Unit I - Tactile and Proprioception Flashcards
2 important functions of tactile system
protection and discrimination
2 main sub divisions in afferent pathways
DCML: fine touch and proprioception
Spinothalamic/anterolateral system: pain and temperature
somatosensory processing occurs in
primary and secondary somatic sensory cortex
represented in the sensory homunculus: representation can be increased with use and can diminish with disuse
lateral inhibition
used to refine tactile discrimination about location and type of somatosensory information
relationship between tactile, proprioception, and pain
- Projections to the reticular system, thalamus, and hypothalamus
- Transmission of both diffuse and chronic pain
- Also connects to limbic system and ANS – generates emotional, neuroendocrine, and cardiovascular responses to pain
- Emotional responses to pain are separated from pain projections (ex. Meds)
- Both DCML and spinothalamic project to thalamus
DCML may inhibit pain transmission in the ST pathway
Could this be why deep-pressure touch diminishes pain
how the tactile system evolves
- Within the context of social interactions and the environment (nature and nurture): interactions with parents, If an environment is sensory deprived
- Discomfort with tactile experiences become heightened as the child grows older
- fine motor difficulties
- Can lead to social problems
May be seen as destructive or aggressive – can’t grade hard versus soft touch - Child may stay in protective mode
Fight of flight response – always on high alert!
tactile hyposensitivity
seen less often than tactile defensiveness
decreased tactile awareness
Child may also “fumble” fine motor tasks, be clumsy.
do not experience touch unless the experience is very intense
child may actually laugh or appear to enjoy a firm pat or spanking when being disciplined
child may seek touch-pressure input
may see self-abusive behaviors (ie. biting, head banging)
may be slow in initiating movement and exploring objects by feel (passive strategy)
demonstrate lag in motor development due to inefficient use of tactile exploration of objects
low muscle tone (sedentary); likes to be left alone; low energy level
may see child sitting half on chair/half off chair
may sit awkwardly and look uncomfortable but have limited perception to this
treatment for hyporesponsiveness
- Combine touch with other sensory channels – vestibular, auditory, and visual.
- Vibration and traction are good activities to introduce, pair proprioception with tactile stimuli.
- try implementing a regular routine that institutes light touch experiences and stroking during the day.
- Incorporate variety and intensity of tactile input with activities
- Activities that provide tactile feedback to entire body
tactile hyper responsiveness (overresponsivitiity)/tactile defensiveness/aversion
Infancy: does not cuddle, keeps hands fisted, curls toes, rejects bottle/feeding difficulties, strongly prefers either no clothing or tight swaddling, dislikes face or hair being washed/lotion
Toddlers: dislikes being touched or cuddled by others, distressed when positioned near others, avoid being near others, likes firm touches best and may enjoy games with intense touch, dislikes having haircut or hair washed, prefers long sleeves and pants in warm weather OR prefers as little clothing as necessary even when it is cold, withdraws from group interactions, aggressive in play
treatment ideas for hyper responsive/overresponsive child
- Provide opportunities in the environment that allow the child to self-initiate touch.
- Encourage games with high contact with other people
- Pair strong sensory system with a weak tactile system
- Pair the vestibular system with the tactile system for those children that enjoy vestibular input. Have a child ride prone in a hammock swing while “skiing” with hands in crazy foam or a sand/rice bin.
- Brushing program
proprioception
perception of joint and body movements in space
role of proprioceptive system
- direction and velocity of movement
- effort needed to lift objects/ force of mx
- spatial orientation of the body or body parts
- the rate and timing of movements
sources of proprioceptive input
- muscle spindles (stimulated by stretch)
- mechanoreceptors of the skin
- centrally generated motor commands
- tactile and proprioceptive information travel in the same pathway, but proprioception refers to sensation of movement or position that arises from one’s sown movement (not from external stimulation)
proprioception as a modulator
Child may have a registration disorder in another system (ie. Tactile defensiveness) and may use proprioception to stay calm and organized in environment. May look like over-activity, biting/pushing/ jumping/ chewing/ hitting excessively. Child may like chewy or crunchy foods. Child may appear aggressive or exhibit self-stimulatory behavior (banging head, biting hands, etc.)
hyporesponsiveness (poor discrimination) of proprioceptive input
Child may also seek excessive proprioception OR may exhibit low tone and sedentary behavior. Will appear clumsy, have difficulty with slow-controlled movement.
