic response to...

Epidemiology of exercise health and aging

A wide perspective to exercise, health and aging is provided by studies investigating the relationships between physical activity, longevity and morbidity. One of the first well-controlled studies in the area was published by Paffenbarger et al. 7 . The authors examined physical activity levels and other lifestyle characteristics of about 17000 Harvard alumni, aged 35-74 years, over a 12-16-year period. Exercise, reported as walking, stair climbing and participation in sport, was inversely...

The magnitude of the problem

One way of getting an impression of the magnitude of the sports injury problem is by counting the absolute number of injuries. When these absolute numbers are compared with, for instance, the number of traffic accidents or the number of work-related injuries the relative extent of the sports injury problem can be revealed. Table 3.1.1 shows data from selected community-based studies from Scandinavia that describe the proportion of sports injuries as a percentage of the total number of acute...

Pathophysiology

A breakthrough in understanding the pathophy-siology of the primary, subacromial impingement came in 1972, when Neer published his article about acromioplasty as treatment of this condition 74 . He recognized that many cases of primary impingement are caused by compression of the supraspinatus tendon between the anterior undersurface of the acromion, the coracoacromial ligament and the acromioclavicular joint on one side, and the humeral head and the greater tuberosity on the other. It is...

Motoneuron firing frequency

Two basic questions can be raised is motoneuron firing frequency influenced by strength training and if that is the case, what is the functional significance To address the latter question first, motor unit discharge rates have been recorded at much higher frequencies than needed to achieve full tetanic fusion in force. Thus, transient firing frequencies of 60-200 Hz were reported in brief bursts of activity during maximal voluntary contraction of human muscles in vivo 83-86 . Muscle...

Pathomechanism and hormonal dysregulation in overtraining

Endogenous hormones are of major importance both in supplying energy during physical exercise and in the adaptations during the subsequent regeneration period. Depending on the duration and intensity of physical exercise, and during periods of intense training or repetitive competitions, changes in the blood concentrations of hormones can be measured, e.g. a decrease of the testosterone cortisol ratio, which indicate an alteration of the anabolic-catabolic balance and can be reversed by...

Neural inhibitory mechanisms

Numerous pathways in the nervous system could be responsible for exerting an inhibitory synaptic drive onto the spinal pool of a-motoneurons. As an important feature, these pathways allow for an integration of spinal and supraspinal inputs. It appears therefore that changes in the spinal neural circuitry induced by training, including alterations in synaptic gating, may emerge as a result of adaptive changes at both spinal and supraspinal levels. Consequently, considerable plasticity can be...

Rotator cuff lesions and tendon trauma Rotator cuff lesions

The rotator cuff muscles and their respective tendinous insertions to the humerus are considered the primary dynamic stabilizers of the glenohumeral joint and are extensively loaded during overhead and contact sports 117 . The rotator cuff of well-conditioned athletes stabilizes the joint successfully without injury. However, where the demands placed on the rotator cuff are increased beyond its capabilities, injury may result. These injuries can progress from inflammation to microtears to...

Medial tibial stress syndrome

Pain at the medial and posterior aspect of the distal leg is called 'medial tibial syndrome' or 'medial tibial stress syndrome' 9,10 . This is caused by overuse and is seen especially in endurance athletes as runners, triathlonists, cross-country skiers, orienteers and joggers. It is seen also in athletes participating in jumping sports, such as basketball, volleyball and other indoor ball games. Some authors state that medial tibial (stress) syndrome begins as a tendinitis, but progresses to a...

Injury and repair

Skeletal muscle injuries can be divided into two basic types. 1 In a less severe in situ necrosis type of injury only the myofibers are damaged, whereas the basal lamina and the mysial sheaths are not breached. In its mildest form such an injury occurs in eccentric exercise and more extensive in situ necrosis can be caused for example by ischemia as seen in compartment syndrome or after injection of local anesthetic (e.g. bupivacaine). Repair after in situ necrosis can be virtually complete. 2...

