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Why Stretching is Important: Stretching for Flexibility, Injury Prevention, Sports Performance

Updated: Dec 17, 2020

Many people neglect stretching regularly, especially in New York City where busy schedules leave little room for something that is often seen as unnecessary. Whether you work out every day or only get exercise from walking through NYC streets, stretching is important to prevent muscle injury. If you are afflicted with muscle injury or pain, stretching can also be used as a tool to relieve pain in addition to the physical therapy and medical massage techniques that are recommended.

 

Stretch much? The usual answer to that question among clients and friends is, “Not as much as I should”. Well to be fair, that’s the same type of answer I usually get regarding exercise (“not as much as I should”) and nutrition (“not as well as I could”). Sound familiar?

People always ask me for info and guidelines on why, when, how, which muscles and how often they should stretch. And to be honest, there’s no single and universal answer to that question. There are so many factors that should go into designing and implementing a smart stretching regiment for yourself that giving a simple answer may not quite cut it.


That’s because there are a multitude of reasons to stretch and there are several types of stretching, so including the proper stretching protocols for yourself partly comes down to your goals and partlv comes down to your biomechanic needs. As with exercise, any time you perform a stretch, ask yourself, "why am I doing this"? What purpose does it serve? Is this actually going to help me in some way or am I doing it just because I think I should be? And might it actually work against me in some way?

I find that people, admittedly in the past myself included at times, don't put enough thought into their stretching routines in order to get the well-established benefits that stretching offers. With that said, let's first take a look at why stretching matters at all.


Why You Should Stretch

Simply stated, stretching is a collection of techniques aimed at lengthening, or elongating, muscles and connective tissue. At its core, there are 4 primary reasons why stretching is important:

  1. To increase range of motion in muscles and joints

  2. To reduce the risk of injury

  3. To enhance sports performance

  4. To alleviate pain and manage stress

While there is an overlap and a direct relationship between these four categories, they can be understood distinctly and it is worth breaking them down in order to better understand how stretching works and why it is important.

Increase Range of Motion: Range of motion refers to the available amount of movement available at a joint. Not having enough range of motion at a joint, whether it is from reduced muscle length or from structural and functional mobility limitations in the joint itself, can lead to injury, pain and the nagging feeling that often comes with constant tight muscles. There has been a lot of research conducted over the past several decades to evaluate whether stretching actually increases joint range of motion and the evidence, while still somewhat complex, indicates that it does.


It is important to note that while muscle length and thus stretching should often be a key component of any attempts to improve joint range of motion, stretching is not always the only solution because other factors affect range of motion, including joint mobility. If there is not proper mobility within a joint, perhaps from arthritis, cartilage damage, impingement, labrum tears or excessive scar tissue, then it may not matter how much you stretch a muscle. It can be like trying to pull a carpet out from underneath furniture. The rug won't go anywhere without possibly tearing or damaging the furniture.


In addition, and we will touch on this later, it is usually not necessary to stretch a muscle that is not short, meaning they cross joints have normal range of motion. It might feel "tight" but tightness doesn't always mean shortness. I treat many dancers who think they need to stretch every muscle in their body because they feel tight and because stretching feels good. But in reality, often times their problems stem from the fact that they are hyper-flexible and/or hyper-mobile. Stretching an already over-lengthened muscle and bringing an already hyper-mobile joint past normal end rage of motion can just contribute to weakness in that muscle and laxity/instability in the joints that it attaches to.

One example is the middle and upper back. If you sit all day and hunch over, the upper back muscles - the erector spinae of the thoracic spine, the rhomboid, middle traps and lower traps - will be under constant tension but NOT from being short, rather from being in a lengthened but tensioned position. That's why you might often feel the need to stretch your middle and upper back.


But the problem is that those muscles are working over time because they are constantly being pulled in a stretched position. So, you don't need to stretch them further. That would just contribute to the problem. To the contrary, you need to stretch the chest muscles while also activating and strengthening the upper back muscles. Without creating more flexibility in the anterior chest muscles and thoracic extension mobility, the results will not be significant or lasting.


