Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website. 86 Anatomy & Physiology Essentials Lab Manual 3. Both the agonist and antagonist muscle must be healthy to perform pain-free movements. How does flexibility of muscles play a role with agonist and antagonist muscles? List one pair of muscles that are often imbalanced when it comes to flexibility. _ __________________________________________________________________________________________________________________ __________________________________________________________________________________________________________________ __________________________________________________________________________________________________________________ __________________________________________________________________________________________________________________ __________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________ Wrap-Up Agonist-antagonist muscle pairs allow humans to perform many highly specific, complex, multi-joint movements. Working together, they allow people to walk, run, sit, jump, reach for things, and avoid obstacles, among many other activities. Understanding each muscle’s primary function, and its counterpart, will help you understand both the healthy human body movements and many injuries that may impact normal movements.