Muscle practical

Temporalis

Location:

• temporal fossa

Function:

• closes jaw

• synergist of the masseter

• enabling jaw movement for chewing, biting, and grinding food

Frontalis

Location:

• forehead region of the head

Function:

• raise eyebrows

Orbicularis oculli

Location:

• beneath the eyelid skin

Function:

• close eyes, squints, blinks, wink

• to close the upper and lower lids

Zygomaticus

Location:

• lateral surface of the zygomatic bone\

• anterior to the zygomaticotemporal suture

• lateral to the origin of zygomaticus minor

Function:

• raises corners of the mouth

• raises the upper lip to bare the upper teeth

Masseter

Location:

• below the cheekbone

• the side of the face

Function:

• closes jaw

• elevate the mandible

Mentalis

Location:

• on the mandible

• each side of the frenulum of the lower lip

Function:

• raise the skin of the chin and elevate

• protrude the lower lip

Buccinator

Location:

• cheeks

• interval between the maxilla and the mandible

Function:

• holding food in place

• compresses the cheeks

Platysma

Location:

• neck

Function:

• depress the lower jaw

• pull down the corners of the mouth and lower lip

• contribute to various facial expressions

Orbicularis oris

Location:

• around the mouth

• lips

Function:

• closes mouth

• protrudes the lips

• contributes to the form and shape of the lips

Levator labii superioris

Location:

• begins at the infraorbital margin of the maxilla and extends toward the upper lip

• originates on the maxilla and zygomatic bone

Function:

• elevates and everts the upper lip

Risorius

Location:

• either side of the lips

• superficial layer of the facial muscles

Function:

• pulls the corners of the mouth laterally

Epicranial aponeurosis

Location:

• extends over the cranium

• upper part of the skull

Function:

• help support a muscle in your skull that controls your facial expressions

• stabilizing layer that allows for movement of the skin over the skull and plays a role in facial expressions

Occipital belly

Location:

• back of the skull

Function:

• retracts the scalp

• move the eyebrows

• wrinkle the forehead

Trapezius

Location:

• upper back

• extending from the base of the skull to the mid-back

Function:

• stabilize and move the scapula

Depressor Labii inferioris

Location:

• chin region of the face

Function:

• allows you to pull your lower lip down or to the side

Digastric

Location:

• neck

• under the jaw

Function:

• depress the mandible (lower jaw) for opening the mouth

• elevates the hyoid bone

• crucial for swallowing and speech

• raise the tongue base

Sternocleidomastoid

Location:

• the sides of the neck

• down both sides of your neck until it ends at your sternum or clavicle

• extends from the base of your skull

Function:

• allows for head flexion and rotation

• expanding the chest to aid in deep breathing

• bend your neck and turn and tilt your head

Splenius capitis

Location:

• posterior and lateral parts of the neck

Function:

• assists in supporting the head in the erect position

• primarily to extend the head and neck

• assists in lateral flexion and rotation

Pectoralis minor

Location:

• upper part of the chest

• beneath the pectoralis major

Function:

• stabilization of the scapula

• assist in rib elevation during deep inspiration

Serratus anterior

Location:

• anterior chest wall

Function:

• lift the ribs

• assisting with respirations

• scapula movement, including protraction and upward rotation

Pectoralis major

Location:

• anterior chest wall

• both sides of the sternum

Function:

• adduction and internal rotation of the arm in the shoulder joint

• internally rotating the humerus at the shoulder joint

Intercostals

Location:

• the spaces between the ribs, spanning the 11 intercostal spaces

• rib cage

Function:

• help form and move the chest wall

• assisting in both inhalation and exhalation by elevating and depressing the rib cage

Infraspinatus

Location:

• dorsal surface of the scapula

• deep to trapezius

Function:

• externally rotate the humerus

• stabilize the shoulder joint

Teres major

Location:

• along the lateral border of the scapula

Function:

• extend, adduct, and internally rotate the humerus

Erector spinae

Location:

• either side of the vertebral column

• between the base of the cranium superiorly and pelvis inferiorly

Function:

• extend and laterally flex the spine

• maintain correct posture and curvature of the spinal column

Rhomboid minor

Location:

• deep to the trapezius

• superior to the rhomboid major

Function:

• retracts the scapula when trapezius is contracted

• contributing to shoulder stability and proper movement

Supraspinatus

Location:

• upper portion of the back

• in the supraspinous fossa of the scapula

Function:

• stabilization of the head of humerus in the joint

• initiate and assist in arm abduction

Latissimus dorsi

Location:

• superficially in the lower two-thirds of the trunk

• extending from the shoulder blades to the lower spine

Function:

