I have been practicing yoga for 5 years, am a 200-RYT with 500 hours of teaching, to include Yin Yoga. When I do Half Happy Baby (more like Folded Pose with the sole of the foot facing the ceiling) with my knee towards my chest and hold it for a while, I experience a mild compression of the upper quad. I usually place a block between my chest and thigh so that I do not move past my Appropriate Edge. The stretching sensation of the hip flexors is just moderate. When I release and lower my extended leg down, the quad feels quite weak and I use my hands to hold the leg as I lower it down. The feeling of quad weakness disappears rapidly. One of my students had a similar experience. There is no pain or tingling. Is this normal? If so, what is going on?
Half Happy Baby is like an upside Dragon pose, but more accessible for most people than the Dragon. I assume that the hip flexor stress you are experiencing is in the extended leg, not the one with the knee close to your chest. But I am not sure what you mean when you say “When I release and lower my extended leg,. Isn't that leg already low? The extended leg in Half Happy Baby is the straight leg. You may feel a stretch in the quad in that leg because the quadricep femoris is a hip flexor. (The other 3 quads are knee extenders and probably were not very active or challenged in this pose.) Since the quadricep femoris has been stressed, it is not as strong as it was before the pose, so a bit of weakness there is not unusual. By the time you have done the other side of the pose, it should be close to normal again.
Or, are you referring to sensation in the quad of the bent leg? If so, perhaps that quad was engaged during the pose as, again, it is a mild hip flexor and you had that hip flex for several minutes. One way to let it relax more is to grab the foot with your hand, or if you cannot reach the foot, use a strap or belt looped around the foot, instead of using the quad itself to keep the hip flexed.
If this continues to happen and you feel it is not beneficial for you, you may want to explore some variations to the pose. The compression feeling can arise if the upper thigh is coming into contact with your torso. So, one alternative is to let the knee wing out away from the chest and see if this alters the sensation. Or, turn it upside down and do a Dragon instead. (I am curious-does it happen on both sides, or just one?)
Thanks for the response Bernie. It is on the leg where the knee is bent. Same sensation of both sides. I have quite a bit of flexibility and the upper quad is indeed pressing into the ribs. I like your suggestion to wing the knee out to the side. I will try it tomorrow in class and let you know the results.
When I do dragon, I place a block between the mat and the quad of the straight leg. This way I cannot sink deeper into the stretch. I remain at the Appropriate Edge and can work on completely relaxing everything.
Bernie, your suggestion about winging the knee out worked! Instead of bringing the knee to the chest, going to Half Happy Baby, as illustrated in your book, worked to alleviate the problem. I also discovered that you can place a block, in the tall position, under the bent knee to keep the intensity of the stretch at the Appropriate Edge, and not keep going deeper into the stretch.