The lumbosacral junction consists of the L5 and S1 vertebra, as well as the corresponding intervertebral discs and apophyseal joints
. It is a well-supported region stabilized by the local paraspinous musculature and iliolumbar ligamentous complex, which connects the transverse processes of L5 to the posterior iliac wing and crest.
Maximum distraction of apophyseal joints
depends on the combination of multiple factors including traction force, time and angle of cervical traction.
The fatigue that TMJ patients so often complain of can be attributed, in part, to the effect of gravity on forward head posture, which causes an increase in forward tension creating a compressive force on soft tissues, apophyseal joints
, and posterior surfaces of vertebral bodies with excessive lengthening of anterior neck flexors and tightening of neck extensors.30 TMJ fatigue can been seen also in cases with shorting of suboccipital and suprahyoid muscles with subsequent elevation of the hyoid bone itself.28 Urbanowicz30 illustrated 10-points physical therapy plan for negating the postural effects of increasing vertical dimension and forward head posture.
Biomechanical implications of degenerative joint disease in the apophyseal joints
of human thoracic and lumbar vertebrae.
(2) The growth of syndesmophytes along the vertebral column in these patients, fusion of the apophyseal joints
and ossification of the spinal ligaments are causes of restricted spinal mobility.
Anterior ankylosis and AJA were considered when vertebral bodies or apophyseal joints
However, after about three hours of compressive loading at a level equivalent to standing, the joints lost approximately 9% of their height, causing the apophyseal joints
to bear approximately 16% of the compressive load compared to zero in the equivalent of an unsupported sitting position.
 In a study by Hogan et al.,  front-row rugby union players presented with asymptomatic, yet significant degenerative changes of the disc spaces and apophyseal joints
. Castinel et al.,  using static magnetic resonance imaging (MRI), found that over half of the rugby union players in their cohort presented with abnormalities of the cervical spine.
Lower, or subaxial, cervical spine lesions occur with changes in apophyseal joints
, the joints of Luschka, interspinous ligaments, and intervertebral discs.
The fusion that ankyloses the joints progresses vertically up the spine.[1,2,4,5,7] Initially, the apophyseal joints
of the superior and inferior articular surfaces of the lumbar vertebrae are spared due to their constant motion. But as the osteoblastosis progressively infiltrates the annulus fibrosis of each veretebral disk and ossifies it, as well as the surrounding soft-tissue attachments, the articulation of the apophyses is hindered and they, too, fuse.[1,2,4,7] The nucleus pulposis of the disk -- the liquid core surrounded by the annulus fibrosis -- may ossify or it may degenerate into a granulomatous pocket due to loss of vascularization from the surrounding osteoblastosis.
Cervical spine X-rays revealed flattening of the cervical lordosis with ankylosis and irregularity of the apophyseal joints
at the C2-C5 level.