Antagonistic muscle groups are defined as what?

Antagonistic muscle groups refer to pairs of muscles that have opposing actions at a joint. When one muscle contracts, the other muscle relaxes, allowing for balanced movement and control. In this context, the pair of biceps and triceps serves as the prime example of antagonistic muscle groups. The biceps, located at the front of the upper arm, flex the elbow joint, while the triceps, located at the back of the upper arm, extend the elbow. This opposing action is vital for a wide range of movements, from lifting to lowering weights, and contributes to overall joint stability and function.

The other groups mentioned do not fit the definition of antagonistic pairs. The chest and triceps, for example, do not have an opposing relationship in the same way since both muscle groups can work together to perform pushing actions. The back and biceps can also work in a cooperative manner during pulling movements. Lastly, indicating biceps and biceps femoris suggests a comparison between two muscles that perform similar functions rather than one opposing the other, which does not represent antagonistic muscles.