• pull the inferior angle of the scapula in various directions

• producing movements on the shoulder joint

• extend, adduct, and internally rotate the arm at the shoulder joint

Rectus abdominis

Location:

• the middle of your abdomen

• midline of the anterior abdominal wall

• running vertically from the ribs to the pelvis

Function:

• flex the spine

• stabilizing the pelvis

• assisting in movements like bending and twisting the torso

External oblique

Location:

• the outer surface of the sides of the abdomen

• each side of the rectus abdominis

Function:

• movement of the trunk, spine, and core

• rotate the trunk to the opposite side

• assist in bending the trunk from side to side

• stabilize the core

Transverse abdominis

Location:

• in the abdomen

• wrapping around the torso from front to back

• spans from the lower ribs down to the pelvis

Function:

• stabilizing the core

• supporting the spine and pelvis

• maintaining internal abdominal pressure

Linea Alba

Location:

• front of the abdomen

Function:

• keep the right and left abdominal muscles separated

Deltoid

Location:

• the upper arms and shoulders

Function:

• stabilizing the shoulder joint

• shoulder abduction

Brachialis

Location:

• beneath the biceps brachii

• lower anterior compartment of the upper arm

Function:

• flex the forearm at the elbow joint

• provides elbow flexion

Biceps

Location:

• front of the upper arm

• between the shoulder and the elbow

Function:

• flexion and supination of the forearm

Triceps

Location:

• dorsal part of the upper arm

• between the shoulder and elbow joints

Function:

• extend the forearm at the elbow joint

• straightening the arm

• helps stabilize the shoulder joint

Pronator Teres

Location:

• anterior aspect of the forearm

Function:

• pronates the forearm

• assists in flexion of the elbow joint

Brachioradialis

Location:

• the radial side of the forearm

Function:

• flexes the forearm at the elbow

Flexor carpi radialis

Location:

• anterior part of the forearm

Function:

• flex and abduct the wrist

Flexor digitorum superficialis

Location:

• anterior aspect of the forearm

• anterior compartment of the forearm

Function:

• flexes the middle phalanges of the four fingers

• assists in flexing the metacarpophalangeal (MCP) joints and the wrist

Palmaris longus

Location:

• anterior forearm

• between the flexor carpi radialis and flexor carpi ulnaris muscles

Function:

• assists in wrist flexion

• tightening the palmar aponeurosis

Flexor pollicis longus

Location:

Function:

Flexor carpi ulnaris

Location:

• within the deep compartment of the anterior forearm

• originates on the anterior surface of the radius

Function:

• flexion of the thumb at the interphalangeal joint

• flex the thumb at the interphalangeal (IP) and metacarpophalangeal (MCP) joints

• contributes to wrist flexion

 Extensor digitorum

Location:

• posterior compartment of the forearm

• within the superficial layer of muscles

Function:

• extends the phalanges, then the wrist, and finally the elbow.

• extend the four medial fingers

Pronator quadratus

Location:

• within the anterior compartment of forearm

Function:

• pulls the lateral side of the radius towards the ulna, thus pronating the hand

• pronate the forearm

• turning the palm downwards

• stabilize the connection between the radius and ulna

Iliotibial tract (IT Band)

Location:

• along the lateral thigh

Function:

• pelvic stabilisation and posture control

• stabilizing the hip and knee during walking and running

• contributes to lateral knee support

Thenar muscles of thumb

Location:

• the base of the thumb on the palm (volar) side of the hand

Function:

• produce the movements of the thumb

• enabling fine motor control and precision grasping

Palmar aponeurosis

Location:

• the palm of the hand

Function:

• improve grip

• protect underlying tendons, vessels, and nerves, and provide a firm attachment to the skin

Flexor digitorum profundus

Location:

• deep in the forearm flexor compartment

Function:

• lexes the distal phalanges of the medial 4 digits at the DIP joints

• assists in flexing the hand and wrist

Abductor pollicis longus

Location:

• below the supinator

• posterior compartment of the forearm

Function:

• abduct the thumb at the carpometacarpal joint

• moving the thumb anteriorly

Supinator

Location:

• superior and posterior compartment of the forearm

• curving around the upper third of the radius

Function:

• to supinate the forearm

• rotating it so the palm faces upwards

• assists with forearm flexion

Tendons of extensor digitorum

Location:

• pass through the 4th extensor compartment at the wrist

Function:

• extends medial four digits at the metacarpophalangeal joints and secondarily at the interphalangeal joints

• extending the medial four digits (fingers 2-5) at both the metacarpophalangeal (MCP) and interphalangeal (IP) joints

• contribute to wrist extension

Illiacus

Location:

• attached to the iliac fossa

Function:

• flexes and externally rotates the femur

• flex the thigh at the hip joint

• contribute to hip stabilization and posture

Psoas major

Location:

• lateral to the lumbar vertebrae

Function:

• flex the thigh at the hip

• flex the trunk at the hip

• laterally rotate the thigh

Pectineus

Location:

• medial compartment of the thigh

• anterior and medial part of the upper thigh

Function:

• flex and adduct the hip joint

Sartorius

Location:

• anterior compartment of the thigh

Function:

• At the hip it flexes, weakly abducts, and rotates the thigh laterally

Adductor longus

Location:

• medial aspect of the thigh

Function:

• adduct the thigh at the hip joint

• contributes to hip flexion and potentially internal rotation

Gracilis

Location:

• medial compartment of the thigh

Function:

• adduct the thigh at the hip joint and flex

• internally rotate the knee

Rectus femoris

Location:

• anterior thigh compartment's

Function:

• extend the knee

• assists iliopsoas in hip flexion

Vastus lateralis

Location:

• lateral side of the thigh

• outer anterior compartment of the thigh

Function:

• extend the knee joint

• promote movement as well as strength and stability

Vastus medialis

Location:

• anterior compartment of the thigh

• medial side of the thigh

Function:

• involved in knee extension

• extend the knee joint

Adductor brevis

Location:

• medial compartment of the thigh

Function:

• adduction of the thigh

• adduct (pull) the thigh towards the midline of the body

• contributes to hip flexion and lateral rotation

Tensor fascia lata

Location:

• thigh

• proximal anterolateral thigh

• between the superficial and deep fibers of the iliotibial (IT) band

Function:

• accessory knee flexor

• stabilize the hip and knee joints

• assist in hip flexion and abduction

Gluteus maximus

Location:

• buttock and hip area

• posterior (back) of the pelvis

Function:

• facilitating core stability and hip extension

• stabilizing the pelvis

• extend and externally rotate the thigh

Adductor magnus

Location:

• both in the posterior and medial fascial compartments of the thigh

• medial compartment of the thigh

Function:

• dynamic stabilizer of the pelvis and femur and a prime femoral adductor

• contributes to hip extension and rotation

Biceps femoris

Location:

• posterior compartment of the thigh

Function:

• movement at both the hip joint and knee joint

• flex the knee and extend the thigh at the hip

• assisting in lateral rotation of the lower leg

Semitendinosus

Location:

• posterior and medial aspect of the thigh

Function:

• extend at the hip and flex at the knee

• flex the knee

• extend the hip

Semimembranosus

Location:

• the posteromedial side of the thigh deep to Semitendinosus

• medial to the Biceps Femoris

Function:

• flexion and internal rotation of the knee joint

• knee flexion and medial rotation of the tibia

Gastrocnemius

Location:

• under your skin at the back of your lower leg

• posterior (back) part of the lower leg

Function:

• walking and posture

Soleus

Location:

• posterior compartment of the lower leg

• deep to the gastrocnemius muscle

Function:

• primary plantar flexor of the ankle

• crucial for walking, running, and maintaining upright posture

• "skeletal muscle pump" to assist in venous blood return

Fibularis longus

Location:

• lateral compartment of the lower leg

• near the fibula bone

Function:

• to tilt the sole of the foot away from the midline of the body

• to extend the foot downward away from the body

Tibialis anterior

Location:

• lateral side of the tibia

• anterior compartment of the lower leg

Function:

• Inversion of the foot

• Adduction of the foot

• maintaining the medial arch of the foot

Fibularis brevis

Location:

• the lateral part of the lower leg deep to the Fibularis Longus

Function:

• responsible for 63% of the power needed to evert the foot as well as assists in plantar flexion

• evert the foot and assists in plantar flexion

Extensor digitorum longus

Location:

• lateral to the tibialis anterior

• anterior compartment of the lower leg

Function:

• allows you to extend your toes

• dorsiflex your feet / ankle

Superior and inferior extensor retinacula

Location:

• distally in the leg just above the ankle joint

• attaching to the anterior aspects of the fibula and tibia

• proximally on the dorsal aspect of the ankle joint

Function:

• stabilize the extensor tendons of the foot and ankle

Extensor hallicus longus

Location:

• anterior compartment of the lower leg

• deep to tibialis anterior and extensor digitorum longus

Function:

• extension of the big toe (hallux)

• assists in dorsiflexing the foot at the ankle joint

Fibularis tertius

Location:

• on the lower lateral aspect of the leg

• anterior compartment of the lower leg

Function:

• tilt the sole of the foot away from the midline of the body (eversion)

• to pull the foot upward toward the body (dorsiflexion)