Utkatasana = stability!

Removing the chair

Utkatasana is known as the powerful, or fierce pose. These names are derived from the sanskrit word Utkata meaning mighty. ‘Chair pose’ is also commonly used to describe this asana as the action is similar to that of sitting on a chair, except that you have to balance yourself, without a chair! The posture may look simple for an outsider, however a student must use the power of ‘fierceness’ through every part of their body to attain the strength and stamina required. The challenge of Utkatasana is to persist without becoming rigid.
This mighty pose promotes overall body strength. In particular it is strengthening for the quadriceps, hamstrings and adductor muscles in the inner thigh; and stretches the ankles, achilles tendons and calves. The arms and shoulders are also stretched; the chest opened; and the core muscles toned. The rib cage is lifted  promoting fuller breaths, and the abdominal organs stimulated.                                                    
When practiced correctly the Muladhara ‘root’ chakra is activated, helping the student to find their own path in life and put down a strong foundation. Energy is draw from the earth providing stability and strength in all subsequent standing postures.

Correct technique and allignment
Technique– 1. begin in Tadasana, inhale and raise arms up above the head bringing the palms together and looking up at the hands. Arms should be extended alongside the ears while back remains straight. 2. Exhale, bend the knees into a squatting position, tuck the tail bone under and
Incorrect technique, overscooping of the lower back.
draw the naval towards the spine engaging the abdominal muscles (this prevents an overscooping in the lower back). The knees should be kept both inline and behind the toes as much as much as possible (to prevent knees bowing outwards inner thighs should be contracted and the femur rotated against the hip). 3. Hold pose and breath. 4. Inhale, straightening the knees. 5. Exhale, slowly lowering the arms down by the side of the body.
Possible limitations-  Tight shoulders: For this student allow them to keep hands apart and raise arms only to shoulder height. Balance difficulties: For this student advise them to have knees and feet slightly apart and hands resting on knees. Another option is to have student stand with back 25-30cms from a wall, as they bend into the squat get them to hinge forward from the hips and rest the tail bone on the wall. The wall acts as a support until students can establish balance.
A quote from BKS Iyengar, ” The right method of doing an asana brings lightness and an exhilarating feeling in the body as well as in the mind and a feeling of oneness of body, mind and soul”. Utkatasana is no exception!