Does Stretching Prevent Injuries? The Evidence

We’ve all stretched before exercising. Some of us like it and some of us (me included) really don’t – but regardless of how you feel about stretching we’ve all grown up being told that stretching is good for you and that it prevents injury. How can it not be? All of our favourite sports starts stretch before games. At school we’re all taught to stretch before we play sport. And how many times have you heard (or said yourself) “I pulled a muscle in my hamstring/calf/quad/back etc etc because I didn’t stretch properly”? We inherently believe that an injury to a muscle or joint is because it has been ‘over-stretched’, this makes intuitive sense but does science support this commonly held belief…

Does Stretching Prevent Injuries?

Anecdotes aren’t helpful when trying to answer whether something prevents another thing from happening, so the only way to assess questions of injury prevention is to perform well-structured studies.

Back in 1998 and 2000, Pope et al studied over 1000 military recruits. Firstly they compared a group that stretched their calves pre-exercise for 12 weeks to another group of people who stretched their shoulders. Which group had the least calf injuries? Neither. There was no reduction in injury rates between the groups. This was a surprising finding so they repeated the study with more recruits and stretched all the muscles of the lower limb and compared them to a group who did NO stretching. The results: no reduction in injury of any type! That’s right, 12 weeks of stretching every muscle in the leg did nothing to prevent injury.

By 2004 a few more studies had been performed and these were grouped together to look for any benefit of stretching (Thacker et al), once again no injury reduction was identified.

By 2014, Lauersen et al performed an enormous review of studies on stretching and injury prevention. They evaluated the results of 26,000 people who between them had experienced 3,500 injuries. They found that good balance reduced injury risk by 35%, better strength reduced injury risk by nearly 70% and stretching…. well stretching did not reduce injuries significantly at all (all types of stretching were looked at).

Is Stretching Good For You?

There is no definitive answer to whether stretching is good for you or not. Regular stretching will improve your flexibility and this may be of benefit, especially if you participate in a sport that requires a large range of movement such as gymnastics or dance. Its also been shown that stretching can reduce the amount of soreness an exerciser feels after activity (Herbert, 2010). But most important of all, a significant number of people simply feel better and report less pain from a number of conditions if they stretch regularly. Even if it doesn’t prevent injury, if it gives you as an individual an improved sense of well being then its a worthwhile activity.

Does Stretching Improve Performance?

As mentioned above, some sports require a large amount of flexibility. In those sports, stretching helps achieve optimum performance. Rubini et al (2007) also noted that stretching for several weeks improved muscular strength despite no dedicated strength training being performed. However, in the majority of studies, stretching immediately before exercise (particularly stretching the same muscle group for more than 120 seconds in total) reduces the maximum amount of power that muscles can generate and can be detrimental to athletic performance.

Why Doesn’t Stretching Help?

If we look at the mechanism of the commonest injuries out there it will help explain why flexibility and stretching do not protect against most injuries.

The commonest muscle injury is the hamstring strain which is responsible for most lost playing time in most sports, including football and AFL. The hamstring tends to ‘strain’ when the hamstrings are trying to slow the shin down as the leg swings through during sprinting. The picture below depicts the running cycle. If you look at the ‘red leg’, the hamstring tends to strain during the ‘double swing (floating)’ phase. At this point the hamstring is decelerating the shin and the hamstring switches from getting longer to getting shorter. This requires coordination between the muscular system and the nervous system. Anything that disrupts this coordination increases the risk of a hamstring strain.

The commonest issue to affect this system is fatigue which is why the majority of hamstring strains occur at the end of a half of football, not the start. At no point in the run cycle would you describe the hamstring as being near maximal stretch, which is why having a more flexible hamstring does not correlate with reduced hamstring strains. To see a hamstring strain in action, carefully watch Usain Bolt’s left leg as he races in his final race at the Worlds, a sad end to a phenomenal career.

The commonest ligament injury, the ankle sprain, is much easier tounderstand. The ankle usually rolls when changing direction with poor technique or when landing on someone else’s foot / in a hole! When the ankle rolls (usually in under the body) the ligaments rather than muscles are injured and stretching does not make much of an impact on ligament flexibility. In fact if the muscles around the ankle had increased tone (less flexibility), there would probably be less chance of an ankle rolling. The best way to prevent an ankle rolling is to have good technique with change of direction movements and to prepare your body’s muscles (peroneal muscles) to activate quickly when your joint is in danger of rolling. This is best achieved by performing a good quality pre-exercise neuromuscular warm-up such as the FIFA 11+.

The commonest severe injury is the anterior cruciate ligament rupture in the knee. This occurs when changing direction/pivoting. If the foot is planted too far outside the body, the knee collapses inwards. In this position the weight of the whole body is placed upon the anterior cruciate ligament, which either withstands the force or it doesn’t, in which case it tears in two and ruptures. Once again this injury is related to poor movement technique and is not influenced by flexibility in the lower limb. The pictures below illustrate correct technique with planting and cutting manoeuvres as well as common technique errors. The accompanying video demonstrates common mechanisms involved in many anterior cruciate ligament ruptures.

So How Can You Prevent Injuries?

Fortunately there is a wealth of top quality research showing that neuromuscular training can reduce injuries by up to 50% and this has been shown to work at amateur level and can be implemented by a coach who has attended one workshop to learn how to deliver the warm-up effectively. The next post in the ‘Highlight reel’ will go into this further.

Summary

Stretching does not prevent the most common injuries
Stretching does improve flexibility
Stretching pre-game probably reduces muscle power output and may reduce athletic performance
Stretching may improve muscular strength
Stretching is not harmful and if you like to stretch you should continue to do so

As ever, please comment below with your thoughts and questions and we will try to respond to as many as possible. Thanks for reading and have an active day!