An upright posture or erect posture is the state of an animal's body where its craniocaudal axis is perpendicular (vertical) to the ground and to the direction it is facing/moving. Examples of such postures include some tetrapods with bipedal gait and the swimming posture of seahorses.
The upper limbs or upper extremities are the forelimbs of an upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digits, including all the musculatures and ligaments involved with the shoulder, elbow, wrist and knuckle joints. In humans, each upper limb is divided into the shoulder, arm, elbow, forearm, wrist and hand, and is primarily used for climbing, lifting and manipulating objects. In anatomy, just as arm refers to the upper arm, leg refers to the lower leg.