Muscle Movements
Skeletal muscles move bones to which they are attached by shortening and pulling the bone. Thus, the
point of attachments of the muscles to bones and the joints spanned by the muscles are important in
determining the movements the muscles will cause. The origins and insertions (points of attachments of
these muscles) for each individual muscle are beyond the scope of this laboratory exercise. However,
the movements performed by the muscles at specific joints are important to consider.
The movements possible at diarthrotic (freely moveable joints) depend upon the type of joint and can
be nonaxial, uniaxial, biaxial, or multiaxial (triaxial). The movements listed below are described fully in
your textbook. You are responsible for identifying the movements listed below.
Define Each of the Following Movements:
Flexion: Decreasing the angle between 2 bones.
Extension: Increasing the angle between 2 bones.
Hyperextension: Extension of a limb or joint beyond normal limits.
Dorsiflexion: Lifting the foot so its superior surface approached the shin.
Plantar Flexion: depressing the foot (pointing the toes)
Lateral Flexion: Movement of a body part toward the side (ex. Head to shoulder)
Abduction: moving a limb away from the body midline.
Adduction: moving a limb toward the body midline
Circumduction: moving a limb or finger so it describes a cone in space.
Rotation: Turning of a bone around its own long axis.
Supination: Rotating the forearm laterally so the palm faces anteriorly or superiorly.
Pronation: Forearm rotates medially and the and the palm faces posteriorly or inferiorly.
Inversion: Sole of the foot turns medially.
Eversion: Sole of the foot faces laterally.
Protraction: The act of moving an anatomical part anteriorly (forward)
Retraction: The act of moving an anatomical part posteriorly (backward)
, Elevation: Lifting a body part superiorly.
Depression: Moving the elevated part inferiorly.
Opposition: Movement that brings the tip of the thumb in contact with the tip of another finger on the
same hand.
Human Muscle Movement
For each muscle, list a major movement by that muscle (e.g. flexion of the humerus, elevation of rib
cage, etc.). Refer to Chapter 10 in your textbook.
Muscles of the Head and Neck
Frontalis: Raises the eyebrows
Masseter: Elevates the mandible
Platysma: Tenses skin of the neck, helps depress the mandible, pulls lower lip back and down
producing downward sag of mouth.
Scalenes: Elevate first two ribs, flex and rotate the neck.
Splenius: Extend or hyperextend the head.
Sternocleidomastoid: Flexes and laterally rotates the head.
Temporalis: Closes the jaw, elevates and retracts the mandible.
Thoracic Muscles
External intercostals: pull ribs toward one another to elevate the rib cage.
Internal intercostals: pull ribs together and depress the rib cage.
Pectoralis major: adducts and medially rotates the arm.
Pectoralis minor: with ribs fixed it pulls the scapula forward and downward, with scapula
fixed it pulls the rib cage superiorly.
Serratus anterior: Rotates scapula so its inferior angle moves laterally and upward
Abdominal Muscles
Skeletal muscles move bones to which they are attached by shortening and pulling the bone. Thus, the
point of attachments of the muscles to bones and the joints spanned by the muscles are important in
determining the movements the muscles will cause. The origins and insertions (points of attachments of
these muscles) for each individual muscle are beyond the scope of this laboratory exercise. However,
the movements performed by the muscles at specific joints are important to consider.
The movements possible at diarthrotic (freely moveable joints) depend upon the type of joint and can
be nonaxial, uniaxial, biaxial, or multiaxial (triaxial). The movements listed below are described fully in
your textbook. You are responsible for identifying the movements listed below.
Define Each of the Following Movements:
Flexion: Decreasing the angle between 2 bones.
Extension: Increasing the angle between 2 bones.
Hyperextension: Extension of a limb or joint beyond normal limits.
Dorsiflexion: Lifting the foot so its superior surface approached the shin.
Plantar Flexion: depressing the foot (pointing the toes)
Lateral Flexion: Movement of a body part toward the side (ex. Head to shoulder)
Abduction: moving a limb away from the body midline.
Adduction: moving a limb toward the body midline
Circumduction: moving a limb or finger so it describes a cone in space.
Rotation: Turning of a bone around its own long axis.
Supination: Rotating the forearm laterally so the palm faces anteriorly or superiorly.
Pronation: Forearm rotates medially and the and the palm faces posteriorly or inferiorly.
Inversion: Sole of the foot turns medially.
Eversion: Sole of the foot faces laterally.
Protraction: The act of moving an anatomical part anteriorly (forward)
Retraction: The act of moving an anatomical part posteriorly (backward)
, Elevation: Lifting a body part superiorly.
Depression: Moving the elevated part inferiorly.
Opposition: Movement that brings the tip of the thumb in contact with the tip of another finger on the
same hand.
Human Muscle Movement
For each muscle, list a major movement by that muscle (e.g. flexion of the humerus, elevation of rib
cage, etc.). Refer to Chapter 10 in your textbook.
Muscles of the Head and Neck
Frontalis: Raises the eyebrows
Masseter: Elevates the mandible
Platysma: Tenses skin of the neck, helps depress the mandible, pulls lower lip back and down
producing downward sag of mouth.
Scalenes: Elevate first two ribs, flex and rotate the neck.
Splenius: Extend or hyperextend the head.
Sternocleidomastoid: Flexes and laterally rotates the head.
Temporalis: Closes the jaw, elevates and retracts the mandible.
Thoracic Muscles
External intercostals: pull ribs toward one another to elevate the rib cage.
Internal intercostals: pull ribs together and depress the rib cage.
Pectoralis major: adducts and medially rotates the arm.
Pectoralis minor: with ribs fixed it pulls the scapula forward and downward, with scapula
fixed it pulls the rib cage superiorly.
Serratus anterior: Rotates scapula so its inferior angle moves laterally and upward
Abdominal Muscles
