Sara Fleming, BA, MS, ISSA CFT

Stretching is generally viewed as beneficial.  However, the type and timing of the stretch can have a positive or negative effect on the person doing the stretching depending on their activity.   Dynamic stretching before a work out helps muscles warm up and increases their range of motion and elasticity prior to exercise.  Static and/or proprio-neuromuscular-facilitation (PNF) stretching after an exercise and/or during the cool-down phase of a work-out can help restore a muscle’s range of motion after repeated contractions, correct a range of motion for correct form during a lift, and may help reduce delayed onset muscle soreness (DOMS).

It has been hypothesized that static stretching immediately prior to athletic competitions requiring power and force may actually diminish performance.   (Shrier, 2004)  In addition, Shrier hypothesizes that static stretching can cause an anesthetic (pain reducing) effect on injured muscles, increasing the performance of the athlete at the risk of increasing the severity of the injury.  Shrier concludes that regular stretching will improve performance, but it should not be done immediately prior to athletic competition.  Therefore, it is reasonable to conclude that although stretching plays an important role in general fitness and athletic competition, close attention must be paid to the both the type (dynamic, static, or PNF ) and the timing of stretches used.

Decreased range of motion (ROM), which can result from a number of factors both within and beyond an individual’s ability to change, can lead to injury and affect an individual’s performance and overall fitness.  However, one must keep in mind that achieving a broad range of motion without complementary strength, disallows the muscles to properly support the new joint position which invites injury as well.  Therefore flexibility and strength training must be done jointly.   In addition to stretching, flexibility can also be achieved through a well-balanced weight training program where agonist/antagonist muscle groups are trained equally with light weight through a full range of motion.

It is important that in the pursuit of increased range of motion, one does not aggressively stretch to the point of causing muscle or tendon damage or diminish the ability of the individual to perform optimally.  Unless a particular sport demands extreme flexibility such as gymnastics, ballet, or martial arts, a standardized range of motion that can be assessed by a qualified coach or trainer is an adequate objective for most fitness programs.

Proprio-Neuromuscular-Facilitation Stretching

This is a big confusing word to mean something very simple.  We can take advantage of our nervous system to enhance our flexibility by selectively contracting and relaxing muscles.  These are the mechanisms by which Yoga stretching works and the reason that dynamic stretching works so well.  The more complex methods are best left to a physical therapist, but I will explain two methods here that are easily used and can greatly enhance your flexibility at home or in the gym.

Contract Relax Method

Inside your muscles are specialized receptors called proprioreceptors which are your safeguards against severe muscular injury.  When there are sudden changes in muscular tension, these inhibit your muscles from stretching any further.  One of these receptors is called the muscle spindle.  It is actually a specialized muscle fiber within the muscle.  In order to reset the muscle spindle and allow the muscle to stretch, you simply have to contract the muscle and then allow it to relax.  Therefore this method is called the contract relax method.

To perform this stretch, you contract your muscle against force either actively or isometrically.  When you relax the muscle and stretch it out, you should be able to move it through a wider range of motion.  For example, try a dumbell Romanian deadlift (stiff-legged deadlift).  Basically you are trying to touch your toes while holding weights.  In order to stand back up straight, you contract your erector spinae, your gluteal muscles, and your hamstrings.  Hold for 6 seconds.  As you lower the weights back down to the floor, you will find that you can get much lower because your muscles can stretch a little further this time.  If you repeat the exercise 2-3 more times, you will find that your range of motion will increase with each repetition.

Another example is a lying hamstring stretch.  I do this by lying flat on my back with one leg up in the air with a towel looped around my foot to pull it up towards me while keeping my leg relatively straight. Using my hamstring muscle, I push my leg back down towards the floor isometrically while holding it in place with the towel. I then relax the muscle and pull my leg towards my head with the towel.  After the muscle contraction, I am able to pull my leg more perpendicular to the floor.

Contract Antagonist-Relax Method

Agonist and antagonist are terms used to describe opposing muscle groups.  For example, a bicep would be the agonist if the triceps was the antagonist.  Similarly, the quadriceps would be the antagonist if the hamstring was the agonist.  There is a phenomenon that occurs in our nervous system known as reciprocal innervation.  Again, to prevent injury, since these muscle groups work on the same body parts, to contract at the same time would be bad.  So, when one contracts, the other MUST relax and lengthen.  To take advantage of this phenomenon, known as reciprocal inhibition, we can contract the antagonist of a muscle group we are trying to stretch in order to optimize its ability to lengthen and relax.

A classic example of this method is the Uttanasana pose in yoga which is basically standing straight legged and bending over and touching the ground.  The erector spinae and hamstring muscles usually feel rather tight and uncomfortable as you bend over and reach the ground with knees bent.  The Uttanasana progression has you relax your knees to relieve the pressure of the stretch and then contract the quadriceps to re-enter the stretch with straight legs.  As you do this, you will find that you can get deeper into the pose more comfortably.  Let the knees bend again and rest a few seconds and when you are ready, engage the quadriceps once more and straighten out your legs, keeping your hands close to the ground.  You will find that you can more comfortably hold the position.

Another version of this stretch is very simply the stretch we all tend to do when getting up in the morning.  Arms are up, elbows are bent, back is arched, and then we contract our back muscles and open up the chest.  When I try opening my chest by just opening my arms as wide as possible, I can only get so far and my chest and anterior shoulders feel tight.  When I contract my back muscles at the same time, my humeral head goes back another inch or two and I do not feel any tightness in my chest or shoulders.

These CR and CA methods of stretching are very similar to the stretching progressions found in yoga, dynamic stretches, plyometrics, and are also very similar to the stretching effect during amortization (the change from concentric to eccentric phase) when weight-lifting or strength training.  Its easy to see how correct form and a complete range of motion while weightlifting can enhance or even increase one’s flexibility.  Personally, I have found yoga and weight lifting to be synergistic both for increasing strength and flexibility.

References

Hatfield, Frederick C.  Fitness: The Complete Guide 8.6.6, ISSA 2004

Shrier, Ian “Does Stretching Improve Performance”, Clin J Sport Med, 14:5, Sept. 2004