Biomechanical implications of skeletal muscle hypertrophy and atrophy: A musculoskeletal model.
It is well-known that a bigger muscle allows for greater joint moment production capabilities. The reasons for this have often been attributed a larger muscle being able to create more force, and while this is true, it ignores another, just as important factor: the muscle's moment arm (or mechanical advantage). We created a theoretical, mathematical, musculoskeletal model of the biceps brachii and brachialis that were modeled to grow (hypertrophy) and shrink (atrophy), and we found that, by changing the muscle's size, it also changes the muscle's moment arm (or mechanical advantage). This is another factor that determines strength that should be considered.