Muscles of the shoulder

 These muscles stabilize the association between the appendicular and

axial skeletons at the pectoral girdle and stabilize and allow movement of
the shoulders and upper arms.
Muscles of the shoulder
The Pectoral Muscles
 Pectoralis Major
 Pectoralis Minor
 Serratus Anterior
Extrinsic Muscles of the Back
 Trapezius Muscle
 Latissimus Dorsi
 Levator Scapulae
The Scapular Muscles
 The Deltoid Muscle
 Teres Major ,
 Rhomboid major,
 Rhomboid minor

Rotator Cuff Muscles

Rotator cuff
 The rotator cuff is an anatomical term given to the group of muscles
and their tendons that act to stabilize the shoulder.
 It is composed of the tendons and muscles (supraspinatus,
infraspinatus, teres minor and subscapularis) that hold the head of the
humerus (ball) in the glenoid fossa (socket).
Deltoid:
 These muscle fibres originate from the clavicle, acromion process and
spine of scapula and radiate over the shoulder joint to be inserted into the
deltoid tuberosity of the humerus.
 It forms the fleshy and rounded contour of the shoulder and the main
function is movement of the arm.
 The anterior part causes flexion, the middle or main part abduction
and the posterior part extends and laterally rotates the shoulder joint.

Pectoralis major:
 The lies on the anterior thoracic wall.
 The fibres originate from the middle third of the clavicle and from the
sternum and are inserted into the lip of the intertubercular groove of the
humerus.
 It draws the arm forward and towards the body i. e flexes and adducts.
Movements possible at the shoulder joint

Extension Latissimus dorsi, teres major

Flexion Coracobrachialis, pectoralis major

Abduction Deltoid,

Adduction Latissimus dorsi, pectoralis major

Lateral Teres minor, posterior part of deltoid

Medial rotation Latissimus dorsi, pectoralis major, teres

major and anterior part of deltoid

Circumduction Combination of actions of above muscles

MUSCLES OF THE UPPER ARM
 The arm is divided by intermuscular septa into two compartments

Anterior compartment of the arm

 Biceps Brachii
 Brachialis
 Coracobrachialis

Posterior compartment of the arm

 Triceps Brachii
 Two other muscles are considered to be partially in the arm:
 deltoid muscle
 brachioradialis

Coracobrachialis:
 This lies on the upper medial aspect of the arm.
 It arises from the coracoid process of the scapula, stretches across
infront of the shoulder joint and is inserted into the middle third of the
humerus.
 It flexes the shoulder joint.

Brachialis:
 This lies on the anterior aspect of the upper arm deep to the biceps.
 It originates from the shaft of the humerus extends across the elbow
joint and is inserted into the ulna just distal to the joint scapule.
 It is the main flexor of the elbow joint.

Biceps brachi
 This lies on the anterior aspect of the upper arm. At its proximal end it
is divided into two parts (heads) each of which has its own tendon.
 The short head rises from the coracoid process of the scapula and
passes in front of the shoulder joint to the arm.
 The long head originates from the rim of the glenoid cavity and its
tendon passes through the joint cavity and the bicipital groove of the
humerus to the arm.
 It is retained in the bicipital groove by a transverse humeral ligament
that stretches across the groove.
 The distal tendon crosses the elbow joint and is inserted into the
radial tuberosity.
 It helps to stabilize and flex the shoulder joint and at the elbow joint it
assists with flexion and Supination

1. ulna
2. humerus
3. radius
4. biceps brachii tendon
5. short head of biceps
tendon
6. scapula
7. coracoid process
8. acromion process
9. biceps brachii
10. long head of biceps
tendon

Triceps
 This lies on the posterior aspect of the humerus.
 It arises from three heads, one from the scapula and two from the
posterior surface of the humerus.
 The insertion is by a common tendon to the Olecronon process of the
ulna.
 It helps to stabilize the shoulder joint, assists in adduction of the arm
and extends the elbow joint.

Movements at the elbow Joint

Flexion the biceps and brachialis

Extension the triceps

MUSCLES OF THE FOREARM

Anterior or flexor compartment

The Superficial Layer of Flexors

 Pronator Teres
 Flexor Carpi Radialis
 The Palmaris Longus
 Flexor Digitorum Superficialis
 Flexor Carpi Ulnaris

Deep Layer
 Supinator
 Pronator Quadratus
 Flexor Digitorum Profundus
 Flexor Pollicis Longus

Pronator Teres:
 This lies obliquely across the upper third of the front of the forearm.
 It arises from the medial epicondyles of the humerus and the coronoid
process of the ulna and passes obliquely across the forearm to be inserted
into the lateral surface of the shaft of the radius.
 It rotates the radioulnar joints, changing the hand from the anatomical
to the writing position i. e Pronation.

