KINE 2031 Midterm #2

What are the 3 muscle types?

1. Skeletal

2. Cardiac

3. Smooth

Skeletal Muscle

-Striated

-Muscle that is under conscious control of the nervous system

-Parallel muscle fibres

Smooth Muscle

-Non-striated, non-parallel muscle fibres

-Involuntary muscle under control of the autonomic nervous system

-Surrounds fluid-containing vessels such as stomach, intestines, glands, etc.

Cardiac Muscle

-Striated, non-parallel muscle fibres

-Involuntary muscle of the heart

-Under autonomic nervous system control

What 2 types of muscle are under control of the autonomic nervous system?

Smooth and cardiac muscle

Functions of Skeletal Muscle

1. Movement: contraction of skeletal muscle causes and inhibits movement

2. Maintain body temperature: contraction of muscle produces heat

3. Posture/balance: maintains posture and balance

4. Protection: abdominal muscles protect abdominal organs; muscles around your mouth and eyes can close for protection of underlying tissue

Types of Muscle Contractions

Isometric: Muscle tension with no movement

Isotonic: The muscle shortens or lengthens during contraction

What are the 2 types of isotonic contractions?

1. Concentric: Tension in muscle as muscle is shortening

2. Eccentric: Tension in muscle as muscle is lengthening; usually the force that causes the movement is gravity

What are the 3 components of a lever system?

1. Fulcrum: point (joint) around which movement occurs

2. Force: Muscle or gravity is the force; force is applied to the moveable bone in the system

3. Resistance: Weight to be moved

1st Class Lever

-Like a seesaw

-Has the fulcrum in the middle and the weight and resistance on either side of the fulcrum

Example: head extension

Fulcrum: Occipital condyles and C1

Force: posterior muscles attachment to base of occipital bone

Resistance: weight of head

2nd Class Lever

-Like a wheelbarrow

-Fulcrum at an end of the lever, with the resistance closer to the fulcrum and the force further (relative to the resistance) from the fulcrum

Example: Plantar flexion

Fulcrum: metatarsal-phalangeal joint

Force: attachment of the superficial plantar flexor muscles (gastrocnemius, soles and planters) to the calcaneus bone

Resistance: weight of body

3rd Class Lever

-Like a long-handled shovel

-Fulcrum at an end of the lever, resistance at the other end of the lever and the force between the fulcrum and the resistance

Example: Elbow flexion at the biceps brachii

Fulcrum: elbow joint

Force: attachment of biceps brachii onto radius

Resistance: weight of forearm

When a muscle crosses a joint...

It produces or restricts movement in the joint

True or False: Muscles can pull and push on bones

False: Muscles can only pull on bones

Prime Movers

The muscles primarily responsible for movement of a bone, or stabilizing bone movement

Agonists

Secondary muscles which contribute to actions of prime movers

Antagonists

Muscles on the opposite side of an articulation which oppose movement or the action of prime movers

Motor Unit

One motor neuron and the muscle fibres it innervates

As resistance to movement increases...

Motor unit recruitment increases

Origin

Attachment of a muscle closer to the trunk or midline of the body (proximal attachment)

Insertion

Distal attachment of a muscle

Action

The action of the muscle on one or more articulations

Muscles of the Shoulder Girdle

-Trapezius

-Rhomboids

-Levator Scapula

-Serratus Anterior

-Pectoralis Minor

Trapezius

Origin:

Insertion:

Joints:

Action:

Origin: Occipital bone, (thoracic) vertebrae

Insertion: Clavicle, scapula

Joints: Scapulothoracic

Actions: Elevate/raise scapula

-Adduct (retract) scapula

-Upward rotation (raise) at the point of the shoulder

Rhomboids

Origin:

Insertion:

Joints:

Action:

Origin: (Thoracic) vertebrae

Insertion: Scapula

Joints: Scapulothoracic

Actions: Adduct scapula

-Downward rotation (lower) at the point of the shoulder

In a chin-up, what do the rhomboids do?

