Anatomy-Muscular
System
Skeletal Muscle
Characteristics &
Function
Bellwork
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What is a concentric
contraction?
Eccentric contraction?
Isometric contraction?
Objectives

Students will be able to:
 Identify skeletal muscles, their attachments &
action
Terminology

Dorsiflexion
 Upward
the foot

bending of
Pulling toes up
Terminology

Plantar Flexion
 Downward
bending of the foot

Pointing toes
Dancers primarily
plantarflex
Face



Origin
 Zygomatic arch
Insertion
 Mandible
Action
Closes the jaw
 Raises the mandible

Masseter

The Chewing
Muscle!

How would we
CONTRACT this
muscle?
Neck Muscle

Sternocleidomastoid
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Sterno – Sternum
Cleido – Clavicle
Mastoid – Mastoid Process
Origin
 Sternum (near manubrium)
 Clavicle (medial end)
Insertion
 Mastoid Process
Sternocleidomastoid

Action
1. Bilaterally, Flex Cervical
2. Unilaterally, rotation to
opposite side
Abdominals



Rectus Abdominis
Origin
 Pubis
Insertion
 Xiphoid process
 Costal cartilage (5-7)
Rectus Abdominus

Action
 Compresses abdominal cavity
 Flexion of trunk
Upper Extremity Muscles
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Trapezius
Origin
 Occipital
 Spinous process C7-T12
Insertion
 Lateral clavicle
 Scapular spine
Trapezius

Action
 Elevation
 Depression
 Retraction
 Stabilizes scapula
Shrugs
Upright Row

What exercises could
someone do to work
their traps?
Scap Retraction with bands
Upper Extremity



Latissimus Dorsi
Origin
 Spinous process T6-S5
 Iliac crest
Insertion
 Medial humerus
Latissimus Dorsi

Action
 Extension @ shoulder
 Adduction of humerus
Upper Extremity



Pectoralis Major
Origin
 Medial clavicle
 Sternum
 Costal cartilage (1-6)
Insertion
 Proximal Humerus
Pectoralis Major

Action
 Flexion
 Adduction of humerus
Upper Extremity



Deltoid - Anterior
Origin
 Lateral clavicle
Insertion
 Deltoid tuberosity of
humerus
Anterior Deltoid

Action
 Flexion
 Horizontal adduction of humerus
Upper Extremity



Deltoid - Middle
Origin
 Acromion process
Insertion
 Deltoid tuberosity of
humerus
Middle Deltoid

Action
 Abduction of humerus to
90 degrees
Upper Extremity



Deltoid - Posterior
Origin
 Scapular spine
Insertion
 Deltoid tuberosity of
humerus
Posterior Deltoid

Action
 Extension
 Horizontal abduction of humerus
Flash Card Time!
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Make Flash Cards for the
following:
Masseter
Sternocleidomastoid
Rectus Abdominus
Trapezius
Latissimus Dorsi
Pectoralis Major
Deltoid



Anterior
Middle
Posterior
On one side: Name
On opposite side: Origin, Insertion & Action
Rotator Cuff Muscles

4 Muscles make up the Rotator
Cuff:
 Supraspinatus
 Infraspinatus
 Teres Minor
 Subscapularis

They originate on the
scapula & insert on the
humeral head

They hold the head of
the humerus IN the
Glenoid Fossa of the
Scapula.

Keep shoulder in socket.
Supraspinatus

Origin:


Insertion


Supraspinous Fossa of Scapula
Greater Tubercle of Humerus
Action
Abduction of humerus
 Stabilize head of humerus

Supraspinatus in Action!

Laying a ball up in
basketball

Jumping Jack

Abduction of
shoulder
Infraspinatus



Origin
 Infraspinous fossa of scapula
Insertion
 Greater tubercle of humerus
Action
 Lateral rotation of humerus



Or External Rotation
Stabilize head of humerus
What view is this picture?
Infraspinatus in Action!
Teres Minor



Origin
 Lateral boarder of scapula
Insertion
 Greater tubercle of humerus
Action
 Lateral rotation of humerus


External Rotation
Stabilize head of humerus
Teres Minor in Action!

Much like the
Infraspinatus…working
on lateral rotation
exercises enhances this
muscle

What other sports
would need to
strengthen their teres
minor?
Subscapularis



Origin
 Subscapular fossa of scapula
Insertion
 Lesser tubercle of humerus
Action
 Medial rotation of humerus


Internal rotation
Stabilize head of humerus
Actions of Rotator Cuff
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Supraspinatus
Infraspinatus
Teres minor
Subscapularis

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Abduction
External Rotation
External rotation
Internal Rotation
Biceps Brachii



Origin
 Short Head-coracoid process
 Long Head-supraglenoid
tubercle of scapula
Insertion
 Radial tuberosity
Action
 Flexion of elbow
Biceps in Action

Discuss:
Eccentrically Contract
 Isometrically Contract

Triceps Brachii

Origin
 Long Head


Lateral Head



Posterior humerus
Medial Head


Infraglenoid tubercle of scapula
Posterior humerus
Insertion
 Olecranon process of ulna
Action
 Extension of elbow
Tricpes In Action!
Skeletal Muscle
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On one side: Name
Make Flash Cards for the
following:
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
Biceps Brachii
Triceps Brachii
On opposite side: Origin, Insertion & Action
Muscles of the Thigh

