Biomechanics Activity Analysis

One thing I do every morning is drink a cup of coffee.  My start position is sitting on the couch holding the cup coffee in my right hand with my elbow flexed at 90 degrees in an isometric contraction.  At this point, my bicep muscle is the agonist and my triceps muscle is the antagonist. I then use my bicep to complete a concentric contraction to flex my elbow further and bring the coffee cup to my mouth.  My bicep would be the agonist muscle, my tricep would be the antagonist and a synergist muscle would be my brachialis muscle. Durning this action of elbow flexion, I am moving in the sagittal plane about the frontal axis. The osteokinematics of this movement would be voluntary flexion of the elbow. Using the concave on convex rule, the arthokinematics of this movement of elbow flexion would be the ulna rolling and sliding in the same anterior direction. To finish my movement, I use an eccentric contraction of my bicep to lower the cup of coffee back to 90 degrees. Here, my bicep is the agonist, my tricep is the antagonist and my brachialis is a synergist muscle. Now, the end position is the same as my starting position.