Proper alignment is to ensure that the body is training symmetrically,
and therefore safely in each pilates exercise.  This alignment of the torso : from 'shoulder to shoulder' and 'hip to hip' is termed the "box" or 'square box' - as a reference for the body in each set of repetitions.

The center of control and strength, 'the core muscles' - are the region of collective muscles that begin every movement. This girdle of strength is the abdominals, gluteals, and lower back musculature. Like a wide seatbelt - the 'powerhouse muscle group' encircles the torsos' lower rib cage, to just below the buttocks.

An external rotation of the leg from the hips, utilizing the gluteal of buttock muscles, to create ' The V ' - a rotating and wrapping of the legs together from the hips to the heels.  A tripod position of the feet is : The Pilates Stance.

The body movement that utilizes a muscle group or a body part in an opposing range of motion and oppositional direction - to another muscle group or body part.

The activation of the small muscle group at the scapula bones - sliding the shoulder blades down and back.  This is the engagement of the core muscles at this highest point of - 'center'.

The energy quality of the motion that is unique to each exercise. The specific energy you perform with, creates dynamic motion of a body part. The dynamics are sustained in the repetitions with a flow of motion.