Contrasting Muscle Motion Flashcards
What is abduction?
Abduction is the movement of a limb(arm or leg) away from the midline of the body (ab- means away from, duct means to lead, and -ion means action). During abduction, the limb moves outward away from the side of the body.
An abductor is
A muscle that moves a body part away from the midline.
What is adduction?
Adduction is the movement of a limb (arm or leg) toward the midline of the body (ad- means toward, duct means to lead, and -ion means action). During adduction, the limb moves inward toward the side of the body.
An adductor is a
Muscle that moves a body part toward the midline.
What is flexion?
Flexion means decreasing the angle between two bones by bending a limb at a joint (flex means to bend, and -ion means action).
During flexion, the knee or elbow is bent. A flexor muscle bends a limb at
A joint
In contrast, extension means
increasing the angle between two bones or the straightening out of a limb (ex- means away from, tens means to stretch out, and -ion means action).
During extension, the knee or elbow is straightened. An extensor muscle straightens a
Limb at a joint.
What is hyperextension?
Ex?
The extreme or overextension of a limb or body part beyond its normal limit.
Ex: movement of the head far backward or far forward beyond normal range of motion causes hyperextension of the muscles of the neck.
What is elevation?
Example?
The act of raising or lifting a body part.
Ex: the elevation of the levator anguli oris muscles of the face raises the corners of the mouth into a smile.
A levator is a muscle that
Raises a body part.
In contrast, depression is the act of
Lowering a body part.
The depressor anguli oris, for example,
Lowers the corner of the mouth into a frown.
A depressor muscle ___________ a body part.
Lowers
What is rotation?
Rotation is a circular movement around an axis such as the shoulder joint.
What is an axis?
An imaginary line that runs lengthwise through the center of the body, and rotation turns a bone on its own axis.
In contrast, what is circumduction?
Ex?
The circular movement at the far end of a limb. Ex: the swinging motion of the far end of the arm.
What is a rotator muscle?
Example?
Turns a body part on its axis
Ex: head of the humerus, which is the bone of the upper arm, rotates within the shoulder joint.
What is the rotator cuff?
The group of muscles and their tendons that hold the head of the humerus securely in place as it rotates within the shoulder joint.
What is supination?
The act of rotating the arm or the leg so that the palm of the hand or sole of the foot is turned forward or upward.
Ex: carrying a bowl of soup
In contrast, what is pronation?
The act of rotating the arm or leg so that the palm of the hand or sole of the foot is turned downward or backward.
What is dorsiflexion?
Is the movement that bends the foot upward at the ankle. Pointing the toes and foot upward decreases the angle between the top of the foot and the front of the leg.
In contrast, what is plantar flexion?
The movement that bends the foot downward at the ankle.
What does plantar mean?
Plantar means pertaining to the sole of the foot. Pointing the toes and foot downward increases the angle between the top of the the foot and the front of the leg.
