According to the BBC, antagonistic muscles are pairs of muscles that work by alternately contracting and relaxing. In the human leg, the quadriceps and hamstrings are one example of antagonistic muscles. As York College explains, skeletal muscles always work in groups and never work in isolation.Know More
Muscles pull on the bones of the skeletal system to cause the body to move. HowStuffWorks.com explains that antagonistic muscle pairs work by pulling a bone in different directions to produce motion. For example, to pull the foot up towards the buttocks, the hamstring contracts, while the quadriceps relax. When it is time to straighten the leg, the quadriceps contract, while the hamstring relaxes, which straightens the leg.
The University of the Western Cape explains that muscles achieve movement by making bones move as levers. The quadriceps and hamstrings produce a third class lever, just as the biceps and triceps of the arm do; other parts of the body use first and second class levers. For example, the calf muscles, which allow humans to walk, produce a second class lever, where the load lies between the fulcrum and the effort applied. By contrast, the head and neck muscles create a first class lever when they cause the head to nod.Learn more about Muscles
The standing lateral raise primarily works the lateral deltoid muscles, which are the muscles found on the sides of the shoulders. Synergists include the middle and lower trapezius and the anterior, or front, deltoid muscles.Full Answer >
The BBC says that the biceps and triceps are antagonistic muscle pairs. Muscles can pull, but they cannot push. If there was only one muscle, then the limb wouldn't be able to get back into its original position. Antogonist muscle pairs are necessary for proper movement.Full Answer >
Skeletal muscles must be arranged in antagonistic pairs so that when one muscle moves a joint the other muscle can return the joint to its original resting position. Without an antagonist muscle pairing, there would be no way for the body to return the joint to its original position.Full Answer >
InnerBody explains that the flexor digitorum profundus muscle flexes the fingers. This muscle, located in the forearm, is classified as a hand muscle since it provides hand functionality. Healthline shows that it starts from the upper part of the ulna and connects to the fingertips with its long tendons.Full Answer >