The National Academy of Sports Medicine indicates 5 yoga poses which are potentially dangerous:
1. Inverted hurdler's stretch
3. Shoulder Stand
4. Straight Leg Toe touch
5. Arching quadriceps.
Now I see the yogis saying that I am being negative and should not speak on this subject.
Of course, exercise can cause injury and each person should strive for improvement without injury, but one should use common sense.
The group yoga leader will say only go as far as your body tells you to go without pain; but alas the group class teacher first demonstrates the desired position in the pose, as taught in teacher training, and afterwards advises beginner positions not so challenging.
Ashtanga yoga has philosophy of learning the sequence from a teacher and progressing with your self practice, which is a good one. Yet many depend too much upon the teacher to master the pose with adjustments, which is another source (major one) of injuries.
Then the Ashanga yoga teachers claim only the Series of Ashtanga yoga are all one needs for daily exercise. This means aerobic exercise like jogging or running are not necessary. And the push, pull, squat, gait, twist and bend from physical fitness academies are not recommended.
I say the advanced yoga people avoid other forms of exercise because they want a body that will make the advanced positions more accessible. Running does tighten the leg muscles making forward fold and others more of a challenge. Pull ups and lifting weights enlarge the muscle tissue and this additional muscle inhibits those often sought after yoga poses. So the yoga person devotes entire life to the yoga practice and thus does not acquire the benefits of an Academy of Sport Medicine workout.
Ashtanga yoga is challenging and uses body weight for improving the body, mind and spirit through the practice. Yet the advanced yogis from Ashtanga add gymnastics moves to the flow making the practice more challenging; yet they claim this is as taught by Jois. I say the literature indicates that these gymnastic moves were added to what was originally taught. Just watch the original practices of those going to Mysore in the early days and compare them to those that went more recently and there is a noticeable difference in how the practice is performed.