To stretch or not to stretch…that is the question!
After “should I use ice or heat?”, stretching is the most common topic of interest among my patients and athletes. Beyond simply “is it good or bad”, I also encounter a fairly large (and growing) group that vehemently states “stretching is BAD!” Or, at the least, that static stretching is “bad”.
Maybe a little too flexible
So, lets discus stretching. What is the purpose, and does it work? Stretching is performed to increase the length of muscle groups. Does it do this? Yes. All forms of stretching have pretty good research indicating an increase in range of motion. Stretching is also performed to reduce the risk of injury and increase performance. Does it do this? Ummm, hard to say. For years the conventional wisdom was YES. Now, over the past decade, that same conventional wisdom has swung to the other side, screaming NO! In fact, a significant minority of the coaches I know are absolutely convinced that stretching (specifically static stretching) will inhibit their athlete’s performance.
THIS STUDY, however, from Florida State University found that static stretching does not inhibit performance among a group of highly trained distance runners. And THIS STUDY from the University of Northampton found no decrease in performance with a static stretch held for 60 seconds or less.
Okay, so does it reduce the risk of injury? This is tougher to measure because injuries are about as easy to predict as earthquakes. Speaking from personal experience as both a former athlete and current doctor with thousands of patient visits in my clinical experience: yes, maintaining and attempting to increase flexibility does reduce the risk and rate of injury. Though the only way to completely eliminate the risk of athletic injuries is to discontinue your athletic activity. In other words, you cannot ever be completely protected from an acute or overuse/chronic injury.
So, lets discuss the main types of stretching. While there are a few dozen methods of which I am aware, I will divide stretching into 5 main groups: ballistic, static, dynamic, active and PNF. Though there are numerous other types of stretching, nearly all of these is trademarked and sold to the athlete, patient or practitioner through seminars or books (in other words, they are not significantly different from the aforementioned 5 types).
BALLISTIC
This involves throwing the body or limb at a high rate of speed to and through its physiologic endpoint (often stretching into the ligaments’ endpoints). For the hamstrings, imagine standing with your knees locked, allowing the momentum of your torso to “bounce” downward multiple times. Benefits: a very rapid increase of range of motion/flexibility. At what cost: causes a strong stretch reflex via the muscle spindles, leading to a potentially much greater rate of injury.
STATIC
This method involves stretching the muscle to but not through its endpoint, then holding for a period of time. Typically, static stretching uses a the athlete’s hands, a stretching strap, or any other apparatus to aid in maintaining the limb’s position. For the hamstrings, imagine lying on your back, straightening your knee and flexing you hip upwards; then gently pull the leg towards its range of motion endpoint. Benefits: easy to perform; good efficacy at increasing muscle length. At what cost: still some claim increased risk of injury; uncomfortable for the less-than-flexible.
DYNAMIC
Similar to ballistic stretching, this method involves motion of the torso and/or limbs. Unlike ballistic stretching, dynamic stretching is a slower, much more controlled motion that does not exceed the normal range of motion of the muscle or ligament. Imagine standing upright, then begin slowly but forcefully swinging your leg forward like a football punter; then return to neutral and repeat. Benefits: excellent warm up method. At what cost: very slight (if any) gains in range of motion.
ACTIVE
This method takes advantage of the principle of reciprocal inhibition–meaning when a muscle on one side of a limb “fires” (eg. quadriceps) the muscle on the opposite side of the limb is inhibited neurologically from “firing” (eg. hamstrings). Like with static stretching, this method brings the limb or torso toward its end range. Unlike static stretching, the motion and maintenance of the stretch is solely the responsibility of the agonist (in the above example, this would be the quadriceps). Benefits: very safe due to the lack of leverage/force applied by the agonist muscle; good relaxation of the relaxed (or antagonist) muscle. At what cost: good for maintaining flexibility, but less efficacious for increasing flexibility.
PNF
What is PNF, you ask? This stands for proprioceptive neuromuscular facilitation. Originally created as part of a neurologic rehabilitation program, PNF is one of the most (if not THE most) effective means of increasing flexibility. This method involves a series of static stretches held for a short (usually 8-20 seconds) period of time followed by an isometric contraction of the target muscle (this means the muscle is “firing” but not moving, held by an immovable object or force). This method takes advantage of several neurologic reflexes (from both the muscle spindles and the golgi tendon organs) to allow for an easily stretched and pliable muscle. Benefits: quick and significant increases in flexibility. At what cost: may require a stretching assistant; much more complex than other methods of stretching.
What then is my advice? If yours is the sort of body that requires a warm up (and not all do), then dynamic stretching before your activity may be for you. After your workout or event, any type of stretching can help. My own choice is static stretching for the “masses”, and PNF stretching for my own patients and athletes. Both of these methods are high on the efficacy scale and mid to low on the risk scale. Yes, these methods involve some degree of risk, but so does everything in life. My experience is that when it comes to stretching, the reward far outweighs the risk.