Points to Watch for:

• make sure that you turn the whole leg to the side from deep inside your hip socket; do not just turn your foot and your lower leg;
• keep your weight evenly distributed over the four corners of your front foot; do not lean on the outer edge;
• keep your weight evenly distributed over the four corners of your rear foot, do not lift the outer edge;
• the front knee should not be rotated inwards;
• the kneecap should be lifted (and the quadriceps engaged);
• the knees or elbows are bent;
• if bending to the right, the right heel should be in the same plane as the right sitting bone;
• due to the unusual asymmetric tensions felt on the hip joints and on the muscles of the thighs, you should not be tempted to compromise the posture by moving the hips out of alignment, twisting the trunk, etc.
• you should not do a forward bend to bring your hand to the floor;
• if you are straining or feel that the breath is not free-flowing, you have gone too far;
• do not collapse the lower back.  Both sides of the trunk should be stretched equally;
• it is the bowl of the pelvis that tips to one side, the spine remains straight.

This realization can be unsettling at first. If there's no one way to do things—well, then how do we know if we're doing them right? Some of us may long for a definitive archaeological discovery: say, a terra-cotta figure of a yogi in Triangle Pose, circa 600 B.C., that will tell us once and for all how far apart the feet should be.
But on another level it's liberating to realize that yoga, like life itself, is infinitely creative, expressing itself in a multitude of forms, re-creating itself to meet the needs of different times and cultures. It's liberating to realize that the yoga poses are not fossils—they're alive and bursting with possibility.
That's not to say that honoring tradition is unimportant. It's vital to honor the common goal that has united yogis for centuries: the quest for awakening. For thousands of years, yogis have sought to contact directly the luminous source of all being; and for hatha yogis in particular, the vehicle for touching the infinite spirit has been the finite human body. Every time we step on the mat, we can honor tradition by "yoking"—the original meaning of the word "yoga"—our purpose with that of the ancient sages.
. But if we cling to the form of the poses as ultimate truth, we miss the point. The poses were born from the practice of yogis who looked inside themselves—who experimented, who innovated, and who shared their discoveries with others. If we're afraid to do the same, we lose the spirit of yoga.
Ultimately, the ancient texts agree on one thing: True yoga is found not in texts, but in the heart of the practitioner. The texts are just the footprints of the elephant, the droppings of the deer. The poses are just the ever-changing manifestations of our life energy; what matters is our devotion to awakening that energy and expressing it in physical form. Yoga is both old and new—it's inconceivably ancient, and yet fresh every time we come to it.

Effects: Strengthens quadriceps and ankles and stretches hamstrings. Stretches and strengthens QL’s of the lower back.

Trikonasana

This Yoga posture stretches the hamstrings and side of the body. The shoulders and arms are toned.
Trikonasana also strengthens an important back muscle called the quadratus lumborum, which connects the hip to the rib cage and allows you to bend sideways. It also helps one side of the pelvis lift higher than the other. You use it repeatedly during any activity in which you shift your body weight from side to side. To also lengthen your quadratus muscle in Trikonasana, Wong suggests using the wall as a prop.
Strengthens lower back muscles.