Bringoux L, Schmerber S, Nougier V, Dumas G, Barraud PA, Raphel C, Perception of slow pitch and roll body tilts in bilateral labyrinthine-defective subjects., Neuropshychologia, 40: 4, 367-72, 2002.  The aim of the present study was to examine whether the perception of slow body tilts in total darkness was affected by a complete loss of vestibular function.  Findings indicate that the accurate perception of body orientation in quasi-static conditions is mainly allowed by somatosensory information rather than by otolithic inputs.

Wyke, M.D., Aspects of Manipulative Therapy 1985.  67-71:

Proprioception provides: conscious awareness of joint position (position sense) and awareness of movement in space (kinesthesia) and feedback from mechanoreceptors exerts 

unconscious, continuous reflex effects on muscle tone and balance, through the

Gamma-motor neuron loop, to provide dynamic stabilization of joints.

Guyton, M.D., 1991 text: Mechanoreceptors: detect mechanical deformation.

Proprioceptive sensation have to do with the physical state of the body, including

Position sensations, tendon and muscle sensations, pressure sensations from the

Bottom of the feet and sensation of equilibrium. They include 1) Static position

Sense: conscious orientation of the different parts of the body with respect to each other.  2) Rate of movement sense also known as kinesthesia or dynamic proprioception.

Seaman, D.C., M.S., D.A.B.C.N., : Journal of Manipulative and Physiological

Therapeutics. 1997; 20(4) 279-284.  Proprioception is a conscious processing of mechanoreceptive input. Proprioception refers to conscious awareness of body

position and body movement. Proprioception is a conscious cortical experience and

not a peripheral sensory phenomenon. It can not occur if cortical center is not intact

Lephart, Ph.D. et al. American Journal of Sports Medicine. 1997; 22(1): 130-137

Articular  structure like ligaments not only provide mechanical restraint but also

provide neurologic feedback that directly mediates reflex muscular stabilization

about the joint, providing dynamic joint stability.

Purpose of proprioception: provide awareness of position sense and kinesthesia.

Produce coordinated reflex effects on muscle tone and balance. Provide peripheral

feedback so the central nervous system can design and modify effective motor

programs.

Guyton, M.D., Medical Physiology, 1996: 687. Propriospinal Tracts: More than half

Of all nerve fiber ascending and descending in the spinal cord are propriospinal

fiber which run from one segment to another providing pathways for

multisegmental reflexes.

Patterson, Ph.D. Somatic Dysfunction in Osteopathic Medicine. The Role of

Subluxation in Chiropractic.  FCER 1997: 26-31.  Various areas of the musculoskeletal system are extensively and richly innervated with mechanoreceptors, especially around the spinal column which seems to operate as one vast proprioceptive organ. 

 

Hongxing, M.D., Ph.D., et al. Spine. 1997; 22(1): 17-25.  Joint receptors contribute to 1) the coordination of muscle tone around joints.  2) provide neurologic feedback to enhance joint stability.  Spinal ligaments, like those around knee joints, are richly innervated, responsive to mechanical stimulation and provide proprioceptive feedback that mediates reflex muscular stabilization about the joint, providing dynamic joint stability-part of a neurologic protective mechanism.  Stretching ligaments stimulates mechanoreceptors and the production of Fos protein.  Synaptic transmission to interneurons and neural nuclei activates production of Fos protein and can be used to tract sensory and functional pathways in the central nervous system.  In chickens, a mechanical load repeatedly stimulated a transverse ligament at T3-4.  Fos production was assessed using a fluorescence microscope.

