chapter 10 and 11 lab practical

Extensor digitorum longus

Location: anterolateral surface of leg. Action: prime mover of toe extension. Origin: lateral condyle of tibia; proximal 3/4 of fibula; interosseous membrane. Insertion: middle and distal phalanges of second to fifth toes via extensor expansion.

Gluteus medius and minimus

Location: covered by gluteus maximus/smallest and deepest gluteal muscle. Action: abducts and medially rotates the thigh. Origin: between anterior and posterior gluteal lines of lateral surface of ilium/between anterior and inferior gluteal lines on external surface of ilium. Insertion: by short tendon into lateral aspect of trochanter of femur/anterior border of greater trochanter of femur.

Pectoralis major

Location: covers superior portion of chest, forms anterior chest. Action: adducts and medially rotates arm. Origin: sternal end of clavicle, sternum, cartilage of ribs 1-6 and aponeurosis of external oblique muscle. Insertion: fibers converge to insert by a short tendon into intertubercular sulcus and greater tubercle of humerus.

Soleus

Location: deep to gastrocnemius on posterior surface of calf. Action: Plantar flexes foot. Origin: extensive origin from superior tibia, fibula, and interosseous membrane. Insertion: posterior calcaneus via calcaneal tendon.

Semimembranosus

Location: deep to semitendinosus Action: extends thigh and flexes leg. Origin: ischial tuberosity. Insertion: medial condyle of tibia; via oblique popliteal ligament to lateral condyle of femur.

Gastrocneumius

Location: form proximal curve of calf. Action: Plantar flexes foot. Origin: by two heads from medial and lateral condyles of femur. Insertion: posterior calcaneus via calcaneal tendon.

Vastus medialis

Location: forms inferomedial aspect of thigh. Action: extends leg. Origin: linea aspera, intertrochantric and medial supracondylar lines. Insertion: as for rectus femoris.

Vastus lateralis

Location: forms lateral aspect of thigh. Action: extends and stabilizes leg. Origin: greater trochanter, intertrochanteric line, linea aspera. Insertion: patella and tibial tuberosity via patellar ligament.

Subscapularis

Location: forms part of posterior wall of axilla. Action: chief medial rotator of arm. Origin: subscapular fossa of scapula. Insertion: lesser tubercle of humerus.

Brachialis

Location: immediately deep to biceps brachii on distal humerus. Action: a major forearm flexor. Origin: front of distal humerus; embraces insertion of deltoid muscle. Insertion: coronoid process of ulna and capsule of elbow joint.

Tensor fasciae latae

Location: lies between vastus laterals and vastus medialis. Action: steadies the leg and trunk on thigh by making iliotubial tract taut. Origin: anterior aspect of iliac crest and anterior superior iliac spine. Insertion: iliotubial tract.

Semitendinosus

Location: lies medial to biceps femoris. Action: extends thigh and flexes leg. Origin: ischial tuberosity in common with long head of biceps femoris. Insertion: medial aspect of upper tibial shaft.

Latissimus dorsi

Location: lower back (lumbar region). Action: prime mover of arm extension; powerful arm adductor; medially rotates arm at shoulder. Origin: indirect attachment via lumbodorsal fascia into spines of lower 6 thoracic vertebrae, lumbar vertebrae, lower 3-4 ribs, and iliac crest; also from scapula's inferior angle. Insertion: spirals around teres major to insert in floor of intertubercular sulcus of humerus.

Biceps femoris

Location: most lateral muscle of hamstrings group. Action: extends thigh and flexes leg. Origin: ischial tuberosity (long head); linea aspera, lateral supracondylar line, and distal femur (short head) Insertion: common tendon passes downward and laterally (forming lateral border of popliteal fossa) to insert into head of fibula and lateral condyle of tibia.

Gluteus maximus

Location: most superficial gluteus muscle; also largest. Action: major extensor of thigh. Origin: dorsal ilium, sacrum, and coccyx. Insertion: gluteal tuberosity of femur; iliotibial tract.

Vastus intermedius

Location: obscured by rectus femoris. Action: extends leg. Origin: anterior and lateral surfaces of proximal femur shaft. Insertion: patella and tibial tuberosity via patellar ligament.

Triceps brachii

Location: only muscle of posterior compartment of arm; three headed origin; long and lateral heads lay superficial to medial head. Action: powerful forearm extensor. Origin: long head; infraglenoid tubercle of scapula; lateral head: posterior shaft of humerus; medial head: posterior humeral shaft distal to radial groove. Insertion: by common tendon into olecranon of ulna.

Adductor longus, magnus, and brevis

Location: overlies middle aspect of magnus (longus). Action: adducts and medially rotates and flexes thigh/adducts, flexes, and medially rotates thigh (longus and brevis)

Deltoid

Location: particularly in males. Action: prime mover of arm abduction when all its fibers contract simultaneously. Origin: embraces insertion of the trapezius; lateral third of clavicle; acromion and spine of scapula. Insertion: deltoid tuberosity of humerus.

Supraspinatus

Location: posterior aspect of scapula; deep to trapezius. Action: initiates abduction of arm. Origin: supraspinous fossa of scapula. Insertion: superior part of greater tubercle of humerus.

Infraspinatus

Location: rotator cuff muscle on scapula. Action: rotates arm laterally. Origin: infraspinous fossa of scapula. Insertion: greater tubercle of humerus posterior to insertion of supraspinatus.

Teres minor

Location: rotator cuff muscle, inferior to infraspinatus and may be inseparable from that muscle. Action: rotates arm laterally. Origin: lateral border of dorsal scapular surface. Insertion: greater tubercle of humerus inferior to infraspinatus insertion.

Tibialis anterior

Location: superficial muscle of anterior leg. Action: prime mover of dorsiflexion. Origin: lateral condyle, upper 2/3 of finial shaft; interosseous membrane. Insertion: by tendon into inferior surface of medial cuneiform and first metatarsal bone.

Rectus femoris

Location: superficial muscle of anterior thigh. Action: extends leg and flexes thigh at rib. Origin: anterior inferior iliac spine and superior margin of acetabulum. Insertion: patella and tibial tuberosity via patellar ligament.

Brachioradialis

Location: superficial muscle of lateral forearm. Action: synergist in flexing forearm. Origin: lateral supracondylar ridge at distal end of humerus. Insertion: base of radial styloid process.

Gracilis

Location: superficial muscle of medial thigh. Action: adducts thigh, flexes and medially rotates thigh. Origin: inferior ramus and body of pubis and adjacent ischial ramus. Insertion: medial surface of tibia just inferior to its medial condyle.

Sartorius

Location: superficial muscle running obliquely across anterior muscle of thigh. Action: flexes, abducts, and laterally rotates thigh. Origin: anterior superior iliac spine. Insertion: winds around medial aspect of knee and inserts into medial aspect of proximal tibia.

Biceps brachii

Location: tendon of long head helps stabilize shoulder joint. Action: Flexes and supinates forearm. Origin: short-head coracoid process; long-head: supraglenoid tubercle and lip of glenoid cavity; tendon of long head runs within capsule and into intertubercular sulcus of humerus. Insertion: by common tendon into radial tuberosity.

Flexor

a muscle whose contraction bends a limb or other part of the body. any of a number of specific muscles in the arm, hand, leg, or foot.

Extensor

muscle whose contraction extends or straightens a limb or other part of the body. any of a number of specific muscles in the arm, hand, leg, and foot.

The chief medial rotator cuff muscle of the arm is

the subscapularis

The four rotator cuff muscles are

the subscapularis, infraspinatus, teres minor, supraspinatus.