RESUMO
In this study we examine the pricing behavior of a non-profit agency, the American National Red Cross blood service units. Two alternative hypotheses are presented: one in which the agency maximizes profits,, and one in which output is maximized subject to a breakeven constraint. Following a general approach developed by Eckstein and Fromm , pricing equations for separate blood products are applied to cross-sectional data from Red Cross blood centers to determine the impact of demand, cost, competition, and subsidy variables. The impact of these variables, in particular the impact of the fixed subsidy on price, is shown to be consistent with the output-maximizing model.
Assuntos
Bancos de Sangue/economia , Honorários e Preços , Organizações sem Fins Lucrativos/economia , Cruz Vermelha , Preservação de Sangue , Humanos , Modelos Teóricos , Análise de Regressão , Estados UnidosRESUMO
Aqua running has been promoted as a method for cardiovascular conditioning for the injured athlete as well as for others who desire a low impact aerobic workout. Recent studies have suggested the need for an environment-specific measure of exercise intensity. Twenty healthy subjects, 10 men and 10 women, underwent a graded exercise test of aqua running to investigate the relationship between cadence and heart rate. This was done to determine the utility of cadence as a measure for exercise prescription. The graded exercise test followed a standard protocol for exercise testing in aqua running. Results demonstrated a high correlation between cadence and heart rate, both as a group as well as individually. We conclude that cadence may be used as a measure for exercise prescription for aqua running.
Assuntos
Frequência Cardíaca/fisiologia , Esforço Físico/fisiologia , Corrida/fisiologia , Adulto , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The purpose of this clinical study was to compare the performance of a new cohesive bandage to that of elastic bandages for joint immobilization. The magnitude of joint immobilization by these bandages was quantitated during isokinetic exercise using a computerized dynamometer. The degree to which the cohesive and elastic bandages reduced range of motion and peak torque of plantar and dorsiflexion was not significantly different. After exercising for 1 hour, the elastic bandage loosens, reducing its ability to immobilize the joint. In contrast, the cohesive bandage maintains its configuration, despite active exercise for 1 hour.
Assuntos
Articulação do Tornozelo , Bandagens/normas , Imobilização , Adesivos , Adulto , Elasticidade , Exercício Físico , Humanos , Masculino , MovimentoRESUMO
Hydrotherapy is based on several important bioengineering principles that permit the design and development of aquatic exercise devices, techniques and programs. These principles involve several forces (buoyancy, drag, inertia), hydrostatic pressure and the specific heat of water. By acquiring a knowledge of these bioengineering principles, an individualized exercise program can be prescribed that will enhance physical fitness which is associated with desirable psychological changes.
Assuntos
Hidroterapia , Fenômenos Biomecânicos , Temperatura Alta , Humanos , Pressão Hidrostática , Aptidão FísicaRESUMO
A new support bandage has been developed that is cohesive, sticking only to itself without adhering to the skin. It is warpknit product, impregnated with an acrylic compound, that consists of individual panels connected by a hinge stitch. It exhibits moderate extensibility under low loads which allows the health professional to apply the bandage so that it gives firm support to the underlying tissue without constriction. Its macroporous structure permits sufficient water vapor transmission to allow the underlying skin and/or wound to remain dry.
Assuntos
Bandagens , Queimaduras/terapia , Adesividade , Elasticidade , HumanosRESUMO
A new leg hydrofitness device has been designed for aquatic exercise. It consists of three separate rectangular-shaped buoyant floats that are positioned around the ankle. A clinical trial indicates its potential value for walking reeducation, strengthening leg muscles, and enhancing joint extensibility.
