- Influence of a two to six year physical education intervention on scholastic performance; The CHAMPS study-DK. [Journal Article]
- SJScand J Med Sci Sports 2017 Apr 27
- CONCLUSIONS: No significant differences were observed between intervention and control schools for scholastic performance. Importantly, there were no negative effects of additional PE on scholastic outcomes, despite more PE and longer school days for intervention children. This article is protected by copyright. All rights reserved.
- Center of Pressure Profiles in Unilateral Compared to Bilateral End-Stage Ankle Osteoarthritis Patients. [Journal Article]
- JOJ Orthop Res 2017 Apr 27
- Ankle osteoarthritis compromises ankle joint stability in regards to static balance. Unilateral and bilateral osteoarthritis patients often exhibit different limb-loading patterns during static balan...
Ankle osteoarthritis compromises ankle joint stability in regards to static balance. Unilateral and bilateral osteoarthritis patients often exhibit different limb-loading patterns during static balance tasks. Symmetrical loading has been posited to improve balance performance. Therefore, the purpose of this study was to quantify balance performance in both ankle osteoarthritis patient groups. Twenty-two unilateral and twenty-one bilateral ankle osteoarthritis patients performed three 10-second quiet standing trials with their feet together. Ground reaction force data was collected from force platforms with one under each foot. Center of pressure excursion in the anteroposterior and mediolateral directions as well as the resultant center of pressure were calculated using custom Matlab software. A 2 × 2 repeated measures ANOVA with Cohen's d were used to analyze the differences between groups (unilateral vs. bilateral) and between limbs (affected vs. unaffected) (α = 0.05). No significant differences were found between limbs or groups in either the anteroposterior or mediolateral direction for any measured variable. Though not statistically different, moderate to large effect sizes were observed for mean resultant distance between unilateral and bilateral (d = 0.096, d: 1.0) as well as anteroposterior excursion (p = 0.077, d: 1.731) and mean velocity (p = 0.084, d: 1.50) between affected and unaffected limbs. These large effect sizes suggested clinically relevant differences may exist, particularly in the anteroposterior direction. These findings may suggest that center of pressure is a better measure of postural strategy while center of mass measures may be more representative of postural steadiness. This article is protected by copyright. All rights reserved.
- Novel bone surrogates for cranial surgery training. [Journal Article]
- JMJ Mech Behav Biomed Mater 2017 Apr 19; 72:49-51
- Parietal graft lifts are trained on human or animal specimens or are directly performed on patients without extensive training. In order to prevent harm to the patient resulting from fast rotating ma...
Parietal graft lifts are trained on human or animal specimens or are directly performed on patients without extensive training. In order to prevent harm to the patient resulting from fast rotating machinery tools, the surgeon needs to apply appropriate forces. Realistic haptics are essential to identify the varying parietal bone layers and to avoid a penetration of the brain. This however, requires experience and training. Therefore, in this study, bone surrogate materials were evaluated with the aim to provide an anatomically correct artificial skull cap with realistic haptic feedback for graft lift training procedures. Polyurethane composites made of calcium carbonate and calcium phosphate were developed and were used to create customized bone surrogates, imitating both cancellous and cortical bone. Mechanical properties of these surrogates were validated for drilling, milling and sawing by comparison with human parietal bones. For that, surgical tool tips were automatically inserted into artificial and human bones in a customized test bench and the maximum axial insertion forces were analyzed. Axial tool insertion measurements in human parietal bones resulted in mean maximum forces of 1.8±0.5N for drilling, 1.7±0.3N for milling and 0.9±0.1N for sawing. Calcium carbonate-based materials achieved higher forces than the human bone for drilling and milling, and lower forces for sawing. The calcium phosphate-based bone surrogates showed comparable axial insertions forces for all investigated tools and were identified as a suitable surrogate for drilling (p=0.87 and 0.41), milling (p=0.92 and 0.63) and sawing (p=0.11 and 0.76) of the cortical layer and the cancellous bone, respectively. In conclusion, our findings suggest, that a suitable material composition for artificial parietal bones has been identified, mimicking the properties of human bone during surgical machinery procedures. Thus, these materials are suitable for surgical training and education in simulator training.
- The effect of equiaxial stretching on the osteogenic differentiation and mechanical properties of human adipose stem cells. [Journal Article]
- JMJ Mech Behav Biomed Mater 2017 Apr 13; 72:38-48
- Although mechanical cues are known to affect stem cell fate and mechanobiology, the significance of such stimuli on the osteogenic differentiation of human adipose stem cells (hASCs) remains unclear....