Move the medial border of the scapula downward toward the spine

Serratus Anterior

Origin:

Insertion:

Joints:

Action:

Origin: Ribs

Insertion: Scapula

Joints: Scapulothoracic

Actions: Abducts scapula

-Raises shoulder

Levator Scapula

Origin:

Insertion:

Joints:

Action:

Origin: Vertebrae

Insertion: Scapula

Joints: Scapulothoracic

Actions: Elevate/raise scapula

-Lowers shoulder

Pectoralis Minor

Origin:

Insertion:

Joints:

Action:

Origin: Ribs

Insertion: Scapula

Joints: Scapulothoracic

Actions: Abducts scapula, lowers the shoulder

What muscles originate at the vertebrae?

Trapezius, rhomboids, levator scapulae, Latissimus Dorsi

What muscles originate at the rib and insert on the scapula?

Serratus anterior and pectoralis minor

What muscles elevate the scapula?

Trapezius, Levator Scapula

What muscles adduct the scapula?

Trapezius, Rhomboids

What muscles abduct the scapula?

Serratus anterior and pectoralis minor

What muscles elevate the shoulder?

Trapezius and Serratus Anterior

What muscles lower the shoulder?

Rhomboids, levator scapula and pectoralis minor

What muscle are responsible for the shoulder shrug movement?

Trapezius and levator scapula

What are the 3 heads of the deltoid?

1. Spinal (Posterior) Head

2. Acromial (Lateral) Head

3. Clavicular (Anterior) Head

Spinal (Posterior) Head

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Humerus

Joints: Shoulder

Actions: Abduct shoulder

-Shoulder extension

-Lateral rotation of the shoulder

Acromial (Lateral) Head

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Humerus

Joints: Shoulder

Actions: Abduct shoulder

Clavicular (Anterior) Head

Origin:

Insertion:

Joints:

Actions:

Origin: Clavicle

Insertion: Humerus

Joints: Shoulder

Actions: Abduct shoulder

-Shoulder flexion

-Medial rotation of the shoulder

Pectoralis Major

Origin:

Insertion:

Joints:

Actions:

Origin: Clavicle, ribs

Insertion: Humerus

Joints: Shoulder

Actions: Flexion, adduction and medial rotation of the shoulder

-Extension of a flexed shoulder

Latissimus Dorsi

Origin:

Insertion:

Joints:

Actions:

Origin: Sacrum, (Lumbar) Vertebrae

Insertion: Humerus

Joints: Shoulder

Actions: Extension, adduction and medial rotation of the shoulder

What muscles originate at the ribs?

Serratus anterior, Pectoralis Minor and Pectoralis Major

What muscles originate at the clavicle?

Clavicular Head, Pectoralis Major

What muscle does shoulder abduction?

Deltoid

What muscle does shoulder adduction?

Pectoralis Major, Latissimus Dorsi, Teres Major

What muscle does shoulder flexion?

Clavicular Head, Pectoralis Major, Biceps Brachii, Coracobrachialis

What muscle does shoulder extension?

Spinal Head, Latissimus Dorsi, Teres Major, Long Head of Triceps Brachii

What muscle does medial rotation of the shoulder?

Clavicular head, Latissimus dorsi, Pectoralis major, Teres Major, Subscapularis

What are the muscles of the rotator cuff?

-Supraspinatus

-Infraspinatus

-Teres Minor

-Subscapularis

Supraspinatus

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Humerus

Joints: Shoulder

Actions: Starts arm (shoulder) abduction

Once the shoulder has started abduction...

The deltoid takes over abduction

What muscles contract to rotate the scapula upward after the humerus abducts about 60 degrees?

Trapezius and serratus anterior

Infraspinatus

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Humerus

Joints: Shoulder

Actions: Lateral shoulder rotation

Teres Minor

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Humerus

Joints: Shoulder

Actions: Lateral shoulder rotation

Subscapularis

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Humerus

Joints: Shoulder

Actions: Medial shoulder rotation

Teres Major

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Humerus

Joints: Shoulder

Actions: Shoulder adduction

-Medial shoulder rotation

-Shoulder extension

What muscle performs the same functions as the latissimus dorsi?

Teres major

How many heads does the biceps brachii have?

