Effects of a lower extremity exercise program on gait biomechanics and clinical outcomes in children and adolescents with obesity: A randomized controlled trial.

BACKGROUND: Research highlights the detrimental effects of obesity on gait biomechanics and the accompanied risk of lower-extremity skeletal malalignments, increased joint stress, pain and discomfort. Individuals with obesity typically show increased knee valgus angles combined with an increased step width. Accompanying muscular dysfunctions impede their ability to compensate for these alterations, especially in the frontal plane. To date, no studies are available, which evaluated the potential effects of an exercise program (EP) in reducing these unfavorable biomechanical changes. RESEARCH QUESTIONS: Is a 12-week EP, which includes hip abductor and knee extensor strength exercises and fosters dynamic knee alignment, effective in positively altering gait biomechanics in children and adolescents with obesity? METHODS: This study was a randomized controlled trial having children and adolescents with obesity assigned to an EP (n = 19) or control (n = 16) group. Pain, self-rated knee function, muscle strength and 3D gait analysis during walking and stair climbing were evaluated. RESULTS: Results indicate that the EP was able to increase muscular strength especially in the hip abductors. In addition, children from the EP group walked with less maximum hip adduction and reduced pelvic drop during weight acceptance at follow-up. No changes were present in self-rated knee function, pain or discomfort. SIGNIFICANCE: Even though effects were small, results indicate that an EP is an effective short-term possibility to counteract the progressive development of biomechanical malalignments of the lower extremity. Clinical parameters indicated that the program was feasible. Nonetheless, low adherence highlights the need to develop more attractive programs. CLINICAL TRIALS REG. NO: clinicaltrials.gov (NCT02545764).

Reliability of joint kinematic calculations based on direct kinematic and inverse kinematic models in obese children.

BACKGROUND: In recent years, the reliability of inverse (IK) and direct kinematic (DK) models in gait analysis have been assessed intensively, but mainly for lean populations. However, obesity is a growing issue. So far, the sparse results available for the reliability of clinical gait analysis in obese populations are limited to direct kinematic models. Reliability error-margins for inverse kinematic models in obese populations have not been reported yet. RESEARCH QUESTIONS: Is there a difference in the reliability of IK models compared with a DK model in obese children? Are there any differences in the joint kinematic output between IK and DK models? METHODS: A test-retest study was conducted using three-dimensional gait analysis data from two obese female and eight obese male participants from an earlier study. Data were analyzed using a DK model and two OpenSim-based IK models. Test-retest reliability was compared by calculating the Standard Error of Measurement (SEM) along with similar absolute reliability measures. A Friedman Test was used to assess whether there were any significant differences in the reliability between the models. Kinematic output of the models was compared by using Statistical Parametric Mapping (SPM). RESULTS: No significant differences were found in the reliability between the DK and IK models. The SPM analysis indicated several significant differences between both IK models and the DK approach. Most of these differences were continuous offsets. SIGNIFICANCE: Reliability values showed clinically acceptable error-margins and were comparable between all models. Therefore, our results support the careful use of IK models in overweight or obese populations, e.g. for musculoskeletal modelling studies. The inconsistent kinematic output can mainly be explained by different model conventions and anatomical segment coordinate frame definitions.

A physiotherapy-directed occupational health programme for Austrian school teachers: a cluster randomised pilot study.

BACKGROUND: Although physiotherapists have long advocated workplace health, school teachers have not traditionally been a focus of study by these professionals. However, classroom teaching contributes to a range of occupational health issues related to general health as well as ergonomics that can be prevented or addressed by physiotherapists. OBJECTIVES: To undertake a pilot study to explore the potential effects of a physiotherapy-directed occupational health programme individualised for school teachers, develop study methodology and gather preliminary data to establish a 'proof of concept' to inform future studies. DESIGN: Cluster randomised pilot study using a convenience sample. SETTING: Eight Austrian regional secondary schools. PARTICIPANTS: Schools and their teachers were recruited and allocated to an intervention group (IG, n=26 teachers) or a control group (CG, n=43 teachers). Teachers were eligible to participate if they reported no health issues that compromised their classroom responsibilities. INTERVENTIONS: The IG participated in an individualised physiotherapy-directed occupational health programme (six 30-minute sessions) related to ergonomics and stress management conducted over a 5-month semester. The CG had a pseudo-intervention of one oral education session. MAIN OUTCOME MEASURES: Primary outcomes included scores from the physical and mental components and health transition item of the Short-Form-36 Health Survey questionnaire (SF-36), and emotional well-being and resistance to stress items from the work-related behaviour and experience patterns questionnaire. Data were collected before and after one semester. RESULTS: The primary outcome measure, the SF-36 physical component score, showed a reduction in the CG and no change in the IG, meaning that the CG deteriorated over the study semester while the IG did not show any change. CONCLUSIONS: A physiotherapy-directed occupational health programme may prevent deterioration of physical health of school teachers in one semester (proof of concept). This pilot study provided valuable information to inform the design of replication and extension studies related to this work.