Results:  Mechanical stimulation of a transverse ligament led to a widespread barrage of neuronal activity in sensory areas of the central nervous system.  Results strongly support that spinal ligaments contribute to muscle coordination around joints increasing joint stability.  Stretching a spinal ligament resulted in massive and widespread neurological input from several levels of the spinal cord and suggests a reflex response to muscles designed to maintain adjacent vertebrae in close alignment and prevent the joints from being damaged.  The involvement of higher brain centers suggests a central involvement of reflex activity in response to the sensory information to maintain general balance and an upright posture.  Scoliosis may be related to misperception of information associated with local motor reflex activity of the spinal cord or central reflex activity in the brain.  Evidence suggests a primary defect of posture, proprioception, or equilibrium control is responsible for the production of the spinal curvature in scoliosis.

McLain, M.D., Picken, D.C., Ph.D.  Spine.  1998; 21(2): 168-173.  Mechanoreceptor endings in Human Thoracic and Lumbar Facet Joints.  Human facets contain mechanoreceptors to detect motion and distortion.  Spinal proprioceptors may play a role in modulating protective proprioceptive mechanoreceptors.  Cervical facets have more receptors.

Zarzecki and Assanuma.  Progress in Brain Research.  1979; 50: 113-119.  Neurons of the motor cortex respond to activation of peripheral somatosensory and proprioceptive afferents.  These input pathways may be involved in the control of the output of the motor cortex.

Abrahams, (Dept. Physiology).  In: Garlick D 9Ed.  Proprioception, Posture, and Emotion.  Committee in Postgraduate Medical Education, Kensington, New South Wales, 1982:  The evidence that the neck plays a critical role in posture is overwhelming.  Muscle receptors may be of great importance in sensing joint position.  A characteristic of neck muscles is an abundance of muscle spindles.  The spindle density in large muscle of the neck range from 46-106 / gram, among the highest of anywhere.  High spindle density is characteristic of muscle executing fine muscle control.  The abundance of afferent information may not only be due to fine motor control.  Polysynaptic pathways from neck muscle afferents to neck motoneurons are powerful.  Afferents leaving neck muscles can exert profound effects on hindlimb motoneuron excitability.  The neck structures are unusually rich in receptors.  Small muscles close to the cervical vertebrae may have up to 500 muscle spindles / gram, a density almost 100 times as great as some muscles of locomotion and 5 times greater than the large dorsal neck muscles which are regarded as spindle rich.  These deep structures play an important role in reflexes and maintenance of posture and provide precise information with respect to position.

Grillner, M.D., Ph.D..  Scientific American.  1996; Jan.: 64-69.  Neural Networks for Locomotion.  Neural networks governing specific, often repeated motions are called Central Pattern Generators.  They can execute a particular action over and over again without need for conscious effort.  The circuits for walking, running and some protective reflexes aren’t located in the brain but reside in the spinal cord.  The essential neural patterns for locomotion are generated completely within the spinal cord.  The brain controls these circuits by a simple control signal from an area of the brain which can generate intricate patterns involving large numbers of muscles in the trunk and limbs by activating pattern generators for locomotion housed within the spinal cord.  Although the brain stem issues the overall command to walk, it delegates the task of coordinating muscle movements to local teams of neurons which process incoming sensory data and adjust their own behavior accordingly.

Zinny, (Dept. of Anatomy).  American Journal of Anatomy.  1988; 182: 16-32.  Joint and muscle receptors detect limits of movement of a joint and play a role in synchronizing mechanisms involved with control of movement.  The densities of mechanoreceptors are greater in areas related to extreme movements.  Mechanoreceptors are the first line of defense in sensing the safe limits of range of motion of a joint.  This input activates reflex mechanisms that act to prevent joint injury.

Roberts, Eisenstein, Menage, Evans, Ashton.  Spine.  1995; Dec 15;20(24):2645-51.  Mechanoreceptors were found in the outer 2-3 lamellae of the human intervertebral disc and anterior longitudinal ligament.  Physiologic studies in other tissues indicate that these provide the individual with sensation of posture and movement, and in the case of Golgi tendon organs, of nociception.  In addition to providing proprioception, mechanoreceptors are thought to have roles in maintaining muscle tone and reflexes.  Their presence in the IVD and ALL can have physiologic and clinical implications.