2 (long and short)

Short Head of Biceps Brachii

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Radius

Joints: Shoulder, elbow

Actions: Shoulder flexion

-Elbow flexion

-Aids in supination of the forearm

Long Head of Biceps Brachii

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Radius

Joints: Shoulder, elbow

Actions: Shoulder flexion

-Elbow flexion

-Aids in supination of the forearm

How many heads does the triceps brachii have?

3

-Long head

-Medial head

-Lateral head

Long Head (Triceps Brachii)

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Ulna

Joints: Shoulder, elbow

Actions: Shoulder extension

-Elbow extension

Medial Head (Triceps Brachii)

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus

Insertion: Ulna

Joints: Elbow

Actions: Elbow extension

Lateral Head (Triceps Brachii)

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus

Insertion: Ulna

Joints: Elbow

Actions: Elbow extension

Coracobrachialis

Origin:

Insertion:

Joints:

Actions:

Origin: Scapula

Insertion: Humerus

Joints: Shoulder

Actions: Shoulder flexion

What muscles do lateral shoulder rotation?

Spinal (Posterior) Head of Deltoid, Infraspinatus, Teres Minor

What muscles make up the elbow joint?

-Biceps brachii

-Triceps brachii

-Brachialis

-Brachioradials

-Supinator

-Pronator Teres

Brachialis

-Origin

-Insertion

-Joints

-Actions

Origin: Humerus

Insertion: Ulna

Joints: Elbow

Actions: Elbow flexion

Brachioradialis

-Origin

-Insertion

-Joints

-Actions

Origin: Humerus

Insertion: Radius

Joints: Elbow

Actions: Flexes the elbow when the forearm is in semi-pronated position

Supinator

-Origin

-Insertion

-Joints

-Actions

Origin: Humerus

Insertion: Radius

Joints: Elbow

Actions: Supination

Pronator Teres

-Origin

-Insertion

-Joints

-Actions

Origin: Humerus

Insertion: Radius

Joints: Elbow

Actions: Pronation

-Elbow flexion

What are the 2 structures associated with the forearm flexor muscles?

1. Palmar aponeurosis: Layer of tendon muscle covering the palm of the hand

-Serves as the insertion of the palmaris longus muscle

-Protects vessels and tendons in the palm

2. Flexor retinaculum: Bands of connective tissue that stretches from the lateral to the medial carpal bones

-Most tendons of the forearm flexor muscles pass under the retinaculum

What forms the carpal tunnel?

Carpal bones and flexor retinaculum

What muscles flex the elbow?

Biceps brachii, brachialis, brachioradialis, pronator teres

What muscles supinate the elbow?

Supinator, Biceps brachii

Flexor Carpi Radialis

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus

Insertion: 2nd metacarpal

Joints: Elbow, wrist

Actions: Elbow flexion

-Wrist flexion

-Wrist abduction

Palmaris Longus

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus

Insertion: Palmar aponeurosis

Joints: Elbow, wrist

Actions: Elbow flexion

-Wrist flexion

Flexor Carpi Ulnaris

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus, ulna

Insertion: 5th metacarpal

Joints: Elbow, wrist

Actions: Elbow flexion

-Wrist flexion

-Wrist adduction

Flexor Digitorum Superficialis

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus, radius

Insertion: 2nd phalanx of each of the 4 fingers

Joints: Elbow, wrist

Actions: Elbow flexion

-Wrist flexion

-Flexion of the metacarpal-phalangeal joint

-Flexion of the 1st interphalangeal joint

Flexor Digitorum Profundus

Origin:

Insertion:

Joints:

Actions:

Origin: Ulna

Insertion: 3rd/distal phalanx of the four fingers

Joints: Wrist

Actions: Wrist flexion

-Flexion of the metacarpal-phalangeal joint

-Flexion of the 1st interphalangeal joint

-Flexion of the 2nd interphalangeal joint

Flexor Pollicis Longus

Origin:

Insertion:

Joints:

Actions:

