Major Muscle Groups

Question 0

Posterior Deltoid

Answer 0

Originates on the spine of the scapula and crosses the shoulder bone attaching to the humerus bone.

Joint Action: Shoulder horizontal abduction

Note: During shoulder horizontal abduction scapular retraction also occurs.

Question 1

Pectoralis Major

Answer 1

Originates on the sternum with fibers that run horizontally and attach to the humerus bone.

Joint Action: Horizontal Adduction
Assists: Shoulder Flexion / Shoulder Abduction

( The hugging muscle )

Question 2

Rhomboid

Answer 2

Deep muscle that originates on the spine and attaches onto the scapula.

Joint Action: Scapular Retraction

Question 3

Serratus Anterior

Answer 3

Originates on the anterior surface of the ribs and attaches to the scapula.

Joint Action: Scapular Protraction

Question 4

Deltoid

Answer 4

Shoulder muscle shaped like an upside down pear that originates on the top of the shoulder and attaches to the lateral side of the humerus.

The Deltoid consists of three different areas that are each responsible for different movements. Anterior, Posterior and Middle Deltoid.

Joint Actions:

Anterior Deltoid - Shoulder Flexion
Assists: Shoulder Horizontal Adduction

Middle Deltoid - Shoulder Abduction

Posterior Deltoid - Shoulder Horizontal Abduction
Assists: Shoulder Extension

Question 5

Latissimus Dorsi

Answer 5

Originates on top of the pelvis and attaches to the humerus crossing the shoulder joint and is responsible for shoulder movement.

Joint Action: Shoulder Adduction / Shoulder Extension

Question 6

Coracobrachialis

Answer 6

A deep muscle that originates on the anterior surface of the scapula and attaches to the humerus.

Joint Action: Assists the Anterior Deltoid with Shoulder Flexion

Question 7

Teres Major

Answer 7

Originates on the inferior angle of the scapula and attaches to the interior head of the humerus.

Joint Action: Assists the Lattisimus Dorsi with Shoulder Adduction

Question 8

Rotator Cuff Group

Answer 8

A group of four muscles SITS

Subscapularis
Infraspinatus
Teres Minor
Supraspinatus

Joint Action: Shoulder Rotation

Question 9

Rotator Cuff: Subscapularis

Answer 9

Located opposite the Infrapinatus the Subscapularis originates on the anterior surface of the scapula near the medial boarder and attaches to the head of the humerus bone.

Joint Action: Shoulder Internal Rotation / Shoulder Medial Rotation

Question 10

Rotator Cuff: Infrapinatus

Answer 10

Located opposite the Subscapularis the Infrapinatus originates on the posterior surface of the scapula near the medial boarder and attaches to the head of the humerus bone.

Joint Action: Shoulder External Rotation / Shoulder Lateral Rotation

Question 11

Rotator Cuff: Teres Minor

Answer 11

The Teres Minor works with the Infrapinatus and originates on the middle of the lateral boarder of the scapula and attaches to the posterior surface if the head of the humerus.

Joint Action: Shoulder External Rotation / Shoulder Lateral Rotation

Question 12

Rotator Cuff: Supraspinatus

Answer 12

The Supraspinatus sits superior on the posterior surface of the scapula and attaches to the superior surface of the head of the humerus.

Joint Action: It stabilizes the shoulder and assists the Middle Deltoid in Shoulder Abduction

Question 13

Biceps Brachii

Answer 13

Sits on the anterior surface of the humerus bone and crosses both the elbow and the shoulder.

Joint Action: Elbow Flexion
Assists: Shoulder Flexion

Question 14

Brachialis

Answer 14

Originates on the humerus bone and attaches to the ulna just below the elbow.

Joint Action: Elbow Flexion

Question 15

Triceps

Answer 15

Sits on the posterior side of the humerus bone and had three heads. All three heads cross the elbow and produce elbow extension.

The long head crosses the shoulder and assists with shoulder extension.

Joint Action: Elbow Flexion
Assists: Shoulder Extension

Question 16

Brachioradialis

Answer 16

Known as the forearm muscles the Brachioradialis originates at the distal end of the humerus and attaches to the distal end of the radius and is active when the forearm is halfway between supination and pronation.

Joint Action: Assists in Elbow Flexion

Question 17

Rectus Abdominis

Answer 17

Runs from the pelvis to the ribs. Because of its location and orientation Spine Flexion can be achieved by bringing the pelvis to the ribs or the ribs to the pelvis.

Joint Action: Spine Flexion

Question 18

Erector Spinae

Answer 18

A group of muscles that run from the pelvis all the way up the sound on the posterior side of the body. The Erector Spinae keeps the body erect and maintains posture,

Joint Action: Spine Extension

Question 19

Obliques

Answer 19

Sit on the lateral side of the abdomen and extend diagonally from the pelvis to the ribs.

