Tadasana

Tadasana, a position in Yoga, is also called Mountain Pose. It is a very basic standing posture with feet together and hands at the sides of the body. Yoga practitioners consider it a pose that promotes confidence and happiness as well as improving posture and creating space within the body. This creating space within the body may allow internal organs to work more efficiently thus improving respiration, digestion and elimination. The pose strengthens the abdomen and the legs. It may help relive sciatica and reduce flat feet. Poses that help prepare for Tadasana include Adho Mukha Svanasana and Uttanasana. Although Tadasana is a very basic pose it is the basis for many standing poses. Urdhva Hastasana is a very similar pose with the hands raised above the head.
Also: Tree Pose,Tadasana: standing straight palm tree, starting on the right side by standing on the left foot lift the right leg grabbing the right foot from underneath with the left hand, sole of the food facing the ceiling, lift the foot as high as possible and rest on the thigh/hip. Standing leg stays straight/locked position, hips forward, upper body leaning back so body is perfectly straight, stretch your spine up, make sure your hips and shoulders are level with the floor. Bring your right hand to the center of your chest-half prayer position-if you can balance comfortably then bring your left hand up to namaskar-full prayer position. Benefits:improves posture, balance, increases the flexibility of ankles, knees, as well as the hip joints. Strengthens the oblique muscles preventing hernia.

Translation: The Sanskrit word tada means mountain. This posture is also known by the name samasthiti-asana. Sama means unmoved, equilibrium, and sthiti means standing upright or firmly, abiding, remaining, thus samasthiti means standing firmly without moving.

Type of pose: Standing
Tadasana can be practiced as a starting position for standing poses, in between standing poses, or by itself to improve posture.

Benefits

Improves posture
Strengthens thighs, knees, and ankles
Firms abdomen and buttocks
Relieves sciatica
Reduces flat feet (by practicing lifting through the arches)
Contraindications/Cautions:
Headache
Insomnia
Low blood pressure
Step by Step
Stand feet together, with the bases of your big toes touching, heels slightly apart. Lift and spread your toes and the balls of your feet, then lay them softly down on the floor. Rock back and forth and side to side. Gradually reduce this swaying to a standstill, with your weight balanced evenly on the feet.

Firm your thigh muscles and lift the knee caps, without hardening your lower belly. Lift the inner ankles to strengthen the inner arches, then imagine a line of energy all the way up along your inner thighs to your groins, and from there through the core of your torso, neck, and head, and out through the crown of your head. Turn the upper thighs slightly inward. Lengthen your tailbone toward the floor and lift the pubis toward the navel.

Draw shoulders back and down. Lift head, chin parallel to the floor – aligning the spine. Without pushing your lower front ribs forward, lift the top of your sternum straight toward the ceiling. Widen your collarbones. Hang your arms beside the torso.

Balance the crown of your head directly over the center of your pelvis, with the underside of your chin parallel to the floor, throat soft, and the tongue wide and flat on the floor of your mouth. Soften your eyes.

Tadasana is usually the starting position for all the standing poses. But it's useful to practice Tadasana as a pose in itself. Stay in the pose for 30 seconds to 1 minute, breathing easily.

Modifications
You can check your alignment in this pose with your back against a wall. Stand with the backs of your heels, sacrum, and shoulder blades (but not the back of your head) touching the wall. For tailbone, back injury or weakness – feet can be hip width apart. For knee injury - knees and quads can be left slightly relaxed.

Variations
You can alter the position of your arms in a variety of ways; for example: stretch the arms upward, perpendicular to the floor and parallel with each other, with the palms facing inward; or, interlace the fingers, extend the arms straight in front of your torso, turn the palms away, then stretch the arms upward, perpendicular to the floor, so the palms face the ceiling; or, cross the arms behind your back, holding each elbow with the opposite-side hand (be sure to reverse the cross of the forearms and repeat for an equal length of time).
Try to recreate the balanced sensation of Tadasana in all the standing poses.