Flexibility is believed to prevent injuries or at least to lower the risk of injuries in many cases. Flexibility itself is the measure of the internal range a muscle can extend in a certain position, and the way to increase body flexibility is primarily through stretching.
In the last four decades, sports professionals have endorsed stretching as one of the prime strategies in increasing body flexibility which in turn is supposed to decrease the risk of injury for a variety of sports such as Basketball, Hockey, Football, Soccer and many more. Some sports require more flexibility than others, and flexibility can more effectively prevent injuries in some sports than in others (for example, stretching can prevent injuries in squash where many injuries are caused from muscle strain, while it may not provide much protection in football, where many injuries are caused by impact).
As a result, coaches and sport medicine professionals have ingrained in the minds of athletes that stretching, especially before practice is the norm. Also, a lot of injuries during practice have been attributed to improper before-practice stretching.
However, the numerous studies conducted trying to prove the connection between flexibility increasing exercises and injuries almost all have failed to provide with conclusive results. Science is divided on if, how and why flexibility prevents injuries. No one has been able to offer a statistically valid link between stretching and reduced risk of injury. Most of the problems with the studies are that flexibility increasing exercises have not been studied in a vacuum. Athletes stretch before practice but they also do warm-up exercises and cardio and it has been difficult to prove which correlates more to reduced risk of injury.
Some studies even show adverse effects of too much stretching and hypo-flexibility adding to injuries. The most conclusive research so far has been that too little flexibility and too much flexibility both increase injuries. As a result, maintaining a healthy level of flexibility might be one of the factors which contribute to preventing injuries but it is not the only one and can’t be viewed as the only go-to strategy.
There are two different ways that clinicians propose in which stretching could help prevent or at least decrease the risk of injuries. By appropriate and consistent stretching the stiffness of the muscles declines because they achieve greater elasticity or indirectly by increasing the reflexes to the muscles which then over time would decrease the stiffness. If the muscles are more elastic, it is easier to achieve broader movements comfortably around the joints. In other words, the range of motion in the joint area is improved and increased and this is the core argument that holds flexibility and stretching (as a tool to achieve flexibility) on a pedestal. One of the leading factors believed to increase the risk of injuries is the low range of motion around the joints.
Stretching has been mainly divided into active and passive stretching. Passive stretching being only low-impact stretching exercises such as low-intensity yoga and active stretching being a combination of different warm exercises with traditional passive exercises. Studies mostly agree that flexibility is better achieved through passive stretching. There are also some findings that longer stretching intervals are more effective than shorter ones.
About 30 studies done since the 1960’s conclude that stretching has most results on flexibility of the joints in the following areas:
Take a look at this guide to stretching from MIT. If we take the hypothesis that joint flexibility decreases the risk of injury as valid, then it can be inferred that with proper passive stretching exercises the injuries in this area of the body can be prevented or at least decreased.
However, different variables apply to different kind of movement ranges and intensity. In other words, it is very much sport specific how much flexibility is needed and how much in turn flexibility will prevent injuries. In sports like gymnastics or figure skating, flexibility is one of the core requirements for success and as a result building upon it is crucial. Flexibility also results in more speed because there is less muscle resistance, so it is crucial for sports such as basketball where it can improve basketball agility as well as jumping power, which you can find at this guide from Piranha. However, flexibility-dependent sports such as gymnastics and figure skating tend to have a high correlation between flexibility and injury, and as such stretching exercises would be a lot more beneficial than in sports that require less flexibility.
In sum, although flexibility has been intuitively held as very important in preventing injuries for a very long time, science is split on the issue. The problem with studies is not as much that half prove that it is not correlated and have proved that it is but the actual statistical validated prove that either is right. As a result, there is a great need for further studies in the area.
However, it can be accepted that flexibility can, in fact, decrease the risk of injury at least in sports that require higher levels of flexibility. Also, both poles of the flexibility spectrum, too little or too much, can, in fact, increase injuries. Finally, stretching, done the right way and in the right amount will result in higher joint flexibility and in turn partly help the body decrease the risk of injury.