How to get into virabhadrasana II

Although it looks that warrior II is a very simple pose, to pose it in a correct alignment and hold for 2 to 3 minutes, is a very hard work. Because each muscle and joint below the waist, around the shoulders, around upper back and upper arms is keenly engaged in this posture.

Strengthen muscles:
Back-leg: adductor magnus, gluteus maximus, glutus medius, tensor fascia lata, quadriceps, tibialis anterior
Front leg: pectineus, psoas, sartorius, quadriceps, calf muscles,
Trunk: erector spinae, quadrates lumborum, rectus abdominus
Shoulders and arms; deltoids, supraspinatus, trapezius, rhomboids, pectoralis minor, triceps
Stretching muscles:
Back-leg: calf muscles
Preparation

1. Loosening hip joints. Flex hip to 90 degrees by raising knee up and rotate from in to out for 20 times, from out to in for 20 times. Swing straight leg back and forth for 20 times and side to side for 20 times. Repeat it for the opposite side.
2. Strengthening pelvic and thigh and stretching calf muscles. Stand opening legs a little wider than prasarita and open toes toward sideways. Bend one knee to side the same direction of the knee sinking hip down and straighten the opposite leg by stretching the back side of the leg. Hands can be prayer pose or placed on the pelvis. Go to the opposite side. Repeat this for 30 times.
3. Opening hip joints and stretching hip muscles. Supta Konasana. Sit and open legs as wide as possible. Move bums up and extend pelvis so that sacrum will face in parallel to the floor. Keeping spine straight and bend forward. Stay here for 3 to 5 minutes.
4. Shoulder blades strengthening. Abduct shoulders to 90 degrees. Relax shoulders by bringing them down and swing arms back as far as possible slowly squeezing shoulder blades. Stay here for 10 breaths. Repeat 2 more times.
5. Core strengthening. Navasana. From legs-front position, lean back with ischium on the floor and bring both legs up, keeping spine and legs straight. Both arms straight in front and count 10. Repeat 4 more times.

Viravhadrasana II.
Alignment check.

1. Front leg is making 90 degree angle and knee is going toward outside.
2. Buttocks are tucked in. Hips are square.
3. Back leg is straight and outer foot is firmly grounded on the floor.
4. Upper body is up straight.
5. Arms are parallel to the floor.
6. Shoulder blades are squeezed
7. Shoulders are relaxed.
8. Gazing toward front middle finger.