Final answer:
Pennate muscles can typically generate more force than parallel muscles due to their structure allowing for more muscle fibers to fit within a given area. Multipennate muscles like the deltoid are particularly strong. However, parallel muscles like the biceps enable a greater range of motion.
Step-by-step explanation:
When comparing the strength of pennate muscles versus parallel muscles, pennate muscles are typically stronger. Pennate muscles, reminiscent of feathers, blend into a tendon throughout their length, enabling them to fit more muscle fibers in a given area, thus producing more tension. An example of a pennate muscle is the extensor digitorum which is unipennate, and the deltoid muscle, which is multipennate.
Parallel muscles, on the other hand, consist of fascicles arranged in the same direction as the long axis of the muscle, where the contractile fibers can shorten significantly. An example is the biceps brachii muscle, which exhibits a large bulge when contracted, known as the muscle belly.
The arrangement of muscle fibers in pennate muscles allows for the generation of more force, while parallel muscles can shorten more and move their tendons further. These muscle types correspond to different functional needs, with pennate muscles being able to exert more force and parallel muscles allowing for greater range of motion and speed.