TY  - JOUR
A1  - Mueller, Steffen
A1  - Carlsohn, Anja
A1  - Mueller, Juliane
A1  - Baur, Heiner
A1  - Mayer, Frank
T1  - Influence of Obesity on Foot Loading Characteristics in Gait for Children Aged 1 to 12 Years
JF  - PLoS one
N2  - Background Overweight and obesity are increasing health problems that are not restricted to adults only. Childhood obesity is associated with metabolic, psychological and musculoskeletal comorbidities. However, knowledge about the effect of obesity on the foot function across maturation is lacking. Decreased foot function with disproportional loading characteristics is expected for obese children. The aim of this study was to examine foot loading characteristics during gait of normal-weight, overweight and obese children aged 1-12 years. Methods Results Mean walking velocity was 0.95 +/- 0.25 m/s with no differences between normal-weight, overweight or obese children (p = 0.0841). Results show higher foot contact area, arch index, peak pressure and force time integral in overweight and obese children (p< 0.001). Obese children showed the 1.48-fold (1 year-old) to 3.49-fold (10 year-old) midfoot loading (FTI) compared to normal-weight. Conclusion Additional body mass leads to higher overall load, with disproportional impact on the midfoot area and longitudinal foot arch showing characteristic foot loading patterns. Already the feet of one and two year old children are significantly affected. Childhood overweight and obesity is not compensated by the musculoskeletal system. To avoid excessive foot loading with potential risk of discomfort or pain in childhood, prevention strategies should be developed and validated for children with a high body mass index and functional changes in the midfoot area. The presented plantar pressure values could additionally serve as reference data to identify suspicious foot loading patterns in children.
Y1  - 2016
U6  - https://doi.org/10.1371/journal.pone.0149924
SN  - 1932-6203
VL  - 11
SP  - 1710
EP  - 1717
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Mueller, Juliane
A1  - Engel, Tilman
A1  - Mueller, Steffen
A1  - Kopinski, Stephan
A1  - Baur, Heiner
A1  - Mayer, Frank
T1  - Neuromuscular response of the trunk to sudden gait disturbances: Forward vs. backward perturbation
JF  - Journal of electromyography and kinesiology
N2  - The study aimed to analyse neuromuscular activity of the trunk comparing four different perturbations during gait. Thirteen subjects (28 +/- 3 yrs) walked (1 m/s) on a split-belt treadmill, while 4 (belt) perturbations (F1, F2, B1, B2) were randomly applied. Perturbations differed, related to treadmill belt translation, in direction (forward (F)/backward (B)) and amplitude (20 m/s(2) (1)/40 m/s(2) (2)). Trunk muscle activity was assessed with a 12-lead-EMG. EMG-RMS [%] (0-200 ms after perturbation; normalized to RMS of normal gait) was analyzed for muscles and four trunk areas (ventral left/right; dorsal left/right). Ratio of ventral: dorsal muscles were calculated. Muscle onset [ms] was determined. Data analysis was conducted descriptively, followed by ANOVA (post hoc Tukey-Kramer (alpha = 0.05)). All perturbations lead to an increase in EMG-RMS (428 +/- 289%). F1 showed the lowest and F2 the highest increase for the flexors. B2 showed the highest increase for the extensors. Significant differences between perturbations could be observed for 6 muscles, as well as the 4 trunk areas. Ratio analysis revealed no significant differences (range 1.25 (B1) to 1.71 (F2) between stimuli. Muscle response time (ventral: 87.0 +/- 21.7 ms; dorsal: 88.4 +/- 17.0 ms) between stimuli was only significant (p = 0.005) for the dorsal muscles. Magnitude significantly influences neuromuscular trunk response patterns in healthy adults. Regardless of direction ventral muscles always revealed higher relative increase of activity while compensating the walking perturbations. (C) 2016 Elsevier Ltd. All rights reserved.
KW  - Stumbling
KW  - Gait perturbation
KW  - EMG
KW  - Core
KW  - MiSpEx*
Y1  - 2016
U6  - https://doi.org/10.1016/j.jelekin.2016.07.005
SN  - 1050-6411
SN  - 1873-5711
VL  - 30
SP  - 168
EP  - 176
PB  - Elsevier
CY  - Oxford
ER  -