[Fatboy]

יש דבר שנקרא מייצב אנטגוניסט:

A muscle that contracts to maintain the tension potential of a biarticulate muscle at the adjacent joint. The antagonist stabilizer may be contracted throughout or at only one extreme of the movement. Also see active insufficiency. The Antagonist Stabilizer are activated during many isolated exercises when biarticulate muscles are utilized. The Antagonist Stabilizer may assist in joint stabilization by countering the rotator force of an agonist. For example, the Rectus Femoris contracts during lying leg curl to counter dislocating forces of Hamstrings. See knee flexion abduction force vector diagram (Rectus Femoris and Tibialis Anterior).