TY  - CHAP
A1  - Kahmann, Stephanie
A1  - Hackl, Michael
A1  - Wegmann, Kilian
A1  - Müller, Lars-Peter
A1  - Staat, Manfred
ED  - Erni, Daniel
T1  - Impact of a proximal radial shortening osteotomy on the distribution of forces and the stability of the elbow
T2  - 1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen
N2  - The human arm consists of the humerus (upper arm), the medial ulna and the lateral radius (forearm). The joint between the humerus and the ulna is called humeroulnar joint and the joint between the humerus and the radius is called humeroradial joint. Lateral and medial collateral ligaments stabilize the elbow. Statistically, 2.5 out of 10,000 people suffer from radial head fractures [1]. In these fractures the cartilage is often affected. Caused by the injured cartilage, degenerative diseases like posttraumatic arthrosis may occur. The resulting pain and reduced range of motion have an impact on the patient’s quality of life. Until now, there has not been a treatment which allows typical loads in daily life activities and offers good long-term results. A new surgical approach was developed with the motivation to reduce the progress of the posttraumatic arthrosis. Here, the radius is shortened by 3 mm in the proximal part [2]. By this means, the load of the radius is intended to be reduced due to a load shift to the ulna. Since the radius is the most important stabilizer of the elbow it has to be confirmed that the stability is not affected. In the first test (Fig. 1 left), pressure distributions within the humeroulnar and humeroradial joints a native and a shortened radius were measured using resistive pressure sensors (I5076 and I5027, Tekscan, USA). The humerus was loaded axially in a tension testing machine (Z010, Zwick Roell, Germany) in 50 N steps up to 400 N. From the humerus the load is transmitted through both the radius and the ulna into the hand which is fixed on the ground. In the second test (Fig. 1 right), the joint stability was investigated using a digital image correlation system to measure the displacement of the ulna. Here, the humerus is fixed with a desired flexion angle and the unconstrained forearm lies on the ground. A rope connects the load actuator with a hook fixed in the ulna. A guide roller is used so that the rope pulls the ulna horizontally when a tensile load is applied. This creates a moment about the elbow joint with a maximum value of 7.5 Nm. Measurements were performed with varying flexion angles (0°, 30°, 60°, 90°, 120°). For both tests and each measurement, seven specimens were used. Student ́s t-test was employed to determine whether the mean values of the measurements in native specimen and operated specimens differ significantly.
Y1  - 2016
U6  - http://dx.doi.org/10.17185/duepublico/40821
SP  - 7
EP  - 8
PB  - Universität Duisburg-Essen
CY  - Duisburg
ER  - 
TY  - CHAP
A1  - Birgel, Stefan
A1  - Leschinger, Tim
A1  - Wegmann, Kilian
A1  - Staat, Manfred
ED  - Erni, Daniel
ED  - Fischerauer, Alice
ED  - Himmel, Jörg
ED  - Seeger, Thomas
ED  - Thelen, Klaus
T1  - Calculation of muscle forces and joint reaction loads in shoulder area via an OpenSim based computer calculation
T2  - 2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West
Y1  - 2017
SN  - 978-3-9814801-9-1
U6  - http://dx.doi.org/10.17185/duepublico/43984
N1  - A young researchers track of the 7th IEEE Workshop & SENSORICA 2017
N1  - In der Druckausgabe des Abstractbandes ist dieser Beitrag lose als Erratum beigefügt.
SP  - 116
EP  - 117
PB  - Universität Duisburg-Essen
CY  - Duisburg
ER  - 
TY  - CHAP
A1  - Kahmann, Stephanie Lucina
A1  - Uschok, Stephan
A1  - Wegmann, Kilian
A1  - Müller, Lars-P.
A1  - Staat, Manfred
T1  - Biomechanical multibody model with refined kinematics of the elbow
T2  - 6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK
N2  - The overall objective of this study is to develop a new external fixator, which closely maps the native kinematics of the elbow to decrease the joint force resulting in reduced rehabilitation time and pain. An experimental setup was designed to determine the native kinematics of the elbow during flexion of cadaveric arms. As a preliminary study, data from literature was used to modify a published biomechanical model for the calculation of the joint and muscle forces. They were compared to the original model and the effect of the kinematic refinement was evaluated. Furthermore, the obtained muscle forces were determined in order to apply them in the experimental setup. The joint forces in the modified model differed slightly from the forces in the original model. The muscle force curves changed particularly for small flexion angles but their magnitude for larger angles was consistent.
Y1  - 2018
ER  -