Proprioception

"Kinesthetics" redirects here. For the album by Scott Kinsey, see Kinesthetics (album).

The cerebellum is largely responsible for coordinating the unconscious aspects of proprioception.

Proprioception (pronounced /ˌproʊpri.ɵˈsɛpʃən/ pro-pree-o-sep-shən), from Latin proprius, meaning "one's own" and perception, is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement.^[1] It is distinguished from exteroception, by which we perceive the outside world, and interoception, by which we perceive pain, hunger, etc., and the movement of internal organs.

History of study

The position-movement sensation was originally described in 1557 by Julius Caesar Scaliger as a "sense of locomotion".^[2] Much later, in 1826, Charles Bell expounded the idea of a "muscle sense"^[3] and this is credited with being one of the first described physiologic feedback mechanisms.^[4] Bell's idea was that commands are carried from the brain to the muscles, and that reports on the muscle's condition would be sent in the reverse direction. Later, in 1880, Henry Charlton Bastian suggested "kinaesthesia" instead of "muscle sense" on the basis that some of the afferent information (back to the brain) was coming from other structures including tendons, joints, and skin.^[5] In 1889, Alfred Goldscheider suggested a classification of kinaesthesia into three types: muscle, tendon, and articular sensitivity.^[6]

In 1906, Charles Scott Sherrington published a landmark work that introduced the terms "proprioception", "interoception", and "exteroception". The "exteroceptors" are the organs responsible for information from outside the body such as the eyes, ears, mouth, and skin. The interoceptors then give information about the internal organs, while "proprioception" is awareness of movement derived from muscular, tendon, and articular sources. Such a system of classification has kept physiologists and anatomists searching for specialised nerve endings that transmit data on joint capsule and muscle tension (such as muscle spindles and Pacini corpuscles).

Proprioception and kinesthesia

Kinesthesia is another term that is often used interchangeably with proprioception, though use of the term "kinesthesia" can place a greater emphasis on motion.^[7][8][9]

Some differentiate the kinesthetic sense from proprioception by excluding the sense of equilibrium or balance from kinesthesia. An inner ear infection, for example, might degrade the sense of balance. This would degrade the proprioceptive sense, but not the kinesthetic sense. The affected individual would be able to walk, but only by using the sense of sight to maintain balance; the person would be unable to walk with eyes closed.

Proprioception and kinesthesia are seen as interrelated and there is considerable disagreement regarding the definition of these terms. Some of this difficulty stems from Sherrington's original description of joint position sense (or the ability to determine exactly where a particular body part is in space) and kinesthesia (or the sensation that the body part has moved) under a more general heading of proprioception. Clinical aspects of proprioception are measured in tests that measure a subject's ability to detect an externally imposed passive movement, or the ability to reposition a joint to a predetermined position. Often it is assumed that the ability of one of these aspects will be related to another; however, experimental evidence suggests there is no strong relation between these two aspects.^{[citation needed]} This suggests that while these components may well be related in a cognitive manner, they may in fact be physiologically separate.

Much of the foregoing work is dependent on the notion that proprioception is, in essence, a feedback mechanism; that is, the body moves (or is moved) and then the information about this is returned to the brain, whereby subsequent adjustments could be made. More recent work^{[citation needed]} into the mechanism of ankle sprains suggests that the role of reflexes may be more limited due to their long latencies (even at the spinal cord level), as ankle sprain events occur in perhaps 100 ms or less. In accordance, a model has been proposed to include a 'feedforward' component of proprioception, whereby the subject will also have central information about the body's position prior to attaining it.

Kinesthesia is a key component in muscle memory and hand-eye coordination, and training can improve this sense (see blind contour drawing). The ability to swing a golf club or to catch a ball requires a finely tuned sense of the position of the joints. This sense needs to become automatic through training to enable a person to concentrate on other aspects of performance, such as maintaining motivation or seeing where other people are.

