• Heidi Dyer

The Science of Stretching

Updated: Jan 21

From time to time I have heard students and clients complain that despite regular stretching in their practice they are not gaining flexibility. Sometimes they even feel that their muscles are tighter. Most often it’s not what they are doing that is the problem but how they are doing it.

Coming from a dance and yoga background where hyper-flexibility can become an unhealthy obsession, I sometimes hesitate to offer advice on stretching. When forced into extreme ranges the body can become permanently altered including: alignment, muscular balance, posture, and wear and tear on joints. That said, I understand that most of us who are not already hyper-flexible are looking for greater ease and freedom and wish to find and maintain it in healthy ways.

The next time you roll out your mat, consider this:

The Science

I know not everybody gets tingly when getting into the scientific side of yoga like I do, but in order to understand how stretching works one must have a basic understanding of the body’s natural reflexes, specifically how the Golgi tendon organ (GTO) and muscle spindles function.

The GTO and muscle spindles are important proprioceptors that help regulate muscle tension. While the muscle spindles serve to contract muscles, when the GTO is stimulated it causes its corresponding muscle to relax.

Imagine the muscle spindles as thin threads coiled around muscle fibers. When the muscle stretches, so do the muscle spindles. This sends a message to contract the muscle in order to avoid being overstretched. This is referred to as the stretch reflex.

When we move into a stretch too quickly, these proprioceptors send messages to the brain to contract in order to protect the nearby joints and soft tissues from being damaged. Moving into a stretch slowly, deliberately, gently can help to counteract this and prevent the tissues and joints from actual damage. Also, when moving into a stretch in this way, we allow for greater awareness of the body’s natural motion barriers.

I have often heard this cued in yoga classes as finding one’s “edge”. Though, I would argue, that if you’ve found your “edge”, you’ve likely already gone too far. In a culture that tends to compete and strive, we have a propensity to stretch to the maximum of what we can endure without pain (sometimes sadly with it) which is counterproductive and potentially dangerous.

If you find yourself pushing to find your "edge" when first moving into a stretch, dial it back.

The Practice

Sensing motion barriers:

The next time you move into a familiar posture, do so very deliberately and slowly. Most of us tend to kind of blast through our motion barriers until we reach a pretty strong sensation of length or stretch. Can you find that initial barrier? Can you go slowly and with enough attention to discover that first moment where a touch of resistance can be discerned?

If not, give yourself time. Return to this practice until you can sense these more subtle layers of sensation. If you can find them, try feeling the layers incrementally. Could you label them on a 0-10 scale? If you wanted to stop when you reach a two or three, could you find that place?


In order to stimulate the GTO one must maintain a stretch for at least 10 seconds. Once you have eased into a stretch, honoring those first barriers, spend some time there. Pay attention to your breath. Is it even and soft or is there strain? Sense other areas of the body that may be unnecessarily holding tension and create as much ease as possible.

I’m a big fan of using props in order to create comfort and support. When the sensation from those initial motion barriers begins to fade, you may try moving slightly deeper into the stretch. Do this incrementally keeping the sensation mild and move out of the posture slowly as well.

Making these simple adjustments to your practice can increase awareness and sensitivity, promote a healthy relationship with your body, and assist you in creating more ease and freedom in your practice.

Proprioceptive Neuromuscular Facilitation (PNF):

If you're still looking for more range, try PNF. While in a moderate stretch, contract the muscle (or muscle group) being stretched for 6-10 seconds. By contracting the muscle while in the stretch the proprioceptors send a message that the muscle is in danger of being overstretched and so it relaxes, allowing for more freedom. After holding the contraction for 6-10 seconds relax and ease deeper into the stretch. As before, breath, move slowly, and remain sensitive to feedback from the body.

An example of a stretch using PNF would be to contract the hamstrings while in a seated forward fold by pressing the heels into the ground as if trying to bend the knees.

When starting out experiment with using PNF for muscle groups such as the hamstrings, quadriceps, glutes, or hip flexors. As with any new practice, go slowly and seek the advice of a professional if you have any questions or doubts.

Want to learn more about Neuromuscular Therapies or try Facilitated Stretching? Visit to book a private session with me. Or, better yet, register for the 200 hour residential yoga teacher training with complementary healing hosted by myself and Nancy Cooke of Paramatma Yoga in June 2019. (

Learn more about techniques like Proprioceptive Neuromuscular Facilitation (PNF) and Reciprocal Inhibition. Improve both active and passive range of motion for improved performance and/or rehabilitation. Most importantly, create a personal practice that is enjoyable, meaningful, and beneficial.

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