{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,20]],"date-time":"2026-03-20T21:41:26Z","timestamp":1774042886156,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2016,8,22]],"date-time":"2016-08-22T00:00:00Z","timestamp":1471824000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>A key point in human movement analysis is measuring the trajectory of a person\u2019s center of mass (CoM). For outdoor applications, differential Global Navigation Satellite Systems (GNSS) can be used for tracking persons since they allow measuring the trajectory and speed of the GNSS antenna with centimeter accuracy. However, the antenna cannot be placed exactly at the person\u2019s CoM, but rather on the head or upper back. Thus, a model is needed to relate the measured antenna trajectory to the CoM trajectory. In this paper we propose to estimate the person\u2019s posture based on measurements obtained from inertial sensors. From this estimated posture the CoM is computed relative to the antenna position and finally fused with the GNSS trajectory information to obtain the absolute CoM trajectory. In a biomechanical field experiment, the method has been applied to alpine ski racing and validated against a camera-based stereo photogrammetric system. CoM position accuracy and precision was found to be 0.08 m and 0.04 m, respectively. CoM speed accuracy and precision was 0.04 m\/s and 0.14 m\/s, respectively. The observed accuracy and precision might be sufficient for measuring performance- or equipment-related trajectory differences in alpine ski racing. Moreover, the CoM estimation was not based on a movement-specific model and could be used for other skiing disciplines or sports as well.<\/jats:p>","DOI":"10.3390\/rs8080671","type":"journal-article","created":{"date-parts":[[2016,8,22]],"date-time":"2016-08-22T10:40:33Z","timestamp":1471862433000},"page":"671","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":68,"title":["Three-Dimensional Body and Centre of Mass Kinematics in Alpine Ski Racing Using Differential GNSS and Inertial Sensors"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9322-0621","authenticated-orcid":false,"given":"Benedikt","family":"Fasel","sequence":"first","affiliation":[{"name":"Laboratory of Movement Analysis and Measurement, Ecole Polytechnique F\u00e9d\u00e9rale de Lausanne, 1015 Lausanne, Switzerland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0353-1021","authenticated-orcid":false,"given":"J\u00f6rg","family":"Sp\u00f6rri","sequence":"additional","affiliation":[{"name":"Department of Sport Science and Kinesiology, University of Salzburg, 5400 Hallein-Rif, Austria"}]},{"given":"Matthias","family":"Gilgien","sequence":"additional","affiliation":[{"name":"Department of Physical Performance, Norwegian School of Sport Sciences, 0806 Oslo, Norway"}]},{"given":"Geo","family":"Boffi","sequence":"additional","affiliation":[{"name":"Laboratory of Movement Analysis and Measurement, Ecole Polytechnique F\u00e9d\u00e9rale de Lausanne, 1015 Lausanne, Switzerland"},{"name":"Institute of Geodesy and Photogrammetry, ETH Zurich, 8093 Zurich, Switzerland"}]},{"given":"Julien","family":"Chardonnens","sequence":"additional","affiliation":[{"name":"Laboratory of Movement Analysis and Measurement, Ecole Polytechnique F\u00e9d\u00e9rale de Lausanne, 1015 Lausanne, Switzerland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3857-2584","authenticated-orcid":false,"given":"Erich","family":"M\u00fcller","sequence":"additional","affiliation":[{"name":"Department of Sport Science and Kinesiology, University of Salzburg, 5400 Hallein-Rif, Austria"}]},{"given":"Kamiar","family":"Aminian","sequence":"additional","affiliation":[{"name":"Laboratory of Movement Analysis and Measurement, Ecole Polytechnique F\u00e9d\u00e9rale de Lausanne, 1015 Lausanne, Switzerland"}]}],"member":"1968","published-online":{"date-parts":[[2016,8,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Kr\u00f6ll, J., Sp\u00f6rri, J., Gilgien, M., Chardonnens, J., and M\u00fcller, E. (2013). Verletzungspr\u00e4vention innerhalb eines internationalen Sportverbandes\u2014Eine Prozessbeschreibung am Beispiel des alpinen Skirennsports. Sport Orthop. Traumatol.","DOI":"10.1016\/j.orthtr.2013.09.002"},{"key":"ref_2","unstructured":"Reid, R.C. (2010). A Kinematic and Kinetic Study of Alpine Skiing Technique in Slalom. [Ph.D. Thesis, Norwegian School of Sport Sciences]."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"647","DOI":"10.1260\/1747-9541.7.4.647","article-title":"Turn characteristics of a Top World Class Athlete in Giant Slalom: A case study assessing current performance prediction concepts","volume":"7","author":"Schwameder","year":"2012","journal-title":"Int. J. Sport Sci. Coach."