Another example is the the hamstring muscle. While there are many people with very short hamstring muscles, I cannot tell you how many people regularly stretch hamstring muscles that do not need to be stretched. To that point, runners and other athletes who experience hamstring strains should be wary of stretching them, both when there is an acute strain and even when there isn't. Often times with hamstring strains, the underlying factors that need to be address might include shortness in calf, hip flexor and low back musculature, weakness in certain Glute muscles and limited hip rotation as well as other factors. Figuring out what might be causing your own hamstring issues is key and may require some help from an experienced injury recovery specialist.


Active and Passive Influences: Muscle tightness and stiff joints can be the result of active muscles being forcefully contracted during sports which can lead to overactivity and spasticity of those muscles. Or muscle tightness can occur passively due to poor posture such as sitting for long periods with the hips in deep flexion and the head in a forward head position. Whether it is an active or passive dynamic at play, or some combination of the two, having limited joint range of motion and muscle elasticity can lead to muscle imbalance and increase the risk of both acute and chronic injuries.

Reduce the Risk of Injuries

When there is insufficient or below average range of motion, muscles and joints cannot perform optimally and the risk of injury may increase. This is in part because the relationship between muscle length and muscle tension (length-tension relationship) gets distorted, making it harder for a muscle to produce the appropriate amount of force at and in the proper angle and direction. When this happens, muscles are vulnerable to injury from altered motor unit recruitment and joint kinematics.


This altered length-tension relationship within and between muscles in essence makes it harder for muscles to contract and lengthen properly which can lead to what is known as the cumulative injury cycle; tissue damage to muscle cells, an inflammatory response, muscle adhesions and perhaps scar tissue formation which may lead to altered joint mechanics which then reinforces the process over time with repetitive movements or poor posture.

So by increasing joint range of motion and reducing stiffness, stretching can reduce the risk of injury in athletes, exercise enthusiasts and more sedentary individuals as well by normalizing length-tension relationships, force production (known as force coupling) and joint alignment.


Stretching has been documented to reduce the risk of injury for athletes in a range of sports when done properly and at the right time. According to the National Academy of Sports Medicine, "decreasing muscle stiffness through stretching will decrease the work required to perform a particular activity and potentially increase overall performance".

Enhance Sports Performance

By reducing stiffness and increasing range of motion, stretching can help create optimal length-tension relationships (as discussed above) and efficient force production. Doing so can help an athlete optimally perform the movements required by their sport, such as pitching, jumping and running. If a pitcher or basketball player is inflexible and stiff to the point where he or she cannot generate accurate and great enough force and movement, not only does injury risk go up but the quality of movement, precision and thus performance can go down.


If, for example, Jacob deGrom or Clayton Kershaw can't fully extend their shoulders and elbow back as they gear up to accelerate and release the ball, chances are they won't be able to generate the velocity and location that make them so dominant.

Reduce Pain and Manage Stress

Constant tension in muscles can be uncomfortable. It's no wonder why sitting all day can cause tightness and pain in the low back and neck, for example, in large part because the tension generated by bone position and muscles that are either overstretched or chronically short sends signals through the nervous system that activate pain and other neuron receptors.


Like with massage therapy and trigger point release, stretching often feels good, in part because the neurological mechanism of stretching includes activation of the parasympathetic nervous system, which helps the entire body relax. The parasympathetic response to stretching is both systemic and local. The systemic response can help the entire body essentially slow down and calm down, including the muscular system as a whole. Locally, receptors in the specific muscles being stretched will activate the stretch reflex which helps them relax and lengthen.

This is one of the reasons that exercises such as Pilates and Yoga are so good for the body and mind. These disciplines tap into the parasympathetic system which lowers heart rate, respiration rate and blood pressure while helping to balance hormones, nervous system activity and digestion while also increasing muscle length and range of motion. And the less stressed you are, the more relaxed all of your muscles might be, including the ones that are chronically shortened and contracted due to poor posture, stress and exercise.


