Flexibility and Aging

by Shari and Nina

Shari and I have talked in the past about how essential it is to maintain strength as we age (see Strength and Aging), but I’ve learned from her that it’s equally essential to maintain our flexibility. I thought today I’d talk with her about this important topic. —Nina

Nina: Why is it important to work on flexibility as we age?

Shari: This question kind of has a long answer because we need to define flexibility and how it might change as we age. The first thing is that as we age we tend to only do things we like to. There isn’t anyone telling us to “stand up straight” or go for a walk or do something other than lay on the couch! I am sort of exaggerating but the truth is that we tend to have habitual postures, and if we don’t reverse these postures often during the day we end up looking like what we do all day. If you sit in a soft sofa or recliner chair all day long when you finally decide you WANT to stand erect, you might not be able to because certain muscle groups have shortened from habitual posture! Also, the adage “use it or lose it” really is true in regards to flexibility. So if you want to continue to be mobile and independent as you age, maintaining flexibility is as important as maintaining strength.

So what should the couch potato do to counteract their sitting posture? Stretch those hips, upper and mid and low back! Move those arms and legs! See yoga does affect our flexibility. But why? When we perform asana, whether it is active or more passive like supported restorative poses, our muscles are often lengthened. We know this intuitively because when we stretch TOO much, we pull back and come out of a pose (at least that is the safe and healthy way to practice asana). But we can also intelligently approach stretching in asana by understanding some fundamental spinal cord reflexes all of us have, at least those of us who are ambulatory with four limbs moving in space.

There are three main spinal cord reflexes: the stretch reflex, the autogenic inhibition, and the reciprocal inhibition.

The stretch reflex is a specialized reflex that regulates the length of your muscles. Whenever you elongate a muscle beyond a certain preset length or unconsciously stretch it too fast, this reflex makes the muscle automatically contract so you can’t lengthen it any further. The stretch reflex is governed by a long thin receptor in the muscles called a muscle spindle. The spindle’s role is to let our feedback systems know about muscle length and the rate of muscle lengthening. When a muscle is rapidly stretched, the spindle (via a loop of nerves) triggers a reflex contraction of the muscle that is undergoing the stretch and this muscle contraction limits the stretching of the muscle.

Within the muscle tendon (which attaches muscle fibers to bone) are structures called Golgi tendon organs (GTO). The GTO’s are stretch sensors, which provide the central nervous system with information on muscle tension. When a muscle is either contracted or lengthened (stretched), this information is processed by the central nervous system. The central nervous system then tells the muscle to release and be inhibited from contracting or to relax and lengthen. This autogenic inhibition protects the muscle from tearing.

The muscle spindle is also responsible for a phenomenon known as reciprocal inhibition. In this case when a muscle contracts, the opposite muscle will relax to allow the movement to occur without resistance. An example here is when you straighten your leg, the quadriceps muscles cause the knee to straighten, but for this to occur the hamstrings on the back of the leg/knee must relax or release at the same time.

We can perform static stretches where our body’s joints are positioned in their outer limits of available range and hold these positions for a certain time, this activity becomes a continuous passive stretch. This type of stretching is typically safe because we don’t go further than we are able. In this type of stretch the connective tissue and the non-contractile tissue is lengthened because of its unique structure. Muscle tissue is called viscoelastic because it CAN lengthen and then return to it’s “resting length.” This is basically what we are doing in asana. AND if we hold a pose for more than 6 -20 seconds, we can stimulate the autogenic inhibitory reflex to trigger a relaxation in the muscle.

If you are interested in a scientific approach to stretching, get Ray Long’s anatomy and asana books for clear through pictures and direct relationship to asana practice. He has six books and you can find them on Amazon. Also, see Fernando Pages Ruiz’s article What science can teach us about flexbility in Yoga Journal March April 2000 issue.

Nina: Which are the most important areas to target for maintaining flexibility as we age?

Shari: How about the entire body? Honestly, I can’t think of any area that should be neglected if we consciously stretch. Of course, we all think about our legs (hamstrings) and hips (hip flexors), but what about keeping mobile ankles and feet and hands? Think about all the arthritic changes that happen in our hands and feet as we age. Also, our spines absolutely need to be maintained to perform full range of motion for flexion, extension, side-bending and rotation. Our activities of daily living aren’t enough and we need to MOVE out of our habitual postures.

Nina: It’s true that most people think about their legs being stiff and maybe their hips, but not so much about their spines, shoulders, feet, ankles, and hands. So what are you favorite poses for maintaining flexibility?

Shari: My favorite poses for maintaining flexibility would be Downward-Facing Dog pose and Purvottanasana (Upward Plank pose). I think of these two poses going together, with the back body being stretch in Downward Dog and the front body in Purvottanasana. Shoulder flexion is nicely addressed in Dog pose and shoulder extension in Purvottanasana. 

And, of course, backbends are important for stretching the muscles that get tight from typical seated positions. Passive backbends are good because they don’t take as much muscular effort as Upward Bow pose (Dhanurasana). In an ideal world we should practice our flexibility poses daily. We could do both Downward Dog pose and Purvottanasana for 30 seconds. Then, if we were on a roll, we could add Triangle pose (Trikonasana), and Extended Side Angle pose (Parsvokonasana). Simple and effective!

Nina: What a great mini practice! Both Downward-Facing Dog pose and Purvottansana are also excellent for building upper body strength. Most people practice Downward-Facing Dog pose on a regular basis, but I think Purvottansana is often overlooked and under-appreciated. Thanks for reminding us about what a valuable pose it is.