title: Evaluation of mechanical allodynia in an animal immobilization model using the von frey method.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the mechanical allodynia in animals after immobilization and chiropractic manipulation using the Activator instrument (Activator Methods International, Phoenix, Ariz) through the Von Frey test in an animal model that had its hind limb immobilized as a form to induce mechanical allodynia.
  
  
  METHODS
  Eighteen adult male Wistar rats were used and divided into 3 groups: control group (C) (n = 6) that was not immobilized; immobilized group (I) (n = 6) that had its right hind limb immobilized; immobilized and adjusted group (IAA) (n = 6) that had its right hind limb immobilized and received chiropractic manipulation after. The mechanical allodynia was induced through the right hind limb immobilization. At the end of the immobilization period, the first Von Frey test was performed, and after that, 6 chiropractic manipulations on the tibial tubercle were made using the Activator instrument. After the manipulation period, Von Frey test was performed again.
  
  
  RESULTS
  It was observed that after the immobilization period, groups I and IAA had an exacerbation of mechanical allodynia when compared with group C (P < .001) and that after the manipulation, group IAA had a reversion of these values (P < .001), whereas group I kept a low pain threshold when compared with group C (P < .001).
  
  
  CONCLUSIONS
  This study demonstrates that immobilization during 4 weeks was sufficient to promote mechanical allodynia. Considering the chiropractic manipulation using the Activator instrument, it was observed that group IAA had decreased levels of mechanical allodynia, obtaining similar values to group C.
authors: Academic of Chiropractic from the University Feevale, Laboratory of Comparative Histophysiology, ICS, University Feevale, Novo Hamburgo, RS, Brazil. jaquetri@gmail.com
authors: Jaqueline
authors: J
authors: Trierweiler
authors: Débora Negrini
authors: DN
authors: Göttert
authors: Günther
authors: G
authors: Gehlen
mesh_terms: D000818:Animals; D005552:Forelimb; D006930:Hyperalgesia / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy*; D007103:Immobilization / Q000009:adverse effects* / Q000379:methods; D008297:Male; D026882:Manipulation, Chiropractic / Q000379:methods*; D023421:Models, Animal; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D012307:Risk Factors