Image credit by Ventures In Sanity
It is very important for Yoga teachers to have a firm grasp on the anatomical structure of the body when they begin teaching students. Their deep knowledge will help them guide their students in a safe manner, and also give students an opportunity to learn more about their own body and why they may be experiencing limitations.
Not every yoga student will understand the terminology of anatomy, and so it is important to exercise inclusivity when teaching classes that involve anatomy teachings. Confusion may cause the student to feel uncomfortable and/or alienated. The teacher may want to ask themselves: to whose benefit am I using these terms? For example, if the teacher decides to reference the glenohumeral joint, she may confuse her students. Referencing the shoulder joint in it’s place allows the language to be understood and she is still able to bring attention to the area of the body that needs to be addressed. Keeping the language relevant to major joints, bones and concepts allows for everyone to feel included in the learning. It is safe to assume that using the terms: wrist/forearm, elbow, shoulder (and scapula and humerus), neck, lumbar spine or lower spine, pelvis/femur, knee, and ankle will all be understood and are sufficient to instruct your students.
Key concepts such as the two types of stress: compression and tension, are valuable to inform the students of during classes. If they are in the Sphinx position in Yin Yoga, for example, the student may notice that they are only able to bend their lower back so far. They may look over at their neighbor and notice that their lower back is more bendy than their own and think that there is something wrong with them. As a teacher who is noticing this, it may be wise to bring up the term ‘compression’, which is when bones come up against muscle tissue or other bones, and further movement is stopped. Also adding that no two people experience yoga poses in the same way due to variants in flexibility, as well as variants in bone structure. If it is a matter of ‘tension’, then over time there will be more and more movement and flexibility. In a Yin Yoga practice, tension can quite often be the case with a beginner student. They may be working at a desk job on a daily basis and their joints have ‘seized’ or atrophied a bit and they just need to loosen up over weeks of practice.
A teacher should also be aware of students who display hyperextension. This happens when the limb moves past it’s straight 180 degrees, most often witnessed in the elbows. Hyperextension can sometimes look wrong, and there is no right and wrong in yoga; there is only how it is, which is usually caused by compression. Bone meets bone, and your body stops there. In Gray's Anatomy, we are told "full extension … is limited by tension in the (elbow's joint) capsule and muscles anterior to the joint ... and the entry of the tip of the olecranon into the olecranon fossa." Another text explains more succinctly, "Elbow extension ROM is limited by contact of the olecranon process of the ulna with the olecranon fossa of the humerus."
A Yin Yoga teacher will know that compression is healthy, as long as there is no sharp pain involved. So therefore, hyperextension would also be seen as nothing to panic about, as long as the student feels comfortable. If the student and teacher are paying attention (which is a great practice), then all should come out well.
For the student who may actually have body injuries, they would be advised to let the teacher know prior to class. The teacher would then determine what their limitations are and help the student to practice in a safe manner. For example, if the student told the teacher that she had a back spasm a few months ago, and was now wanting to join the Yin Yoga class. The teacher would recognize that the student’s lower lumbar spine may have a lot of tension, and therefore a lot of props would be needed in poses such as Butterfly (which involves a forward fold creating tension), and that more extreme poses such as Seal (lower spinal compression) should be avoided for the first month or so. A gentle Sphinx (less compression than Seal) would be a more comfortable starting point as far as working on gently releasing the spinal tension. Over time, the student would begin to gain more and more flexibility in her spine, sacrum and hips and the stress and pain she may be experiencing will greatly diminish. Because of her Yin practice, she may also have greater range of movement in her Hatha Yoga practice as well, slowly building strength in her core muscles and psoas to better support her spine.
For any yoga student, basic anatomy learned during class is a way to become even more in tune with their body. The yoga teacher might invite the student to gently touch the sacrum (area around the tailbone) during a pose to get a more somatic sense of the term and where it is in the body. Students learning the limitations of their own body is also extremely valuable. To have an attentive teacher who is knowledgeable in anatomy, without letting her ego or terminology go too far with it, can be an invaluable resource for the enthusiastic yoga practitioner.
1 -- Gray's Anatomy: The Anatomical Basis of Clinical Practice, 39th Edition, 2205, page 861.
2 -- Joint Range of Motion and Muscle Length Testing by Reese and Bandy, page 79. See also The Physiology of the Joints, Vol. 1 Upper Limb, 5th Edition by Kapandji IA, Churchill Livingstone, 1980.