2 abstracts for articles I want to read

Warm-up and stretching in the prevention of muscular injury.

Woods K, Bishop P, Jones E.

Human Performance Laboratory, University of Alabama, Tuscaloosa, Alabama, USA. woods021@bama.ua.edu

Abstrac 

M

uscular injury is one of the major problems facing today's athletes, both recreational and professional. Injuries to skeletal muscle represent >30% of the injuries seen in sports medicine clinics. As a result, it is imperative to utilise the most effective means to aid in deterring these injuries. However, there are conflicting opinions regarding methods of reducing muscular injury through warm-up and stretching techniques.Therefore, the purpose of this article is to examine the potential of a warm-up and/or stretching routine in deterring muscular injury during physical activity. The article examines a variety of studies regarding warm-up, stretching and muscular injury. The article also provides a definition of warm-up and stretching to provide clarity on this topic. Many of the differences within previous research were due to conflicting definitions. We also address this issue by examining research on muscular injury and physical adaptations to muscular injury and training. This article provides contradictory evidence to conclusions that have been drawn in previous review articles, which determined that warm-up and/or stretching protocols did not deter injury. The research included here conveys that certain techniques and protocols have shown a positive outcome on deterring injuries. As a result, a warm-up and stretching protocol should be implemented prior to physical activity. The routine should allow the stretching protocol to occur within the 15 minutes immediately prior to the activity in order to rec

Stretching and injury prevention: an obscure relationship.

Department of Rehabilitation Sciences and Physical Therapy, Faculty of Medicine and Health Sciences, Ghent University, Belgium. erik.witvrouw@UGent.be

Abstract

It is generally accepted that increasing the flexibility of a muscle-tendon unit promotes better performances and decreases the number of injuries. Stretching exercises are regularly included in warm-up and cooling-down exercises; however, contradictory findings have been reported in the literature. Several authors have suggested that stretching has a beneficial effect on injury prevention. In contrast, clinical evidence suggesting that stretching before exercise does not prevent injuries has also been reported. Apparently, no scientifically based prescription for stretching exercises exists and no conclusive statements can be made about the relationship of stretching and athletic injuries. Stretching recommendations are clouded by misconceptions and conflicting research reports. We believe that part of these contradictions can be explained by considering the type of sports activity in which an individual is participating. Sports involving bouncing and jumping activities with a high intensity of stretch-shortening cycles (SSCs) [e.g. soccer and football] require a muscle-tendon unit that is compliant enough to store and release the high amount of elastic energy that benefits performance in such sports. If the participants of these sports have an insufficient compliant muscle-tendon unit, the demands in energy absorption and release may rapidly exceed the capacity of the muscle-tendon unit. This may lead to an increased risk for injury of this structure. Consequently, the rationale for injury prevention in these sports is to increase the compliance of the muscle-tendon unit. Recent studies have shown that stretching programmes can significantly influence the viscosity of the tendon and make it significantly more compliant, and when a sport demands SSCs of high intensity, stretching may be important for injury prevention. This conjecture is in agreement with the available scientific clinical evidence from these types of sports activities. In contrast, when the type of sports activity contains low-intensity, or limited SSCs (e.g. jogging, cycling and swimming) there is no need for a very compliant muscle-tendon unit since most of its power generation is a consequence of active (contractile) muscle work that needs to be directly transferred (by the tendon) to the articular system to generate motion. Therefore, stretching (and thus making the tendon more compliant) may not be advantageous. This conjecture is supported by the literature, where strong evidence exists that stretching has no beneficial effect on injury prevention in these sports. If this point of view is used when examining research findings concerning stretching and injuries, the reasons for the contrasting findings in the literature are in many instances resolved.

PMID:

 

15233597

 

[PubMed - indexed for MEDLINE]