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.
That's this one here: the triceps muscle. And, vice versa. When the triceps contracts, pulling the lower arm back down to its starting position, the biceps relaxes. Most, but not all, of the skeletal muscles in your body work in these agonist-antagonist pairs.If the agonist flexes a muscle then its antagonist extends.hat's this one here: the triceps muscle. And, vice versa. When the triceps contracts, pulling the lower arm back down to its starting position, the biceps relaxes. Most, but not all, of the skeletal muscles in your body work in these agonist-antagonist pairs.