Many people who walk in the door to come to yoga do so to alleviate low back pain. We usually hear about bulging or herniated discs, degenerative discs, sciatic pain, and a whole host of other aches and pains. What you may not know is that the lower back and the neck are connected. Whatever you do to the neck, you do to the lower back.
Try this: Sit cross legged and put your hand on your lower back. Look up. What do you notice about the curve of your lower spine (lumbar spine)? It actually increases when you look up.
Now, apply this same principle to updog or cobra. When you look up, increasing the curve in your neck (cervical spine), you actually increase the curve in the low back (lumbar spine) and put your low back at greater risk of compression and possible injury. When you look up, the vertebra of the lower back go into compression and can exacerbate low back pain. In a flow class there is often not time to get the pelvic position correct to reduce this curve. Therefore, it is safer (most of the time) to look forward at the horizon in your updogs and cobras.
One other piece to ensure low back safety is to place the tops of the feet down and press slightly through all ten toenails until the thighs lift gently off the earth. Then pull arms back with triceps engaged and heart forward, eyes gazing straight ahead.
Take care of your spine. It is the only one you’ve got.
**When doing sun salutations or half sun salutations, it does feel nice to look up. If you choose to do so, be sure to tuck the tailbone very slightly toward the heels in cat tilt. This way you can take a gentle backbend that feels good and is good for the whole spine.