title: Kinematic and kinetic assessment of upper limb movements in patients with writer's cramp.
abstract: BACKGROUND
  The assessment and treatment of writer's cramp is complicated due to the variations in the forces and angles of involved joints. Additionally, in some cases compensatory movements for cramp relief further complicates assessment. Currently these variables are subjectively measured with clinical scales and visual assessments. This subjectivity makes it difficult to successfully administer interventions such as Botulinum toxin injection or orthotics resulting in poor efficacy and significant side effects.
  
  
  METHODS
  A multi-sensor system was used to record finger and wrist forces along with deviation angles at the wrist, elbow and shoulder while 9 patients with writer's cramp performed a series of standardized tasks on surfaces inclined at different angles. Clinical, kinetic, and kinematic information regarding cramping was collected.
  
  
  RESULTS
  First, four tasks appeared to best predict cramp occurrence. Second, unique biomechanical profiles emerged for patients regarding force, angles and cramp severity. Third, cluster analyses using these features showed a clear separation of patients into two severity classes. Finally, a relationship between severity and kinetic-kinematic information suggested that primary cramping versus compensatory movements could be potentially inferred.
  
  
  CONCLUSIONS
  The results demonstrate that using a set of standardized tasks and objective measures, individual profiles for arm movements and applied forces associated with writer's cramp can be generated. The clinician can then accurately target the biomechanics specifically, whether it is with injection or other rehabilitative measures, fulfilling an important unmet need in the treatment of writer's cramp.
authors.affiliation: K. N. Toosi University of Technology, Faculty of Electrical and Computer Engineering, Tehran, 19697, Iran. delrobaei@kntu.ac.ir.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Delrobaei
authors.affiliation: Department of Electrical and Computer Engineering, Bonab University, Bonab, East Azerbaijan, Iran. frahimi@bonabu.ac.ir.
authors.forename: Fariborz
authors.initials: F
authors.lastname: Rahimi
authors.affiliation: Department of Clinical Neurological Sciences, Western University, London, ON, Canada. mjackma3@uwo.ca.
authors.forename: Mallory E
authors.initials: ME
authors.lastname: Jackman
authors.affiliation: Canadian Surgical Technologies & Advanced Robotics, Department of Electrical and Computer Engineering, Western University, London, ON, Canada. satashza@uwo.ca.
authors.forename: S Farokh
authors.initials: SF
authors.lastname: Atashzar
authors.affiliation: Canadian Surgical Technologies & Advanced Robotics, Department of Electrical and Computer Engineering, Western University, London, ON, Canada. mshahba2@uwo.ca.
authors.forename: Mahya
authors.initials: M
authors.lastname: Shahbazi
authors.affiliation: Canadian Surgical Technologies & Advanced Robotics, Department of Electrical and Computer Engineering, Western University, London, ON, Canada. rvpatel@uwo.ca.|Department of Surgery, Western University, London, ON, Canada. rvpatel@uwo.ca.
authors.forename: Rajni
authors.initials: R
authors.lastname: Patel
authors.affiliation: Lawson Health Research Institute, And the Department of Clinical Neurological Sciences, Western University, London, ON, Canada. mandar.jog@lhsc.on.ca.
authors.forename: Mandar
authors.initials: M
authors.lastname: Jog
mesh_terms: D000368:Aged; D000465:Algorithms; D001696:Biomechanical Phenomena; D004421:Dystonia / Q000503:physiopathology; D020821:Dystonic Disorders / Q000503:physiopathology*; D004550:Elbow / Q000503:physiopathology; D005260:Female; D006225:Hand / Q000503:physiopathology; D018737:Hand Strength; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement; D011237:Predictive Value of Tests; D012782:Shoulder / Q000503:physiopathology; D034941:Upper Extremity / Q000503:physiopathology*; D014953:Wrist / Q000503:physiopathology