Determinants of flexibility

Unquestionably people exhibit differences in musculoskeletal flexibility. A component of a person's existing flexibility may be inherited, a sport-specific adaptation (loading history) or achieved by flexibility training. Previous investigations on human flexibility have measured maximal joint range of motion, but not the passive properties of the muscle-tendon unit. At the same time, it has been shown that tolerance to tensile load plays an important role in short-term and long-term gains in...

Ulnar nerve cubital tunnel syndrome and compression

The nerve which is most often affected in the arm is the ulnar nerve. Around the elbow it can be entrapped at three sites 6-8 cm proximal to the elbow at the arcade of Struthers, in the cubital tunnel, and about 4 cm distal to the elbow at the flexor carpi ulnaris and the medial intermuscular septum. Entrapment in the cubital tunnel (posterior to the medial humeral condyle and roofed by the arcuate ligament) is the most common. The ulnar nerve is elongated about 5 mm in the tunnel during normal...

References

Soccer injuries and their mechanisms a prospective study. Med Sci Sports Exerc 1983 15 267-70. 2 Ekstrand J, Hilding J. The incidence and differential diagnosis of acute groin injuries in male soccer players. Scand J Med Sci Sports 1999 9 98-103. 3 Engstrom B, Forssblad M, Johansson C, Tornkvist H. Does a major knee injury definitely sideline an elite soccer player Am J Sports Med 1990 18 101-5. 4 Nielsen AB, Yde J. Epidemiology and traumatology of injuries in soccer....

Effects of altered weightbearing

Altered weight-bearing in the joint predisposes the individual to osteoarthritis. Osteotomy through an oper ation of a 30 valgus angulation of the young beagle tibia shifts load from the medial to the lateral condyle and causes a slowly progressive osteoarthritis in immature and young adult canine knee (stifle) joints 62 . On account of the altered weight-bearing with local peak loads, early degenerative changes in articular cartilage can be observed 7 months after the operation and the lesions...

Acute ligament injuries

A sprained ankle is the most common sport-related injury, mainly in the younger age groups 48-50 . The injury may occur as an athletic trauma or during activities of daily living. The reported incidence of ankle ligament injuries varies, mainly due to the profile of sporting activities in the population (Figs 6.1.8 and 6.1.9). The incidence in a high-risk sports population is between 2 and 6 per 100 participants per season. It has been estimated that these injuries constitute approximately 25...

Principles of rehabilitation of sports injuries

Athletes, athletic demands of various sports, different injuries and many other components contribute to making the rehabilitation of an individual with a specific injury a considerable challenge. Thus, it is difficult, if not impossible, to have a cookbook approach to the rehabilitation process. While specific rehabilitation protocols exist and may indeed be useful they should only serve as guidelines. It is not within the scope of this chapter to provide detailed descriptions of those many...

History

Sports organizations for the deaf were set up many years before the First World War. They really are the forerunners of the modern sports organizations for the disabled and, with greatly improved educational and other social services, for the deaf. As early as 1924 the first world sports organization for the hearing disabled was created (Table 3.5.1). Table 3.5.1 The history of international organizations in sports for the disabled. Table 3.5.1 The history of international organizations in...

Anaerobic training

In a number of sports an athlete performs activities that require rapid development of force, such as sprinting, quickly changing direction or jumping. Also, in many sports the lactate-producing energy system (glycolysis) is highly stimulated during periods of competition. Therefore, the capacity to perform high-intensity exercise may specifically have to be trained. This can be achieved through anaerobic training. Anaerobic training results in an increase in the activity of creatine kinase...

Epidemiology

Hand and wrist injuries are common in all sports. They are more common in children than adults 7 . A study from the Cleveland Clinic showed that 14.8 of all athletic participants under the age of 16 years sustained upper extremity injuries. Of these 16 involved the hand and 9 involved the wrist 8 . Of 113 injuries of the hand and wrist 97 occurred in football, six in soccer, three in wrestling, three in baseball, two in basketball, one in ice hockey and one in rugby. They reported 96 fractures,...

Low back pain

The lifetime, i-year and point prevalence of low back pain in the adult general population is reduced in persons who are physically active for at least 3 h week 23 . Back pain is more common in the general population than in former elite athletes 24 . Weight-lifting is associated with degeneration of the entire spine, and soccer with degeneration in the lower lumbar region. The prevalence of back pain and degeneration is low in runners. The incidence of chronic low back pain varied from 50 to...