Origin: Radius

Insertion: 2nd/distal phalanx of the thumb

Joints: Wrist

Actions: Wrist flexion

-Flexion of the carpal-metacarpal joint

-Flexion of the metacarpal-phalangeal joint

-Flexion of the 1st interphalangeal joint

Pronator Quadratus

Origin:

Insertion:

Joints:

Actions:

Origin: Ulna

Insertion: Radius

Joints: Radius/ulna

Actions: Forearm pronation

Carpal tunnel syndrome

Irritation or swelling of the synovial membrane tubes in the carpal tunnel which can put pressure on the median nerve that runs under the retinaculum

Extensor Carpi Radialis Longus

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus

Insertion: 2nd metacarpal

Joints: Elbow, wrist

Actions: Elbow extension

-Wrist extension

-Wrist abduction

Extensor Carpi Radialis Brevis

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus

Insertion: 3rd metacarpal

Joints: Elbow, wrist

Actions: Elbow extension

-Wrist extension

-Wrist abduction

Extensor Digitorum Communis

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus

Insertion: Dorsal expansion of 4 fingers

Joints: Elbow, wrist

Actions: Elbow extension

-Wrist extension

-Extension of the metacarpal-phalangeal joint

-Extension of the 1st and 2nd interphalangeal joint

Extensor Carpi Ulnaris

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus, ulna

Insertion: 5th metacarpal

Joints: Elbow, wrist

Actions: Elbow extension

-Wrist extension

-Wrist adduction

Extensor Digiti Minimi

Origin:

Insertion:

Joints:

Actions:

Origin: Humerus

Insertion: Dorsal expansion of the 5th finger

Joints: Elbow, wrist

Actions: Elbow extension

-Wrist extension

-Extension of the metacarpal-phalangeal joint

-Extension of the 1st and 2nd interphalangeal joint

Abductor Pollicis Longus

Origin:

Insertion:

Joints:

Actions:

Origin: Radius, ulna

Insertion: Metacarpal of the thumb

Joints: Wrist

Actions: Abducts the carpal/metacarpal joint

Extensor Pollicis Brevis

Origin:

Insertion:

Joints:

Actions:

Origin: Radius

Insertion: 1st phalanx of the thumb

Joints: Wrist, carpal/metacarpal, metacarpal/phalangeal

Actions: Extension of the metacarpal/phalangeal joint

Extensor Pollicis Longus

Origin:

Insertion:

Joints:

Actions:

Origin: Ulna

Insertion: Distal phalanx of the thumb

Joints: Wrist, carpal/metacarpal, metacarpal/phalangeal

Actions: Extension of the metacarpal/phalangeal joint

-Extension of the interphalangeal joint

Extensor Indicis

Origin:

Insertion:

Joints:

Actions:

Origin: Ulna

Insertion: Dorsal expansion of the index finger

Joints: Wrist, carpal/metacarpal, metacarpal/phalangeal

Actions: Extension of the metacarpal-phalangeal and interphalangeal joints

Adductor Pollicis

Origin:

Insertion:

Joints:

Actions:

Origin: Metacarpal

Insertion: Head of the 1st metacarpal

Joints: Carpal/metacarpal

Actions: Adduction

How many interossei muscles are there?

7

-3 Palmar

-4 Dorsal

Palmar Interossei

Origin:

Insertion:

Joints:

Actions:

Origin: Metacarpal

Insertion: Dorsal expansion of fingers

Joints: Metacarpal/phalangeal

Actions: Adduct fingers

Dorsal Interossei

Origin:

Insertion:

Joints:

Actions:

Origin: Metacarpals

Insertion: Dorsal expansion of fingers

Joints: Metacarpal/phalangeal

Actions: Abduct fingers

Lumbricals

Origin:

Insertion:

Joints:

Actions:

Origin: Tendon of flexor digitorum profundus

Insertion: Dorsal expansion of fingers

Joints: Metacarpal/phalangeal, interphalangeal

Actions: Flexion of the metacarpal/phalangeal joint

-Extend interphalangeal joint

Thenar Muscles

A group of 3 muscles located at the base of the thumb

-Important in allowing the thumb to oppose the other digits and supplement flexion and abduction of the thumb