Like the side plank, http://thenamastecounsel.com/vasisthasana-side-plank-2/ I include long held tree poses in my Dem Bones workshops. Similarly, trees can be practiced against a wall, to focus on bone strength http://thenamastecounsel.com/yoga-therapy-for-healthy-bones-2/ rather than balance.
There should never be any pressure on the supporting knee in tree pose. Secondly, one should try to open the hip flexors so that the bent knee is pointing to the side wall, without turning the hips. Most important, maintain your dristhi (gaze) if you are doing this as a balance pose. For a real challenge, try closing the eyes.
As we age, we lose our sense of balance. Many accidents, such as serious hip fractures, are provoked by a loss of balance. What’s more, hip injuries often are complicated, deteriorating one’s health significantly follow the fracture. That’s why balance poses are essential for the aging population, especially older women, who are prone to a loss in bone density.
Dr. Mercola includes tree as one of five poses “to help you wake up, get centered and begin your day with positive energy.” I find the pose to be centering, rather than invigorating. My teacher training alma mater, Yandara Institute, says that the tree pose “calms the mental body,” helping us to focus, and be grounded. Hence, it’s particularly good for vata types. And, most of us have excess vata from time to time, if not always.
For a Yin variation to this pose, try it lying supine. I practice this frequently as part of my pre-bedtime “cool down.” When resting in this supine version for several minutes, it relaxes and stretches the hip flexors, thereby releasing negative emotions.
Just like with any other new diet or work out plan, consult a yoga therapist to determine what is best suited for your particular physical and emotional wellbeing.