Anatomy-Muscular System Skeletal Muscle Characteristics & Function

Bellwork What is a concentric contraction? Eccentric contraction? Isometric contraction?

Objectives Students will be able to: Identify skeletal muscles, their attachments & action

Terminology Dorsiflexion Upward bending of the foot 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 Origin Sternum (near manubrium) Sterno – Sternum Cleido – Clavicle Mastoid – Mastoid Process Origin Sternum (near manubrium) Clavicle (medial end) Insertion Mastoid Process

Sternocleidomastoid Action Bilaterally, Flex Cervical 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 Trapezius Origin Occipital Spinous process C7-T12 Insertion Lateral clavicle Scapular spine

Trapezius What exercises could someone do to work their traps? Action Elevation Depression Retraction Stabilizes scapula What exercises could someone do to work their traps? Shrugs Upright Row 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

Bellwork Pectoralis Major O: I: A: Rectus Abdominus A Masseter

Flash Card Time! On one side: Name 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 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. 4 Muscles make up the Rotator Cuff: Supraspinatus Infraspinatus Teres Minor Subscapularis

Supraspinatus Origin: Insertion Action 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 What view is this picture? 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 Abduction External Rotation External rotation Internal Rotation Supraspinatus Infraspinatus Teres minor Subscapularis

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 Medial Head Insertion Infraglenoid tubercle of scapula Lateral Head Posterior humerus Medial Head Insertion Olecranon process of ulna Action Extension of elbow

Tricpes In Action!

Skeletal Muscle On one side: Name Make Flash Cards for the following: Supraspinatus Infraspinatus Teres Minor Subscapularis Biceps Brachii Triceps Brachii On one side: Name 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 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 Semitendinosus Biceps Femoris Semimembranosus

Hamstrings Biceps Femoris Semitendinosus Semimembranosus

Quadriceps Rectus Femoris Origin Anterior inferior iliac spine (AIIS) Insertion Tibial tuberosity Action Extension of the knee Hip flexion

Quadriceps Vastus Lateralis Origin Femur Insertion Tibial tuberosity Action Extension of the knee

Quadriceps Vastus Medialis Origin Femur Insertion Tibial tuberosity Action Extension of the knee

Quadriceps 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 Quads On one side: Name 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! Today will be the muscles of the low leg 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

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 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 SOLEUS To isolate the GASTROC

Skeletal Muscle On one side: Name 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 Masseter Sternocleidomastoid Rectus Abdominus Trapezius Latissimus Dorsi Pectoralis Major Deltoid Anterior Middle Posterior Supraspinatus Infraspinatus Teres Minor Subscapularis Biceps Brachii Triceps Brachii 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