ISSN:0112-1642    

DOI:10.2165/00007256-199009010-00001

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

AbstractVertical jumping ability is of importance for good performance in sports such as basketball and volleyball. Coaches are in need of exercises that consume only little time and still help to improve their players’ jumping ability, without involving a high risk of injury. Drop jumping is assumed to satisfy these requirements. This assumption is supported by a review of results of training studies. However, it appears that regular jumping exercises can be just as helpful. The same holds for exercises with weights, provided the subjects have no weight-training history. In fact, for unskilled jumpers who have no weight-training history, the effects of training programmes utilising these different exercises are additive. The most effective, efficient and safe way for a coach to improve the jumping achievement of his athletes may well be to submit them first to a training programme utilising regular jumps, then to a weight-training programme and finally to a drop jump training programme.In drop jump training programmes themselves, the improvement in jumping height varies greatly among studies. This variation cannot be explained satisfactorily with the information available on subjects and training programmes. Given the current state of knowledge, coaches seem to have no other option than to strictly copy a programme which has proved to be very effective. Obviously there is a need for more systematic research of the relationship between design and effect of drop jump training programmes. The most important variable to be controlled is drop jumping technique. From a review of biomechanical studies of drop jumping, it becomes clear that jumping technique strongly affects the mechanical output of muscles. The biomechanics of 2 techniques are discussed. In the bounce drop jump the downward movement after the drop is reversed as soon as possible into an upward push-off, while in the countermovement drop jump this is done more gradually by increasing the amplitude of the downward movement after landing. It is speculated that the bounce drop jump might trigger improvement of the power output capacity of muscles, whereas the repetition of the countermovement drop jump may help to improve coordination. Future training studies are needed to determine whether drop jumping technique really affects the outcome of the training, and if so, which technique should be preferred. Also, further biomechanical research is needed to determine kinematics and kinetics of other drop jumping techniques, and to trace potential dangers. The author urges for a close cooperation between coaches and scientists in future research.

ISSN:0112-1642    

DOI:10.2165/00007256-199009010-00002

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryExercise results in marked alterations in amino acid metabolism within the body. The branched-chain amino acids, especially leucine, are particularly important since they contribute as energy substrates and as nitrogen donors in the formation of alanine, glutamine and aspartate. Leucine oxidation increases during whole-body exercise. Nonetheless, leucine’s contribution as a muscle energy substrate is small, being 3 to 4% at rest, and even lower (1%) during exercise. Traditional energy substrates (carbohydrates, lipid) remain most important. These rates of leucine oxidation can be readily attributed to skeletal muscle. Following endurance training, whole-body leucine oxidation is increased at rest and during exercise. Since its oxidation by muscle is not augmented, this whole-body increase is not due to muscle. Thus, other tissues within the body (i.e. liver) must account for this. Comparisons of leucine oxidation in rats and humans indicate that species differences exist. Much larger increases in leucine oxidation are brought about by exercise in humans. Calculations based on steady-state rates of leucine oxidation at rest and during exercise indicate that the recommended dietary intake of leucine is inadequate, since it is lower than measured whole-body rates of leucine oxidation. This inadequacy is exacerbated in individuals who are physically active.

ISSN:0112-1642    

DOI:10.2165/00007256-199009010-00003

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

AbstractThe most common location of horse-related injuries is the upper extremity (24% to 61%) with injuries to the lower extremity second in frequency (36% to 40%). The head and face sustain 20% of horse-related injuries. The most common type of injury is a soft tissue injury (92% to 1%), followed by a fracture (57% to 3%). Concussion is the third most common type of injury (63% to 2%). The most frequent cause of hospitalisation is concussion (38% to 4%) with fracture second. The most common injury which leaves residual impairment is injury to the central nervous system.The age at which most injury occurred is less than 21 years. In the latest NEISS report (1987–1988), injuries have decreased in the younger riders, but have increased in the older riders (above 24 years). More women are injured than men, but over the age of 44 years more men are injured than women, with the difference more marked in the 1987–1988 NEISS report. Previous horse-related injuries are reported frequently (37% to 25%).In mortality studies from Australia and the United States, head injuries caused the majority of deaths (78% and 60%), followed by chest injuries (9%). In the Australian study each sex had 50% of the deaths. In the United States, 60% were male, 40% female. Above the age of 24 years male deaths increasingly predominate, being 15 male deaths to 1 female above the age of 64.Concussion is divided into 3 divisions of severity which require different medical evaluation and treatment: mild in which rider is stunned or disoriented for a brief period; moderate in which there is loss of consciousness for less than 5 minutes; and severe in which there is a loss of consciousness for more than 5 minutes.Investigative need is cited in the areas of previous horse-related injury, lessons, experiencevsknowledge, epilepsy, drowning, gender, deaths, safety helmets, stirrups, and body protectors.No horse is a safe horse; some are safer than others but the horse is a potentially lethal animal. Prevention of accidents and injuries is dependent upon using knowledge previously obtained from studying horse activities. Much more information is available than in the past through the medical studies that have been done and the recommendations made by these investigators. The medical community has a responsibility to educate the horse riding public and to participate in investigations requested by the horse organizations.The foremost requirement for riders is that secured certified protective headgear secured by a chin strap or harness be worn by all riders at all times when mounted.

