Overview Rectus abdominis seems simple but is notably variable. It is a broad, flat muscle on the anterior abdomen with fibers that connect the pubic bone to the arch of the ribs. It is one of those muscles that are hard to label with an “origin” or “insertion,” but we’ll do that for illustrative purposes. […]
Overview Quadratus lumborum means “the square muscle in the low back.” It connects the lumbar vertebrae to the ribs and iliac crest, trapping T12 and the sacrum between its attachments. Origin Insertion Function Innervation The innervation suggests that it is an abdominal muscle, but most practitioners see it as a low-back muscle. Quadratus Lumborum has
Multifidi and Rotatores The anatomy studies and illustrations of the multifidus and rotatores vary a great deal. In general, They anchor near the base of the transverse process of a vertebra. Then, strands of muscle extend to spinous processes of the five vertebrae above them. There are exceptions to that generalization. Overall Structure Multifidi and
Overview Origin Insertion Function Innervation Labored Breathing In labored breathing, extrinsic back muscles stabilize and retract the scapula. This allows the deep extrinsic chest muscles to expand the rib cage and increase breathing capacity. Extrinsic back muscles are typically less variant than other muscles. However, the levator scapula muscle has a high percentage of variability.
Overview Trapezius anatomy is complex. Basically, the trapezius is a broad, flat muscle covering the upper back. It is named for the trapezoid shape that these paired muscles create. It has three major sections that originate on the axial skeleton and insert on the pectoral girdle, making it an extrinsic back muscle. Each section has
The anatomy of the latissimus dorsi seems simple but ends up attaching to more bones in the back than almost any other muscle. It connects the mid-back, low-back, and pelvis to the humerus through the thoracic vertebrae, clavicle, and scapula. The latissimus dorsi is a broad, flat muscle covering the mid-back. The name comes from
Rhomboid Muscles The anatomy of the rhomboid major and minor seems straightforward. These muscles attach the upper thoracic and lower cervical vertebrae to the scapula. Consequently, these muscles trap the ribs, sternum, and clavicle between their attachments. Rhomboid Minor Origin Insertion Function Rhomboid Major: Origin Insertion Function The rhomboid major and minor are usually thought of
Rhomboid Major and Minor Muscles – Functional Anatomy Read More »
Overview The Levator scapula is a ropy extrinsic back muscle that connects the scapula to the upper cervical vertebrae. Its function and variations are more involved than most muscles. Origin Insertion Function Nerve As the name implies, it elevates the scapula. This action assists in the downward rotation of the scapula. Anchoring the upper extremity
The anatomy of the extrinsic chest muscles is more complicated than the first glance suggests. They originate on the front of the axial skeleton and insert on the upper extremity. Generally speaking, they protract the scapula and draw the humerus toward the midline. This arrangement gets a little more complicated with the pectoralis major. The
The subclavius is a short, thick triangular muscle along the inferior aspect of the clavicle. Origin – first rib Insertion – medial clavicle. Function – lowers clavicle. The origin is a flat tendon that attaches on the first rib, near the sternal cartilage. It gradually transitions to muscle fibers. The insertion is a tendon that
