Muscles and Primary Function

Question 1

Upper Trapezius

Answer 1

Extends the neck and elevates the scapula (such as would happen in a shoulder shrug).

Question 2

Middle Trapezius

Answer 2

Retraction, adduction,elevation and upward rotation of the scapula.

Question 3

Rhomboids

Answer 3

Retraction, adduction and downward rotation of the scapula.

Question 4

Lower Trapezius

Answer 4

Depression of the scapula.

Question 5

Levator Scapula

Answer 5

Elevates the scapulae and performs lateral flexion and rotation of the spine (cervical).

Question 6

Latissiumus Dorsi

Answer 6

Extension, adduction and medial rotation of the humerus (pulls arms down from the overhead position).

Question 7

Erector Spinae

Answer 7

Extends the spine/back.

Question 8

Anterior Deltoid

Answer 8

Flexion and horizontal adduction of the humerus.

Question 9

Medial Deltoid

Answer 9

Abduction of the humerus.

Question 10

Posterior Deltoid

Answer 10

Extension and horizontal abduction of the humerus.

Question 11

Deltoids (all)

Answer 11

Working all together perform abduction of the humerus.

Question 12

Pectoralis Major

Answer 12

Horizontal Adduction (arms across the chest)

Question 13

Rotator Cuff Muscles (SITS)

Answer 13

Support the shoulder joint by holding the head of the humerus in the glenoid cavity of the scapula.

Question 14

Rectus abdominis

Answer 14

Flexion of the spine

Question 15

Obliques

Answer 15

Flexion and rotation of the spine

Question 16

Transverse abdominis

Answer 16

Compresses the abdominal cavity (stabilizes the spine).

Question 17

Sternocleidomastoid

Answer 17

Flexion of the neck (when acting together) Rotation of the head (when one side contracting).

Question 18

Triceps

Answer 18

Elbow Extension

Question 19

Biceps

Answer 19

Elbow Flexion

Question 20

Brachialis

Answer 20

Elbow Flexion

Question 21

Brachioradialis

Answer 21

Assists in elbow flexion (strongest when the elbow is partially flexed and semi-pronated).

Question 22

Gluteus maximus

Answer 22

Extends the hip (during forceful extension) and laterally rotates hip.

Question 23

Gluteus medius

Answer 23

Abduct the thigh, external rotation, and laterally rotates the hip during abduction.

Question 24

Hamstrings

Answer 24

Knee flexion and hip extension.

Question 25

Quadriceps

Answer 25

Extension at the knee/hip flexion

Question 26

Gastrocnemius (Calves)

Answer 26

Plantarflexion of the ankle (assists in knee flexion)

Question 27

Soleus

Answer 27

Plantarflexion of the ankle (when knee is flexed)

Question 28

Tibialis anterior

Answer 28

Dorsiflexion of the ankle

Question 29

Iliopsoas (Hip flexors)

Answer 29

Hip flexion

Question 30

Supraspinatus (Part of SITS)

Answer 30

Stabilization of shoulder joint in prevention of downward dislocation of humerus, when carrying heavy weight. Assistive in abduction of humerus.
Supraspinatus abducts the arm.

Question 31

Infraspinatus (Part of SITS)

Answer 31

Stabilizes the shoulder joint and holds head of humerus in scapula and lateral rotation of humerus.
Infraspinatus externally rotates the arm

Question 32

Teres Minor (Part of SITS)

Answer 32

Lies inferior to the infraspinatus. Same as infraspinatus

Teres minor externally rotates the arm.

Question 33

Subscapularis (Part of SITS)

Answer 33

Works with the pectoralis major as primary medial rotator of the humerus. Holds head of humerus in scapula.
Subscapularis internally rotates the arm.

Question 34

ACL

Answer 34

The ACL retrains excessive forward movement of the lower leg bone (the tibia) in relation to the thigh bone (the femur).

Question 35

PCL

Answer 35

The PCL’s primary function is to prevent posterior translation of the tibia on the femur.

Question 36

MCL

Answer 36

The MCL stabilizes the knee in lateral movements such as side shuffling.

Question 37

LCL

Answer 37

The LCL stabilizes the knee in lateral movements such as side shuffling.

Question 38

Pectoralis Minor

Answer 38

Depresses and protracts scapula (rotates forward) when the ribs are fixed and elevates the ribs when the scapula is fixed.