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 main purpose of the gastrocnemius muscle is to facilitate leg movements, such as jumping, walking, running and knee bending. The gastrocnemius muscle pushes the leg down during these types activities. The location of this muscle is the back of the leg on the calf area.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 >
According to the University of the Western Cape, skeletal muscles work in pairs so that they can alternately pull on a bone to achieve movement. In other words, when a human wants to bend his elbow, he must relax his triceps muscle, while contracting his biceps. Such muscle groups are called antagonistic muscles, because they pull in opposite directions.Full Answer >
The hip abductor muscles are a group of four muscles that stabilize the gait and control the ability of the leg to rotate away from the body. These four muscles include the gluteus minimus, the tensor fascia lata, the gluteus maximus and the gluteus medias.Full Answer >