Download C5.3 Notes - Destiny High School

Today’s Objectives:
• Describe and give examples of the types of body motions that occur in the sagittal, frontal, and transverse planes.
• Identify the locations and functions of the muscles of the head and neck.
• Identify the locations and functions of the trunk muscles.
• Identify the locations and functions of the muscles of the upper limb.
• Identify the locations and functions of the muscles of the lower limb.
Lesson 5.3: The Major Skeletal Muscles
What We’re Covering Today
•
directional motions
•
head and neck muscles
•
trunk muscles
•
upper limb muscles
•
lower limb muscles
Major Skeletal Muscles
•
There are more than 650 skeletal muscles in the human body.
•
Most of the muscles we will look at are arranged in agonist-antagonist pairs.
•
Remember: The agonist-antagonist muscle pairs oppose each other’s movements.
Skeletal Muscle Attachments
Directional Motions

Skeletal muscles attach at either end of the muscle; the most common attachments are tendon connections to the bone.

origin
o

The end of a muscle that attaches to a relatively fixed structure.
insertion
o
The end of a muscle that attaches to a bone that typically moves when the muscle contracts.
o
Example:

o
Origin of the brachialis begins on the humerus, while the insertion point is on the ulna.

When the brachialis contracts, the forearm (ulna) is pulled toward the upper arm, while the upper arm remains
stationary.
In line with forward and backward motions.
Frontal Plane

o

Sagittal Plane

o
Brachialis
In line with sideways movement
Transverse Plane

Rotational movements
Sagittal Plan Movements

Flexion
o
Forward bending motion of the head, trunk, upper arm, forearm, hand, and hip
o
Backward motion of the lower leg at the knee.
o

Extension
o

Body surfaces come together.
Returns body segments from a position of flexion to anatomical position.
Hyperextension
o
Continues extension beyond anatomical position.

Two movements of the foot:

Dorsiflexion
o

Bringing the top of the foot toward the lower leg.
plantar flexion
o
Moving the foot in the opposite direction away from the lower leg.

Frontal Plane Movements

Abduction
o

Adduction
o

Rolling the sole of the foot outward.
radial deviation
o

Rolling the sole of the foot inward.
Eversion
o

Movements that bring the arm and leg closer to the midline of the body.
Inversion
o

Movements at the shoulder and hip that take the arm and leg away from the midline of the body.
Abduction of the hand toward the thumb
ulnar deviation
o
Adduction of the hand toward the little finger.
Transverse Plane Movements

Transverse plane movements mostly involve rotation around the long axis of a body segment.

medial rotation
o

lateral rotation
o

Movement directed laterally or outward.
Pronation
o

Rotation of an arm of a leg directed medially or inward.
Rotation of the forearm medially (palm down)
supination
o
Rotation of the forearm laterally (palm up)
Multiplanar Movement

Movements that do not fall into a single plan are called multiplanar movements.

Circumduction
o

Rotational movement of a body segment such that the end of the segment traces a circle.
Opposition
o
Touching any of your four fingers to the thumb.
o
This movement allows you to grasp objects.
Head and Neck Muscles

Head and Neck muscles can be divided into 3 groups:
o
Facial muscles

Muscle insertions connect to other muscles or skin resulting in our ability to create facial expressions.
o
Chewing muscles
o
Neck muscles
Trunk Muscles

Provide stability for the vertebral column.

Responsible for helping to maintain an upright posture.

Trunk muscles enable flexion, extension, hyperextension, lateral flexion, and rotation of the head and trunk.

Diaphragm muscle regulates our breathing.
Upper Limb Muscles

Remember: The should is a ball and socket joint…meaning it is freely movable.

Shoulder joint is susceptible to dislocation.

The large muscles of the shoulder maintain stability.
Lower Limb Muscles

Lower limb muscles are designed for standing and walking.

Lower limb muscles have strong, stringlike tendons.