biomechanics exam 2- human trunk

7

how many cervical vertebrae

12

How many thoracic vertebrae are there?

5

how many lumbar vertebrae

body

primary weight bearing part of vertebrae

transverse process

where muscles attach to vertebrae

spinous process

you can palpate this part of the vertebrae

no

are there discs at C1 and C2

intervertebral discs

-sits between two vertebrae

-shock absorption and stability

nucleus pulposus

center of the intervertebral disc

-high h2o content

annulus fibrosus

Outer ring of intervertebral disc.

intervertebral joints

symphysis (slightly moveable)

-shock absorption

-restrict unwanted movement

facet joints

synovial joints (gliding) that link vertebrae and provide movement.

articulating bones of facet joint

superior articulating facet of inferior vertebrae + inferior articulating facet of superior vertebrae

Anterior Longitudinal Ligament (ALL)

A ligament that runs along the anterior surface of the vertebral bodies

-increases stability

-limits extenstion

ligamentum flavum

runs between lamina of vertebrae's

-highly elastic

-limits flexion

-has tension even when in anatomical position

Posterior Longitudinal Ligament (PLL)

runs along the posterior vertebral bodies

-increasing stability by limiting flexion

lordosis

cervical and lumbar concave curve

kyphosis

thoracic and sacral convex curve

thoracic and sacral curves

primary curves of spine (develop first)

cervical and lumbar curves

secondary curves of spine (develop second)

motion segment

two adjacent vertebrae and the associated soft tissues;

-the functional unit of the spine

-3 degrees of freedom

anterior section of motion segment

made up of body, disc, (PLL), (ALL), intervertebral joint

posterior section of motion segment

made up of spinous process, facet joint (2), ligamentum flavum

cervical vertebrae

-greatest mobility, lowest stability

-transverse foramen for blood supply

cervical vertebrae

largest vertebral foramen

cervical vertebrae

smallest vertebral body

cervical vertebrae

which vertebrae region has a bifid spinous process

Atlantooccipital joint

The condyloid joint between the occipital bone and atlas (C1)

- capital flexion +extension

-supports weight of skull

antlantoaxial joint

pivot joint between atlas(c1) and axis(c2)

-rotation

75 degrees

normal ROM for cervical extension

60 degrees

normal ROM for cervical flexion

80 degrees

normal ROM for cervical rotation

45 degrees

normal ROM for cervical lateral flextion

Sternocleidomastoid (SCM)

origin: sternum and clavicle

insertion: mastoid process

-flexion, contralateral rotation, lateral flexion

-over active of this muscle causes "forward head" or "tech neck:

scalenes

triangular shaped muscle, deep to SCM.

-accessory breathing muscle

-assists flexion, ipsilateral lateral flexion

origin: transverse process of cervical vertebrae

insertion: 1st and 2nd ribs

Selenius capitis and cervicis

origin: spinous process C7-T6

insertion: occipital bone, mastoid process, transverse process c1-c3

-extension, ipsilateral rotation, lateral flexion origin

cervical flexors

sternocleidomastoid, scalenes

(anterior muscles)

cervical extensors

splenius capitis and splenius cervicis

(posterior muscles)

cervical lateral flexors

sternocleidomastoid, scalenes, splenius capitals and cervical

cervical rotators

Sternocleidomastoid, splenius capitis and cervicis

(run on angle)

thoracic vertebrae

vertebrae with greatest stability and lowest mobility

thoracic vertebrae

which vertebrae has an angled/long spinous process

costovertebral joint

gliding joint between a rib and a vertebra

-helps ribs move up and out while we breathe

diaphragm and intercostals

muscles that facilitate breathing

lumbar vertebrae

which vertebrae has a square shaped spinous process

lumbar vertebrae

-pretty equal in mobility and stability

stabilizer muscles of abdomen

transverse abdominis, internal obliques, multifidus, deep erector spinae

-revisit movement

-maintains neutral spine postion

movement muscles of abdomen

rectus abdominis, superficial erector spinae, external obliques, quadratic lumborum

transverse abdominis

origin: iliac crest, ribs 6-12

insertion: linea alba, crest of pubis

-increases intra-abdominal pressure to stabilize lumbar spine

-resists excessive lordosis

weak transverse abdominis

if someone has excessive lumbar lordosis, what muscle might be weak

internal obliques

-increases intra-abdominal pressure to stabilize lumbar spine

-flexion, lateral flexion, ipsilateral rotation

-resists unwanted rotation

multifidus

active in upright positions, help maintain posture.

-resists unwanted rotation

-low back pain often caused by this weak muscle

origin: transverse process

insertion: superior spinous process

erector spinae

prime mover of spinal extension, maintains lumbar lordosis

-resists reduced lordosis

-eccentrically controls flexion

weak erector spinae

if someone has reduced lordosis, this muscle might be weak/underactive

rectus abdominis

-spinal flexion (15 degrees)

-eccentrically controls extensions

-parallel muscle (really long fascicles)

external obliques

-flexion, ipsilateral flexion, contralateral rotation

-controls rotation

Quadratus Lumborum (Q.L.)

-important pelvic stabilizer

-assists extension

-ipsilateral lateral flexion

-controls flexion

origin: iliac crest

insertion: rib 12, T12-L4

trunk flexors

rectus abdominis, external oblique, internal oblique (anterior muscles)

trunk extensors

erector spinae, quadratus lumborum, multifidus (posterior muscles)

Trunk Lateral Flexors

external oblique; internal oblique; quadratus lumborum; rectus abdominis, erector spinae

trunk rotators

external oblique, internal oblique, multifidus

cervical

articulation of ___ vertebral body that rotates on the transverse plane

thoracic

articulation of ___ vertebral body that laterally flexes on the frontal plane

lumbar

articulation of ___ vertebral body that flexes and extends on the sagittal plane

loads on spine

gravitation force, muscle force, and tension from ligaments

extension

tension on the anterior part of disc

compression on posterior part of disc+ facet joint

A.L.L. is being stretched

flexion

compression on anterior part of disc + IV joint

tension on posterior part of disc +stretchingg of P.L.L. + Ligamentum flavum

lateral flexion

ipsilateral -> compression of disc

contralateral -> tension of disc

rotation

shear stress on disc

lumbosacral joint

L5-S1

-intervertebral joint

sacroiliac joint

gliding/plane joint

-connection between axial +appendicular skeleton

-high stability

symphysis pubis

slightly moveable joint of pelvic girdle

anterior pelvic tilt

ASIS in front of pubis + excessive lordosis

anterior pelvic tilt

force coupling of hip flexors + erector spinae

anterior pelvic tilt

postural dysfunction with tight hip flexors + erector spinae

-weak abdominals and hamstrings

posterior pelivc tilt

pubis in front of ASIS

reduced lordosis

posterior pelivc tilt

force coupling of abdominals and hamstrings

posterior pelivc tilt

postural dysfunction with weak hip flexors and erector spinae

gravity

what causes a pelvic lateral tilt

no

should u see a pelvic lateral tilt in anatomical position

erector spinae + Q.L.

what muscles support the unsupported side of a lateral tilt

gluteus medius + minimus

what muscles support the supported side of a lateral tilt

hyper(extension)

what spinal movement does an anterior pelvic tilt cause

flexion

what spinal movement does an posterior pelvic tilt cause

lateral flex

what spinal movement does an lateral pelvic tilt cause

rotation

what spinal movement does an rotation of the pelvic girdle cause

as close to the body as possible

Where should you position the weight of an object being lifted?

neurtral lordotic curve

spine position when lifting

produces more concentric force

why do we lift slowly

wide

what should our base of support be while lifting.