Although mechanical cues are known to affect stem cell fate and mechanobiology, the significance of such stimuli on the osteogenic differentiation of human adipose stem cells (hASCs) remains unclear. In this study, we investigated the effect of long-term mechanical stimulation on the attachment, osteogenic differentiation and mechanical properties of hASCs. Tailor-made, pneumatic cell stretching devices were used to expose hASCs to cyclic equiaxial stretching in osteogenic medium. Cell attachment and focal adhesions were visualised using immunocytochemical vinculin staining on days 3 and 6, and the proliferation and alkaline phosphatase activity, as a sign of early osteogenic differentiation, were analysed on days 0, 6 and 10. Furthermore, the mechanical properties of hASCs, in terms of apparent Young's modulus and normalised contractility, were obtained using a combination of atomic force microscopy based indentation and computational approaches. Our results indicated that cyclic equiaxial stretching delayed proliferation and promoted osteogenic differentiation of hASCs. Stretching also reduced cell size and intensified focal adhesions and actin cytoskeleton. Moreover, cell stiffening was observed during osteogenic differentiation and especially under mechanical stimulation. These results suggest that cyclic equiaxial stretching modifies cell morphology, focal adhesion formation and mechanical properties of hASCs. This could be exploited to enhance osteogenic differentiation.
- Biological impacts of glyphosate on morphology, embryo biomechanics and larval behavior in zebrafish (Danio rerio). [Journal Article]
- CChemosphere 2017 Apr 21; 181:270-280
- All of these days, residues of herbicides such as glyphosate are widely distributed in the environment. The ubiquitous use of glyphosate has drawn extensive attention to its toxicity as an organic po...
All of these days, residues of herbicides such as glyphosate are widely distributed in the environment. The ubiquitous use of glyphosate has drawn extensive attention to its toxicity as an organic pollutant. In this study, we employed larval zebrafish as an animal model to evaluate the effect of different concentrations of glyphosate on early development via morphological, biomechanics, behavioral and physiological analyses. Morphological results showed that an obvious delay occurred in the epiboly process and body length, eye and head area were reduced at concentrations higher than 10 mg/L. The expression of ntl (no tail) shortened and krox20 (also known as Egr2b, early growth response 2b) changed as the glyphosate concentration increased, but there was no change in the expression of shh (sonic hedgehog). In addition, biomechanical analysis of the elasticity of chorion indicated that treated embryos' surface tension was declined. Furthermore, a 48-h locomotion test revealed that embryonic exposure to glyphosate significantly elevated locomotor activities, which is probably attributed to motoneuronal damage. The decreased surface tension of chorion and the increased locomotive activities may contribute to the hatching rates after glyphosate treatment. Our study enriches the researches of evaluating glyphosate toxicity and probablely plays a warning role in herbicides used in farming.
- [Ligamentun teres of the hip. Bibliographic revision]. [Review]
- AOActa Ortop Mex 2016 Sep-Oct; 30(5):267-271
- The role and function of the ligamentum teres has drawn our attention in the last years due to the increasing and performance in hip arthroscopy, few is written in the literature, this is why we prop...
The role and function of the ligamentum teres has drawn our attention in the last years due to the increasing and performance in hip arthroscopy, few is written in the literature, this is why we proposed to perform and assessed a review on the current literature of the anatomy, function, diagnose and rupture of the ligamentum teres of the hip.
- A new in vitro spine test rig to track multiple vertebral motions under physiological conditions. [Journal Article]
- BTBiomed Tech (Berl) 2017 Apr 27
- In vitro pure moment spine tests are commonly used to analyse surgical implants in cadaveric models. Most of the tests are performed at room temperature. However, some new dynamic instrumentation dev...
In vitro pure moment spine tests are commonly used to analyse surgical implants in cadaveric models. Most of the tests are performed at room temperature. However, some new dynamic instrumentation devices and soft tissues show temperature-dependent material properties. Therefore, the aim of this study is to develop a new test rig, which allows applying pure moments on lumbar spine specimens in a vapour-filled chamber at body temperature. As no direct sight is given in the vapour-filled closed chamber, a magnetic tracking (MT) system with implantable receivers was used. Four human cadaveric lumbar spines (L2-L5) were tested in a vapour atmosphere at body temperature with a native and rigid instrumented group. In conclusion, the experimental set-up allows vertebral motion tracking of multiple functional spinal units (FSUs) in a moisture environment at body temperature.
- Standardized error severity score (ESS) ratings to quantify risk associated with child restraint system (CRS) and booster seat misuse. [Journal Article]
- TITraffic Inj Prev 2017 Apr 27; :0
- CONCLUSIONS: Collectively, findings indicate that standardized ESS ratings are useful for estimating injury risk potential associated with real world CRS and booster seat installation errors.
- LncRNA-H19 Modulates Wnt/β-catenin Signaling by Targeting Dkk4 in Hindlimb Unloaded Rat. [Journal Article]
- OSOrthop Surg 2017 Apr 26
- CONCLUSIONS: Our findings demonstrated that low expression of H19, induced by mechanical unloading, leads to development of DOP through inhibition of Wnt signaling by promoting Dkk4 expression.
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- Medial shoe-ground pressure and specific running injuries: A 1-year prospective cohort study. [Journal Article]
- JSJ Sci Med Sport 2017 Apr 15
- CONCLUSIONS: Runners displaying a more medial pressure during stance phase at baseline sustained a greater amount of APM-injuries compared to those displaying a lateral shod pressure during stance phase. Prospective studies including a greater amount of runners are needed to confirm this relationship.