Major Muscle Groups Flashcards
Posterior Deltoid
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.
Pectoralis Major
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 )
Rhomboid
Deep muscle that originates on the spine and attaches onto the scapula.
Joint Action: Scapular Retraction
Serratus Anterior
Originates on the anterior surface of the ribs and attaches to the scapula.
Joint Action: Scapular Protraction
Deltoid
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
Latissimus Dorsi
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
Coracobrachialis
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
Teres Major
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
Rotator Cuff Group
A group of four muscles SITS
Subscapularis
Infraspinatus
Teres Minor
Supraspinatus
Joint Action: Shoulder Rotation
Rotator Cuff: Subscapularis
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
Rotator Cuff: Infrapinatus
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
Rotator Cuff: Teres Minor
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
Rotator Cuff: Supraspinatus
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
Biceps Brachii
Sits on the anterior surface of the humerus bone and crosses both the elbow and the shoulder.
Joint Action: Elbow Flexion
Assists: Shoulder Flexion
Brachialis
Originates on the humerus bone and attaches to the ulna just below the elbow.
Joint Action: Elbow Flexion
Triceps
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
Brachioradialis
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
Rectus Abdominis
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
Erector Spinae
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
Obliques
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
Quadratus Lumborum
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
Iliopsoas
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
Gluteus Maximus
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
Gluteus Medius & Gluteus Minimus
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