Lecture C

Movement

Movement

The act of changing position or location, achieved by muscles moving on attached bones.

Origin

The point of attachment of a muscle to an immovable bone.

Insertion

The point of attachment of a muscle to a movable bone.

Flexion

The movement that decreases the angle of a joint and brings two bones closer together, commonly seen in hinge joints like the knee and elbow.

Extension

The movement that increases the angle between two bones, opposite of flexion.

Rotation

The movement of a bone around its longitudinal axis, commonly observed in ball-and-socket joints.

Abduction

The movement of a limb away from the midline of the body.

Adduction

The movement of a limb toward the midline of the body, opposite of abduction.

Circumduction

The combination of flexion, extension, abduction, and adduction, commonly seen in ball-and-socket joints.

Dorsiflexion

The movement of lifting the foot so that the superior surface approaches the shin.

Plantar flexion

The movement of depressing the foot or pointing the toes.

Inversion

The movement of turning the sole of the foot medially.

Eversion

The movement of turning the sole of the foot laterally.

Supination

The movement where the forearm rotates laterally, causing the palm to face anteriorly.

Pronation

The movement where the forearm rotates medially, causing the palm to face posteriorly.

Opposition

The movement of the thumb to touch the tips of other fingers on the same hand.

Prime mover

The muscle with the major responsibility for a certain movement.

Antagonist

The muscle that opposes or reverses the action of a prime mover.

Synergist

The muscle that aids a prime mover in a movement and helps prevent rotation.

Fixator

The muscle that stabilizes the origin of a prime mover.

Rectus

A muscle with straight muscle fibers.

Maximus

A muscle that is the largest in size.

Temporalis

A muscle located on the temporal bone.

Triceps

A muscle with three origins or heads.

Sternocleidomastoid

A muscle that flexes the neck and rotates the head.

Frontalis

A muscle that raises the eyebrows.

Orbicularis oculi

A muscle that closes the eyes, squints, blinks, or winks.

Orbicularis oris

A muscle that closes the mouth and protrudes the lips.

Buccinator

A muscle that flattens the cheek and aids in chewing.

Masseter

A muscle that closes the jaw and elevates the mandible.

Pectoralis major

A muscle that adducts and flexes the humerus.

Intercostal muscles

Muscles that raise or depress the ribcage during inhalation and exhalation.

Rectus abdominis

A muscle that flexes the vertebral column and compresses the abdominal contents.

Trapezius

A muscle that elevates, depresses, adducts, and stabilizes the scapula.

Latissimus dorsi

A muscle that extends and adducts the humerus.

Erector spinae

A muscle group responsible for back extension.

Deltoid

A muscle responsible for arm abduction.

Biceps brachii

A muscle that supinates the forearm and flexes the elbow.

Brachialis

A muscle responsible for elbow flexion.

Triceps brachii

A muscle that extends the elbow and acts as an antagonist to the biceps brachii.

Gluteus maximus

A muscle that extends the hip.

Gluteus medius

A muscle that abducts the hip and stabilizes the pelvis during walking.

Iliopsoas

A muscle that flexes the hip and prevents the upper body from falling backward when standing erect.

Hamstring group

A group of muscles responsible for thigh extension and knee flexion.

Sartorius

A muscle that flexes the thigh.

Quadriceps group

A group of muscles responsible for knee extension.

Tibialis anterior

A muscle responsible for dorsiflexion and foot inversion.

Extensor digitorum longus

A muscle responsible for toe extension and dorsiflexion of the foot.

Fibularis muscles

Muscles responsible for plantar flexion and foot eversion.

Soleus

A muscle responsible for plantar flexion.