摘要:

SummaryThis article provides a review of the progress that has been made on the biomechanical, functional performance and epidemiological investigations into the effectiveness of prophylactic knee braces (PKBs) since the position statement against their use was issued in 1987 by the American Academy of Orthopaedics and a review of this subject was last published inSports Medicinein 1989 by Montgomery and Korziris.The evolution of the salient design features of three surrogate knee models are reviewed along with the results of PKB effectiveness and safety factor testing.While still too limited in scope to be totally realistic, major advances have been made in the sophistication of the present biomechanics laboratory testing conditions. The on-the-field functional performance effects of wearing a knee brace are not always manifest in all individuals.The efficacy of PKBs remains in question but recent studies have taught us enough to put their use into perspective. While they may play some role, PKBs probably represent the least important factor in influencing the likelihood that a medial collateral ligament (MCL) sprain will occur. On the other hand, there is no evidence that such braces put added valgus pressure on some knees, or that wearing a brace is associated with an increased frequency or severity of knee or ankle injury. All else being equal, from the biomechanical studies, we know that whilst some braces are better than others, currently available PKBs can provide 20 to 30% greater resistance to a lateral blow, with the possibility that the anterior cruciate ligament (ACL) is given even greater protection than the MCL. This appears to be true when the lateral blow is of sufficient medial joint line opening, but is not as great at the very lowest levels of impact. Regardless of the material they are made of, the most effective PKBs are those sufficiently stiff to prevent an external blow at the joint line from causing brace hinge contact with the knee tissues. Based on the superior results of the custom-fit functional braces, the most important future design feature appears to be the sizing and fitting of the thigh and tibial cuffs.On the negative side, the presence of a brace may slow an athlete’s straight-ahead sprint speed and cause early fatigue to its wearer. This effect appears to vary from one brace to another according to its weight, design features, and pressure from the leg and thigh straps. However, it appears that knee braces do have the potential to restrict performance of the athlete for high-speed running but the effect is related to several factors. The weight of the brace resultant friction of the hinges, completeness of fit, and tightness of straps appear to be important. The most measurable effects include: increased muscular relaxation pressures; increased energy expenditure; and a related increase in blood lactate levels, maximal torque output, oxygen consumption and heart rate. On the other hand, experienced brace wearers and larger, stronger individuals displayed fewer, or no effects of donning a brace.Improvements in the protectiveness of the PKB are likely to accompany improvements in the ability to contour the braces to fit each individual’s leg in the equipment room without the added expense of the cast-moulding process. Further improvement may be realised by friction-free polycentric joints, as well as an attachment system that minimises thigh and calf soft tissue compression perhaps by incorporating the braces into the trousers of the uniform to provide suspension from the waist.

ISSN:0112-1642    

DOI:10.2165/00007256-199520050-00001

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

ISSN:0112-1642    

DOI:10.2165/00007256-199520050-00002

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

ISSN:0112-1642    

DOI:10.2165/00007256-199520050-00003

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryCircadian rhythms have been documented for various physiological variables, such as body temperature, heart rate, blood pressure, Cortisol, adrenaline (epinephrine) and noradrenaline (norepinephrine) under resting, as well as exercise conditions. The extent to which psychological variables, such as perception of effort, mood states and anxiety, are subject to circadian rhythms at rest and during exercise, is not as well understood.Body temperature follows a circadian rhythm in which temperature is highest in the evening and lowest in the early morning. Exercise heart rate follows a similar rhythm, but peaks a little earlier. The findings for exercise blood pressure are not consistent. Performance of physical activity is generally improved in the afternoon or evening, compared with morning. Cortisol levels follow a circadian rhythm in which Cortisol peaks in the morning and decreases throughout the rest of the day, at rest and during exercise. Plasma catecholamines show a rhythm at rest, but the findings during exercise are inconsistent.Research on circadian rhythms of perceived exertion and mood states are equivocal and the limited research on anxiety suggests that the anxiolytic response to exercise is not influenced by time of day.

ISSN:0112-1642    

DOI:10.2165/00007256-199520050-00004

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryMeniscal injuries are reported to be the most common injury sustained by athletes, with sports injuries being responsible for over 30% of the total number of lesions. Treatment of meniscal lesions has evolved considerably over the past 20 years and partial meniscectomies, or menisci repairs, are now the treatment of choice for the majority of lesions. Following arthroscopic meniscectomy, patients are routinely able to walk without support within 1 to 3 days, return to work after 1 to 2 weeks, resume athletic training by 2 to 4 weeks and return to competition in 3 to 4 weeks.Physiotherapy has been widely prescribed following arthroscopic meniscectomy and exercise protocols have been described in the literature. However, few studies have actually ascertained whether or not physiotherapy accelerates recovery. From these studies, there is little doubt that some form of rehabilitation, e.g. pain control or exercises, may be effective in accelerating the recovery of muscle strength to preoperative values. Therefore, whether or not physiotherapy is required following arthroscopic meniscectomy may depend on the presence or absence of preoperative strength deficits, and thus, on whether it is the dominant or nondominant leg that is injured. In patients with no preoperative deficits, and a normal post-surgery evolution, full recovery may be expected within 6 weeks if pain and swelling are brought under control. Physiotherapy intervention may not, perhaps, be justified for these patients, except in professional athletes where a faster return to preoperative values may be desired.

ISSN:0112-1642    

DOI:10.2165/00007256-199520050-00005

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryCycling accidents are responsible for significant morbidity and mortality, especially in boys under the age of 16. While most cycling injuries result from simple falls from the bicycle, the majority of fatalities are caused by head injuries resulting from accidents involving motor vehicles. It is estimated that up to 85% of all cycling fatalities caused by head injuries could be prevented by the use of an appropriate cycling helmet.Although the majority of adult cyclists wear helmets the reverse is true for children, who comprise the greatest proportion of all cyclists. Intensive educational programmes increase the number of cycling helmets that are sold, but have a lesser effect on the number used while cycling. Legislation, compassionately enforced on minors, i.e. with an understanding attitude towards their developmental stage, is the only proven technique that substantially improves rates of helmet use by young cyclists. Such legislation reduces their morbidity and mortality from head injuries.This article reviews the epidemiological factors associated with traumatic cycling injuries and the nature of these injuries. Special attention is paid to head injuries and the evidence that these are largely preventable with the use of appropriate 3-layered cycling helmets, the features of which are detailed. Factors promoting or discouraging helmet use by children are reviewed. These include the following factors: age, since helmet use is highest in mature cyclists and lowest in children because of negative peer pressure; parental example, including an attitude of safety consciousness and parental concern; higher levels of education; access to discounted helmets; public campaigns to promote helmet use; and, most importantly, appropriate legislation.But it is clear that appropriate legislation making helmet use compulsory for all cyclists is the only effective method for increasing helmet use, especially by young cyclists. Such legislation would reduce a mortality rate among young cyclists that has been equated to the mortality caused by some childhood infections in the pre-vaccination era. Some argue that physicians have a particular responsibility for promoting effective legislation for mandatory helmet use so that young children can be ‘vaccinated’ against the risk of the modern childhood epidemic; fatal head injury while cycling.

ISSN:0112-1642    

DOI:10.2165/00007256-199520050-00006

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS