title: Effect of fixation of shoulder and elbow joint movement on the precision of laparoscopic instrument manipulations.
abstract: BACKGROUND
  Motion analysis of the upper limb and the surgical instruments is used for objective assessment of endoscopic manipulations. The aim of this study was to investigate the effect of fixation of shoulder and elbow joint movement on the precision of laparoscopic instrument manipulations.
  
  
  METHODS
  Two experiments were conducted to correlate hand movement with instrument tip during free and restricted movement of the shoulder and elbow joints. A three-dimensional infrared optical tracking system has been used. Five subjects participated in the study, and each completed the range of movements twice. End points were velocity (m/s), angular velocity (r/s) and acceleration (m/s2).
  
  
  RESULTS
  There was a weak correlation for all end points between the instrument tip and individual joint movement during free upper limb movement (r < 0.4). With restricted movement of the shoulder and elbow joints, the correlation between hand movement and instrument tip was found to be good for the velocity (r = 0.66 for flexion; r = 0.72 for abduction; r = 0.56 for supination) and angular velocity (r = -0.83 for flexion; r = -0.48 for abduction; r = -0.70 for supination), but weak for the acceleration (r < 0.4).
  
  
  CONCLUSIONS
  The characteristics of hand movements do not correlate with movement of the laparoscopic instrument tip when the upper limb is unsupported. The precision of laparoscopic surgical manipulations is increased if both joints (shoulder and elbow) are supported.
authors.affiliation: Surgical Skills Unit and Surgery and Molecular Oncology, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, Scotland, UK.
authors.forename: P V
authors.initials: PV
authors.lastname: Patil
authors.forename: G B
authors.initials: GB
authors.lastname: Hanna
authors.forename: T G
authors.initials: TG
authors.lastname: Frank
authors.forename: A
authors.initials: A
authors.lastname: Cuschieri
mesh_terms: D004551:Elbow Joint / Q000502:physiology*; D006225:Hand / Q000502:physiology*; D006801:Humans; D020706:Laparoscopes; D010535:Laparoscopy / Q000379:methods*; D016059:Range of Motion, Articular; D012785:Shoulder Joint / Q000502:physiology*