left shoulder
Refers to the left shoulder of a person or animal. Used in everyday contexts.
He has a bag slung over his left shoulder.
My left shoulder hurts, so I went to the hospital.
右肩 refers to the right shoulder, while 左肩 refers to the left shoulder, the opposite side of the body.
Compound of 左 (ひだり, 'left') and 肩 (かた, 'shoulder').