Supinator:
 This lies obliquely across the posterior and lateral aspects of the
forearm.
 Its fibres arise from the lateral epicondyles of the humerus and the
upper part of the ulna and are inserted into the lateral surface of the upper
third of the radius.
 It rotates the radioulnar joints, often with help form the biceps,
changing the hand from the writing to the anatomical position, i. e
Supination.
Flexor Carpi Radialis
 This lies on the anterior surface of the forearm. It originates from the
medial epicondyles of the humerus and is inserted into the second and third
metacarpal bones. It flexes the wrist joint and when acting with the extensor
carpi radialis, abducts the joint.

Flexor Carpi Ulnaris

 This lies on the medial aspect of the forearm. It originates from the
medial epicondyles of the humerus and the upper parts of the ulna and is
inserted into the pisiform, the hamate and the fifth meta

Pronator Quadratus:
 This square shaped muscle is the main muscle causing Pronation of
the hand and has attachments on the lower sections of both the radius and
the ulna.
Muscles that control finger movements
 Large muscles in the forearm that extend to the hand give power to
the hand and fingers, but not the delicacy of movement needed for fine and
dextrous finger control.
 Flexor Digitorum Superficialis
 Flexor Digitorum Profundus
 Flexor Pollicis Longus

MUSCLES OF THE FOREARM

Posterior or extensor compartment

 Brachioradialis Muscle
 Extensor Carpi Radialis Longus
 Extensor Carpi Radialis Brevis
 Extensor Digitorum
 Extensor Digiti Minimi
 Extensor Carpi Ulnaris
 Abductor Pollicis Longus
 Extensor Pollicis Brevis
 Extensor Pollicis Longus
 Extensor Indicis

Brachioradialis:
 The brachioradialis spans the elbow joint, originating on the distal end
of the humerus and inserts on the lateral epicondyles of the radius.
 When it contracts, it flexes the elbow joint.

Proximal and distal radioulnar joints

Pronation (turning palm down) pronator teres and quadratus

Supination (turning palm up). the supinator and biceps muscles

Muscles and Movements at the wrist joints

Flexion Flexor carpi radialis, flexor carpi

ulnaris

Extension Extensors carpi radialis (longus and

brevis) extensor carpi ulnaris

Abduction Flexor carpi ulnaris, extensor carpi

ulnaris

Adduction Flexor carpi radialis, extensor carpi

radialis

Muscles of the hand

 Smaller muscles which originate on the carpal and metacarpal bones,
control tiny and precise finger movements via tendinous attachments on the
phalanges muscle fibres do not extend into the fingers.

They can be divided into 3 groups:

 the thumb or thenar muscles
 the little finger or hypothenar muscles
 the lumbrical and interosseous muscles

Thenar muscles
 abductor pollicis brevis,
 flexor pollicis brevis, and
 opponens pollicis,
 adductor pollicis

Hypothenar muscles
 Abductor Digiti Minimi
 Flexor Digiti Minimi Brevis
 Opponens Digiti Minimi Muscle
lumbrical and interosseous muscles
 There are 4 slender lumbrical muscles-one for each digit.
 There are 7 interossei muscles located between the metacarpal bones.
 They are arranged in 2 layers:
 3 palmar
 4 dorsal muscles.
Muscles of the hip and lower limb
 The biggest muscles of the body are found here, since their function is
largely in weight bearing.
The lower parts of the body are designed to
 transmit the force of body weight in walking, running etc evenly
throughout weight bearing structures
 Act as shock absorbers.

Muscles of the hip

Iliopsoas group
 The iliacus and psoas major

Gluteal group (abductors)

 Gluteus maximus, gluteus medius, gluteus minimus, tensor fasciae
latae.

Lateral rotator group

 Externus and internus obturators, the piriformis, the superior and
inferior gemelli, and the quadratus femoris.

Adductor group
 The adductor brevis, adductor longus, adductor magnus, pectineus,
and gracilis

Muscles of the hip

Psoas:
 This arises from the transverse processes and bodies of the lumbar
vertebrae.
 It passes across the flat part of the ilium and behind the inguinal
ligament to be inserted into the femur.
 Together with the iliacus it flexes the hip joint.

Iliacus:
 This lies in the iliac fossa of the innominate bone.
 It originates from the iliac crest, passes over the iliac fossa and joins
the tendon of the psoas muscle to be inserted into the lesser trochanter of the
femur.
 The combined action of the iliacus and psoas flexes the hip joint.

Gluteals:
 These consist of the gluteus maximus, medius and minimus which
together form the fleshy part of the buttock.
 They originate from the ilium and sacrum and are inserted into the
femur.
 They cause extension, abduction and medial rotation at the hip joint.
Obturators:
 The obturators deep muscles of the buttock have their origins in the
rim of the obturator foramen of the pelvis and insert into the proximal femur.
 Their main function lies in lateral rotation at the hip joint.