The muscles of the thigh run from the hip to the
knee


What movements can the hip and knee joint
perform?
What muscles/muscle group do you know?
Gluteus Maximus



Origin
 Posterior sacrum & ilium
Insertion
 Gluteal tuberosity of femur
Action
 Extension of femur/hip
 External Rotation of hip
Glute Strength


Squats are known to
help build glute
strength…
What other exercises
would concentrically
contract this muscle?
Hamstrings
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Biceps Femoris
Origin
 Long head-ischial tuberosity
 Short head-posterior femur
Insertion
 Head of fibula
Action
 Extension of hip
 Flexion of the knee
Hamstrings




Semitendinosus
Origin
 Ischial tuberosity
Insertion
 Anterior tibia
Action
 Extension of hip
 Flexion of the knee
Hamstrings




Semimembranosus
Origin
 Ischial tuberosity
Insertion
 Posterior medial tibia
Action
 Extension of hip
 Flexion of the knee
Hamstrings
O: Ischial
tuberosity
I: Fibula
& Tibia
A: Flex knee
Extend hip
Biceps Femoris
Semimembranosus
Semitendinosus
Hamstrings

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
Biceps Femoris
Semitendinosus
Semimembranosus
Quadriceps
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
Rectus Femoris
Origin
 Anterior inferior iliac spine
(AIIS)
Insertion
 Tibial tuberosity
Action
 Extension of the knee
 Hip flexion
Quadriceps
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
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Vastus Lateralis
Origin
 Femur
Insertion
 Tibial tuberosity
Action
 Extension of the knee
Quadriceps
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Vastus Medialis
Origin
 Femur
Insertion
 Tibial tuberosity
Action
 Extension of the knee
Quadriceps
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Vastus Intermedius
Origin
 Anterior femur
Insertion
 Tibial tuberosity
Action
 Extension of the knee
Lower Extremity




Rectus Femoris
Vastus Lateralis
Vastus Medialis
Vastus Intermedius
Skeletal Muscle



Make Flash Cards for the
following:
Gluteus Maximus
Hamstrings




Biceps Femoris
Semitendinosus
Semimembranosus
Quads
Rectus Femoris
 Vastus Lateralis
 Vastus Medialis
 Vastus Intermedialis

On one side: Name
On opposite side: Origin, Insertion & Action
Final Chapter!


This last group of
muscles is the end of
this muscle segment.
So far we have
identified:




Face and Neck
Shoulders and Back
Abs and Glutes
Hamstrings and Quads

Today will be the
muscles of the low leg

What is one muscle
group that you already
know?
Calf Muscles
 Why do you think they
call them the calves?


I have no idea!!
Lower Extremity




Tibialis Anterior
Origin
 Lateral condyle of tibia
Insertion
 Plantar surface of 1st metatarsal
Action
 Dorsiflexion


Recall….what does this mean?
Inversion of ankle

Recall….what does this mean?
Dorsiflexion
&
Inversion
Pointing toes out:
EVERSION
Pulling toes up:
DORSIFLEXION
Pointing toes down:
Plantarflexion
Pointing toes in:
Inversion
Lower Extremity




Peroneus Longus
Origin
 Proximal fibula
Insertion
 Plantar surface of 1st
metatarsal
Action

Eversion of ankle
Lower Extremity




Peroneus Brevis
Origin
 Distal fibula
Insertion
 Base of 5th metatarsal
Action

Eversion of ankle
Eversion Exercises


A commonly used
rehab tool are
resistance bands
Eversion exercises
strengthen the
Peroneus Longus
Lower Extremity


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Soleus
Origin
 Upper tibia
 Posterior fibula
Insertion
 Calcaneus (Heel Bone)
Action

Plantarflexion of ankle
Lower Extremity




Gastrocnemius
Origin
 Medial head-medial
epicondyle of femur
 Lateral head-lateral
epicondyle of femur
Insertion
 Calcaneus (Heel Bone)
Action


Plantarflexion of ankle
This muscle is SUPERFICIAL
to the Soleus
Gastrocnemius vs. Soleus
To isolate the GASTROC
To isolate the SOLEUS
Skeletal Muscle
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Make Flash Cards for the
following:
Tibialis Anterior
Peroneus Longus
Peroneus Brevis
Soleus
Gastrocnemius
On one side: Name
On opposite side: Origin, Insertion & Action
Skeletal Muscle
List of muscles learned
Name
Origin, Insertion & Action
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Masseter
Sternocleidomastoid
Rectus Abdominus
Trapezius
Latissimus Dorsi
Pectoralis Major
Deltoid

Anterior

Middle

Posterior
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
Biceps Brachii
Triceps Brachii
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Tibialis Anterior
Peroneus Longus
Peroneus Brevis
Soleus
Gastrocnemius
Gluteus Maximus
Hamstrings

Biceps Femoris

Semitendinosus

Semimembranosus
Quads

Rectus Femoris

Vastus Lateralis

Vastus Medialis

Vastus Intermedialis
Skeletal Muscle