What to look for in a prenatal vitamin. Prenatal vitamins are available by both over-the-counter and by prescription. Although formulations can vary from brand to brand, these are the most important vitamins and minerals to look for:
Muscle pairs. Antagonistic pairs of muscles create movement when one (the prime mover) contracts and the other (the antagonist) relaxes. Examples of antagonistic pairs working are: 1  the quadriceps and hamstrings in the leg.2  the biceps and triceps in the arm.uscle pairs. Antagonistic pairs of muscles create movement when one (the prime mover) contracts and the other (the antagonist) relaxes. Examples of antagonistic pairs working are: 1  the quadriceps and hamstrings in the leg.
The balance between agonist and antagonist muscles allows precise control of the final action. See also: muscle. agonist muscle prime mover (see agonist). antagonist muscle muscles or muscle groups which neutralize action of another muscle or muscle group (see antagonist; muscle contraction). cardiac muscle; myocardium striated heart muscle.