There seems to be no single text that lists the contraindications for each Yoga technique; the reason being - the monumental task of listing, categorizing, and matching up each technique, with a corresponding contraindication, would be a feat that would take years to complete.
Therefore, let's look at techniques, in groups, and match them to corresponding advice.
Standing Postures seem easy enough for most of us, but can still be quite challenging for your legs, regardless of age or physical condition.
Many commonly seen standing poses are Warrior (Virabhadrasana) postures.
Here are some cautions, which will open your eyes to modify your practice and that of your students.
At the same time, always research and remain current in your knowledge of Yoga posture contraindications, because medical and sports medical research changes by the day.
General Guidelines for all Standing Postures If pregnant, do not stand for prolonged periods of time.
If you are in your third trimester, please use a chair and modify your standing and warrior poses.
Most of all, unless you are an expert teacher, please work with a certified and competent prenatal Yoga teacher specialist.
Never stiffen, or apply extra isometric force, to the muscles in your legs and arms.
These postures give wonderful results without pushing the limits.
People can collapse from over exertion while performing standing asanas; especially when practicing on warm days, in hot rooms, and in the sun.
Never lock the joints.
Hyperextension of any joint tends to lead to premature skeletal wear.
Who wants arthritis earlier? You should not be locking joints in any activity, especially Hatha Yoga practice, which is designed to enhance long term health.
If you have high blood pressure, or heart problems, you should be moderate in your practice of standing postures and consult your physician or cardiologist.
Why are there precautions here? People often hold their breath when practicing strenuous postures.
Never hold your breath if you have high blood pressure.
Be cautious about keeping the hands over the head for prolonged periods of time.
The heart, of a person people with high blood pressure, pumps less blood with each beat, than someone without high blood pressure.
When performing Warrior I, do not look up at your hands if you are experiencing neck problems or have a pre-existing neck injury.
Warrior II: Avoid if you have diarrhea, and do not force your head or neck forward, if you have neck problems.
Warrior III and all Standing Postures: Use your core muscles, rather than place excessive stress on your joints.
Proper head, neck, shoulder, spinal, back, hip, knee, and ankle alignment is essential.
Never place excessive stress on any joint.
When in doubt, always consult with a physician or specialist.