Research interests

Angles

• Joint motions can be described in angles. This is implicitly an normalization to segment length. Typically euler/cardan angles are used but depending on the application specific angle definitions are more powerful: Direction cosine or projection angles, adjunct and conjunct rotation angles.
• As an example: The gimbal lock problems produced by the big range of shoulder motion can be avoided by usage of conjunct rotation angles.
  

Upper extremity motion analysis

• Analysis of supporting arm movement during gait and other daily life arm movements
• Development of kinematic and kinetic moduls for analysing arm and shoulder movements, development of the Heidelberg upper extremity measurement method
• Implementation and support of a complete desktop application for modeling and data analysis
• Functional methods to estimate joint axes and centers from specific calibration movements.

Inertial sensors and its application for human motion analysis

Advanced modeling and anlysis methods

• Kinematic models based on optimization methods, functional calibration etc.
• Inverse dynamics based on force plate data
• Phase diagrams and analyses based on continuous relative phases
• Unconstrained manifold analyses (UCM)

Classification algorithms

• Step counting algorithms
• Event detection algorithms, e.g. foot strike and foot off event detection during gait
  
• Daily life motion pattern recognition
• Indizes for quantification of motion qualtity

Conference contributions

ESMAC 2003, O. Rettig, Best poster award: Kinetics of a carbon spring AF-orthosis and its influence on the kinetics of gait. Gait & Posture 2003 Dec, 18(3):P196-P209

ESMAC 2004, O. Rettig, Poster: Upper Extremity – Optical marker based joint center calculation and elbow flexion angle determination. Gait & Posture 2004 Aug, 20:S61-S112

ESMAC 2005, O. Rettig, Oral: An upper extremity model based on optimized joint centers and axes. Gait & Posture 2005 Sep, 22(3):P1-53

ESMAC 2005, S. Wolf u. O. Rettig, Poster: Euler is not really what the clinician wants. Gait & Posture 2005 Sep, 22(3):P1-53

Biomechanics of the lower limb in health desease and rehabilitation 2006, S. Wolf u. O. Rettig, Oral: Rotation in ball joints – a solution for the Codeman paradoxon.

ESMAC 2006, S. Wolf u. O. Rettig, D. Patikas, Poster: Proper joint angle representation in the context of femoral derotation osteotomy. Gait & Posture 2006 Dec, 24(2):S181-S182

GCMAS 2007 O. Rettig, Oral: Practical details and experiences of shoulder center (SJC) estimation using a least squres functional method.

ESMAC 2007 O. Rettig, Oral: Arm orientations and movements during gait: Normal data and quantification of its variability.

ESMAC 2008, O. Rettig, Poster: Upper extremity joint angles in static positions. Gait & Postrue 2008 Sep, 28(2):S93-S94

ESMAC 2008, O. Rettig, Symposium Oral: Functional methods for shoulder joint centre estimation based on a minimized marker set and comparison of three different computation methods for clinical feasibility.

ESMAC 2008, S. Wolf, L. Fradet, O. Rettig, Poster: Conjunct rotation of the shoulder. Gait & Posture 2009 Nov, 30(2):S56

ISG 2008, S. Wolf u. O. Rettig, Oral: Conjunct and adjunct rotation in the shoulder.

ESMAC 2011, Oral: O. Rettig, M. Maier, Reverse Shoulder Prosthesis - Markerbased Measurement of the Center of Rotation Localisation. Gait & Posture, 2012 Jun 36(1):S34-S35

ESMAC 2013, Poster: O. Rettig, D. Heitzmann, J. Block, S. Wolf, Is slope walking less stable in frontal plane than level walking? Gait & Posture, 2013 Nov, 38(1):S90-S91

ESMAC 2013, Poster: M. W. Maier, M. Niklasch, T. Dreher, F. Zeifang, O. Rettig, S. Wolf, P. Kasten, Can hemi shoulder arthroplasty restore the normal range of motion in activities of daily living in patients with degenerative osteoarthritis of the glenohumeral joint? A prospective 3D Video Motion Analysis Study. Gait & Posture 2013 Nov, 38(1):S31-S32

ESMAC 2013, Poster: M. Maier, F. Zeifang, M. Caspers, T. Dreher, O. Rettig, S. Wolf, P. Raiss, P. Kasten, How does reverse shoulder replacement changes the range of motion in activities of daily living in patients with cuff tear arthropathy? A proserctive 3D video motion analysis analysis study. Gait & Posture 2014 Jun, 39(1):S39-S40

ESMAC 2014, Poster: O. Rettig, B. Krautwurst, M. Maier, S. Wolf, Shoulder girdle elevation during humerus ad-/abduction. Gait & posture 2014 Jun, 39(1) S126-S127

