TY - INPR A1 - Baur, Heiner A1 - Hoffmann, Jan A1 - Reichmuth, Anne A1 - Müller, Steffen A1 - Mayer, Frank T1 - Influence of carbon fiber foot orthoses on plantar pressure distribution in cycling T2 - Sportverletzung, Sportschaden : Grundlagen, Prävention, Rehabilitation N2 - Background: Several equipment interventions like optimizing seat position or optimizing shoe/insole/pedal interface are suggested to reduce overuse injury in cycling. Data analyzing clinical or biomechanical effects of those interventions is sparse. Foot orthoses out of carbon fiber are one possibility to alter the interface between foot and pedal. The aim of this study was therefore to analyze plantar pressure distribution in carbon fiber foot orthoses in comparison to standard insoles of commercially available cycling shoes. Materials and Methods: 11 pain-free triathletes (Age: 29 +/- 9, 1.77 +/- 0.04 m, 68 5 kg) were tested on a cycle ergometer at 60 and 90 rotations per minute (rpm) at workloads of 200 and 300 Watts. Subjects wore in randomized order a cycling shoe with its standard insole (control condition CO) or the shoe with carbon fiber foot orthoses (Condition CA). Mean peak pressure out of 30 movement cycles were extracted for the total foot and specific foot regions (rear, mid, fore foot (medial, central, lateral) and toe region). Three-factor ANOVAs (factor foot orthoses, rpm, workload) for repeated measures (alpha = 0.05) were used to analyze the main question of a foot orthoses effect on peak in-shoe plantar pressure. Results: Peak pressures in the total foot were in a range of 70-75 kPa for 200 Watts (W) (300 W: 85-110 kPa). The carbon fiber foot orthoses reduced peak pressures by -4,1% compared to the standard insole (p = 0,10). In the foot regions rear(-16,6%, p<0.001), mid (-20,0%, p<0.001) and fore foot (-5.9%, p < 0.03)CA reduced peak pressure compared to CO. In the toe region, peak pressure was higher in CA (+16,2%) compared to CO (p<0,001). The lateral fore foot showed higher peak pressures in CA (+34%) and CO (+59%) compared to medial and central fore foot. Conclusion: Carbon fiber can serve as a suitable material for foot orthoses manufacturing in cycling. Plantar pressures do not increase due to the stiffness of the carbon. Individual customization may have the potential to reduce peak pressure in certain foot areas. KW - Carbon KW - Cycling KW - Foot orthoses KW - In-shoe measurement KW - Plantar Pressure Distribution Y1 - 2012 SN - 0932-0555 VL - 26 IS - 1 SP - 12 EP - 17 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Müller, Juliane A1 - Müller, Steffen A1 - Stoll, Josefine A1 - Rector, Michael V. A1 - Baur, Heiner A1 - Mayer, Frank T1 - Influence of Load on Three-Dimensional Segmental Trunk Kinematics in One-Handed Lifting: A Pilot Study JF - Journal of applied biomechanics N2 - Stability of the trunk is relevant in determining trunk response to different loading in everyday tasks initiated by the limbs. Descriptions of the trunk’s mechanical movement patterns in response to different loads while lifting objects are still under debate. Hence, the aim of this study was to analyze the influence of weight on 3-dimensional segmental motion of the trunk during 1-handed lifting. Ten asymptomatic subjects were included (29 ± 3 y; 1.79 ± 0.09 m; 75 ± 14 kg). Subjects lifted 3× a light and heavy load from the ground up onto a table. Three-dimensional segmental trunk motion was measured (12 markers; 3 segments: upper thoracic area [UTA], lower thoracic area [LTA], lumbar area [LA]). Outcomes were total motion amplitudes (ROM;[°]) for anterior flexion, lateral flexion, and rotation of each segment. The highest ROM was observed in the LTA segment (anterior flexion), and the smallest ROM in the UTA segment (lateral flexion). ROM differed for all planes between the 3 segments for both tasks (P < .001). There were no differences in ROM between light and heavy loads (P > .05). No interaction effects (load × segment) were observed, as ROM did not reveal differences between loading tasks. Regardless of weight, the 3 segments did reflect differences, supporting the relevance of multisegmental analysis. KW - trunk motion KW - kinematic trunk model KW - everyday task KW - MiSpEx* Y1 - 2016 U6 - https://doi.org/10.1123/jab.2015-0227 SN - 1065-8483 SN - 1543-2688 VL - 32 SP - 520 EP - 525 PB - Human Kinetics Publ. CY - Champaign ER - 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 - GEN A1 - Müller, Steffen A1 - Carlsohn, Anja A1 - Müller, Juliane A1 - Baur, Heiner A1 - Mayer, Frank T1 - Influence of Obesity on Foot Loading Characteristics in Gait for Children Aged 1 to 12 Years 