Muscles of the Muscles of the upper and lower upper and lower

limbslimbsAppendicular Appendicular

MusclesMuscles

Upper limb muscles have 3 Upper limb muscles have 3 major groupsmajor groups

Lower limb muscles are the Lower limb muscles are the largest largest

Upper limb MusclesUpper limb Muscles

• 3 groups3 groups– The first group arises from the shoulder The first group arises from the shoulder

girdle and insert into the humerusgirdle and insert into the humerus– The second group encloses the humerus The second group encloses the humerus

and insert into the forearm bones and insert into the forearm bones causing movement at the elbow jointcausing movement at the elbow joint

– The third group is the muscles of the The third group is the muscles of the forearm which insert into the hand and forearm which insert into the hand and wristwrist

Upper limb MusclesUpper limb Muscles

• Group 1 Group 1 – Already discussedAlready discussed

• Pectoralis majorPectoralis major• Latissimus dorsiLatissimus dorsi• DletoidDletoid

• Group 2Group 2– Biceps brachiiBiceps brachii

• Most familiar muscleMost familiar muscle• Two origin in the shoulder girdleTwo origin in the shoulder girdle• Inserts into the radial tuberosityInserts into the radial tuberosity• Prime mover of the forearm flexion and supinates the Prime mover of the forearm flexion and supinates the

forearmforearm

Upper limb MusclesUpper limb Muscles

• Group 2Group 2– BrachialisBrachialis

• Deep to the biceps muscle and is a synergist Deep to the biceps muscle and is a synergist to the biceps muscle in forearm movementto the biceps muscle in forearm movement

– BrachioradialisBrachioradialis• Weak muscle Weak muscle • Arises on the humerusArises on the humerus• Inserts into the distal forearmInserts into the distal forearm

Upper limb musclesUpper limb muscles

• Group 2Group 2– Triceps brachiiTriceps brachii

• Only posterior muscle on the humerusOnly posterior muscle on the humerus• Has 3 headsHas 3 heads• Origin in the shoulder girdle and proximal Origin in the shoulder girdle and proximal

humerushumerus• Inserts into the olecranon process of the Inserts into the olecranon process of the

ulnaulna• Extends the forearm at the elbowExtends the forearm at the elbow

Upper limb musclesUpper limb muscles

• Group 3Group 3– Supinator muscleSupinator muscle

• Under the upper posterior portion of the radiusUnder the upper posterior portion of the radius• Works synergistically with the biceps brachii to Works synergistically with the biceps brachii to

supinate the handsupinate the hand

– Pronator teresPronator teres• Located on the upper medial side of the forearmLocated on the upper medial side of the forearm• Origin is in the medial epicondyle of the humerusOrigin is in the medial epicondyle of the humerus• Inserts on the upper lateral shaft of the radiusInserts on the upper lateral shaft of the radius• Pronates the handPronates the hand

Upper limb musclesUpper limb muscles

• Group 3 Group 3 – Pronator quadratusPronator quadratus

• Extends between the ulna and the radiusExtends between the ulna and the radius• Origin is on the ulna, inserts on the radiusOrigin is on the ulna, inserts on the radius• Works synergistic with the pronator teres Works synergistic with the pronator teres

and rotates the palmand rotates the palm

Lower limb muscles

Divided into 3 groupsMovement of the hipMovement of the kneeMovement of the foot

Lower limb muscles

Group 1Gluteus maximus

Superficial muscle of the hip Forms the buttock Hip extensor Not important in walking, but is important when

power is needed for climbing Origin is in the sacrum and iliac Inserts into the gluteal tuberosity of the femur

Lower limb muscles

Group 1Gluteus medius

Runs from the ilium to the femur Beneath the gluteus maximus Hip abductor Steadies the plevis during walking Used for injections

Lower limb muscles

Group 1 iliopsoas

Fused muscle Iliacus Psoas major

Prime mover of the hip flexion Keeps the upper body from falling backwards

Lower limb muscles

Group 1Adductor muscles

Group of muscles Medial side of each thigh Press the thighs together

Lower limb muscles

Group 2Muscles causing movement at the knee joint

Quadriceps group Sartorius – obliquely crosses the anterior aspect of the

thigh. It arises from the anterior superior spine of the ilium and extends medially to insert into the proximal medial surface of the tibia

Acts on the hip and knee joints

Lower limb muscles

Group 2Quadriceps femoris – composite of 4 distinct

muscles Have separate origins, but a common insertion via

the patella tendon Function synergistically to extend the leg

Rectus femoris – occupies a superficial position, functions with both the hip and the knee

Lower limb muscles

Group 2 Vastus lateralis – the largest muscle of the quadriceps

femoris, extends the knee Vastus medialis – occupies the medial position along the

thigh, extends the knee Vastus intermedius – lies deep to the previous 2 muscles,

extends the knee

Muscles of the hamstring group Biceps femoris – occupies the posterior lateral aspect of the

thigh, flexes the knee and moves the hip joint. It has a superficial long head and a deep short head

Lower limb muscles

Group 2Muscles of the hamstring group

Semitendinosus – is a fusiform muscle and is located on the posterior medial aspect of the thigh

Works over 2 joints, the medial rotation of the leg (hip) and flexion of the lower leg

Semimembranous – is deep to the semitendinosus, synergistic to the semitendinosus

Lower limb muscles

Group 3Muscles that move the foot (crural muscles)

3 groups of crural muscles Anterior crural muscles – tibialis anterior, extensor

digitorum longus, extensor hallucis longus, and peroneus tertius

Lateral crural muscles – peroneus longus, peroneus brevis

Posterior crural muscles – gastrocnemius, soleus [triceps surae], plantaris, popliteus, flexor hallucis longus, flexor digitorum longus, and tibialis posterior