TY  - JOUR
A1  - Müller, Juliane
A1  - Müller, Steffen
A1  - Baur, Heiner
A1  - Mayer, Frank
T1  - Intra-individual gait speed variability in healthy children aged 1-15 years
JF  - Gait & posture
N2  - Introduction: Gait speed is one of the most commonly and frequently used parameters to evaluate gait development. It is characterized by high variability when comparing different steps in children. The objective of this study was to determine intra-individual gait speed variability in children.
 Methods: Gait speed measurements (6-10 trials across a 3 m walkway) were performed and analyzed in 8263 children, aged 1-15 years. The coefficient of variation (CV) served as a measure for intra-individual gait speed variability measured in 6.6 +/- 1.0 trials per child. Multiple linear regression analysis was conducted to evaluate the influence of age and body height on changes in variability. Additionally, a subgroup analysis for height within the group of 6-year-old children was applied.
 Results: A successive reduction in gait speed variability (CV) was observed for age groups (age: 1-15 years) and body height groups (height: 0.70-1.90 m). The CV in the oldest subjects was only one third of the CV (CV 6.25 +/- 3.52%) in the youngest subjects (CV 16.58 +/- 10.01%). Up to the age of 8 years (or 1.40 m height) there was a significant reduction in CV over time, compared to a leveling off for the older (taller) children.
 Discussion: The straightforward approach measuring gait speed variability in repeated trials might serve as a fundamental indicator for gait development in children. Walking velocity seems to increase to age 8. Enhanced gait speed consistency of repeated trials develops up to age 15.
KW  - Development
KW  - Gait
KW  - Speed
KW  - Variability
KW  - Children
Y1  - 2013
U6  - https://doi.org/10.1016/j.gaitpost.2013.02.011
SN  - 0966-6362
SN  - 1879-2219
VL  - 38
IS  - 4
SP  - 631
EP  - 636
PB  - Elsevier
CY  - Clare
ER  - 
TY  - JOUR
A1  - König, Niklas
A1  - Reschke, Antje
A1  - Wolter, Martin
A1  - Müller, Steffen
A1  - Mayer, Frank
A1  - Baur, Heiner
T1  - Plantar pressure trigger for reliable nerve stimulus application during dynamic H-reflex measurements
JF  - Gait & posture
N2  - In dynamic H-reflex measurements, the standardisation of the nerve stimulation to the gait cycle is crucial to avoid misinterpretation due to altered pre-synaptic inhibition. In this pilot study, a plantar pressure sole was used to trigger the stimulation of the tibialis nerve with respect to the gait cycle. Consequently, the intersession reliability of the soleus muscle H-reflex during treadmill walking was investigated.
 Seven young participants performed walking trials on a treadmill at 5 km/h. The stimulating electrode was placed on the tibial nerve in the popliteal fossa. An EMG was recorded from the soleus muscle. To synchronize the stimulus to the gait cycle, initial heel strike was detected with a plantar pressure sole. Maximum H-reflex amplitude and M-wave amplitude were obtained and the Hmax/Mmax ratio was calculated.
 Data reveals excellent reliability, ICC = 0.89. Test-retest variability was 13.0% (+/- 11.8). The Bland-Altman analysis showed a systematic error of 2.4%.
 The plantar pressure sole was capable of triggering the stimulation of the tibialis nerve in a reliable way and offers a simple technique for the evaluation of reflex activity during walking.
KW  - Monosynaptic reflexes
KW  - Reflex reproducibility
KW  - Treadmill walking
Y1  - 2013
U6  - https://doi.org/10.1016/j.gaitpost.2012.09.021
SN  - 0966-6362
VL  - 37
IS  - 4
SP  - 637
EP  - 639
PB  - Elsevier
CY  - Clare
ER  -