Upper and Lower Extremity Muscles- Origin, Insertions, & actions

Upper/Lower extremity muscle identification, origins/insertions + actions

Triceps brachii

O-
Long head: scapula (infraglenoid tubercle)
Lateral head: posterior shaft of humerus above radial groove.
Medial head: posterior shaft of humerus below radial groove.
I-
Olecranon of ulna.

ACTION:
-Extension of forearm

-Extension of arm (long head)

Biceps brachii

O-
Long head: scapula (supraglenoid tubercle)
Short head: scapula (coracoid process)
I-
Tendon: radius (tuberosity)
Aponeurosis: deep fascia (proximal medial forearm)

ACTION:
-Supination of forearm

-Flexion of forearm

-Flexion of arm (weak)

Pronator quadratus

O- Ulna (anterior distal shaft)
I- Radius (anterior distal shaft)

ACTION:
pronation of forearm

Supinator

O-
Ulna (posterior proximal shaft),

Lateral epicondyle of humerus
I- Radius (lateral proximal shaft)

ACTION:
Supination of forearm

Flexor carpi radialis

O- Humerus (medial epicondyle)
I- Metacarpals II and III (base)

ACTION:
-Flexion of wrist

-Abduction of hand (lateral deviation)

Flexor Carpi ulnaris

O-
Humerus (medial epicondyle)

Ulna (olecranon and posterior border of ulna)
I-
Carpal bones (pisiform and hamate)

Metacarpal V (base)

ACTION:
-Flexion of wrist

-Adduction of hand (medial deviation)

Palmaris longus

O- Humerus (medial epicondyle)
I- Palmar aponeurosis

ACTION:

• Flexion of wrist (weak)

• Tense palmar aponeurosis

Extensor carpi radialis longus

O- Humerus (lateral supracondylar ridge)
I- Metacarpal II (base)

ACTION:

• Extension of wrist

• Abduction of hand (lateral deviation)

Extensor carpi radialis brevis

O- Humerus (lateral epicondyle)
I- Metacarpal III (base)

ACTION:

• Extension of wrist

• Abduction of hand (lateral deviation)

Extensor carpi ulnaris

O-
Humerus (lateral epicondyle)

Ulna (posterior shaft)
I-
Metacarpal V (base)

ACTION:

• Extension of wrist

• Adduction of hand (medial deviation)

Rectus femoris

O-
Anterior inferior iliac spine

Groove superior to acetabulum
I-
Patella

ACTION:

• Extension of leg

• Flexion of thigh

Vastus lateralis

O- Femur (lateral side of greater trochanter and linea aspera)
I- Patella (via a common quadriceps tendon)

ACTION:
Extension of leg

Vastus medialis

O- Femur (medial side of intertrochanteric line and linea aspera)
I- Patella (via a common quadriceps tendon)

ACTION:
Extension of leg

Vastus intermedius

O- Femur (anterolateral surface of shaft)
I- Patella (via a common quadriceps tendon)

ACTION:
Extension of leg

Biceps femoris

O-
Long head: Ischium (tuberosity)
Short head: Femur (linea aspera)
I-
Long head: Fibula (head)
Short head: Fibula (head)

ACTION:
Long head: Flexion of leg, extension of thigh
Short head: Flexion of leg

Semitendinosus

O- Ischium (tuberosity)
I- Tibia (proximal medial shaft)

ACTION:
-Flexion of leg

-Extension of thigh

Semimembranosus

O- Ischium (tuberosity)
I- Tibia (medial condyle)

ACTION:

• Flexion of leg

• Extension of thigh

Gastrocnemius

O-
Medial belly: femur (medial condyle)

Lateral belly: femur (lateral condyle)
I-
Calcaneus

ACTION:

• Plantar flexion of foot

• Flexion of leg

(green)

Soleus

O-
Tibia (proximal posterior shaft)

Fibula (proximal posterior shaft)
I-
Calcaneus (through calcaneal tendon)

ACTION:
Plantar flexion of foot

Tibialis anterior

O-

Tibia (anterior lateral shaft)

Interosseous membrane
I-
Metatarsal I

Medial cuneiform

ACTION:

• Dorsiflexion of foot

• Inversion of foot

Tibialis posterior

O-
Tibia (posterior shaft)

Fibula (posterior shaft)

Interosseous membrane
I-

Calcaneus

Navicular

Cuneiform bones

Cuboid

Metatarsals II-IV

ACTION:

• Plantar flexion of foot

• Inversion of foot

Fibularis (peroneus) longus

O- Fibula (proximal shaft)
I-
Metatarsal I

Medial cuneiform

ACTION:
-Eversion of foot

-Plantar flexion of foot