Question

True or False: When a muscle contracts, the movable bone moves AWAY from the muscle's origin?

Answer 1

False . because:  When the muscles contracts, usually just one bone moves towards the origin.

For example when the biceps in the arm contracts, the radius moves but the scapula does not.

ORIGIN AND INSERTION

The origin is where the muscle joins the stationary bone. The insertion is where it joins the moving bone.

When a muscle contracts, usually just one bone moves. The other is stationary . When a muscle contracts, the insertion moves towards the origin.

TENDONS

Tendons are the cords and straps that connect muscles to bones. At the bone, the fibres of the tendon are embedded in the periosteum of the bone. This anchors the tendon strongly and spreads the force of the contraction, so the tendon won’t tear away easily.

TYPES OF CONTRACTION

The contraction of a muscle does not necessarily imply that the muscle shortens; it only means that tension has been generated. Muscles can contract in the following ways:

isometric contraction

This is a contraction in which no movement takes place, because the load on the muscle exceeds the tension generated by the contracting muscle. This occurs when a muscle attempts to push or pull an immovable object.

isotonic contraction

This is a contraction in which movement does take place, because the tension generated by the contracting muscle exceeds the load on the muscle. This occurs when you use your muscles to successfully push or pull an object.

Isotonic contractions are further divided into two types:

concentric contraction

This is a contraction in which the muscle decreases in length (shortens) against an opposing load, such as lifting a weight up.

eccentric contraction

This is a contraction in which the muscle increases in length (lengthens) as it resists a load, such as lowering a weight down in a slow, controlled fashion.