What is another medical term for synergism?

Synergism, or the process of working together, is often times applied to muscles in the body of an organism that have origins and insertions which allow for them to contract and affect the same area of the body in the same way. For example, the latissimus dorsi and the trapezius are considered synergists because they both have the ability to adduct the humerus. There are no other terms for this, other than PERHAPS sister muscles, or cooperating muscles.