when u flex it, it tightens, when u extend it, it stretches
Flexion is when a muscle action decreases the angle at a joint, extension is when the angle increases. A simple example is bicep curl, flexion is when the hand is brought up towards the shoulder, decreasing the angle at the elbow joint. Just because a muscle is performing flexion or extension does not not mean it is contracting or stretching, that is eccentric and concentric movement. A muscle can still be tight when performing extension.
Inn other words muscle flexing can be called muscle shortening and extension when muscle is elongating. For example when you bend you arm towards your shoulder your bicep muscle is shortening and you can feel a bump. When you extend your arm you can feel that the bump is stretching out and disappearing, that is muscle extension.
Flexing the thigh, extending the leg, adducts leg
biceps brachii muscle.
The triceps muscle is located on the back of the upper arm and has three heads, while the biceps muscle is located on the front of the upper arm and has two heads. The triceps muscle is responsible for extending the arm, while the biceps muscle is responsible for flexing the arm.
The muscle in your arm contracts. The muscle on the other side of your arm, opposite from the side that you are flexing, stretches.
Flexing Your PC Muscle - 2013 was released on: USA: 1 January 2013 (Denver, Colorado)
The difference between muscle mass and muscle hypertrophy is that muscle hypertrophy is the increase in size of skeletal muscle while muscle mass is the weight of your body muscle.
It is called the Sartorius muscle located in the thigh. Here is the long definition. Assists in flexing, abduction and later rotation of the hip and flexing of the knee.
Triceps and Biceps
An agonist muscle is a muscle that plays a part in the extension of a muscle. The agonist muscles for a knee extension are the quadriceps and hamstrings.
i don't no what is the answer?
Muscle extension is when a muscle lengthens, while flexion is when a muscle shortens. Extension helps with stretching and increasing flexibility, while flexion helps with bending and contracting. Both movements are important for maintaining range of motion and strength in the body.