Bottom 八 — also 共's indexing radical. Originally a divider/splitter shape; here it serves as the legs or platform under the lifted load. Indexes 共 alongside 兵, 典, 兴 — characters that share this stable two-leg base.
Top — two hands lifting together. The original oracle-bone form depicted a pair of hands cooperating to raise an object, the literal picture of joint labor. In the modern stylized 共 these become the upper horizontal plus the two short verticals.
Middle horizontal — the object being raised by the hands above. In the original ideograph this stood for whatever was being lifted in the cooperative act; the modern character keeps it as a structural waistline between hands and feet.