ISSN:0112-1642    

DOI:10.2165/00007256-199009010-00004

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummarySports-related injuries to the intricate small joints of the hand are quite frequent. The majority of such injuries result in joint contusions, partial tears or ligament sprains which do not jeopardise the basic stability of the joint and readily respond to a short course of protective splinting with rapid recovery of motion, strength and function. In fact, many patients never seek medical attention unless persisting pain, chronic swelling or restriction of motion persuade them to do so.Partial tears or sprains need to be distinguished from more serious injuries that cause profound ligamentous and capsular disruption resulting in dislocations, articular incongruency, joint instability or fracture-dislocations. While simple dislocations are readily reducible and generally stable, a complex dislocation by definition implies irreducibility by closed means. This category of complex joint injury requires prompt diagnosis, as optimal management warrants active surgical intervention to achieve a stable and congruous reduction. Following surgical repairs the injured joint is immobilised for a variable length of time, determined by the type, extent and the nature of the specific injury, prior to initiating remobilisation efforts. A supervised and well-executed rehabilitation programme should encompass all the various modalities of physical therapy that are effective in increasing mobility, correcting deformity and restoring strength and function to the injured hand. The ultimate goal of treatment is to enable the athlete to resume sports, unimpaired with the same skill, dexterity and competitive edge as before.

ISSN:0112-1642    

DOI:10.2165/00007256-199009010-00005

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

AbstractAn effort-related compartmental syndrome is a condition in which increased pressure in a muscle compartment impedes blood flow and compromises metabolic demands of the tissues within that space.One can clinically distinguish acute irreversible and chronic reversible types. The aetiology relates in most instances to a limiting noncompliant fascia surrounding the affected muscle compartment. Sports activity leads to increased muscle volume and if there is a noncompliant fascia this will result in an excessive intracompartmental pressure which interferes with muscle blood flow. As a consequence of a reduced intracompartmental blood flow a reversible (recurrent) or irreversible (acute) exercise ischaemia, a so-called ‘compartmental syndrome’ occurs.A compartment syndrome is typically encountered in the lower leg, but it can be also observed in the upper leg and even in the forearm.Clinical history plays a key role in the diagnosis. Pain, muscle tightness and cramplike feeling are the most common complaints.Weakness, paralysis and numbness are seen, especially in the acute syndrome. Symptoms appear at a certain intensity of activity and disappear at rest in the chronic compartment syndrome, but in the acute type pain will persist and will be severe. It is clearly an effort-related pain syndrome. Physical examination is not always useful in diagnosing a recurrent syndrome, but in the acute syndrome one will find high sensitivity to pressure and tenseness over the involved muscle compartment. Decreased or loss of active motion and sensation in the involved compartment are frequently seen. Tissue pressure monitoring can confirm the diagnosis for both types.Differential diagnosis has to be made with tendinitis, bone stress fracture and less frequent causes of leg pain in athletes, such as vascular disorders, osteomyelitis or a tumour.Conservative treatment is of no value. Only surgery or a restriction of sports activity will bring relief of the symptoms in a recurrent case, while a surgical release of the fascia as an emergency is necessary for an acute compartment syndrome.

ISSN:0112-1642    

DOI:10.2165/00007256-199009010-00006

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

ISSN:0112-1642    

DOI:10.2165/00007256-199009010-00007

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS