The Impact of Stretching on Sports Injury Risk
Stretching before participation in athletic activities is standard practice for all levels of sports, competitive or recreational. Athletes, coaches, trainers, physiotherapists, and physicians recommend stretching in an effort to both prevent injury and enhance performance.
This paper conducted systematic review on flexibility and its relation to stretching and sports injuries, effectiveness of stretching as a tool to prevent sports injuries and adverse effects of stretching.
Stretching to improve flexibility. Stretching methods including passive stretching, static stretching, ballistic stretching, isometric contractions, and PNF, have been compared for their effects on flexibility. Stretching was demonstrated to increase joint flexibility and can improve range of motion within the joint.
Adverse effects of stretching/flexibility
There is some evidence of adverse effects of stretching and/or increased flexibility. Stretching has been associated with a temporary strength deficit. Recent studies of passive stretching show significant adverse effects on jump performance. Increased flexibility decreases running economical peak performance however, these findings are not consistent and there is some evidence that increased flexibility enhances performance. “Thus, we are not sure if stretching helps or hinders the performance. In my opinion each individual athlete should obtain warm up routine specific to the sporting demands”.
Warm-up to prevent injury
Warm-up together with stretching increases the flexibility but does not prevent muscle soreness. Several programs that combine warm-up, strength, and balance training with stretching have demonstrated effectiveness in the prevention of knee and ankle injuries. Additionally, flexibility and performance (especially strength and speed) in a number of sporting activities improved after warm-up.
Two different approaches appear in the literature to determine whether the lack of flexibility puts athletes at risk for injury or whether stretching prevents injury. One approach is to examine flexibility or stretching specifically to determine whether they are associated with injury. NO association with injury was found. “In my opinion one of the greatest risk factors for acute soft tissues injury is muscular disbalance and not flexibility”.
Reported that stretching not only might not prevent injuries but also might compromise performance. Animal studies also suggest that stretching does not protect against acute injury. Muscle strain injuries occur during eccentric motion (muscles develop tension while lengthening); fatigue and weakness make muscle more susceptible to injury. Several theories explain how performance could be compromised because of stretching: decrease joint stability, decrease in the ability of tendon and muscle tissue to absorb energy leading to injury, dangerous loading effects that could stretch ligaments too far, decreased strength before the recovery phase of training, and increased pain tolerance leading to cytoskeletal and tissue damage. Finally, because most injuries occur during eccentric contractions within the normal range of joint motion, it is not clear how increasing the range of motion through stretching will decrease injury risk. The three RCT in this study that address stretching and injuries fail to demonstrate a protective effect of supervised stretching.
Stronger evidence demonstrates that strength training, plyometrics, and proprioception training both enhance performance and prevent certain kinds of injury. This suggests that strength training, conditioning, and warm-up play an important role in injury prevention.
Why Warm up
Warm-up increases blood flow to muscles, speed of nerve impulses, oxygen and energy substrate delivery to working muscle while removing waste products, and oxygen release from hemoglobin and myoglobin; warm-up decreases both the activation energy for cellular reactions and muscle viscosity. These changes prepare the body for vigorous exercise by accelerating metabolism in muscle fibers and decreasing intramuscular resistance, thus increasing both mechanical efficiency and range of motion (i.e., flexibility), as well as the speed and force of muscle contraction.
It is also evident that strength training, conditioning, and warm-up have an important role in injury prevention, and we suggest that when stretching is done, it should be conducted in the context of adequate conditioning and appropriate warm-up.
Studies also suggest that extremes of inflexibility and hyperflexibility (increased flexibility) increase the risk of injury. Also, flexibility might improve performance under specific sports such as gymnastics and swimming. At the same time, it is not clear whether there is a flexibility threshold for optimal performance or that additional flexibility in already flexible athletes is necessary or desirable.
Source: Thacker SB, Gilchrist J, Stroup DF, Kimsey Jr CD. The impact of stretching on sports injury risk: a systematic review of the literature. Medicine & Science in Sports & Exercise. 2004
NOTE: There is no blue print for success in sports, every athlete requires a unique approach for his/her specific sporting needs as well as individual needs. As I mentioned earlier every athlete should obtain a warm-up and stretch routine that address the specific needs of the individual. Furthermore, majority soft tissue type of injuries occurs during eccentric contraction within normal range of motion. Therefore, instead of static stretching of the muscle and a joint capsule, athlete should load the muscle and perform sport specific movements to prevent the injury.
This is not a medical advice, medical information on this site/page is not intended to be a substitute for a professional medical advice.