Is what you see what you get? Standard inclinometry of set upper arm elevation angles.

Previous research suggests inclinometers (INC) underestimate upper arm elevation. This study was designed to quantify possible bias in occupationally relevant postures, and test whether INC performance could be improved using calibration. Participants were meticulously positioned in set arm flexion and abduction angles between 0° and 150°. Different subject-specific and group-level regression models comprising linear and quadratic components describing the relationship between set and INC-registered elevation were developed using subsets of data, and validated using additional data. INC measured arm elevation showed a downward bias, particularly above 60°. INC data adjusted using the regression models were superior to unadjusted data; a subject-specific, two-point calibration based on measurements at 0° and 90° gave results closest to the 'true' set angles. Thus, inclinometer measured arm elevation data required calibration to arrive at 'true' elevation angles. Calibration to a common measurement scale should be considered when comparing arm elevation data collected using different methods.

[1]  Svend Erik Mathiassen,et al.  Upper arm postures and movements in female hairdressers across four full working days. , 2010, The Annals of occupational hygiene.

[2]  J P Bonde,et al.  Work related shoulder disorders: quantitative exposure-response relations with reference to arm posture , 2004, Occupational and Environmental Medicine.

[3]  J P Bonde,et al.  Task based exposure assessment in ergonomic epidemiology: a study of upper arm elevation in the jobs of machinists, car mechanics, and house painters , 2004, Occupational and Environmental Medicine.

[4]  G. Hansson,et al.  Validity and reliability of triaxial accelerometers for inclinometry in posture analysis , 2001, Medical and Biological Engineering and Computing.

[5]  Kerstina Ohlsson,et al.  Physical workload in various types of work: Part II. Neck, shoulder and upper arm , 2010 .

[6]  Andreas Holtermann,et al.  Validity of the Acti4 software using ActiGraph GT3X+accelerometer for recording of arm and upper body inclination in simulated work tasks , 2014, Ergonomics.

[7]  Alex Burdorf,et al.  Equal task, equal exposure? Are men and women with the same tasks equally exposed to awkward working postures? , 2009, Ergonomics.

[8]  W Gerbino,et al.  Retinal vs. environmental orientation in the perception of the right angle. , 1995, Acta psychologica.

[9]  S E Mathiassen,et al.  Precision of measurements of physical workload during standardised manual handling. Part II: Inclinometry of head, upper back, neck and upper arms. , 2006, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[10]  Svend Erik Mathiassen,et al.  Cost-efficient measurement strategies for posture observations based on video recordings. , 2013, Applied ergonomics.

[11]  C. Wiktorin,et al.  A triaxial accelerometer for measuring arm movements. , 2002, Applied ergonomics.

[12]  Kaj Bo Veiersted,et al.  Effect of an intervention addressing working technique on the biomechanical load of the neck and shoulders among hairdressers. , 2008, Applied ergonomics.

[13]  Nathan B Fethke,et al.  Comparison of biomechanical loading during use of conventional stud welding equipment and an alternate system. , 2011, Applied ergonomics.

[14]  L. Portney,et al.  Foundations of Clinical Research: Applications to Practice , 2015 .

[15]  W. M. Keyserling,et al.  Back disorders and nonneutral trunk postures of automobile assembly workers. , 1991, Scandinavian journal of work, environment & health.

[16]  E Goldmeier,et al.  Similarity in visually perceived forms. , 1972, Psychological issues.

[17]  Lorenzo Chiari,et al.  Human movement analysis using stereophotogrammetry. Part 4: assessment of anatomical landmark misplacement and its effects on joint kinematics. , 2005, Gait & posture.

[18]  N. Fallentin,et al.  Assessment of work postures and movements using a video-based observation method and direct technical measurements. , 2001, Applied ergonomics.

[19]  Laurel Kincl,et al.  Validation of tri-axial accelerometer for the calculation of elevation angles , 2009 .

[20]  A J van der Beek,et al.  Assessment of mechanical exposure in ergonomic epidemiology. , 1998, Occupational and environmental medicine.

[21]  Daniel Imbeau,et al.  Comparison of three computer office workstations offering forearm support: impact on upper limb posture and muscle activation , 2006, Ergonomics.

[22]  A M Genaidy,et al.  Can visual perception be used to estimate body part angles? , 1993, Ergonomics.

[23]  S E Mathiassen,et al.  Assessment of physical work load in epidemiologic studies: concepts, issues and operational considerations. , 1994, Ergonomics.

[24]  Svend Erik Mathiassen,et al.  Work above shoulder level and degenerative alterations of the rotator cuff tendons: a magnetic resonance imaging study. , 2004, Arthritis and rheumatism.

[25]  S. G. Heuvel,et al.  Do work-related physical factors predict neck and upper limb symptoms in office workers? , 2006, International archives of occupational and environmental health.

[26]  Barbara Silverstein,et al.  Interrater Reliability of Posture Observations , 2009, Hum. Factors.

[27]  Svend Erik Mathiassen,et al.  Data collection costs in industrial environments for three occupational posture exposure assessment methods , 2012, BMC Medical Research Methodology.

[28]  C Fransson-Hall,et al.  A portable ergonomic observation method (PEO) for computerized on-line recording of postures and manual handling. , 1995, Applied ergonomics.

[29]  Erich Goldmeier,et al.  Über Ähnlichkeit bei gesehenen Figuren , 1937 .

[30]  J P Callaghan,et al.  The effect of camera viewing angle on posture assessment repeatability and cumulative spinal loading , 2007, Ergonomics.

[31]  Svend Erik Mathiassen,et al.  Data processing costs for three posture assessment methods , 2013, BMC Medical Research Methodology.

[32]  Svend Erik Mathiassen,et al.  Cost efficiency comparison of four video-based techniques for assessing upper arm postures , 2012, Ergonomics.

[33]  Eva Bernmark,et al.  Awkward work postures: association with occupational gender segregation. , 2005, American journal of industrial medicine.

[34]  D B Chaffin,et al.  Shoulder disorders and postural stress in automobile assembly work. , 2000, Scandinavian journal of work, environment & health.