3.6: Prime Movers: Major Skeletal Muscles Flashcards
Prime movers are also known as _____
agonists
What are prime movers?
Primarily responsible for the movement. They create the ROM in a joint.
These muscles act to return a limb to its original place, they oppose the movement of the agonist.
Antagonists
These muscles neutralize the extra motion from the agonists; they provide balance and make sure the motion is in the desired plane of motion
Synergists (neutralizers)
These muscles provide stabilization to support the rest of the body during the movement
Fixators (stabilizers)
What is a ‘simple movement’ ?
When there is movement that uses only one joint to target only one muscle
What is a ‘compound movement’ ?
When there is a movement that uses more than one joint and targets more than one muscle/group
What are the primary functions of the pectorals?
adduct, flex, and medially rotate the arm at the shoulder joint
What is the main function of the Pectoralis Major?
Adduction and flexion of the humerus
What is the main function of the Pectoralis Minor?
Depresses and protracts the scapula
Deltoids are the prime movers for ___ ______.
arm abduction
The deltoids insert together at the _______.
deltoid tuberosity (the middle anterior surface of the humerus)
What is the main function of the deltoids?
abduction of the humerus; medial rotation of the humerus
What is the main function of the posterior deltoid?
horizontal abduction; extension abduction and external rotation of the shoulder joint
The ______ is located under the deltoids.
rotator cuff
The rotator cuff is a group of ___ muscles.
4
This rotator cuff muscle abducts the arm.
Supraspinatus
These two rotator cuff muscles externally rotate the arm.
Infraspinatus and the Teres Minor
This rotator cuff muscle internally rotates the humerus.
Subscapularis
Where do the biceps originate from and insert to?
Originate from the scapula, then stretch downward to form one single muscle inserting to the medial part of the forearm.
How do the biceps act as a prime mover?
Supination of the forearm and flexion of the elbow
Where do all three heads of the triceps join/insert to?
Proximal end of the ulna at the elbow
How do triceps act as prime movers?
Extension of the elbow
What side of the forearms are extensors?
posterior
What side of the forearms are flexors?
anterior
How many muscles does the adductor consist of?
6—adductor longus, adductor magnus, pectineus, gracilis, adductor brevis, obturator externus
What is the main function of the adductors?
Brings legs across midline of body
How many muscles of the Quadriceps?
rectus femoris, vastus lateralis, vastus medialis, vastus intermedius
All of the quad muscles originate from the femur except ______.
Rectus femoris—originates from the ilium
The quad tendon becomes the _____ ligament.
patellar
What is the main function of the quads?
Extension at the knee joint
How many muscles of the hamstrings?
3—-biceps femoris, semitendinosus, semimembranosus
What is the main function of the hamstrings?
Flexion of the knee and aids in hip extension
What are the two muscles of the calves?
How many heads are there?
gastrocnemus (medial and lateral) and soleus; 3
What is the main function of the calves?
Plantar flexion of the foot and stabilization of the ankle
How many muscles of the Gluteals?
3—-gluteus maximus, gluteus medius and minimus
What is the primary function of the gluteus maximus?
hip extension
What is the primary function of the gluteal medius and minimus?
abduction
What is the main function of the gluteals?
Stabilization of the pelvis
What is the Lateral Rotator Group?
6 muscles of the hip in the gluteal region that laterally rotate the femur at the hip joint.
How many layers does the abdominals have?
3
What are the 4 muscles of the abdominals?
Rectus (straight), External obliques, Internal obliques, Transversus (across)
What bodily functions do abdominals perform and assist with?
breathing, protection of organs, postural support, multi-directional movement of the body/parts
What is the Rectus abdominis?
flat, long muscle extending the entire length of the abdomen “6-pack”
What is the main function of the rectus abdominis?
lumbar spine flexion
What are the External obliques?
Largest and outermost muscles of the abdomen (superficial)
What is the main function of the external obliques?
bilateral and lateral flexion of the trunk; unilateral rotation of the torso (to the opposite side)
What are the Internal obliques?
run below (deep) and perpendicular to the external obliques
What is the main function of the internal obliques?
Bilateral and lateral flexion of the trunk; unilateral rotation of the torso (to the same side)
What are the Transversus abdominals?
run below (deep) the internal obliques–innermost muscle of abdominals
What is the main function of the transversus abdominals?
Stabilizes the trunk
What are the 5 muscle groups of the back?
Latissimus dorsi, teres major, rhomboids, trapezius, erector spinae (lower back)
The widest most powerful muscle in the back is the ________.
Latissimus Dorsi (Lats)
What are the main functions of the lats?
Extension, internal rotation and adduction of the shoulder joint.
What is the teres major?
A muscle of the upper back/extremity
What are the rhomboids (major/minor)?
Rhombus shaped muscles originating from the neck and insert at the boarder of the scapula
What is the main function of the rhomboids?
Retraction of the scapula
What is the Trapezius?
Flat, triangular muscle the that has three functional areas that rotate, elevate and retract the scapula (superior, middle, inferior)
What is the superior (upper) trap function?
upward rotation, elevation, cervical spine extension (bilaterally); (unilaterally) cervical spine lateral flexion, cervical spine rotation
What is the middle trap function?
retraction
What is the inferior (lower) trap function?
depression, downward rotation
How many major muscles make up the erector spinae?
3—-iliocostalis, longissimus, spinalis
In the cervical region the erector spinae attach at the ________.
base of the skull
What is the main function of the erector spinae?
lumbar extension
The core is where the body’s _______ is derived.
Power
The erector spinae is the foundation of the ________.
core
What are the multifidus?
deep spinal muscles that run from the cervical spine to the sacrum. They allow for extension and provide stability of joints at discs of the spine.
What are interpsinales, intertransversarii, and rotatores?
Deep structures that attach directly to the spinal column. Important for rotational motion and lateral stability.
How many parts of the core are there? Name them?
9—–erector Spinae, external obliques, internal obliques, transversus abdominis, rectus abdominis, latissimus dorsi, quadratus lumborum, thoracolumbar fascia, abdominal fascia
What does the Quadratus Lumborum do?
Stabilizes the lumbar spine in all planes of motion while stabilizing the 12th rib
What dos the Thoracolumbar Fasica do?
Connects the lats, glutes, internal obliques and transverse abdominis. Support lumbar spine and load transfer though lumbar and thoracic regions
What does the abdominal fascia do?
3 layered membrane that covers the deep muscles of the back. Connects to the obliques, rectus abdominis and pectoralis major. Transmit forces to the muscles opposite side.
