Kinesiology
- Shoulder Girdle – needs attendance.
- For Structural & Functional normalcy, the connectivity of rib cage with clavicle in front and scapula behind should be understood.
- Similarly, connectivity of cervical, Thoracic spine with scapula and shoulder joint should be understood.
- Cervical Spine has anterior convexity, called Lordosis.
- Thoracic spine has posterior convexity, called Kyphosis.
- Due to prolonged sitting, office work, computer work, occupations like beauticians, teachers (notebook correction) develop fixed posture.
- This leads to predominant one set of action at shoulder joint, namely flexion, adduction, medial rotation, minimum rib cage movement & minimum – scapular movement
- This also leads to overwork to cervical spine extensors.
Forward Head Posture
A forward Head posture is one in which the head is positioned anteriorly, and the normal anterior cervical convexity is increased with the apex of the lordotic cervical curve at a considerable distance from the Log in comparison with optimal posture.
The constant assumption of forward head posture causes abnormal compression of the posterior zygapophyseal joints and the posterior portion of intervertebral disks and narrowing of the intervertebral foramina in the lordotic areas of the cervical region.
The cervical extensor muscles may become ischemic because of the constant isometric contraction required to counteract the larger than normal external flexion moment and maintain the head in its forward position.
The posterior aspect of the zygapophyseal joint capsules may become adaptively shortened and the narrowed intervertebral foramen may cause nerve root compression.
The structure of the Temporomandibular joint may become altered due to forward head posture causing disturbance in its function.
In forward head posture the scapulae may rotate medially, a thoracic kyphosis may develop, the thoracic cavity may be diminished, vital capacity may be reduced, overall body height may be shortened.
Pathophysiology
- Cervical Spondylosis is a degenerative disorder of cervical intervertebral joints and intervertebral disc.
- Changes in both structures are similar to those occurring in Lumbar Spondylosis.
- Cause of degeneration is, both being weight bearing structures.
- Weight bearing function by IV joints and IVD is shared by body of vertebra, ligaments and muscles.
- The cervical IV joints & IVD bear the weight of head.
The process of degeneration is accelerated due to :-
- Prolonged hours of work with head and neck in one position.
- This is due to computer work, beautician’s work, teachers note – book correction, certain technical work as well as kitchen work.
- Lack of proper exercise leads to weakness of muscles of shoulder girdle.
- This leads to neck muscles stiffness, thoracic hump, rib cage compression, scapular fixation, decreased ROM of shoulder joint, laxity of abdominal muscles etc.
The net effect is degeneration of articular cartilage of IV joints, causing painful movements, osteophytes formation, which may put pressure on spinal nerve in intervertebral foramen.
Similarly, herniation or prolapse of IVD may occur laterally, damaging the spinal nerve in intervertebral foramen or posteriorly in the vertebral foramen compressing the spinal cord.
PID in cervical region is extremely dangerous, as spinal cord (present in Cervical Vertebral Canal) controls the whole of body.
Initially symptoms arise due to muscle stiffness, later on due to joint involvement causing increase in severity and frequency of pain & stiffness, further may lead nerve compression due to paracentral disc bulge/prolapsed or osteophytes.
Symptoms arising from nerve compression are felt in both upper extremities. This is called Radiculopathy.