Anatomy and biodynamics Elbow and forearm

The elbow is a hinge joint with two possible motions flexion and extension. The proximal joint surface consists of the distal end of the humerus, and is divided into the trochlea, to which the semilunar notch of the ulna (olecranon) articulates, and the capitulum, onto which the radial head articulates. The distal joint surface is therefore made up of two bones, and the bony stability of the joint is dependent on both of these if the radial head is fractured or surgically removed, this reduces...

NSAIDs for treatment of tendon overuse injury

An early study showed that NSAIDs were able to inhibit the production of prostaglandins 89 . It is now thought that the mechanism of action by NSAIDs is through inhibiting cyclooxygenase (COX), which is the key enzyme for the formation of prostaglandins from arachidonic acid. Recently, two COX isoforms have been discovered. These are COX-i and COX-2, which are variably expressed in different tissues. COX-i is expressed constitutively in most tissues throughout the body, including the...

Ergometric testing and blood chemistry in overtraining

The objective assessment of the decrease in performance, which should still represent the cardinal symptom of an OTS, is often difficult under laboratory conditions. It requires a specific and standardized test ing methodology, the comparison with individual reference values respecting the periodization of training and knowledge with regard to the mechanisms of the limited energy supply during OTS. The existing findings indicate at least in endurance-trained athletes an impairment of the speed...

Muscle crosssectional area and volume

During recent years there has been a progressively growing interest in the use of non-invasive imaging techniques such as magnetic resonance imaging (MRI), computed tomography (CT) and ultrasonog- raphy to address the alteration in macroscopic muscle dimensions evoked by resistance training (Fig. i .4. i6). An accurate estimate of the total volume of a given muscle can be provided by the recording of successive axial MR images along the entire length of the limb. Fig. 1.4.16 (a) Coronal MRI...

Nerve entrapment

Peripheral nerves may become entrapped after direct trauma or inflammatory conditions. Nerves most commonly affected are the ilioinguinal, genitofemoral and lateral cutaneous femoral nerves. The obturatorial and iliohypogastric nerves may also be involved (Fig. 6.3.3). The ilioinguinal nerve transmits sensations from the proximal part of the external genitals and parts of the medial thigh. Pain in these areas should lead to suspicion of engagement of the nerve. These sensations may be elicited...

Antagonist muscle coactivation

Coactivation of antagonist muscles is involved in many types of joint movements 147,148 . Antagonist muscle coactivation could be important for several reasons to protect ligaments at the end-range of joint motion 149,150 , to ensure a homogeneous distribution of compression forces over the articular surfaces of the joint i5i , and to increase joint stiffness thereby providing protection against external impact forces as well as enhancing the stiffness of the entire limb 152 . In addition,...

Chapter

Tennis elbow is lateral epicondylitis. Lateral pain caused by degenerative cartilage disease can be seen in combination with medial pain in the case of thrower's elbow, and will show with tenderness of the lateral joint line and not tenderness at the lateral epicondyle, as typical for tennis elbow. b Yes. Valgus overload of the elbow during throwing applies stress to the medial collateral ligament, at first causing degenerative changes of the ligament and gradually loss of tension and...

Acute highaltitude illnesses

Unacclimatized healthy individuals who ascend too fast to high altitudes are at risk of developing acute high-altitude illnesses. The faster they climb and the higher they go the greater the chances of developing a serious, possibly life-threatening illness. We distinguish between acute mountain sickness (AMS), an illness dominated by cerebral symptoms which can progress to overt cerebral edema (high-altitude cerebral edema, HACE) and high-altitude pulmonary edema (HAPE). AMS often also...

Knee pain in adolescents

The structures in and around the knee are frequently injured in children in athletics as a result of chronic overuse and the special anatomic and morphologic situations in the growing adolescent. This section will focus on common causes of knee pain in the adolescent, but will also emphasize the importance of tumors and referred pain in the diagnostic approach. Traumatic, acute disorders have been covered in the previous sections. Knee pain in adolescents has many etiologies and the clinician...