Types of Stretching

Stretching is often categorized differently depending on the source, so there is no single agreed upon categorization system. In addition, many stretch techniques can be performed passively with the assistance of a partner or actively by oneself which is why I do not include active and passive stretching as distinct categories in and of themselves. Here are some of the most common stretching techniques.

Static Stretching is the most well-known and commonly used form of stretching. It is characterized by long duration and low force. After finding the initial tissue stretch barrier, a static stretch is held for about 30-60 seconds. Static stretching increases muscle length due to its affect on the nervous system via the Renshaw, GTO, and Muscle Spindle receptors in muscle and connective tissue cells - in other words, the stretch reflex. Static stretching can be active (performed by oneself) or passive (partner-assisted).


PNF Stretching (Peripheral Neuromuscular Facilitation) is a relatively newer technique that has become widely used over the past 25 years due to its effectiveness in increasing range of motion. The basic premise is to use specific hard-wired features of the nervous system such as reciprocal inhibition, GTO stretch reflex and the latency period following a muscle contraction. The two most common types of PNF stretching are Tense and Relax and Contract-Relax-Antagonist-Contract (CRAC). These techniques involve gently contracting the targeted muscle and then stretching that muscle further, either by passively stretching the opposite muscle (antagonist, or a combination of the two. By actively contracting one muscle, the opposing muscle must relax due to a neurological reflex called reciprocal inhibition. See below for detailed guidelines on how to perform these techniques.

Dynamic Stretching is a functional, repetitive movement-based approach, often used prior to workouts and sporting events as a warm-up, as it replicates the types of movements which are common in specific sports and can be adapted to suit the sport and individual. Dynamic stretches involve taking a muscle through its entire range of motion, starting with a small movement and gradually increasing both movement range and speed. In a warm-up, dynamic stretches are usually performed following an initial period of cardiovascular exercise and usually include a minimum of 5 of this type of drill, each performed 6-8 times at slow, medium and fast speeds. All movements should be under complete control.

Active -Isolated Stretching (AI) involves taking the stretch past the point of low level discomfort into the pain threshold but only holding it for 3 seconds and repeating 5-10 times. Then back off for a second or two and repeat 5-10 time or more. The 3 seconds of stretch should be very uncomfortable to the point that you would not be able to hold that level of intensity for much longer. It is meant to be a short, repetitive and more aggressive technique. This technique deals more with the mechanical aspect of muscle fibers and connective tissue than it does with utilizing the nervous system. With that said, don't rush through the process or go so far that the rest of your body tenses up or so that the pain is unbearable.


Guidelines for Safe and Effective Stretching

Hold for 30-60 Seconds. In order to achieve the goal of inhibiting the neuron receptors known as the Muscle Spindles and others, static stretching should be held for no less than 30 seconds and for adults over the age of 65, for 60 seconds. See below for guidelines on PNF stretching protocols.

Slow and Steady. Go slow, gently and smoothly. Getting into a stretch too quickly could have several negative consequences. First, you might accidentally take a stretch too far before it's too late. Doing so might cause an inflammatory response and even a tear. Second, too much speed too quickly might over-stimulate the very neuron receptors (GTO, Renshaw and muscle spindles) in the muscle cells that you are trying to quiet down in order to induce a lengthening in the muscle and connective tissues. Similarly, getting out of a stretch too fast might stimulate these same receptors and also force a muscle to contract in an overly lengthened position in which it does not possess the mechanical positioning to optimally perform that movement and therefore could lead to a muscle strain or even a tear.


Do Not Bounce a Stretch. Unless you are doing a sports-specific stretch such as ballistic stretching for a track sprint or a football game, then bouncing a stretch should be avoided, for the same reasons as not going into and coming out of a stretch too quickly and aggressively.

Discomfort, Not Pain. This can be tricky because it is very subjective. So what I usually recommend is to take a stretch to the point of initial barrier to where there is some discomfort but not pain. Since this is a grey area, use your judgement but always remember that too much pain might cause excitability of the neuron receptors in the muscles you are trying to lengthen.