Basis of proprioceptive sense

The initiation of proprioception is the activation of a proprioreceptor in the periphery.^[10] The proprioceptive sense is believed to be composed of information from sensory neurons located in the inner ear (motion and orientation) and in the stretch receptors located in the muscles and the joint-supporting ligaments (stance). There are specific nerve receptors for this form of perception termed "proprioreceptors," just as there are specific receptors for pressure, light, temperature, sound, and other sensory experiences. Proprioreceptors are sometimes known as adequate stimuli receptors.

Although it was known that finger kinesthesia relies on skin sensation, recent research has found that kinesthesia-based haptic perception relies strongly on the forces experienced during touch.^[11] This research allows the creation of "virtual", illusory haptic shapes with different perceived qualities.^[12]

David Bohm expands the idea of proprioception to include the "self perception of thought" in which thought is aware of its movement.^{[13] [14]}

Conscious and unconscious proprioception

In humans, a distinction is made between conscious proprioception and unconscious proprioception:

• Conscious proprioception is communicated by the posterior column-medial lemniscus pathway to the cerebrum.^[15]

• Unconscious proprioception is communicated primarily via the dorsal spinocerebellar tract,^[16] to the cerebellum.

• An unconscious reaction is seen in the human proprioceptive reflex, or Law of Righting – in the event that the body tilts in any direction, the person will cock their head back to level the eyes against the horizon.^[17] This is seen even in infants as soon as they gain control of their neck muscles. This control comes from the cerebellum, the part of the brain affecting balance.

Applications

Law enforcement

Proprioception is tested by American police officers using the field sobriety test, wherein the subject is required to touch his or her nose with eyes closed. People with normal proprioception may make an error of no more than 20 millimeters. People suffering from impaired proprioception (a symptom of moderate to severe alcohol intoxication) fail this test due to difficulty locating their limbs in space relative to their noses.

Diagnosis

There are several relatively specific tests of the subject's ability to propriorecept. These tests are used in the diagnosis of neurological disorders. They include the visual and tactile placing reflexes.^[18]

Learning new skills

Proprioception is what allows someone to learn to walk in complete darkness without losing balance. During the learning of any new skill, sport, or art, it is usually necessary to become familiar with some proprioceptive tasks specific to that activity. Without the appropriate integration of proprioceptive input, an artist would not be able to brush paint onto a canvas without looking at the hand as it moved the brush over the canvas; it would be impossible to drive an automobile because a motorist would not be able to steer or use the foot pedals while looking at the road ahead; a person could not touch type or perform ballet; and people would not even be able to walk without watching where they put their feet.

Oliver Sacks once reported the case of a young woman who lost her proprioception due to a viral infection of her spinal cord.^[19] At first she was not able to move properly at all or even control her tone of voice (as voice modulation is primarily proprioceptive). Later she relearned by using her sight (watching her feet) and inner ear only for movement while using hearing to judge voice modulation. She eventually acquired a stiff and slow movement and nearly normal speech, which is believed to be the best possible in the absence of this sense. She could not judge effort involved in picking up objects and would grip them painfully to be sure she did not drop them.

Training

The proprioceptive sense can be sharpened through study of many disciplines. Examples are the Feldenkrais method^[20] and the Alexander Technique. Juggling trains reaction time, spatial location, and efficient movement. Standing on a wobble board or balance board is often used to retrain or increase proprioception abilities, particularly as physical therapy for ankle or knee injuries. Standing on one leg (stork standing) and various other body-position challenges are also used in such disciplines as Yoga, Wing Chun and T'ai chi.^{[citation needed]} Several studies have shown that the efficacy of these types of training is challenged by closing the eyes,^{[citation needed]} because the eyes give invaluable feedback to establishing the moment-to-moment information of balance. There are even specific devices designed for proprioception training, such as the exercise ball, which works on balancing the abdominal and back muscles.

Impairment

It has been seen that temporary loss or impairment of proprioception may happen periodically during growth, mostly during adolescence. Growth that might also influence this would be large increases or drops in bodyweight/size due to fluctuations of fat (liposuction, rapid fat loss or gain) and/or muscle content (bodybuilding, anabolic steroids, catabolisis/starvation). It can also occur in those that gain new levels of flexibility, stretching, and contortion. A limb's being in a new range of motion never experienced (or at least, not for a long time since youth perhaps) can disrupt one's sense of location of that limb. Possible experiences include suddenly feeling that feet or legs are missing from one's mental self-image; needing to look down at one's limbs to be sure they are still there; and falling down while walking, especially when attention is focused upon something other than the act of walking.

