Ans. is 'c' i.e. Long Thoracic nerve Winging of the scapula ie. excessive prominence of the medial border of the scapula (Normally the pull of serratus anterior muscle keeps the medial border against the thoracic wall) is seen in injury to the long thoracic nerve. Long thoracic nerve supplies the serratus anterior muscle. - Actions of the serratus anterior muscle It pulls the scapula forwards around the chest wall to protect the upper limb (in pushing and punching action) It rotates the scapula so that the glenoid cavity is turned upwards, this allows abduction of the arm above 90 degree. In paralysis of the serratus anterior muscle when these movements (like pushing/punching or raising arm above 90 degree) are attempted, winging of scapula occurs. Also remember Long thoracic nerve is known as Nerve of Bell * Serratus anterior muscle arises by the eight digital ions from the upper 8 ribs *