MSS 6 Muscular System Review: Core, Abdominals, Lower Back, and Rotator Cuff

Flashcards covering core stability mechanisms, abdominal wall layer architecture, lower back musculature, and rotator cuff stability from the Chapter 1-6 transcript.

Which muscle is the deepest within the abdominal wall?

Transverse abdominis (TVA)

What is the key result of co-contraction between the transverse abdominis and multifidus?

It decompresses the intervertebral discs and provides stability to the lumbar spine.

Which specific vertebrae are particularly important regarding multifidus contraction during core conditioning?

L1 to S1 (lumbar vertebra 1 to sacrum 1)

Through what fascial structures does contraction of the transverse abdominis pull to cause the multifidus to contract?

The internal oblique fascia and thoracolumbar fascia

What type of muscle contraction does the multifidus perform to hold the lumbar vertebral bodies in place?

An isometric contraction

Who originally created the core conditioning process involving transverse abdominis and multifidus recruitment?

Joseph Pilates

What term describes the circular tension created around the abdominal cavity when the transverse abdominis contracts?

Hoop tension

Which two structures act as secondary or support mechanisms by receiving downward and upward pressure when the transverse abdominis contracts?

The pelvic floor (downward) and the diaphragm (upward)

What are the three layers of the abdominal wall from outermost to innermost?

The outer layer consists of rectus abdominis and external oblique, the middle layer is internal oblique, and the inside layer is transverse abdominis.

What primary movement is performed by rectus abdominis?

Spine flexion

How do the diagonal fibers of the external oblique and internal oblique line up across the body?

The right external oblique lines up diagonally with the left internal oblique, and the left external oblique lines up diagonally with the right internal oblique.

What primary movements are created by both the internal and external obliques?

Trunk rotation and lateral flexion of the spine

Approximately how many individual muscles make up the erector spinae muscle group?

9 individual muscles

What is the primary action of the erector spinae muscle group?

Extension of the spine

What specific bony landmarks do the rotator (rotatores) muscles connect between?

From the transverse process of the vertebral body below to the spinous process of the vertebral body above

What role do the rotator (rotatores) muscles play during high-force movements like throwing?

They provide segmental stability of the vertebral column.

What are the three anatomical attachment points of the quadratus lumborum?

The iliac crest of the pelvis, the transverse processes of the lumbar discs, and the T12 floating rib

How can improper crunch technique cause lower back pain via the quadratus lumborum?

If the T12 rib falls in front of the axis of rotation, the quadratus lumborum acts as a spine flexor and creates shearing forces through the lumbar discs.

Why is the scapulothoracic joint referred to as a pseudo joint?

Because it has no ligamentous base or ligament anchorage back to the spine or thoracic rib cage.

Which four muscles comprise the rotator cuff group?

Supraspinatus, infraspinatus, teres minor, and subscapularis

What is the key joint-stabilizing function of the rotator cuff muscles?

Holding the head of the humerus close to the glenoid fossa of the scapula

Where is the supraspinatus located, and what movement does it assist?

It sits in the supraspinous fossa above the scapular spine and assists the medial deltoid in abduction.

What action is shared by both the infraspinatus and teres minor?

External rotation of the humerus

Which muscle is the only anterior rotator cuff muscle, and what is its rotational action?

Subscapularis, which acts as an internal rotator of the humerus