Juvenile Idiopathic Arthritis

Biomechanical diagnostics in children and adolescents with juvenile idiopathic arthritis for individual physical activity promotion (BEWARE project)

Juvenile idiopathic arthritis (JIA) is often associated with impairments in everyday functionality and accompanying physical inactivity. The goal of this study is to early advise children and adolescents with JIA to a safe physical activity in order to prevent impairments and malfunctions. The advice is based on the clinical disease status, patients’ anthropometrics, patients’ self-assessment and on functional analyses, which includes a biomechanical examination with a 3D-motion analysis and a motor function test. Only newly diagnosed JIA patients of the German Center for Pediatric and Adolescent Rheumatology (Garmisch-Partenkirchen) will be included and measured for a minimum of three times in this study.

After a successful study ending, pediatric rheumatologists and pediatricians will get an advisory tool, which allows an adequate physical activity promotion of their patient.

The project is funded by the „Innovationsausschuss des Gemeinsamen Bundesausschuss“.

Project partners:

More informations about the project

Prof. Dr. Ansgar Schwirtz | Dr. Josephine Merker


Biomechanical analysis of daily activity of young patients to assess sports capability

The goal of this study is to evaluate children and adolescents of the Inception Cohort of Newly Diagnosed Patients (ICON) with juvenile idiopathic arthritis (JIA) concerning their everyday functionality and their motor skills. The patients` function will be examined with a 3D-motion analysis system and with a motor function test during two hospital stays in the German Center for Pediatric and Adolescent Rheumatology, Garmisch-Partenkirchen. At the end of their hospitalizations they receive individual recommendations on physical activity based on the “Rheuma und Sport Kompass”.

This is a cooperation project between the German Center for Pediatric and Adolescent Rheumatology (Garmisch-Partenkirchen) and the Department of Biomechanics in Sports (TUM).

The project is funded by the „Dr. Melitta Berkemann Stiftung“.

Prof. Dr. Ansgar Schwirtz | Dr. Josephine Merker | Nadja Krumm

History dependence of muscle action

Active force production of skeletal muscles is dependent on muscle length and the instantaneous rate and direction of length change. However, the basic theories on muscle contraction do not account for the fact that muscular force production is dependent upon the muscle’s contractile history, such that when one type of contraction (e. g. isometric) is preceded by another type (e. g. eccentric/ lengthening contraction) distinctly different forces can be achieved.

Keywords: residual force enhancement, stretch-shortening cycle, eccentric muscle action

Denis Holzer, Florian Paternoster, Dr. Wolfgang Seiberl

DFG-Project: Contractile, elastic, and neural mechanisms of muscular performance enhancement during stretch-shortening cycles.

Cooperation: Prof. Dr. Daniel Hahn (Ruhr-Universität Bochum); Prof. Dr. Tobias Siebert (Universität Stuttgart)

Intervention study regarding changes in the kinematic chain and ball speed of elite-youth tennis players

The goal of the project is to evaluate the impact of two different interventions (technique, strength training) regarding changes in the kinematic chain as well as the speed of the ball during a tennis serve. According to data from Craig O’Shannessy (braingametennis.com) a tennis rally of elite players typically end within four shots, highlighting the impact of a good serve. The subjects of this project are consisting of elite-youth tennis players, assigned to a control and an intervention group. For the kinematic chain, the project focuses on the speed and the chronological sequence of the different segments, starting from the bottom to the top of the players. For this purpose, we will use markeless 3D motion tracking provided by SIMI. For the speed of the tennis ball, the peak velocity is considered.

Sarah Reisinger, Prof. Dr. Ansgar Schwirtz, Dr. Florian Paternoster

Without good collaborators, such a project would not be possible. This Team consists of:

This project is funded by the Bundesinstitut für Sportwissenschaft.