Proprioception is occasionally impaired spontaneously, especially when one is tired. One's body may appear too large or too small, or parts of the body may appear distorted in size. Similar effects can sometimes occur during epilepsy or migraine auras. These effects are presumed to arise from abnormal stimulation of the part of the parietal cortex of the brain involved with integrating information from different parts of the body.^[21]

Proprioceptive illusions can also be induced, such as the Pinocchio illusion.

The proprioceptive sense is often unnoticed because humans will adapt to a continuously-present stimulus; this is called habituation, desensitization, or adaptation. The effect is that proprioceptive sensory impressions disappear, just as a scent can disappear over time. One practical advantage of this is that unnoticed actions or sensation continue in the background while an individual's attention can move to another concern. The Alexander Technique addresses these issues.

People that have a limb amputated may still have a confused sense of that limb existence on their body, known as phantom limb syndrome. Phantom sensations can occur as passive proprioceptive sensations of the limb's presence, or more active sensations such as perceived movement, pressure, pain, itching, or temperature. There are a variety of theories concerning the etiology of phantom limb sensations and experience. Jack Tsao, MD. at Walter Reed Hospital has advanced a theory based on the concept of "proprioceptive memory." This theory argues that the brain retains a memory of specific limb positions and that after amputation there is a conflict between the visual system, which literally sees that the limb is missing, and the memory system which remembers the limb as a functioning part of the body.^[22] Phantom sensations and phantom pain may also occur after the removal of body parts other than the limbs, such as after amputation of the breast, extraction of a tooth (phantom tooth pain), or removal of an eye (phantom eye syndrome).

Temporary impairment of proprioception has also been known to occur from an overdose of vitamin B6 (pyridoxine and pyridoxamine). Most of the impaired function returns to normal shortly after the intake of vitamins returns to normal. Impairment can also be caused by cytotoxic factors such as chemotherapy.

It has been proposed that even common tinnitus and the attendant hearing frequency-gaps masked by the perceived sounds may cause erroneous proprioceptive information to the balance and comprehension centers of the brain, precipitating mild confusion.

Proprioception is permanently impaired in patients that suffer from joint hypermobility or Ehlers-Danlos Syndrome (a genetic condition that results in weak connective tissue throughout the body). It can also be permanently impaired from viral infections as reported by Sacks. The catastrophic effect of major proprioceptive loss is reviewed by Robles-De-La-Torre (2006).^[23]

