Validation and Comparison of Three Positioning Protocols of Inertial Measurement Units for Measuring Trunk Movement

  • Liyun YangEmail author
  • Dennis Borgström
  • Mikael Forsman
Conference paper
Part of the Advances in Intelligent Systems and Computing book series (AISC, volume 820)


Postures and movements of the trunk are of ergonomic concern when evaluating the risks at work. Technical measurement methods can be used for measurements of trunk movements for long duration with high accuracy, and are therefore increasingly used in practice and research. However, currently there is no standardized protocol for the sensor placement for trunk measurement. Three placement protocols of inertial measurement units (IMUs), including placement on C7, T4 and sternum (St), in combination with S1 spinous process, were compared with an optical motion capture (OMC) system. Four subjects performed a movement test including forward to backward bending, sideward bending and twisting of the trunk, and a symmetrical lifting task. Root-mean-square differences (RMSDs) and Pearson’s correlation were calculated between the two systems. For the movement tests, the RMSDs of the forward inclination at the 10th, 50th and 90th percentiles from the three IMUs were all smaller than 7.3°. Larger differences were shown for C7 of the sideward inclination at 90th percentile (10.8°). Also for the twisting, larger differences were shown, especially for C7-S1 and T4-S1 (RMSD = 16.5° and 19.8°). For the lifting tests of forward inclination, St had the smallest differences compared to OMC (RMSDs < 4.1°), while slightly larger errors were found for C7 and T4 at the 90th percentile (RMSDs = 8.1° and 8.2°). Different positioning protocols seem to have a slightly different effect on the measurement accuracy of trunk movement. Considerations should be taken when comparing results across studies applying different protocols.


Trunk motion Inertial sensor Postural assessment 


  1. Afshari D, Motamedzade M, Salehi R, Soltanian AR (2014) Continuous assessment of back and upper arm postures by long-term inclinometry in carpet weavers. Appl Ergon 45(2):278–284. Scholar
  2. Amasay T, Zodrow K, Kincl L, Hess J, Karduna A (2009) Validation of tri-axial accelerometer for the calculation of elevation angles. Int J Ind Ergon 39(5):783–789. Scholar
  3. Coenen P, Douwes M, van den Heuvel S, Bosch T (2016) Towards exposure limits for working postures and musculoskeletal symptoms – a prospective cohort study. Ergonomics 59(9):1182–1192.
  4. Dahlqvist C, Hansson G-Å, Forsman M (2016) Validity of a small low-cost triaxial accelerometer with integrated logger for uncomplicated measurements of postures and movements of head, upper back and upper arms. Appl Ergon 55(July):108–116. Scholar
  5. Delleman NJ, Haslegrave CM, Chaffin DB (2004) Working postures and movements: tools foe evaluation and engineering. CRC Press, Boca RatonGoogle Scholar
  6. Hansson G-Å, Balogh I, Ohlsson K, Granqvist L, Nordander C, Arvidsson I, Åkesson I et al (2010) Physical workload in various types of work: part II. neck, shoulder and upper arm. Int J Ind Ergon 40(3):267–281. Scholar
  7. Korshoj M, Skotte JH, Christiansen CS, Mortensen P, Kristiansen J, Hanisch C, Ingebrigtsen J, Holtermann A (2014) Validity of the Acti4 software using ActiGraph GT3X+accelerometer for recording of arm and upper body inclination in simulated work tasks. Ergonomics 57(2):247–253. Scholar
  8. Labaj A, Diesbourg T, Dumas G, Plamondon A, Mercheri H, Larue C (2016) Posture and lifting exposures for daycare workers. Int J Ind Ergon 54:83–92. Scholar
  9. NIOSH, National Institute for Occupational Health and Safety (1997) Musculoskeletal disorders and workplace factors: a critical review of epidemiologic evidence for work-related musculoskeletal disorders of the neck, upper extremity, and low backGoogle Scholar
  10. Robert-Lachaine X, Mecheri H, Larue C, Plamondon A (2017) Effect of local magnetic field disturbances on inertial measurement units accuracy. Appl Ergon 63:123–132. Scholar
  11. Schall MC, Fethke NB, Chen H, Gerr F (2015) A comparison of instrumentation methods to estimate thoracolumbar motion in field-based occupational studies. Appl Ergon 48(May):224–231. Scholar
  12. Straker L, Campbell A, Coleman J, Ciccarelli M, Dankaerts W (2010) In vivo laboratory validation of the physiometer: a measurement system for long-term recording of posture and movements in the workplace. Ergonomics 53(5):672–684. Scholar
  13. Teschke K, Trask C, Johnson P, Chow Y, Village J, Koehoorn M (2009) Measuring posture for epidemiology: comparing inclinometry, observations and self-reports. Ergonomics 52(9):1067–1078.
  14. Trask C, Mathiassen SE, Wahlström J, Forsman M (2014) Cost-Efficient assessment of biomechanical exposure in occupational groups, exemplified by posture observation and inclinometry. Scand J Work Environ Health 40(3):252–265. Scholar
  15. Wahlström J, Bergsten E, Trask C, Mathiassen SE, Jackson J, Forsman M (2016) Full-shift trunk and upper arm postures and movements among aircraft baggage handlers. Ann Occup Hyg 60(8):977–990. Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Division of ErgonomicsKTH Royal Institute of TechnologyHuddingeSweden
  2. 2.Institute of Environmental Medicine, Karolinska InstitutetStockholmSweden

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