Best Flexibility Methods?

The default option that comes to mind for improving flexibility is to perform stretching exercises. The most common form of stretching being a passive static stretch where one moves into the available end range of motion and holds for time, usually aiming to relax and sink farther into the stretch and advance the range of motion. Also well known to fitness professionals and enthusiasts are stretching methods such as active static stretching, dynamic stretching, ballistic stretching, low threshold stretching, and combinations such as proprioceptive neuromuscular facilitation (PNF), multifunction stretching, multiple plane stretching, and stretching along myofascial nets or chains of interconnected muscles. There are challenges researching what works best as it is difficult to measure stretching intensity in an objective way. Nevertheless, a lot of research has been done in the field of improving flexibility and many of these options have been shown to be effective at increasing range of motion, while others that may be even more effective don’t appear to be as well researched, but should not be discounted entirely.
I suspect I will come back to this entry over time with updates and citations in greater detail, but wanted to get out some main thoughts that are actionable now. Perhaps, I should add a TLDR section below for those who like to dig into evidence and leave this part as basic education on how to take action.

Active Static Stretching

Active static stretching differs from passive by nature of only stretching as far as opposing muscle groups can pull and hold the stretch, so it actively uses the muscles to create the stretch instead of passively allowing gravity and support to stretch. For example, pulling the arms out wide while puffing the chest and holding that position to stretch out the pectoral muscles would be an active static stretch, whereas bracing the hands on the wall and leaning forward would make it a passive stretch.
Due to the fact that active range of motion is generally less than passive range of motion this method can feel like it isn’t accomplishing as much as static stretching and yet it is still associated with improvements in available movement and should have the added benefit of teaching the opposing muscle groups to more effectively use that range of motion. This may be more effective for postural correction stretches as it simultaneously strengthens the underactive and/or lengthened muscles while lengthening the overactive/tight muscles.

Dynamic Stretching

Dynamic stretching refers to movements through the available range of joint motion without stopping to hold. This is often referred to as mobility work. While this also can help to improve range of motion, my personal experience and observation is that this is better for restoring usually available ranges of motion than it is for attaining new ones. Thus, I haven’t seen in practice or the literature a case for this type of stretching to be the default for increasing flexibility. However, it has the advantage for warming up by not inhibiting muscle activation potential that holding stretches does. Thus it is quite possibly among the best ways to stretch pre-activity to avoid temporary stretch-induced power loss while still making sure the joints are well lubricated and muscles pliable.

Ballistic Stretching

This stretching method is similar to dynamic stretching in that it is not held, but differs in that the movement is done with momentum to carry the tissues into further ranges than they would otherwise achieve. Because it causes movement past what the preset nervous system safety limits are (the reason our tissues don’t lengthen after a certain point is due to nervous system feedback in the absence of hard joint restrictions as might be seen with bone bumping into bone for example) it comes with increased injury potential. While this method also appears to be helpful for increasing range of motion, it is generally discouraged as safer means are available and just as effective.

Low Threshold Stretching

Most accurately described as a subcategory of passive static stretching, low threshold stretching is geared toward getting a strong relaxing effect with minimal tension to avoid reflexive tightening. The most well studied low threshold stretching protocol I’m aware of is branded as Microstretching. This is done by passively stretching to the point that a stretch is barely perceived as opposed to stretching to the point that the stretch feels strong. On a scale of perceived exertion where zero is no stretch at all and feels so tight that going any further would break something, low threshold stretching aims to only achieve a 3-4 and hold for 60 seconds compared to “normal” stretching where usually the stretch intensity is perceived in more of the 7-9 range.

Interestingly, this method of stretching has been shown to not only improve available passive range of motion, but also to improve the active range of motion even in the absence of strengthening opposing muscle groups in the range. It is also very effective for shifting the nervous system into a rest and recovery pattern making it useful for relaxing and helping with sleep and likely speeding up the recovery process from training. It is also well suited to individuals who are fragile and prone to avoiding other stretching protocols out of fear of injury or concern with discomfort.

Multifunction Stretching

This is perhaps one of the most novel and cool stretching methods I’ve ever come across. I would like to see more research done on it to increase our understanding of how best to make use of it. As it stands, I can’t say that I’m aware of any real evidence-base (literature) for the method, but I can say that it seems to work quite well.
It’s done by taking advantage of secondary muscle functions. You see many muscles (I think most?) have more than one movement function. This is especially obvious in muscles that cross multiple joints. For instance, the hamstrings muscle group performs both hip extension (straightening up the hips from a forward bend) and knee flexion (bending the knee). Working with this example, one way to use multifunctional stretching for the hamstrings could look like doing a forward bend from the hip over an outstretched leg to stretch the hamstring in a pretty typical manner. The difference kicks in by taking advantage a secondary function of the muscle (in this example knee flexion). Once the normal stretch is achieved, more space is created by shortening the muscle at it’s other end (or even the same end with a secondary function, but the other end in this example) and then stretching further.

Let me break this down a little more clearly. Sitting on the floor with one leg outstretched and hinging forward from the hip over it (stretching the hamstrings at the hip) then bend the knee slightly creating more space and folding down farther toward the thigh. The magic happens when suddenly the knee can straighten out again and upon bending it again more motion can be achieved. These are not meant to be held for an extended period as they also appear to be taking advantage of neuromuscular reflexive “tricks” to allow for greater range of motion and holding the stretch will allow for the various length and tension receptors to catch up and restrict further movement. Even though the position is not being held it is programming the nervous system to recognize the movement is available and over time the new ranges become available without trickery, this seems to work especially well when combined with exercises that take advantage of the newly acquired range – but that’s moving outside the realm of stretching as per our discussion of the moment.

Multiplane Stretching

Because we are not two-dimensional beings we have multiple planes of movement available to us and while muscles can be described as having the job of bringing two attachment points closer together, not all muscle fibers run in the exact same direction and therefore stretching in different planes and angles can help to ensure that muscles are being stretched more thoroughly than only stretching in the exact same position all the time. This idea can be moved into any other protocol by simply making sure to play with angles.

Myofascial Nets and Chains

Stretching along myofascial nets and chains builds on the concept of stretching in multiple directions and adds the concept of stretching muscles that are connected via networks of connective tissue known as fascia. This involves avoiding looking at muscles that have interconnected actions as separate and to stretch them along the chain. An example here would be to stretch the calves, along with the hamstrings, glutes and lower back in a series realizing that tightness in any of these could impair movement along the chain.

Potential Best Applications

For increasing range of motion, as mentioned above, all methods appear to be reasonably effective. It does seem that PNF stretching techniques may take an edge to the other methods based on some studies out there, but this also runs into the complication mentioned above that even the same method can be applied for longer and shorter durations with varying effects, and best in class protocols aren’t established.

Outside of simply increasing flexibility, there are some other reasons to stretch. Downregulating the nervous system in response to static stretching is often cited as a reason to avoid stretching as part of a warm-up, and yet it’s precisely the reason that targeted stretches for over-active muscles seems promising for improving movement quality as part of a corrective warm-up series where stretching is used to inhibit muscles that are having a tendency to jump into action faster or more intensely than they should for optimal movement. Thus holding static stretches for specific muscle groups may very well be appropriate during warm-up, whereas a general routine of stretching everything is likely about as effective as loosening all of the spokes on an imbalanced bike wheel – the imbalance remains as the ratio remains the same.

Dynamic stretching certainly also has a place as part of warm-up since it helps to improve viscoelastic properties in the tissues without being held long enough to create significant decrements in performance. In fact, it will likely improve performance by making movement more fluid while also lessening the chances of injury.