Assuntos
Terapia por Exercício/instrumentação , Hidroterapia/instrumentação , Perna (Membro)/fisiologia , Músculos/fisiologia , Fenômenos Biomecânicos , Desenho de Equipamento , Humanos , Artropatias/reabilitação , Doenças Musculares/reabilitaçãoRESUMO
Understanding the principles of cross-training and periodization will assist the coach and team physician in designing training programs that maximize performance while minimizing risk of injury. Cross-training is defined as simultaneous training for two or more sports or the use of multiple modes of training to enhance performance in one particular sport. This manuscript will review the benefits of three commonly used forms of cross training, deep water running, cycling and swimming, on running, training and performance. Periodization refers to the process of designing a progressive and appropriate training plan in order to optimize performance, yet minimize injury related to overtraining. The main structural components for periodization are macrocycles, mesocycles and microcycles. Physiological determinants for distance running performance, including VO2 max, lactate threshold and running economy, are presented as key components for the design of endurance training programs. Training intensity can be prescribed or monitored using running speed, heart rate, and rating of perceived exertion (RPE). The clinician must often make recommendations regarding the appropriate level of training or offer an alternative. By understanding the principles of cross-training and periodization, the clinician can assist the coach or athlete in preventing injury as well as assisting the attainment of peak performance.
RESUMO
The treatment of elbow injuries necessitates establishment of a proper diagnosis. An understanding of anatomic relationships serves as the basis for clinical evaluation. The history must ascertain the details of specific injury as well as identify intrinsic and extrinsic risk factors. Physical examination includes inspection, range of motion testing, palpation, provocative testing, and neuromuscular testing. Radiologic and ancillary testing supplement the clinical evaluation.
RESUMO
Aqua running is an effective form of cardiovascular conditioning for both injured athletes and those who desire a low-impact aerobic workout. Sufficient cardiovascular responses have been demonstrated to result in a training effect. Understanding the bioengineering principles of the aquatic environment, proper technique, physiological response, and methods of exercise prescription help practitioners incorporate aqua running into rehabilitation and training programs.
RESUMO
The increasing involvement of children in sport and fitness related activity has been parallel by an increase in the frequency of sports-related childhood injury. Immature, open epiphyses, as well as soft articular cartilage predispose children to age-specific injury. An understanding of osseous development, normal radiologic variants, and the diagnosis and treatment of common elbow injuries in the pediatric population will assist the clinician who treats younger patients.
RESUMO
The evaluation of the injured runner emphasizes the identification of intrinsic and extrinsic risk factors in addition to establishing injury specific diagnosis. The history emphasizes identification of contributory changes in training regimen or technique. The physical examination includes a biomechanical screening to identify related imbalances in posture, alignment, strength, and flexibility. This comprehensive, running specific approach to diagnosis will assist the clinician in developing optimum rehabilitation programs.
RESUMO
Overuse injuries result from repetitive microtrauma that can lead to inflammation and local tissue damage in the form of cellular and extracellular degeneration. The elbow, secondary to its central positioning, is predisposed to an array of injuries that are often companion to associated pathology of the spine, shoulder, and hand/wrist complex. An understanding of etiology and rehabilitative management will assist the clinician in the diagnosis and treatment of common overuse injuries involving the elbow.
RESUMO
The majority of athletic injuries of the hip and pelvis are caused by overuse. Most of these injuries will respond to adequate rehabilitative management, including the correction of intrinsic and extrinsic risk factors and controlling abusive force loads that may have contributed to injury. In addition to injury-specific rehabilitation, imbalances and abnormalities at each level of the kinetic chain also must be corrected to ensure optimal healing.
RESUMO
This self-directed learning module highlights new advances in this topic area. It is part of the chapter on musculoskeletal rehabilitation and sports medicine in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article discusses physiatric duties as a team physician, preparticipation physical examinations, ergogenic aids, heat-related illness, pediatric sports injuries, female sports injuries, and sports medicine topics pertinent to geriatric and physically or mentally challenged athletes. New advances covered in this section include use of creatine, guidelines for the preparticipation examination, sudden cardiac athletic death, pediatric and female anterior cruciate ligament injuries, the female athlete triad, spine screening in Down syndrome athletes, and "boosting" in athletes with spinal cord injury.