ESMAC 2015, Poster: S. Mattner, T. Dreher, B. Krautwurst, O. Rettig, S.Wolf, M. Niklasch, The objective measurement of diadochokinesis in children with bilateral spastic cerebral palsy. Gait & posture 2015 Sep; 42(1) S19

ESMAC 2015 Oral: O. Rettig, S. Wolf, Gaitmatscher – Search for gait kinematics twins, Gait & posture 2015 Sept, 42(1) S100-S101

DGfB 2015, Oral: O. Rettig, Gaitmatcher – Suche nach Gangbild-Zwillingen     

Gamma Kongress 2016, Oral: O. Rettig, Fortschritte bei der Suche nach Gangbild-Zwillingen

IAS-15, 2018: Oral: O. Rettig, S. Müller, M. Strand, D. Katic, Unsupervised Hump Detection for Mobile Robots Based on Kinematic Measurements and Deep-Learning Based Autoencoder

Books and journal contributions

2004, O. Rettig, Galileo Computing, Tomcat 5, printed edition 530 pages

2007, P. Raiss, O. Rettig, et. al., Range of motion of shoulder and elbow in activities of daily life in 3D motion analysis. Z Orthop Unfall, 145, 493-498

2008, S. Wolf, M. Alimusaj, O.Rettig, L. Döderlein, Gait and posture: Dynamic assist by carbon fiber spring AFOs for patients with myelomeningocele. Gait & posture 2008, 28, 175-177

2009, S. Wolf, O. Rettig, et. al., Conjunct rotation: Codman's paradox revisited. Med Biol Eng Comput, 47, 551-556

2009, P. Kasten, M. Maier, O. Rettig, P. Raiss, S. Wolf, M. Loew, Proprioception in total, hemi- and reverse shoulder arthroplasty in 3D motion analyses: a prospective study, Int Orthop, 33, 1641-1664

2009, O. Rettig, et. al., A new kinematic model of the upper extremity based on functional joint parameter determination for shoulder and elbow, Gait and posture, 30, 469-476

2009, P. Kasten, O. Rettig, M. Loew, S. Wolf, P. Raiss, Three-dimensional motion analysis of compensatory movements in patients with radioulnar synostosis performing activities of daily living, J Orthop Sci, 14, 307-212

2010, P. Kasten, M. Maier, P. Wendy, O. Rettig, P. Raiss, S. Wolf, M. Loew, Can shoulder arthroplasty restore the range of motion in activities of daily living? A prospective 3D video motion analysis study, J Shoulder Elbow Surg, 19, 59-65

2012, O. Rettig, M. W. Maier, S. Gantz, P. Raiss, F. Zeifang, S. Wolf, Does the reverse shoulder prosthesis medialize the center of rotation in the glenohumeral joint? Gait & Posture, 2013 Jan; 37(1):29-31

2014, Matthias C.M. Klotz, S. van Drongelen , O. Rettig, P. Wenger, S. Gantz, T. Dreher, S. Wolf, Motion analysis of the upper extremity in children with unilateral cerebral palsy—An assessment of six daily tasks, Research in Developmental Disabilities 2014; 35:2950–2957

2015, L.Fradet, B. Liefhold, O. Rettig, T. Bruckner, M. Wolf, S. Wolf, Proposition of a protocol to evaluate upper‐extremity functional deficits and compensation mechanisms: application to elbow contracture, J Orthop Sci 2015; 20:321–330

2015, O. Rettig, B. Krautwurst, M. W. Maier and S. Wolf, Definition of anatomical zero positions for assessing shoulder pose with 3D motion capture during bilateral abduction of the arms, BMC Musculoskeletal Disorders 2015; 16:383

2016, M. Sreenivasa, C. J. G. Chamorro, D. Gonzalez-Alvarado, O. Rettig, S. Wolf, Patient-specific bone geometry and segment inertia from MRI images for model-based analysis of pathological gait, Journal of Biomechanics 2016; 49:1918–1925

2017, P.P. Pott, S.I. Wolf, J. block, S. van Drongelen, M. Grün, D. WW. Heizmann, J. Hielscher, A. Horn, R. Müller, O. Rettig, U. Konigorski, r. Werthschützky, h.f. schlaak, T. Meiß, Knee-ankle-foot orthesis with powered knee for support in elderly, Proc IMechE Part H: J engineering in Medcine 231(8):715-727

2018, M. Lenk, P. Hilsendegen, O. Rettig, M. Strand, Simulation and Transfer of Reinforcement Learning Algorithms for Autonomous Obstacle Avoidance, accpeted to be published by Springer in Advances in Intelligent Systems and Computing.

2018, O. Rettig, S. Müller, D. Katic, Which deep artifical neural network architecture to use for anomaly detection in Mobile Robots kinematic data? (accepted to be published by Springer)

2018, O. Rettig, B. Friesenbichler, Adjunct SHR - a new version of the "classical" Scapulohumeral Rhythm ratio, Gait & Posture, s0966-6362(18)30826-9