Joint Action: Spine Lateral Flexion / Spine Rotation
Assists: The Rectus Abdominus with Spine Flexion

Question 20

Quadratus Lumborum

Answer 20

Originates on the posterior portion of the Iliac Crest and inserts in the Lumbar Vertebrae on the 12th rib. It works with the obliques during Spine Lateral Flexion and stabilizes the pelvis and lumbar spine.

Joint Action: Spine Lateral Flexion

Joi

Question 21

Iliopsoas

Answer 21

A group of two muscles the Iliac and the Psoas Major. The Iliac runs from the iliac bone of the pelvis to the head of the femur and the Psosa Major runs for the lumbar vertebrae of the Sind to the head of the femur.

Joint Action: Hip Flexion
Assists: Spine Flexion

Question 22

Gluteus Maximus

Answer 22

A large meaty muscle located on the posterior side of the pelvis that crosses the hip joint and attaches to the posterior side of the femur.

Joint Action: Hip Extension

Question 23

Gluteus Medius & Gluteus Minimus

Answer 23

Located on the lateral side of the pelvis Gluteus Medius sits on top of the Gluteus Minimus and is the larger of the two. They both cross the hip and attach to the head of the femur.

Joint Action: Hip Abduction

Question 24

Adductor Group: 
Adductor Mangus 
Adductor Longus
Adductor Brevi
Gracilis

Answer 24

All originate on the pelvis and attach to the medial side of the femur except the Gracilis which attaches to the tibia just below the knee joint.

Joint Action: Hip Adduction
Gracilis Assists: Knee Flexion

Question 25

Quadriceps Group:
Vastus Lateralis
Vastus Medialis
Vastus Intermedius 
Rectus Femoris

Answer 25

Group of four muscles that sit on the anterior side of the thigh. All four muscles attach to the Patella via the quadricep tendon.

The Vastus Lateralis, Vastus Medialis and Vastus Intermedius lay under the Rectus Femoris and originate at the femur and attach to the Patella while the Rectus Femoris originates on the Ilium and occupies the middle of the thigh covering the other three.

The Vastus Lateralis lays on the lateral side of the femur while the Vastus Medialis lays on the medial side of the femur and the Vastus Intermedius lays between them and deep under the Rectus Femoris.

Joint Action: Knee Extension
Assists: The Rectus Femoris assists with Hip Flexion because it crosses the hip.

Question 26

Hamstring Group: Called “strings” because the tendon can be felt behind the knee. These are the posterior thigh muscles.

Semitendinosus
Semimembranous
Biceps Femoris Long Head
Biceps Femoris Short Head

Answer 26

The Semitendinosus, Semimembranous and the Long Head of the Biceps Femoris originate at the Ishial Tubeosity of the pelvis and attach at various points just below the knee and cross both the hip and knee joints.

Joint Action: Knee Flexion / Hip Extension

The Short Head of the Biceps originates on the distal posterior surface of the Femur.

Joint Action: Knee Flexion

Question 27

Calf Muscles: 
Posterior Complex:
Gastrocnemius 
Soleus
Anterior Complex:
Tibialis Anterior 
Tibialis Posterior

Answer 27

The Gastrocnemius is a heart shaped muscle that originates on the lateral and medial condites just superior to the knee and attaches to the calcaneus bone of the foot through the Achilles tendon and crosses the knee and ankle joints.

Joint Action: Ankle Planter Flexion
Assists: Knee Flexion

The Soleus originates just inferior to the knee and joins the Achilles’ tendon to attach to the calcaneus bone of the foot.

Joint Action: Ankle Plantar Flexion

The Tibialis Anterior or shin muscle originates on the lateral surface of the tibia just below the knee and inserts at the base of the big toe.

Joint Action: Ankle Dorsiflexion
Assists: Ankle Inversion

The Tibialis Posterior originates on the posterior surface of the tibia and fibula and attaches to the posterior or planar surface of several toes and supports the medial arch of the foot. The tendon wraps around the medial side of the heel.

Joint Action: Ankle Inversion
Assists: Ankle Plantar Flexion

Question 28

Peroneus Muscles or Fibularis Muscles:

Peroneus Longus
Peroneus Brevis
Peroneus Tertius

Answer 28

The Peroneus Longus, Peroneus Brevis and Peroneus Tertius originate on the Fibula inserting to the metatarsals.

The Peroneus Longus and Peroneus Brevis are part of the lateral compartment.

Joint Action:
Assists: Ankle Plantar Flexion / Ankle Dorsiflexion

The Peroneus Tertius is part of the anterior compartment.

Joint Action: Ankle Eversion
Assists: Ankle Dorsiflexion

Question 29

Muscles assume one of four roles. What are they?

Answer 29

Agonist: The a prime mover or the muscle most responsible for movement.

Antagonist: Muscle opposing the prime mover. It lengthens as the agonist muscles shortens.

Stabilizer: Holds the joint in proper position for the agonist to preform movement.

Neutralizer: Prevents unwanted movement in the rest of e body during other movements.