We are very familiar with the general concept of yoga being about ‘balance’ and ‘harmony’ for the physical, mental, and energetic body. These relationships of balance cross their respective boundaries influencing each other. In terms of the physical body, it is essential that we respect the musculoskeletal relationship of balanced muscle tension.
Each muscle (or muscle group) has an opposing muscle. For example, the biceps muscles are opposed by the triceps muscles. Our muscles have an optimum function when maintained at a certain length. This is very true for the psoas (the muscle running from the upper thigh bone to the spine acting as a hip flexor, spinal extensor, and overall core support engagement). When we sit all day, the psoas is chronically shortened and taken out of it optimum functioning length (which is when we are standing). Besides loosing functional length, the psoas’ opposing muscle, the gluteus maximus becomes inhibited and can no longer act with tension against the psoas. This compounds into postural dysfunction since 2 major muscles providing pelvic and spinal support are no longer working effectively against each other.
Knowing the importance of having tension balance, I often ask yoga participants “do you have one side that is more flexible?” from which I get 99% of people replying ‘yes’. And often this imbalance of flexibility is experienced across the hips and back of the thighs (ie hamstrings). By not respecting and acknowledging these clear flexibility imbalances, we can readily flow into injury development.
In the case of the hamstrings, they travel from the back of the knee and insert into the sit bone (ischial tuberosity). What many people do not know is that the hamstrings have a fascial connection to the sacrotuberous ligament (connective tissue that provides critical support and structure for the sacroiliac joint). Also, the piriformis (a lateral thigh rotator muscle running from the greater trochanter of the upper thigh to the back of the pelvis) also has a fascial connection to this same ligament.
The hamstrings and/or piriformis can exert tensile forces on the sacrotuberous ligament which can then lead to destabilization of the SI joint. This can more readily occur when we have one set of hamstrings and/or one piriformis more tense than the other side. Imbalanced drag forces from these muscles on the sacrotuberous ligament can promote sacral slippage on one side. Since the SI joint is critical in receiving and distributing force loads, any kind of joint dysfunction, destabilization, or slippage leads to variations of localized or referred pain.
Knowing these potential cascades of injury, I continuously remind participants to address areas of flexibility imbalance. Rather than simply moving through your yoga flows allowing yourself to stretch, bend and bind with one side going more open than the other, I tell students to purposefully limit themselves to going only as deep and open as the lesser side. Make the ‘less flexible’ side be the gauge of range of motion and limit in both sides of your postures. This will greatly reduce the onset of tension imbalance injuries as well as put focus on letting your lesser side catch up to the more open side of your body.
Some people ask me ‘won’t my more open side then become less flexible’? I respond, ‘well yes, and if it does, GOOD’! I would rather have less range of motion and BALANCE instead of chronic imbalances that send dysfunction into my joints. Emphasize having both sides of the body working in harmony with each other. This requires dampening of the ego and, at times, pulling back on what seems like inherent space and openness. Flexibility is irrelevant if it does not provide function. With every increase in openness, we should observe if it brings us an equalized sense of harmony.