Download trapezius

MUSCLES OF THE BACK
Extrinsic back muscles
Superficial group
Movements of the upper limb
Intermediate group
Attached to the ribs
May serve as a respiratory function.
Intrinsic (deep) back muscles
Act on the vertebral column
Its movements
Maintain posture
SUPERFICIAL GROUP OF BACK MUSCLES
Immediately deep to the skin and superficial fascia.
Connected with the shoulder girdle.
Attach the superior part of the appendicular skeleton
(clavicle, scapula, and humerus) to the axial skeleton
(skull, ribs, and vertebral column).
SUPERFICIAL GROUP OF BACK MUSCLES
Produce and control limb movements.
Trapezius
Latissimus dorsi
Rhomboid major
Rhomboid minor
Levator scapulae
Covers posterior aspect of neck & superior half of trunk
trapezium (G. irregular four-sided figure)
muscle's origin: base of triangle situated along vertebral column
muscle's insertion: apex pointing toward tip of shoulder
Occipital bone
Scapula
Vertebral
column
attaches the pectoral girdle
to cranium & vertebral column
assists in suspending the upper limb.
Descending (superior) fibers
elevate the scapula
(e.g., when squaring the
shoulders).
Middle fibers
retract the scapula
(i.e., pull it posteriorly).
Ascending (inferior) fibers
depress the scapula and
lower the shoulder.
Superior fibers of trapezius
from the skull and upper portion of the vertebral column
descend to attach to
lateral 1/3 clavicle & acromion of scapula.
Lateral 1/3
Spine of scapula
C7 to T12
Superior and inferior fibers work together
to rotate the lateral aspect of the scapula upward, which needs to
occur when raising the upper limb above the head.
Descending and ascending trapezius fibers act
together in rotating the scapula on the thoracic wall in
different directions.
The trapezius also braces the shoulders by pulling the scapulae
posteriorly and superiorly, fixing them in position on the thoracic wall
with tonic contraction; consequently, weakness of this muscle causes
drooping of the shoulders.
Motor innervation of trapezius accessory nerve [XI]
descends from the neck onto the deep surface of the
muscle.
Proprioceptive fibers from trapezius pass in the
branches of the cervical plexus and enter the spinal
cord at spinal cord levels C3 &C4.
LATTISIUMUS DORSI
L. widest of back
Begins in the lower portion of the back
Tapers as it ascends to a narrow tendon that attaches
to the humerus anteriorly.
LATTISIUMUS DORSI
Posterior axillary fold
LATTISIUMUS DORSI
•
•
•
•
Spinous processes of T7 to L5
Sacrum
Iliac crest
Ribs 10 to 12
Floor of intertubercular
sulcus of humerus
LATTISIUMUS DORSI
Passes from the trunk to the humerus.
Acts directly on the glenohumeral joint.
Acts indirectly on the pectoral girdle.
LATTISIUMUS DORSI
Extend
Adduct
Medially rotate
humerus (arm,upper limb)
Apley scratch test.
can also depress the shoulder, preventing its upward movement
LATTISIUMUS DORSI
In combination with pectoralis major
powerful adductor of the humerus
plays a major role in
downward rotation of the scapula in association with
this movement.
LATTISIUMUS DORSI
also useful in restoring the upper limb from abduction superior
to the shoulder; important in climbing.
LATTISIUMUS DORSI
In conjunction with pectoralis major,
raises the trunk to the arm,
performingchin-ups or climbing a tree
LATTISIUMUS DORSI
Innervation: thoracodorsal nerve
LEVATOR SCAPULAE
Superior 1/3 deep to sternocleidomastoid
Inferior 1/3 deep to trapezius
LEVATOR SCAPULAE
Upper
portion
medial
border of
scapula
superior to
root of spine
of scapula
LEVATOR SCAPULAE
LEVATOR SCAPULAE
acts with the descending part of the trapezius to
elevate the scapula, or fix it!
resists forces that would depress it, as when carrying a load.
LEVATOR SCAPULAE
With rhomboids & pectoralis minor,
rotates the scapula,
depressing the glenoid cavity
rotating the lateral aspect of scapula inferiorly
LEVATOR SCAPULAE
Acting bilaterally (also with the trapezius), the levators
extend the neck.
Acting unilaterally, may contribute to lateral flexion of
the neck
toward the side of the active muscle.
RHOMBOID MAJOR
RHOMBOID MINOR
Deep to trapezius, inferior to levator scapulae
Broad parallel bands
Pass inferolaterally from vertebrae to medial border of scapulae
RHOMBOID MINOR
Lower portion of ligamentum nuchae
Spinous processes of C7 and T1
Medial border of scapula at the spine of scapula
RHOMBOID MAJOR
Spinous processes of T3 to T5
Medial border of scapula between spine & inferior angle
RHOMBOID MAJOR ET MINOR
Retract (adduct) and elevate scapula
Assist serratus anterior in holding the
scapula against the thoracic wall and
fixing the scapula during movements of
the upper limb.
Innervation: dorsal scapular nerve branch of brachial plexus
C4 & C5
SERRATUS POSTERIOR SUPERIOR
SERRATUS POSTERIOR INFERIOR
Deep to the muscles in the superficial
.
group
Related to the movements of the thoracic
cage
Superficial respiratory muscles
More likely proprioceptive rather
than motor in function
Serratus posterior superior lies deep to the rhomboids
Serratus posterior inferior lies deep to the latissimus dorsi
.
SERRATUS POSTERIOR SUPERIOR
SERRATUS POSTERIOR INFERIOR
attached to the vertebral column and associated structures
.
medially
Either descend (fibers of serratus posterior superior) or Ascend
(fibers of serratus posterior inferior)
to attach to the ribs.
These two muscles therefore elevate and depress the ribs
SERRATUS POSTERIOR SUPERIOR
SERRATUS POSTERIOR INFERIOR
.
Lower portion of ligamentum nuchae
Spinous processes of C7 to T3
Supraspinous ligaments
Upper border of ribs 2 to 5
just lateral to their angles
Spinous processes of T11 to L3
Supraspinous ligaments
Lower border of ribs 9 to 12
just lateral to their angles
SERRATUS POSTERIOR SUPERIOR
first four intercostal spinel nerves
.
SERRATUS POSTERIOR INFERIOR
last four intercostal spinel nerves
TRAPEZIUS
fxn of spinal accessory nerve [CN XI]
person attempts to raise the shoulders as the examiner presses down on them
LATISSIMUS DORSI
fxn of thoracodorsal nerve
arm is abducted 90° and then adducted against resistance provided by the examiner
RHOMBOIDS
fxn of dorsal scapular nerve
hands placed posteriorly on the hips
elbow pushed posteriorly against resistance provided by the examiner.
If the rhomboids are acting normally, they can be palpated along the medial borders of
the scapulae; because they lie deep to the trapezius, they are unlikely to be visible
during testing.
Auscultatory Triangle
latissimus dorsi
trapezius
medial border of scapula
Levator scapulae
levator scapula which connects
the neck and shoulder.
most usual complaint
pain when trying to turn the head
to the side where it hurts, often
turning the body instead of the
neck to look behind.
It is often associated with a
headache but not always.
The most common causes for developing this kind of stiff neck are; turning the head to one side while
typing, long phone calls without a headset, sleeping without proper pillow support with the neck tilted
or rotated, sitting in a chair with armrests too high and exposure of the neck to a cold draft. There are
other causes basically from shortening of this muscle as illustrated with using a cane that is too long.
Activities such as vigorous tennis, swimming the crawl stroke and watching a tennis match rotating
the head back and forth can also cause a stiff neck.