A term introduced by Nikolai A. Bernstein (1896-1966) to indicate a functional grouping of muscles spanning a number of joints that is flexibly assembled to achieve a specific goal. Also referred to as a synergy or functional generator. It is seen as a solution to the degrees-of-freedom problem in that muscles are not controlled as separate units, but as task-specific, functional groupings.
See Biomechanical degrees of freedom problem, Coordination, Degrees of freedom (or Bernstein’s problem, Movement coordination, Non-univocality principle, Synergy