title: Cervical spine mobilisation forces applied by physiotherapy students.
abstract: OBJECTIVE
  Postero-anterior (PA) mobilisation is commonly used in cervical spine treatment and included in physiotherapy curricula. The manual forces that students apply while learning cervical mobilisation are not known. Quantifying these forces informs the development of strategies for learning to apply cervical mobilisation effectively and safely. This study describes the mechanical properties of cervical PA mobilisation techniques applied by students, and investigates factors associated with force application.
  
  
  METHODS
  Physiotherapy students (n=120) mobilised one of 32 asymptomatic subjects.
  
  
  METHODS
  Students applied Grades I to IV central and unilateral PA mobilisation to C2 and C7 of one asymptomatic subject. Manual forces were measured in three directions using an instrumented treatment table. Spinal stiffness of mobilised subjects was measured at C2 and C7 using a device that applied a standard oscillating force while measuring this force and its concurrent displacement. Analysis of variance was used to determine differences between techniques and grades, intraclass correlation coefficients (ICC) were used to calculate the inter- and intrastudent repeatability of forces, and linear regression was used to determine the associations between applied forces and characteristics of students and mobilised subjects.
  
  
  RESULTS
  Mobilisation forces increased from Grades I to IV (highest mean peak force, Grade IV C7 central PA technique: 63.7N). Interstudent reliability was poor [ICC(2,1)=0.23, 95% confidence interval (CI) 0.14 to 0.43], but intrastudent repeatability of forces was somewhat better (0.83, 95% CI 0.81 to 0.86). Higher applied force was associated with greater C7 stiffness, increased frequency of thumb pain, male gender of the student or mobilised subject, and a student being earlier in their learning process. Lower forces were associated with greater C2 stiffness.
  
  
  CONCLUSIONS
  This study describes the cervical mobilisation forces applied by students, and the characteristics of the student and mobilised subject associated with these forces. These results form a basis for the development of strategies to provide objective feedback to students learning to apply cervical mobilisation.
authors.affiliation: Discipline of Physiotherapy, University of Newcastle, Hunter Building, Callaghan, NSW 2308, Australia. Suzanne.Snodgrass@newcastle.edu.au
authors.forename: Suzanne J
authors.initials: SJ
authors.lastname: Snodgrass
authors.forename: Darren A
authors.initials: DA
authors.lastname: Rivett
authors.forename: Val J
authors.initials: VJ
authors.lastname: Robertson
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Stojanovski
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae; D005260:Female; D006801:Humans; D008297:Male; D020393:Manipulation, Spinal / Q000379:methods; D026741:Physical Therapy Modalities / Q000193:education*; D015203:Reproducibility of Results; D012737:Sex Factors; D013997:Time Factors