Training Induced Reduction of Lower-limb Joint Loads During Locomotion in Obese Children

The Effects of a Strength and Neuromuscular Exercise Programme for the Lower Extremity on Knee Load, Pain and Function in Obese Children and Adolescents: a Randomised, Single-blinded Controlled Trial

Childhood obesity is one of the most critical and accelerating health challenges throughout the world. It is a major risk factor for developing varus/valgus misalignments of the knee joint. The combination of misalignment at the knee and excess body mass may result in increased joint stress and damage to articular cartilage. A training programme, which aims at developing a more neutral alignment of the trunk and lower limbs during movement tasks may be able to reduce knee loading during locomotion. Despite the large number of guidelines for muscle strength training and neuromuscular exercises that exists, most are not specifically designed to target the obese children and adolescent demographic. The purpose of this study is to evaluate a training programme which combines strength and neuromuscular exercises specifically designed to the needs and limitations of obese children and adolescents and analyse the effects of the training programme from a biomechanical and clinical point of view.

Changes of function and strength of the targeted muscle groups will be assessed by a physical therapist. Therefore, a hand-dynamometer to investigate differences in muscle strength will be used.

The Austria-German version of the Knee Injury and Osteoarthritis Outcome Score will be used to assess the participants' opinion about their knee.

Kinematics and external joint moments for the sagittal and frontal plane for hip, knee and ankle joints as well as spatio-temporal parameters will be assessed by 3D gait analysis during walking and stair climbing.

Adherence will be considered as the percentage of actually completed sessions during the intervention period among the number of intended exercise sessions.

The influence of the training programme on aerobic fitness will be assessed by submitting the participants to a symptom-limited cardiopulmonary exercise testing on a cycle ergometer.

The anthropometric evaluation will include the measurement of height, weight, waist circumference, hip circumference, waist-to-hip ratio and calculation of the body mass index.

Body composition parameters will include, fat mass, fat free mass, total body water, body cell mass, extracellular mass and lean body mass.

The nutritional status will be assessed using the 24-hour recall method. This method records the daily, self-reported consumption of food-intake. In combination with a standardized nutritional food programme (EBISpro) the intake of macro- and micronutrients will be estimated.

The AD-EVA test inventory as well as the Child Behavior Checklist (CBCL/4 -18 ) will be used to determine the psychological status of the participants.

Quantification of routine blood sampling in obese patients and growth hormones and inflammation will be performed from venous blood samples in the Laboratory of the Department of Pediatrics and Adolescent Medicine at the Medical University of Vienna.

Inclusion Criteria: Male or female Age: 10 -18 years BMI greater than the 97th percentile Availability: can participate in two exercises session per week for a period of 12 weeks Exclusion Criteria: Present syndromes Chronic joint diseases, osteoarthritic surgery or Neuro-motor diseases

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Horsak B, Schwab C, Baca A, Greber-Platzer S, Kreissl A, Nehrer S, Keilani M, Crevenna R, Kranzl A, Wondrasch B. Effects of a lower extremity exercise program on gait biomechanics and clinical outcomes in children and adolescents with obesity: A randomized controlled trial. Gait Posture. 2019 May;70:122-129. doi: 10.1016/j.gaitpost.2019.02.032. Epub 2019 Feb 27.

Horsak B, Artner D, Baca A, Pobatschnig B, Greber-Platzer S, Nehrer S, Wondrasch B. The effects of a strength and neuromuscular exercise programme for the lower extremity on knee load, pain and function in obese children and adolescents: study protocol for a randomised controlled trial. Trials. 2015 Dec 23;16:586. doi: 10.1186/s13063-015-1091-5.