title: Correlation of lumbar-hip kinematics between trunk flexion and other functional tasks.
abstract: OBJECTIVE
  The purpose of this study was to explore the relationship between the kinematic profiles of flexion of the upper lumbar and lower lumbar (LL) spine and hip and 3 sagittally dominant functional tasks (lifting, stand-to-sit, and sit-to-stand).
  
  
  METHODS
  Fifty-three participants were recruited for this study. Four sensors were attached to the skin over the S1, L3, T12, and lateral thigh. Relative angles between adjacent sensors were used to quantify the motion for the hip, LL, and upper lumbar spine. Pearson correlation coefficients were used to explore the relationship between the movements and more functional tasks. One-way analysis of variance was used to determine the significance of differences between the variables.
  
  
  RESULTS
  Flexion resulted in a greater or similar range of motion (ROM) to the other tasks investigated for both spinal regions but less ROM for the hip. Strong correlations for ROM are reported between forward flexion tasks and lifting for the LL spine (r = 0.83) and all regions during stand-to-sit and sit-to-stand (r = 0.70-0.73). No tasks were strongly correlated for velocity (r = 0.03-0.55).
  
  
  CONCLUSIONS
  Strong correlations were only evident for the LL spine ROM between lifting and flexion; all other tasks afforded moderate or weak correlations. This study suggests that sagittal tasks use different lumbar-hip kinematics and place different demands on the lumbar spine and hip.
authors.affiliation: Student, Institute of Medical Engineering & Medical Physics, Cardiff School of Engineering, Cardiff University, Cardiff, UK; Physiotherapy Specialist, Ministry of Health, Riyadh, Kingdom of Saudi Arabia. Electronic address: AlqhtaniRS@cardiff.ac.uk.
authors.forename: Raee S
authors.initials: RS
authors.lastname: Alqhtani
authors.affiliation: Senior Lecturer, Cardiff University, Institute of Medical Engineering & Medical Physics, Cardiff School of Engineering, Cardiff University, Cardiff, UK.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Jones
authors.affiliation: Lecturer, Cardiff University, Institute of Medical Engineering & Medical Physics, Cardiff School of Engineering, Cardiff University, Cardiff, UK.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Theobald
authors.affiliation: Senior Lecturer, Faculty of Health and Social Sciences, Bournemouth University, Dorset, UK.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Williams
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D064368:Healthy Volunteers; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology*; D008297:Male; D011187:Posture / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology*; D013647:Task Performance and Analysis; D055815:Young Adult
keywords: Correlation; Flexion; Function; Hip; Lifting; Lumbar; Sitting; Standing; Tasks