The kinaesthetic senses

Viktig studie som oppsummerer det meste rundt de kinestetiske sansene, og nevner spesielt at hudens nerveender har mer å si for ledd utslag enn selve ledd-cellene. Den nevner også hvordan hjernens egengenererte opplevelse av bevegelsen spiller inn.

«Peripheral receptors which contribute to kinaesthesia are muscle spindles and skin stretch receptors. Joint receptors do not appear to play a major role at most joints. The evidence supports the existence of two separate senses, the sense of limb position and the sense of limb movement.»

«The term ‘kinaesthesia’ was coined by Bastian (1888) and refers to the ability to sense the position and movement of our limbs and trunk. It is a mysterious sense since, by comparison with our other senses such as vision and hearing, we are largely unaware of it in our daily activities.»

«The cutaneous receptor most likely to subserve a kinaesthetic role is the skin stretch receptor, the slowly adapting Type II receptor served by Ruffini endings (Chambers et al. 1972; Edin, 1992).»

«More recent observations have shown that skin input can also have an occluding action. Signals from local, rapidly adapting receptors evoked by low-amplitude, high frequency vibration can impede movement detection (Weerakkody et al. 2007).»

«While joint receptors were first thought to be all-important in kinaesthesia, the present-day view is that their contribution at most joints is likely to be minor. Typically they respond to joint movement, but often with response peaks at both limits of the range of joint motion (Burgess & Clark, 1969). They are now thought of as limit detectors. »

«It was believed that signals of motor command could calibrate sensory input coming from the periphery but did not generate sensations in their own right. For a review see Gandevia (1987). In these new experiments (Gandevia et al. 2006) conduction in both afferent and motor fibres to the hand was blocked with a pressure cuff applied to the upper arm. When subjects tried to move their paralysed, anaesthetised hand they perceived a distinct displacement of the hand by up to 20 deg (Fig. 3). »

«Thus most kinaesthetic afferents must reside in muscle or skin since joint replacement surgery does not lead to any deficit in kinaesthesia (Grigg et al. 1973).»

«It has been reported by Shergill et al. (2003) that self-generated forces were perceived as weaker than externally generated forces, suggesting that central mechanisms allow us to distinguish between our own actions and those imposed on us from outside. It reminds us that to be able to move about freely in the environment and to carry out actions with the necessary levels of accuracy requires us to know what parts belong to our own body, the sense of ownership, and where those parts are located. We have a body map, or schema, of our body parts (e.g. Maravita et al. 2003).»

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