title: Identification of spinal tissues loaded by manual therapy: a robot-based serial dissection technique applied in porcine motion segments.
abstract: METHODS
  Serial dissection of porcine motion segments during robotic control of vertebral kinematics.
  
  
  OBJECTIVE
  To identify which spinal tissues are loaded in response to manual therapy (manipulation and mobilization) and to what magnitude.
  
  
  BACKGROUND
  Various theoretical constructs attempt to explain how manual therapies load specific spinal tissues. By using a parallel robot to control vertebral kinematics during serial dissection, it is possible to quantify the loads experienced by discrete spinal tissues undergoing common therapeutic procedures such as manual therapy.
  
  
  METHODS
  In 9 porcine cadavers, manual therapy was provided to L3 and the kinematic response of L3-L4 recorded. The exact kinematic trajectory experienced by L3-L4 in response to manual therapy was then replayed to the isolated segment by a parallel robot equipped with a 6-axis load cell. Discrete spinal tissues were then removed and the kinematic pathway replayed. The change in forces and moments following tissue removal were considered to be those applied to that specific tissue by manual therapy.
  
  
  RESULTS
  In this study, both manual therapies affected spinal tissues. The intervertebral disc experienced the greatest forces and moments arising from both manipulation and mobilization.
  
  
  CONCLUSIONS
  This study is the first to identify which tissues are loaded in response to manual therapy. The observation that manual therapy loads some tissues to a much greater magnitude than others offers a possible explanation for its modest treatment effect; only conditions involving these tissues may be influenced by manual therapy. Future studies are planned to determine if manual therapy can be altered to target (or avoid) specific spinal tissues.
authors.affiliation: University of Alberta, Edmonton, AB, Canada. greg.kawchuk@ualberta.ca
authors.forename: Gregory N
authors.initials: GN
authors.lastname: Kawchuk
authors.forename: Alejandro
authors.initials: A
authors.lastname: Carrasco
authors.forename: Grayson
authors.initials: G
authors.lastname: Beecher
authors.forename: Darrell
authors.initials: D
authors.lastname: Goertzen
authors.forename: Narasimha
authors.initials: N
authors.lastname: Prasad
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology*; D004210:Dissection / Q000295:instrumentation / Q000379:methods*; D020393:Manipulation, Spinal / Q000379:methods / Q000592:standards*; D023421:Models, Animal; D016059:Range of Motion, Articular / Q000502:physiology*; D012371:Robotics / Q000295:instrumentation / Q000379:methods*; D012399:Rotation; D013131:Spine / Q000502:physiology*; D034421:Sus scrofa; D019415:Torque