There are many benefits that yoga can bring to you, for example pain relief and relaxation. But there is one myth that I noticed to be repeated over and over again, that is that you can correct your posture and restore the natural shape of your body with yoga.
This is simply false most asanas address the lower extremities of your body like your low back, hips, calves and ankles. Like a lot of other physical healing modality yoga neglects the part that in modern humans who are spending the majority of their time sitting requires the most intervention. That is your neck.
There are very little asanas that address your neck, like most people the yogi failed to understand how the equilibrium of your body causes other joints to change relative to other joints.
I guess the main idea in yoga is to start from the ground up, as your lower extremities are the foundation of your body. And if you have a weak foundation the entire body is going to change and adapt to that weak foundation.
This is quit the opposite from how it works in reality, upper joints have to be supported on lower joints. So if you have any muscular imbalance in your upper body all the joints under that joint are going to shift in order to maintain the center of gravity so you won't lose your balance.
The highest joint of your body is the first vertebra of your spine, do to excessive sitting most people get really tight muscles in the back of the neck, which is causing them to have a reverse curve in the neck. Which is what is probably causing 80% of all problems related to bad posture.
Another problem with yoga is that you are basically eating a salad. Most yoga routines consist of a series of seemingly randomly selected exercises picked on who knows what criteria. If you have a health issue that you are trying to rehabilitate it is very lightly that one exercise is going to help while another might hurt you. So like all forms of exercise there is a high risk of injury.
Also the stretches are being maintained for really short periods of time, usually 30 seconds to a minute. This is way shorter than it is necessary to change the length of a muscle. Low intensity high duration stretches work better when you are trying to rehabilitate something.
And perhaps the worst thing about yoga is that it doesn't addresses the cause of the pain that people are experiencing, which is the lack of motion through out the day, the 13 hours of sitting that the average person is doing in a day. It creates the illusion that you can do whatever you want through out the day, just as long as you do 30 minutes of yoga at the end of the day.