Only stretch short and/or overactive muscles and connective tissue. Stretching muscles that don’t need to be lengthened can be an inefficient use of time and more importantly can be a negative with respect to performance, pain, injury and recovery. We will touch on this point below.

Do Not Stretch Acutely Injured Muscles and Joints: If you have an acute muscle strain, be very careful and hesitant to stretch that muscle. A muscle strain is, by definition, a tearing of muscle tissue. So further stretching a muscle that feels strained could increase and exacerbate a tear, cause pain and increase inflammation. In addition, do not stretch a muscle if the joint(s) they cross are swollen, if you felt a 'pop' and of course if there is a potentially broken bone. In these cases, first see a sports medicine doctor or injury recovery specialist.


Be Consistent. As with exercise and nutrition, it is important to stretch regularly, especially if you sit for hours on end and exercise a lot. Stretching once a week just doesn't cut it. Avoid the excuses and just do it. Do it while you are waiting for the train or elevator, do it in the morning or at night while laying in bed, do it while watching the game or your favorite show, do it for 5 minutes after your workouts. Make the time. Studies show that to get the main goal of increased range of motion, stretching needs to be performed daily for a period of 6 weeks.

Stretch if you sit a lot. Hours and hours of sitting can cause a chronic shortening of the hip flexors which can cause back pain, of the anterior neck muscles which can cause headaches and neck pain, and of the chest and shoulders which can exacerbate neck pain and cause shoulder problems. One important way to counter these postural distoritions is to stretch once or twice during the day at work.


Be Consistent. As with exercise and nutrition, it is important to stretch regularly, especially if you sit for hours on end and exercise a lot. Stretching once a week just doesn't cut it. Avoid the excuses and just do it. Do it while you are waiting for the train or elevator, do it in the morning or at night while laying in bed, do it while watching the game or your favorite show, do it for 5 minutes after your workouts. Make the time. Studies show that to get the main goal of increased range of motion, stretching needs to be performed daily for a period of 6 weeks.

Stretch After You Exercise: Since stretching helps to relax muscles, it is generally not advised to overstretch muscles prior to using them for exercise because it weakens their force production capabilities and slows their reaction times. To that point, it is ok to stretch muscles prior to exercise if they are chronically short and overactive but not if those muscles are the primary ones being engaged in the upcoming workout. The main other exceptions to this rule are for sports-specific stretches for certain athletes such as sprinters and for specific injuries that may benefit from light stretching prior to exercise. For guidance with stretching for injury recovery, you may want to find a qualified injury rehabilitation specialist

PNF Stretching Guidelines. The two most common types of PNF stretching are Tense and Relax and Contract-Relax-Antagonist-Contract (CRAC). For tense and relax, first bring the muscle to be stretched to the initial soft barrier where a stretch begins. Next, lightly contract that muscle with about 30% of max force and hold for 8-15 seconds. Then stretch the muscle a little further and hold for 30 seconds, Repeat once or twice.

For CRAC, the main difference is that after the initial contraction of the muscle you are trying to stretch, then contract the antagonist muscle to further enhance the stretch through the muscle reflex known as reciprocal inhibition. For example, if you want to stretch the hamstring, first stretch the hamstring gently, then contract the hamstring for 8-15 seconds, then contract the quadriceps muscles to further stretch the hamstrings.

Active Isolated Stretching(AI) involves taking the stretch past the point of low level discomfort into the pain threshold but only holding it for 3 seconds and repeating 5-10 times. Then back off for a second or two and repeat 5-10 time or more. The 3 seconds of stretch should be very uncomfortable to the point that you would not be able to hold that level of intensity for much longer. It is meant to be a short, repetitive and more aggressive technique. This technique deals more with the mechanical aspect of muscle fibers and connective tissue than it does with utilizing the nervous system. With that said, don't rush through the process or go so far that the rest of your body tenses up or so that the pain is unbearable.


In summary, stretching is good for you! It relieves tension in muscles, restores flexibility and range of motion, reduces injury risk, enhances athletic performance, reduces pain and induces a relaxation response. So the short take-home message is, stretch! But do so thoughtfully, carefully and consistently in order to get the most from doing so.


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