Muscles and Primary Function Flashcards
Upper Trapezius
Extends the neck and elevates the scapula (such as would happen in a shoulder shrug).
Middle Trapezius
Retraction, adduction,elevation and upward rotation of the scapula.
Rhomboids
Retraction, adduction and downward rotation of the scapula.
Lower Trapezius
Depression of the scapula.
Levator Scapula
Elevates the scapulae and performs lateral flexion and rotation of the spine (cervical).
Latissiumus Dorsi
Extension, adduction and medial rotation of the humerus (pulls arms down from the overhead position).
Erector Spinae
Extends the spine/back.
Anterior Deltoid
Flexion and horizontal adduction of the humerus.
Medial Deltoid
Abduction of the humerus.
Posterior Deltoid
Extension and horizontal abduction of the humerus.
Deltoids (all)
Working all together perform abduction of the humerus.
Pectoralis Major
Horizontal Adduction (arms across the chest)
Rotator Cuff Muscles (SITS)
Support the shoulder joint by holding the head of the humerus in the glenoid cavity of the scapula.
Rectus abdominis
Flexion of the spine
Obliques
Flexion and rotation of the spine
Transverse abdominis
Compresses the abdominal cavity (stabilizes the spine).
Sternocleidomastoid
Flexion of the neck (when acting together) Rotation of the head (when one side contracting).
Triceps
Elbow Extension
Biceps
Elbow Flexion
Brachialis
Elbow Flexion
Brachioradialis
Assists in elbow flexion (strongest when the elbow is partially flexed and semi-pronated).
Gluteus maximus
Extends the hip (during forceful extension) and laterally rotates hip.
Gluteus medius
Abduct the thigh, external rotation, and laterally rotates the hip during abduction.
Hamstrings
Knee flexion and hip extension.
Quadriceps
Extension at the knee/hip flexion
Gastrocnemius (Calves)
Plantarflexion of the ankle (assists in knee flexion)
Soleus
Plantarflexion of the ankle (when knee is flexed)
Tibialis anterior
Dorsiflexion of the ankle
Iliopsoas (Hip flexors)
Hip flexion
Supraspinatus (Part of SITS)
Stabilization of shoulder joint in prevention of downward dislocation of humerus, when carrying heavy weight. Assistive in abduction of humerus.
Supraspinatus abducts the arm.
Infraspinatus (Part of SITS)
Stabilizes the shoulder joint and holds head of humerus in scapula and lateral rotation of humerus.
Infraspinatus externally rotates the arm
Teres Minor (Part of SITS)
Lies inferior to the infraspinatus. Same as infraspinatus
Teres minor externally rotates the arm.
Subscapularis (Part of SITS)
Works with the pectoralis major as primary medial rotator of the humerus. Holds head of humerus in scapula.
Subscapularis internally rotates the arm.
ACL
The ACL retrains excessive forward movement of the lower leg bone (the tibia) in relation to the thigh bone (the femur).
PCL
The PCL’s primary function is to prevent posterior translation of the tibia on the femur.
MCL
The MCL stabilizes the knee in lateral movements such as side shuffling.
LCL
The LCL stabilizes the knee in lateral movements such as side shuffling.
Pectoralis Minor
Depresses and protracts scapula (rotates forward) when the ribs are fixed and elevates the ribs when the scapula is fixed.
