Cervical Pt 1 (Biomechanics)

cervical spine components

OA joint = C0-1
AA joint = C1-2
lower cervical spine = C3-7

cervical spine functions

OA & AA = mobility
lower cervical = stability & load bearing

cervical flexion

inferior facet slides ant & sup on superior facet
opening

OA flexion

convex on concave
ant roll, post slide

cervical extension

inferior facets slide post & inf on sup facets
closing

OA extension

convex on concave
post roll & ant slide

cervical rotation

IL inf facets slide post & inf
CL inf facets slide ant & sup
close on IL side, open on CL side

AA joint rotation

performs 50% of cervical rotation ROM
40 degrees
IL facets slide post, CL facets slide ant

cervical lateral flexion

same mechanics as rotation
IL post & inf, CL ant & sup

cervical protraction & retraction

protraction = upper ext & lower flex
retraction = upper flex & lower ext, can decr stress on nerve roots

facet joints biomechanics

flexion (open), extension (close)
side-bending & rotation (IL close, CL open)
if glide poorly, can impinge & cause local pain

intervertebral foramen (IVF)

flexion incr diameter
extension decr diameter
side-bend & rotation incr diameter CL & decr diameter IL
nerves exit here — decr space can impinge (radicular symptoms)

cervical ligaments

limit extreme ROM
ant longitudinal = limits ext
post longitudinal = limits flex
ligamentum flavum = upright posture, return from flexion
intertransverse = limits lat flex