FMA. 22356. Anatomical terms of muscle. The biceps femoris (/ˈbaɪsɛps ˈfɛmərɪs/) is a muscle of the thigh located to the posterior, or back. As its name implies, it has two parts, one of which (the long head) forms part of the hamstrings muscle group.

Antagonist and agonist muscles often occur in pairs, called antagonistic pairs. As one muscle contracts, the other relaxes. An example of an antagonistic pair is the biceps and triceps; to contract, the triceps relaxes while the biceps contracts to lift the arm.

Antagonistic Muscle (biology definition): a muscle that opposes the action of another. For example, when the triceps oppose the contraction of the flexing biceps by relaxing, the triceps would be regarded as the antagonistic muscle to the biceps whereas the biceps, the agonist muscle.

Biceps and triceps are called antagonistic muscles. Because during flexion at the elbow, biceps contract and triceps relaxes, during extension at an equivalent joint, triceps contract, and biceps relax.

Action: It flexes and rotates the leg, especially when the knee is flexed, and also extends the thigh. Synergist: Prime Movers: Gluteus maximus, Adductor magnus (posterior part). Accessory Movers: Semimembranosus, Semitendinosus, Biceps femoris (long head), Piriformis.

Triceps brachii is the antagonist and brachialis is a synergist with biceps brachii.

4. Wall bicep stretch

1. Press your left palm against a wall or sturdy object.
2. Slowly turn your body away from the wall.
3. Feel the stretch in your chest, shoulder, and arm.
4. Hold this position for up to 30 seconds.
5. Repeat on the opposite side.

In general, the biceps femoris muscle acts on both the knee and hip joints. Although, due to its attachments, the short head of this muscle acts only on the knee joint while the long head acts on both. When acting on the hip joint, biceps femoris produces the movement of hip extension.

A typical injury to the biceps femoris occurs during sprinting (athletics, football, rugby, hockey etc.). If the muscle is not strong enough to cope with the forces going through it, the muscle fibres can tear. If this happens, the athlete will often feel a very sharp pain at the back of their thigh.

The zygomaticus major is a muscle of the human body. It is a muscle of facial expression which draws the angle of the mouth superiorly and posteriorly to allow one to smile….Zygomaticus major muscle.

All three hamstring muscles (except the short head of the biceps femoris) cross two joints – the hip and the knee. The short head of the biceps femoris is a single joint muscle that originates on the upper part of the femur and inserts on the fibula.

A two-joint muscle (or biarticular) is one that crosses two joints. Many are familiar with the rectus femoris as a two-joint hip flexor because it crosses both the hip and knee joint. However, the rectus femoris is not alone in this function. The sartorius and gracilis cross both the hip and knee joints as well.

Other two-joint muscles such as the biceps muscle of the arm and gastrocnemius muscle of the shin have a very strong action at one end, and a less powerful action at the other end. For example, the biceps is most powerful in elbow flexion as in the bicep curl exercise and is an assistant in shoulder joint flexion.

In another article, I addressed the two-jointed muscles (TJM) of the lower body. This discussion will focus on the TJM of the arms: the biceps and triceps. So, here is a quick tutorial on two-jointed muscles: As the name implies, a TJM crosses two joints and performs dual functions.

The biceps is a two-joint muscle. In the shoulder joint both muscle heads partially enforce opposite movements. The long head pulls the arm away from the trunk (abduction) and turns it inwards (inward rotation) whereas the short head pulls the arm back towards the trunk (adduction).

Triceps is pretty much in direct opposition to the biceps brachii muscle, both in terms of its location as well as its function. In a number of actions they are antagonistic to one another. The triceps crosses two joints, the shoulder and elbow joints.

Given that this is a two joint muscle (with attachments that cross both the elbow and shoulder) the most comprehensive training approach will have you train the triceps with exercises that fully straighten the elbow with the arm behind the body (to fully shorten the triceps long head).