16 research outputs found
Prediction of Anthropometric Foot Characteristics in Children
BACKGROUND: The establishment of growth reference values is needed in pediatric practice where pathologic conditions can have a detrimental effect on the growth and development of the pediatric foot. This study aims to use multiple regression to evaluate the effects of multiple predictor variables (height, age, body mass, and gender) on anthropometric characteristics of the peripubescent foot. METHODS: Two hundred children aged 9 to 12 years were recruited, and three anthropometric measurements of the pediatric foot were recorded (foot length, forefoot width, and navicular height). RESULTS: Multiple regression analysis was conducted, and coefficients for gender, height, and body mass all had significant relationships for the prediction of forefoot width and foot length (P or = 0.7). The coefficients for gender and body mass were not significant for the prediction of navicular height (P > or = .05), whereas height was (P < or = .05).CONCLUSIONS: Normative growth reference values and prognostic regression equations are presented for the peripubescent foot
Anthropometric Foot Structure of Peripubescent Children with Excessive versus Normal Body Mass
BACKGROUND: A variety of musculoskeletal problems have been associated with excessive body mass in children, including structural foot problems. METHODS: Two hundred children aged 9 to 12 years were recruited to evaluate the effect of body mass on foot structure. Three reliable anthropometric measures were recorded: foot length, forefoot width, and navicular height. RESULTS: Following independent sample t test analysis of the data, significant differences were found for the three anthropometric variables when children with normal body mass were compared with those with excessive body mass. The research indicates that foot length and width increase with body mass, whereas navicular height drops. CONCLUSIONS: Excessive body mass affects the discrete anthropometric structure of the peripubescent foot. With the growing concern about childhood obesity, further research is essential to develop a comprehensive understanding of the issues identified and to quantify the findings presented here
Enhancement of electrical conductivity of carbon nanotube sheets through copper addition using reduction expansion synthesis
17 USC 105 interim-entered record; under review.The article of record as published may be found at https://doi.org/10.1016/j.materresbull.2020.110969The ability to translate the high electrical conductivity of individual carbon nanotubes to bulk carbon nanotube
materials has proven challenging. In this work, we present the use of reduction expansion synthesis to attach
copper nanoparticles to the surface of tubes within carbon nanotube sheets. Those metallic particulates serve as a
link between the tube strands in the carbon nanotube network and promote an increase in electrical con ductivity. The reduction expansion synthesis process included the introduction of copper salts into the carbon
nanotube structure and thermal treatment of the sheets in the presence of urea, under inert atmospheres. As a
result, through the reduction process promoted by the urea decomposition byproducts, copper nanoparticles
directly nucleate on the nanotube surface. The enhanced conductive nature of the Cu-carbon nanotube sheets
observed establishes reduction expansion synthesis as an inexpensive, rapid and scalable alternative to increase
the electrical conductivity of bulk carbon nanotube materials
Defining phases for the sit-to-walk movement
Objective. To define phases of the sit-to-walk movement and test their consistency in a normal population. Design. An observational study of thirteen healthy volunteers. Background. Moving from sitting to walking is a daily activity that may present difficulty for some populations in terms of control and stability. Methods. The movement was partitioned into phases according to changes in ground reaction forces and peak velocity of the total body centre of mass. Consistency of each phase duration was assessed. Results. Four phases of sit-to-walk were defined; flexion momentum, extension, unloading and stance. ICC scores for phase duration ranged from 0.54 (extension) to 0.81 (stance). Conclusions. This is the first study to define distinct phases of the sit-to-walk movement. There was moderate to good consistency for phase duration
Timing phases of the sit-to-walk movement: validity of a clinical test
The sit-to-walk (STW) movement is a functional task that challenges balance and co-ordination. There is a paucity of literature investigating the phases of this movement and its significance in a clinical rehabilitation context. Measuring phases of this movement may provide clinically applicable data for screening subjects for mobility problems and evaluating interventions. Fifty-six subjects from three groups; young (65 years old) and elderly at risk of falling (EARF), performed the STW movement freely from a chair. Switches placed on the backrest, chair seat and two on the floor identified the times of movement events: onset, seat-off, swing-off and stance-off. These events defined three phases: flexion, extension and stance. Timing of events and phase duration data derived from this switch system were correlated with those taken from a three-dimensional motion analysis system. All switch events closely matched the motion analysis events with ICC (model 2.1) scores ranging from 0.93 to 1.00. Duration of all STW phases were statistically longer in the EARF group compared to both unimpaired groups (p < 0.05). Data from the four switch configuration demonstrated excellent concurrent validity when associated with data from a three-dimensional motion analysis system in identifying the phases of STW. Measurement of the phases of the STW task has potential in screening those at risk of falling and informing care strategies to prevent falls