Adductor Group
 This lies on the medial aspect of the thigh.
 They originate from the pubic bone and are inserted into the linea
aspera of the femur.
 They adduct and medially rotate the thigh.
Muscles and Movements at the hip joints

Extension Gluteus maximus, hamstrings

Flexion Psoas, illacus, sartorius

Abduction Gluteus medius and minimus,

sartorius

Adduction Adductor group (longus, brevis and

magnus

Lateral Rotation Gluteus maximus, quadratus,

femoris, obturators

Medial rotation Gluteus medius and minimus,

adductor group
Muscles of the thigh
 Anterior thigh muscles- the quadriceps femoris.
rectus femoris
vastus intermedius
vastus medialis
vastus lateralis.
sartorius
 posterior thigh muscles-hamstrings
biceps femoris has two heads
semitendiosus
semimembranosus
Quadriceps femoris:
 This is a group of four muscles lying on the front and sides of the
thigh.
 They are the rectus femoris and three vasti: lateralis, medialis and
intermedius.
 The rectus femoris originates from the ilium
 The three vasti from the upper end of the femur.
 Together they pass over the front of the knee joint to be inserted into
the tibia by the patellar tendon.
 Only the rectus femoris flexes the hip joint.
 Together, the group acts as a very strong extensor of the knee joint.

Sartorius:
 This is the longest muscle in the body and crosses both the hip and
knee joints.
 It originates from the anterior superior iliac spine and passes obliquely
across the hip joint, thigh and knee joint to be inserted into the medial
surface of the upper part of the tibia.
 It is associated with flexion and abduction at the hip joint and flexion
at the knee.
Hamstrings:
 These lies on the posterior aspect of the thigh.
 They originate from the Ischium and are inserted into the upper end of
the tibia.
 They are the biceps femoris, semimembranosus and semitendinosus
muscles.
 They flex the knee joint.

Muscles and movements of Knee joint

flexion Gastrocnemius and Hamstrings.

extension The quadriceps femoris

rotary movement that locks the joint it is possible to stand upright for long
when it is fully extended periods of time without tiring the
knee extensors.
Muscles of the leg
Three of the anterior muscles are extensors.
 tibialis anterior
 extensor digitorum longus
 extensor hallucis longus

Peroneal group
 Peroneus longus ,brevis and tertius

Posterior muscles
Three are in the superficial layer.
 triceps surae - the soleus, and the two heads of gastrocnemius These
muscles unite in a large terminal tendon, the Achilles tendon
 Plantaris

Three In the deep layer,

 tibialis posterior
 flexor hallucis longus
 flexor digitorum longus,

Gastrocnemius:
 This forms the bulk of the calf of the leg.
 It arises by two heads, one from each condyle of the femur, and passes
down behind the tibia to be inserted into the calcaneous by the calcaneal
tendon (Achilles tendon).
 It crosses both knee and ankle joints, causing flexion at the knee and
Plantarflexion (rising onto the ball of the foot) at the ankle.

Soleus:
 This is one of the main muscles of the calf of the leg, lying
immediately deep to the gastrocnemius.
 It originates from the heads and upper parts of the fibula and the tibia.
 Its tendon joins that of the gastrocnemius so that they have a common
insertion into the calcaneous by the Calcanium (Achilles) tendon.
 It causes Plantarflexion at the ankle and helps to stabilize the joint
when standing.
Anterior Tibialis:
 This originates from the upper end of the tibia, lies on the anterior
surface of the leg and is inserted into the middle cuneiform bone by a long
tendon.
 It is associated with Dorsiflexion of the foot.
 extensor digitorum longus
 extensor hallucis longus
Lateral or peroneal muscles
Peroneus longus ,brevis and tertius

Muscles and movements at the ankle joint

Dorsiflexion (lifting toes upwards) anterior tibialis and toe extensors

Plantar flexion (rising on tiptoe) Gastrocnemius, soleus and toe

flexors
Movements at the subtalar joint
Inversion (Supination) Tibialis anterior
Turning the foot medially resulting Tibialis posterior
in the sole moving inward.

Eversion (Pronation) Peroneus longus

Turning the foot latererally resulting Peroneus brevis
in the sole moving outward. Peroneus tertius

Foot Muscles – Plantar Surface

Superficial Layer
1. Abductor Hallucis
2. Abductor Digiti Minimi
3. Flexor Digitorum Brevis

Middle Layer
1. Quadratus Plantae
2. Lumbricals

Deep Layer
1. Flexor Hallucis Brevis
2. Adductor Hallucis
Transverse and Oblique Heads
3. Flexor Digiti Minimi
4.
Foot Muscles – Dorsal Surface
 Extensor Digitorum Brevis
 Extensor Hallucis Brevis