See also

• Body image
• Body schema
• Deep receptor

References

1. ^ Mosby's Medical, Nursing and Allied Health Dictionary, Fourth Edition, Mosby-Year Book 1994, p. 1285
2. ^ Jerosch, Jörg; Heisel, Jürgen (May 2010) (in German). Management der Arthrose: Innovative Therapiekonzepte. Deutscher Ärzteverlag. p. 107. ISBN 9783769105995. http://books.google.com/books?id=p8-2j4d-hqwC&pg=PA107. Retrieved 8 April 2011. 
3. ^ Singh, Arun Kumar (September 1991). The Comprehensive History of Psychology. Motilal Banarsidass Publ.. p. 66. ISBN 9788120808041. http://books.google.com/books?id=dXZnwvs6gYIC&pg=PA66. Retrieved 8 April 2011. 
4. ^ Dickinson, John (1976). Proprioceptive control of human movement. Princeton Book Co.. p. 4. http://books.google.com/books?id=CI8XAQAAMAAJ. Retrieved 8 April 2011. 
5. ^ Foster, Susan Leigh (15 December 2010). Choreographing Empathy: Kinesthesia in Performance. Taylor & Francis. p. 74. ISBN 9780415596558. http://books.google.com/books?id=MDWuaqZiHZcC&pg=PA74. Retrieved 8 April 2011. 
6. ^ Brookhart, John M.; Mountcastle, Vernon B. (Vernon Benjamin); Geiger, Stephen R. (1984). The Nervous system: Sensory processes ; volume editor: Ian Darian-Smith. American Physiological Society. p. 784. ISBN 9780683011081. http://books.google.com/books?id=n7fwAAAAMAAJ. Retrieved 8 April 2011. 
7. ^ kinesthesia at eMedicine Dictionary
8. ^ proprioception at eMedicine Dictionary
9. ^ Costello J. T., Donnelly A. E. (2010). "The effects of cryotherapy on joint position sense in healthy participants: A systematic review". Journal of Athletic Training 43: 306–316. 
10. ^ Sherrington CS (1907). "On the proprioceptive system, especially in its reflex aspect". Brain 29 (4): 467–85. doi:10.1093/brain/29.4.467. http://brain.oxfordjournals.org/cgi/reprint/29/4/467. 
11. ^ Robles-De-La-Torre G, Hayward V (2001). "Force can overcome object geometry in the perception of shape through active touch". Nature 412 (6845): 445–8. doi:10.1038/35086588. PMID 11473320. http://www.roblesdelatorre.com/gabriel/GR-VH-Nature2001.pdf. 
12. ^ the MIT Technology Review article "The Cutting Edge of Haptics"
13. ^ Thought as a System by David Bohm
14. ^ SELF, SOCIETY AND PROPRIOCEPTION http://thinkg.net/david_bohm/self_society_proprioception.html
15. ^ Fix, James D. (2002). Neuroanatomy. Hagerstown, MD: Lippincott Williams & Wilkins. pp. 127. ISBN 0-7817-2829-0. 
16. ^ Swenson RS. "Review of Clinical and Functional Neuroscience, Chapter 7A: Somatosensory Systems". (online version Dartmouth college). http://www.dartmouth.edu/~rswenson/NeuroSci/chapter_7A.html#Unconscious_sensation. Retrieved 2008-04-10. 
17. ^ http://erikdalton.com/NewslettersOnline/Feb06Newsletter.htm
18. ^ Introduction to Neurology, 2nd Edition 1976, A.C.Palmer, Blackwell Scientific, Oxford
19. ^ Sacks, O.. "The Disembodied Lady", in The Man Who Mistook His Wife for a Hat and his autobiographical case study A Leg to Stand On.
20. ^ http://ecam.oxfordjournals.org/cgi/content/full/nep055
21. ^ Ehrsson H, Kito T, Sadato N, Passingham R, Naito E (2005). "Neural substrate of body size: illusory feeling of shrinking of the waist". PLoS Biol. 3 (12): e412. doi:10.1371/journal.pbio.0030412. PMC 1287503. PMID 16336049. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1287503. 
22. ^ Weeks, S.R., Anderson-Barnes, V.C., Tsao, J. (2010). "Phantom limb pain: Theories and therapies". The Neurologist 16 (5): 277–286.[1]
23. ^ Robles-De-La-Torre G (2006). "The Importance of the Sense of Touch in Virtual and Real Environments". IEEE Multimedia 13 (3): 24–30. doi:10.1109/MMUL.2006.69. http://www.roblesdelatorre.com/gabriel/GR-IEEE-MM-2006.pdf. 

External links

• Somatosensory Pathways from the Body from the Washington University School of Medicine's Neuroscience Tutorial
• Joint & Bone – Ehlers-Danlos/Joint Hypermobility Syndrome – Proprioception
• Humans have six senses, why does everyone think we only have five? at Everything2
• Proprioception this essay by Charles Wolfe takes its cue from such thinkers & artists as Charles Olson, Merleau-Ponty, James J. Gibson, and Andy Clark to illustrate the view of the "priority of dynamic embodied activity over isolated 'mental' and 'physical' regions" to define this concept
• WNYC – Radio Lab: Where Am I? (May 05, 2006) radio program looks at the relationship between the brain and the body
• The Dancers Mind ABC (Aust) podcast on the nature of proprioception.
• MeSH Proprioception