While holding up your own body weight in yoga is one reason it's so effective at toning your entire body, you won't get sexy yoga anything if your wrists are hurting too much to hold certain poses for even half a breath. Soreness is common because this joint is weak, and rightfully so — it's not like we're used to walking on our hands all day long! If wrist discomfort keeps you from enjoying your yoga practice, here are some ways to alleviate the pain in common poses.
Instead of placing your palms flat on the floor, make fists with your hands, or place your forearms on the mat, coming into Quarter Dog. A foam wedge is also helpful since it allows your hands to tilt up, taking pressure off the joint.
Try bending your top knee and planting your foot in front of your other knee, or rest on your forearm instead, as in this variation of side plank.
Use the foam wedge mentioned above, or keep the top of your head resting on the floor. Another great wrist-pain remedy is to do your backbend by holding onto someone's ankles. Have a friend stand by your head facing you. Place your palms on the front of their ankles with your fingers pointing down. When you lift up into backbend, you're pressing away instead of down, which is much easier on the wrists.
Try resting one hand on a heel at a time in a One-Armed Camel variation, and extend the opposite arm into the air, then switch. Or rest your hands on your hips or in prayer position at your chest and just lean back without bringing your hands to your heels. Whichever variation you try, concentrate on pressing your hips forward, so most of your weight is in your knees and thighs.
Instead of doing this pose with straight legs, bend your knees and do Tabletop or place your forearms on the floor.
Strengthening the muscles in the hands and forearms is the best remedy for wrist pain in this pose, so just practicing Crow will eventually dissolve wrist pain. Also focus on spreading your fingers wide, and pretend you're gripping the ground to alleviate direct pressure on the wrists. Rest your knees on your triceps instead of having your knees hang off your arms, and squeeze your knees together to make yourself feel lighter and more compact.
When putting all your weight into your hands in this pose, spread your fingers as wide as you can and concentrate on pressing into your fingertips (as if you're gripping the ground) to take the pressure off your wrists. If that doesn't help, do handstand by placing a block under each hand. This will give your hands something to grip, although you may need help kicking up into this pose.