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1072","DOI":"10.1136\/bjsports-2012-091425","article-title":"Course setting and selected biomechanical variables related to injury risk in alpine ski racing: An explorative case study","volume":"46","author":"Schwameder","year":"2012","journal-title":"Br. J. Sports Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e72","DOI":"10.1111\/j.1600-0838.2010.01159.x","article-title":"Mechanical parameters as predictors of performance in alpine World Cup slalom racing","volume":"21","author":"Supej","year":"2011","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1007\/s40279-013-0132-z","article-title":"Biomechanical factors influencing the performance of Elite Alpine Ski Racers","volume":"44","author":"Supej","year":"2014","journal-title":"Sport Med."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1136\/bjsports-2015-095465","article-title":"Sidecut radius and the mechanics of turning\u2014Equipment designed to reduce risk of severe traumatic knee injuries in alpine giant slalom ski racing","volume":"50","author":"Gilgien","year":"2016","journal-title":"Br. J. Sports Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1136\/bjsports-2015-095465","article-title":"Effect of ski geometry on aggressive ski behaviour and visual aesthetics: Equipment designed to reduce risk of severe traumatic knee injuries in Alpine Giant Slalom Ski Racing","volume":"50","author":"Gilgien","year":"2016","journal-title":"Br. J. Sports Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1136\/bjsports-2015-095465","article-title":"Sidecut radius and kinetic energy: Equipment designed to reduce risk of severe traumatic knee injuries in Alpine Giant Slalom Ski Racing","volume":"50","author":"Gilgien","year":"2016","journal-title":"Br. J. Sports Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1063","DOI":"10.1080\/02640414.2012.690073","article-title":"Quantifying instantaneous performance in alpine ski racing","volume":"30","author":"Federolf","year":"2012","journal-title":"J. Sports Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1345","DOI":"10.1080\/02640414.2010.507253","article-title":"Collecting kinematic data on a ski\/snowboard track with panning, tilting, and zooming cameras: Is there sufficient accuracy for a biomechanical analysis?","volume":"28","author":"Klous","year":"2010","journal-title":"J. Sports Sci."},{"key":"ref_12","first-page":"11","article-title":"Kinematic determination of the beginning of a ski turn","volume":"9","author":"Supej","year":"2003","journal-title":"Kinesiol. Slov."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"9821","DOI":"10.3390\/s130809821","article-title":"Determination of external forces in alpine skiing using a differential global navigation satellite system","volume":"13","author":"Gilgien","year":"2013","journal-title":"Sensors"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"960","DOI":"10.1080\/02640414.2014.977934","article-title":"Determination of the centre of mass kinematics in alpine skiing using differential global navigation satellite systems","volume":"33","author":"Gilgien","year":"2015","journal-title":"J. Sports Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"18433","DOI":"10.3390\/s141018433","article-title":"The effect of different Global Navigation Satellite System methods on positioning accuracy in Elite Alpine Skiing","volume":"14","author":"Gilgien","year":"2014","journal-title":"Sensors"},{"key":"ref_16","unstructured":"Lachapelle, G., Morrison, A., and Ong, R. (2009, January 27\u201330). Ultra-Precise positioning for sport applications. Proceedings of the 13th IAIN World Congress, Stockholm, Sweden."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1007\/s10291-009-0124-5","article-title":"Optimization of two GPS\/MEMS-IMU integration strategies with application to sports","volume":"13","author":"Waegli","year":"2009","journal-title":"GPS Solut."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1080\/02640411003716934","article-title":"3D measurements of alpine skiing with an inertial sensor motion capture suit and GNSS RTK system","volume":"28","author":"Supej","year":"2010","journal-title":"J. Sports Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1080\/19346182.2008.9648447","article-title":"Fusion motion capture: A prototype system using inertial measurement units and GPS for the biomechanical analysis of ski racing","volume":"1","author":"Brodie","year":"2008","journal-title":"Sport Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"362","DOI":"10.1016\/j.proeng.2014.06.063","article-title":"On bending characteristics of skis in use","volume":"72","author":"Adelsberger","year":"2014","journal-title":"Procedia Eng."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Gilgien, M., Crivelli, P., Sp\u00f6rri, J., Kr\u00f6ll, J., and M\u00fcller, E. (2015). Correction: Characterization of course and terrain and their effect on skier speed in World Cup Alpine Ski Racing. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0128899"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Gilgien, M., Crivelli, P., Sp\u00f6rri, J., Kr\u00f6ll, J., and M\u00fcller, E. (2015). Characterization of Course and terrain and their effect on skier speed in World Cup Alpine Ski Racing. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0128899"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"742","DOI":"10.1136\/bjsports-2013-092994","article-title":"Mechanics of turning and jumping and skier speed are associated with injury risk in men\u2019s World Cup alpine skiing: A comparison between the competition disciplines","volume":"48","author":"Gilgien","year":"2014","journal-title":"Br. J. Sports Med."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1136\/bjsports-2015-095465","article-title":"Effect of ski geometry and standing height on kinetic energy: Equipment designed to reduce risk of severe traumatic injuries in alpine downhill ski racing","volume":"50","author":"Gilgien","year":"2016","journal-title":"Br. J. Sports Med."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e38","DOI":"10.1111\/sms.12007","article-title":"Aerodynamic drag is not the major determinant of performance during giant slalom skiing at the elite level","volume":"23","author":"Supej","year":"2013","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.jbiomech.2012.10.005","article-title":"A system to measure the kinematics during the entire ski jump sequence using inertial sensors","volume":"46","author":"Chardonnens","year":"2013","journal-title":"J. Biomech."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1080\/19346182.2009.9648494","article-title":"Biomechanical analysis in freestyle snowboarding: Application of a full-body inertial measurement system and a bilateral insole measurement system","volume":"2","year":"2009","journal-title":"Sport Technol."},{"key":"ref_28","unstructured":"Fasel, B., Sp\u00f6rri, J., Kr\u00f6ll, J., M\u00fcller, E., and Aminian, K. (July, January 29). Using inertial sensors for reconstructing 3D full-body movement in sports\u2014Possibilities and limitations on the example of Alpine Ski Racing. Proceedings of the 33rd International Conference on Biomechanics in Sports, Poitiers, France."},{"key":"ref_29","first-page":"311","article-title":"Procedure for effortless in-field calibration of three-axis rate gyros and accelerometers","volume":"7","author":"Ferraris","year":"1995","journal-title":"Sens. Mater."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"18625","DOI":"10.3390\/s141018625","article-title":"Estimating orientation using magnetic and inertial sensors and different sensor fusion approaches: Accuracy assessment in manual and locomotion tasks","volume":"14","author":"Bergamini","year":"2014","journal-title":"Sensors"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"612","DOI":"10.1049\/el:20060124","article-title":"Quaternion-based fusion of gyroscopes and accelerometers to improve 3D angle measurement","volume":"42","author":"Favre","year":"2006","journal-title":"Electron. Lett."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1385","DOI":"10.1109\/TBME.2006.873678","article-title":"Estimation and visualization of sagittal kinematics of lower limbs orientation using body-fixed sensors","volume":"53","author":"Dejnabadi","year":"2006","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1257","DOI":"10.1016\/0021-9290(95)00017-C","article-title":"ISB recommendations in the reporting for standardization of kinematic data","volume":"28","author":"Wu","year":"1995","journal-title":"J. Biomech."},{"key":"ref_34","unstructured":"Fasel, B., Sp\u00f6rri, J., Chardonnens, J., Gilgien, M., Kr\u00f6ll, J., M\u00fcller, E., and Aminian, K. (2013, January 14\u201319). 3D measurement of lower limb kinematics in alpine ski racing using inertial sensors. Proceedings of the 6th International Congress on Science and Skiing, St. Christoph am Arlberg, Austria."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1080\/02640414.2013.845679","article-title":"Measurement of the dynamics in ski jumping using a wearable inertial sensor-based system","volume":"32","author":"Chardonnens","year":"2014","journal-title":"J. Sports Sci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1223","DOI":"10.1016\/0021-9290(95)00178-6","article-title":"Adjustments to Zatsiorsky-Seluyanov\u2019s segment inertia parameters","volume":"29","year":"1996","journal-title":"J. Biomech."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1016\/j.jbiomech.2006.02.013","article-title":"Adjustments to McConville et al. and Young et al. body segment inertial parameters","volume":"40","author":"Dumas","year":"2007","journal-title":"J. Biomech."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1787","DOI":"10.1109\/TIE.2009.2032431","article-title":"A kalman\/particle filter-based position and orientation estimation method using a position sensor\/inertial measurement unit hybrid system","volume":"57","author":"Won","year":"2010","journal-title":"IEEE Trans. Ind. Electron."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/8\/8\/671\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:28:54Z","timestamp":1760210934000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/8\/8\/671"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,8,22]]},"references-count":38,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2016,8]]}},"alternative-id":["rs8080671"],"URL":"https:\/\/doi.org\/10.3390\/rs8080671","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,8,22]]}}}