—Pam Guthrie, Minneapolis, MN
Roger Cole's reply:
Medically, the groin is the junction between the abdomen and thigh. When you lift your thigh toward your chest, a crease forms at this junction. Technically, the groin runs along the entire length of the crease, and it's still the groin after the thigh descends and the crease goes away.
When a teacher talks about moving the groin, they often mean to move the very uppermost part of the thigh immediately below the groin. The plural "groins" simply refers to the groin of the left leg and that of the right leg, taken together. However, when some teachers say "groin," they are referring only to the part of the groin nearest the inner thigh. Other teachers call this area the "inner groin" and its counterpart near the outer end of the hip crease the "outer groin." In this case, they sometime use the plural "groins" to refer to the inner and outer parts of the groin of the same leg, as in, "lift the inner and outer groins equally."
To make matters worse, B.K.S. Iyengar has expanded the definition of "groin" to include the whole junction of the thigh and pelvis, around the entire circumference of the thigh. Thus, he calls the crease below the buttock where it joins the back of the thigh the "back groin." This logically gives rise to terms like the "inner back groin" and the "outer back groin." It's enough to make you groan!
But, in fact, when you understand what the teacher is saying, and you learn to make the various parts of the groin move as directed, it can really enhance your asana practice. As you can see, different teachers use the word "groins" differently. It's good teaching practice to define a confusing word like this to the class before using it, so you might consider asking your yoga teacher to do so for your class next time the term is used.
Roger Cole, Ph.D., is a certified Iyengar Yoga teacher and a research scientist specializing in the physiology of relaxation, sleep, and biological rhythms. He trains yoga teachers and students in the anatomy, physiology, and practice of asana and Pranayama. He teaches workshops worldwide. For more information, visit http://rogercoleyoga.com.