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 A total of 10382 children aged one to twelve years were enrolled in the study. Finally, 7575 children (m/f: n = 3630/3945; 7.0 +/- 2.9yr; 1.23 +/- 0.19m; 26.6 +/- 10.6kg; BMI: 17.1 +/- 2.4kg/m(2)) were included for (complete case) data analysis. Children were categorized to normalweight (>= 3rd and <90th percentile; n = 6458), overweight (>= 90rd and <97th percentile; n = 746) or obese (>97th percentile; n = 371) according to the German reference system that is based on age and gender-specific body mass indices (BMI). Plantar pressure measurements were assessed during gait on an instrumented walkway. Contact area, arch index (AI), peak pressure (PP) and force time integral (FTI) were calculated for the total, fore-, mid-and hindfoot. Data was analyzed descriptively (mean +/- SD) followed by ANOVA/Welch-test (according to homogeneity of variances: yes/no) for group differences according to BMI categorization (normal-weight, overweight, obesity) and for each age group 1 to 12yrs (post-hoc Tukey Kramer/Dunnett's C; alpha = 0.05). 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 284 KW - plantar pressure distribution KW - body-mass index KW - prepubescent children KW - overweight children KW - childhood obesity KW - walking KW - speed KW - forces KW - adolescents KW - prevalence Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-90108 ER - TY - JOUR A1 - Müller, Steffen A1 - Carlsohn, Anja A1 - Müller, 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 A total of 10382 children aged one to twelve years were enrolled in the study. Finally, 7575 children (m/f: n = 3630/3945; 7.0 +/- 2.9yr; 1.23 +/- 0.19m; 26.6 +/- 10.6kg; BMI: 17.1 +/- 2.4kg/m(2)) were included for (complete case) data analysis. Children were categorized to normalweight (>= 3rd and <90th percentile; n = 6458), overweight (>= 90rd and <97th percentile; n = 746) or obese (>97th percentile; n = 371) according to the German reference system that is based on age and gender-specific body mass indices (BMI). Plantar pressure measurements were assessed during gait on an instrumented walkway. Contact area, arch index (AI), peak pressure (PP) and force time integral (FTI) were calculated for the total, fore-, mid-and hindfoot. Data was analyzed descriptively (mean +/- SD) followed by ANOVA/Welch-test (according to homogeneity of variances: yes/no) for group differences according to BMI categorization (normal-weight, overweight, obesity) and for each age group 1 to 12yrs (post-hoc Tukey Kramer/Dunnett's C; alpha = 0.05). 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. KW - plantar pressure distribution KW - body-mass index KW - prepubescent children KW - overweight children KW - childhood obesity KW - walking KW - speed KW - forces KW - adolescents KW - prevalence Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0149924 SN - 1932-6203 VL - 11 IS - 2 PB - Public Library of Science CY - Lawrence, Kan. ER - TY - JOUR A1 - Cassel, Michael A1 - Müller, Steffen A1 - Carlsohn, Anja A1 - Baur, Heiner A1 - Jerusel, N. A1 - Mayer, Frank T1 - Intra- and interrater variability of sonographic investigations of patella and achilles tendons JF - Sportverletzung, Sportschaden : Grundlagen, Prävention, Rehabilitation N2 - Background: Clinical examinations of tendon disorders routinely include ultrasound examinations, despite the fact that availability of data concerning validity criteria of these measurements are limited. The present study therefore aims to evaluate the reliability of measurements of Achilles- and Patella tendon diameter and in the detection of structural adaptations. Materials and Methods: In 14 healthy, recreationally active subjects both asymptomatic Achilles (AT) and patella tendons (PT) were measured twice by two examiners in a test-retest design. Besides the detection of anteroposterior (a.p.-) and mediolateral (m.l.-) diameters, areas of hypoechogenicity and neovascularisation were registered. Data were analysed descriptively with calculation of test-retest variability (TRV), intraclass-correlation coefficient (ICC) and Bland and Altman's plots with bias and 95% limits of agreement (LOA). Results: Intra- and interrater differences of AT- and PT-a.p.-diameter varied from 0.2 - 1.2 mm, those of AT- and PT-m.l-diameter from 0.7-5.1 mm. Areas of hypoechogenicity were visible in 24% of the tendons, while 15% showed neovascularisations. Intrarater AT-a.p.-diameters showed sparse deviations (TRV 4.5-7.4%; ICC 0.60-0.84; bias -0.05-0.07 mm; LOA-0.6-0.5 to -1.1 - 1.0 mm), while interrater AT- and PT-m.l.