Acute and overuse injuries

Both acute and overuse sport injuries are common in children and adolescents and account for a significant proportion of visits to the primary care physician. Minor injuries that do not lead to medical attention are even more frequent and may only be recognized if they cause loss of participation in practice or competition. In a recent Dutch study of children 4-13 years of age, the incidence of school sport injuries was lower in the younger children than in the older (0.5 1000 in the 4-5-year...

Stimulants amphetamine ephedrine cocaine and caffeine

Substances belonging to this group range from the potent amphetamines to the weaker caffeine and ephedrine. The substances are called sympath-omimetics and imitate the effects of the stress hormones epinephrine and norepinephrine. Amphetamines were synthesized first in 1887 and were initially commercially available as a nasal decongestant. They cause the release of excitatory neurotransmitters, such as dopamine, to stimulate the central nervous system (CNS). The main effects on the CNS include...

Choosing a test

To obtain useful information from a test, it is important that the test to be performed is relevant and resembles the conditions of the sport in question. For example, a cycle test is of minor relevance for a swimmer. There are a number of laboratory tests which evaluate various aspects of performance (Fig. 2.2.2) and are commonly used. These include determination of maximum aerobic power (maximum oxygen uptake) to evaluate the athlete's ability to take up and utilize oxygen as described in...

Etiology

Like GnRH inhibition, osteopenia may also be an adaptive response to chronic low energy intake. Metabolic factors in response to nutritional insults might mediate reproductive and bone growth adaptations. Two homeostatic mechanisms act on bone simultaneously hormones and mechanical stress. In normal circumstances, these homeostatic mechanisms maintain both skeletal integrity and serum calcium levels. However, with aging or menstrual disturbance, factors such as diet, hormonal levels and...

Eccentric muscle contraction

It has been suggested that eccentric muscle contractions require unique activation strategies by the nervous system 121 . Indications of a preferential activation of high-threshold motor units have been demonstrated during eccentric muscle contraction of submaximal intensity 122,123 , which was suggested to originate from an increased presynaptic inhibition of Ia afferents synapsing onto the low-threshold mo-toneurons I23,I24 . Measurements based on the H-reflex technique (see above) have shown...

Patellofemoral pain syndrome PFPSanterior knee pain

The diagnosis of PFPS is made if the patient has three of the symptoms listed in Table 6.2.7. The diagnosis is clinical a radiograph, CT scan or MRI will not give further information. The diagnosis of chondromala-cia during an arthroscopic procedure is inconclusive. Many patients without any symptoms from the patellofemoral joint may have chondromalacia on their patella and patients with major patellofemoral pain may have normal cartilage under arthroscopic examination. The patient will be...

Chronic myotendinous groin injuries

Image Coordination Exercise

In the athlete with longstanding groin pain the symptoms are often more diffuse. In some cases the symptoms even seem to be contradictory and confusing. The athlete describes the pain as 'moving around' and the examiner will have to be aware of the possibility that more than one cause for the chronic groin pain very often can be found 11,16 . The multiple clinical entities responsible for the chronic groin pain are probably the result of the 'first' injury causing an imbalance and altered...

Exerciseinduced bronchospasm EIB

It is well recognized that physical exercise has adverse effects in asthmatic subjects. In the 2nd century ad, Aretaeus of Cappadocia wrote 'If from running, gymnastic exercise, or any other work the breathing becomes difficult, it is called asthma' 8 , and the observation was repeated in the 17th century by the asthmatic physician, Sir John Floyer 'All exercise makes the asthmatic to breathe short and if the Exercise be continued it occasions a Fit' 9 . This phenomenon is described by the...

The assessment of maximal muscle strength

For more than seven decades the contractile strength of human skeletal muscle in vivo has been evaluated by use of various types of dynamometers. Early mechanical devices allowed muscle contraction strength to be determined during isometric (static) contraction conditions. In addition, in vivo mechanical muscle performance was assessed in dynamic contractions using sophisticated flywheel methodology 2,3 . With the evolution of motor-driven dynamometers it became possible to obtain maximal...