Obesity can damage the joints and increases the risk of developing joint osteoarthritis – which means suffering from joint wear – early on.
The project “Children's KNEEs”, a project of the St. Pölten University of Applied Sciences in collaboration with partner institutions, investigated the effects of overweight on the joints of children and adolescents, developed a physiotherapeutic training program and evaluated this program from a clinical and biomechanical point of view.
Rise of obesity
Approximately 17 percent of children in Austria are overweight and seven percent suffer from obesity – with a rising tendency. Worldwide, the number of people with obesity has nearly tripled over the last three decades; currently about 340 million adults and children are either obese or overweight. With every step, the weight puts strain on the bones and joints, which can lead to joint problems. Studies found a strong connection between obesity and its negative impact on biomechanical processes when moving.
“The combination of increased body weight and biomechanical malalignment in particular can lead to an increased and thus unphysiological joint load in hip and knee joints. When this strain continues over an extended period of time, the risk of early osteoarthritis increases”, says Brian Horsak, Senior Researcher at the Institute of Health Sciences and head of the focus area Motor Rehabilitation at the Center for Digital Health Innovation of the St. Pölten UAS.
The “Children's KNEEs” project is one of the first randomized controlled clinical trials in the world which evaluated the effects of special lower-extremity training for obese children and adolescents from a predominantly biomechanical and clinical perspective.
The results show that the training strengthened the hip muscles of children and adolescents. As a result, they were better at stabilizing their lower-extremity joints while walking or climbing stairs, which means that the training contributed to a normalization of the gait pattern. There was, however, no difference in the self-perception of the participants’ knee function, pain and discomfort.
“Although the training effects for the study are relatively small, they show that the right training is able to reduce the progression of malalignment after a short time”, explains Horsak. According to Barbara Wondrasch, the project's lead physiotherapist, the development of evidence-based and attractive training programs is essential: "Sustainable improvements in the gait pattern can only be achieved if children and adolescents follow the programs over a longer time period”, states Wondrasch.
Relevance to Society
To this day, overweight or obese children and adolescents do not receive any social insurance-funded preventive measures. A key objective of this study was therefore to provide initial data demonstrating that such programs are highly effective and could – in the long term – help reduce costs in the healthcare system by preventing degenerative joint disease.
Project partners were the Danube University Krems (Stefan Nehrer), the Medical University of Vienna (Susanne Greber-Platzer and Richard Crevenna), the University of Vienna (Arnold Baca) and the Orthopedic Hospital Speising (Andreas Kranzl).
3D Gait Analysis: Movement Transformed into Bits and Pixels
The project uses motion capturing technology that allows for a very realistic and detailed digital simulation of motion in bits and pixels. Human movements are transferred to computer-generated 3D models. These then allow a precise analysis of the movement and of the forces acting in the body.
The technology is used at the St. Pölten UAS in the recently established “ReMoCap-Lab” (Laboratory for Capturing Motion and Augmenting Environment in Motor Rehabilitation). It bundles the expertise of the St. Pölten UAS in the fields of rehabilitation, movement analysis, visual analytics, machine learning and virtual/mixed reality. “With the laboratory, we want to actively shape the future in motor rehabilitation. We combine our versatile skills and apply them in an interdisciplinary manner”, explains Horsak.
Over recent years, the St. Pölten UAS has steadily expanded its expertise in the field of gait and movement analysis and set up the St. Pölten Center for Digital Health Innovation in the digital health sector. In several research projects, researchers investigated intelligent gait pattern analysis for the detection of gait disorders, developed a learning software for gait analysis used by physiotherapists and an created an intelligent shoe sole which makes gait disturbances audible.
Publications on the Knee Study
- Effects of a lower extremity exercise program on gait biomechanics and clinical outcomes in children and adolescents with obesity: A randomized controlled trial
- B. Horsak, C. Schwab, A. Baca, S. Greber-Platzer, A. Kreissl, S. Nehrer, M. Keilani, R. Crevenna, A. Kranzl, B.Wondrasch
- The study is available for download (free of charge).
Project “Children‘s KNEEs Study”
The project “Children's KNEEs Study” was subsidised by the Province of Lower Austria in the course of the life-science-call of the Lower Austrian Forschungs- und Bildunges.m.b.H. (NFB, Research and Education). Partners in the project were the Center for Regenerative Medicine and Orthopedics of the Danube University Krems, the University Clinic for Physical Medicine, Rehabilitation and Occupational Medicine and the Department of Pediatrics of the Medical University of Vienna, the Institute of Sports Science of the University of Vienna and the Gait and Movement Analysis Laboratory of the Orthopedic Hospital Speising in Vienna.