-diameters were highly variable (TRV 13.7-19.7%; ICC 0.11-0.20; bias -1.4-4.3 mm; LOA-5.5-2.7 to -10.5 - 1.9 mm). Conclusion: Our results suggest that the measurement of AT- and PT-a.p.-diameters is a reliable parameter. In contrast, reproducibility of AT- and PT-m.l.-diameters is questionable. The study corroborates the presence of hypoechogenicity and neovascularisation in asymptomatic tendons. KW - ultrasound KW - Achilles tendon KW - Patella tendon KW - intra- and inter-rater variability KW - tendon diameter Y1 - 2012 U6 - https://doi.org/10.1055/s-0031-1281839 SN - 0932-0555 VL - 26 IS - 1 SP - 21 EP - 26 PB - Thieme CY - Stuttgart ER - 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 - CHAP A1 - König, Niklas A1 - Stoll, Andreas A1 - Mayer, Frank A1 - Baur, Heiner T1 - Intrasession reliability of insole in-shoe plantar pressure measurements in different foot areas T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2012 SN - 0195-9131 VL - 44 SP - 941 EP - 941 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Baur, Heiner A1 - Hirschmüller, Anja A1 - Müller, Steffen A1 - Cassel, Michael A1 - Mayer, Frank T1 - Is EMG of the lower leg dependent on weekly running mileage? JF - International journal of sports medicine N2 - Neuromuscular activity of the lower leg is dependent on the task performed, speed of movement and gender. Whether training volume influences neuromuscular activity is not known. The EMG of physically active persons differing in running mileage was analysed to investigate this. 55 volunteers were allocated to a low (LM: < 30 km), intermediate (IM: > 30 km & < 45 km) or high mileage (HM: > 45 km) group according to their weekly running volume. Neuromuscular activity of the lower leg was measured during running (3.33 m.s(-1)). Mean amplitude values for preactivation, weight acceptance and push-off were calculated and normalised to the mean activity of the entire gait cycle. Higher activity in the gastrocnemius group was observed in weight acceptance in LM compared to IM (+30%) and HM (+25%) but lower activity was present in the push-off for LM compared to IM and HM. For the peroneal muscle, differences were present in the push-off where HM showed increased activity compared to IM (+24%) and LM (+60%). The tibial muscle revealed slightly lower activity during preactivation for the high mileage runners. Neuromuscular activity differs during stance between the high and intermediate group compared to low mileage runners. Slight adaptations in neuromuscular activation indicate a more target-oriented activation strategy possibly due to repetitive training in runners with higher weekly mileage. KW - locomotion KW - neuromuscular control KW - running gait KW - training volume Y1 - 2012 U6 - https://doi.org/10.1055/s-0031-1286250 SN - 0172-4622 VL - 33 IS - 1 SP - 53 EP - 57 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Verch, Ronald A1 - Hirschmüller, Anja A1 - Müller, Juliane A1 - Baur, Heiner A1 - Mayer, Frank A1 - Müller, Steffen T1 - Is in-toing gait physiological in children? BT - Results of a large cohort study in 5910 healthy (pre-) school children JF - Gait & posture N2 - Research question: This study aimed to establish reference values in 1-14 year old healthy children and to implement FPA-percentile curves for daily clinical use. Methods: 5910 healthy children performed at least 3 repetitions of barefoot walking over an instrumented walkway using a pressure measurement platform. The FPA [degrees] was extracted and analyzed by age and gender (mean +/- standard deviation; median with percentiles, MANOVA (age, gender) and Wilcoxon-Signed-Rank test for intra-individual side differences (alpha = 0.05). Results: FPA maximum was observed in 2-year-old children and diminished significant until the age of 4 to moderate out-toeing. For ages 5-14, no statistically significant differences in FPA values were present (p > 0.05). MANOVA confirmed age (p < 0.001) and gender (p < 0.001) as significant FPA influencing factors, without combined effect (p > 0.05). In every age group, right feet showed significantly greater out-toeing (p < 0.05). Significance: Percentile values indicate a wide FPA range in children. FPA development in young children shows a spontaneous shift towards moderate external rotation (age 2-4), whereby in-toeing <= 1-5 degrees can be present, but can return to normal. Bilateral in-toeing after the age of four and unilateral in-toeing after the age of seven should be monitored. KW - Foot progression angle KW - Children KW - In-toeing KW - Out-toeing KW - Gait Y1 - 2018 U6 - https://doi.org/10.1016/j.gaitpost.2018.08.019 SN - 0966-6362 SN - 1879-2219 VL - 66 SP - 70 EP - 75 PB - Elsevier CY - Clare ER -