Nerve cross-sectional area in extremes of age

Introduction: Nerve cross-sectional area reference values have been reported for many nerves, but there have been few studies in pediatric and geriatric populations. This study was conducted to determine the influence of age on nerve cross-sectional area. Methods: Thirty-two children (3 months to 16 years) and 20 geriatric adults (67–92 years) without known neurologic conditions underwent bilateral ultrasound to measure the area of the following nerves: median at the wrist and forearm; ulnar at the wrist and elbow; radial in the spiral groove; sciatic in the distal thigh; fibular at the knee; tibial at the knee and ankle; and sural at the ankle. Results: In general, nerve cross-sectional area increased with age. Nerve size correlated most closely with age, but a correlation was also seen with body mass index. Conclusions: Nerve cross-sectional area increases with age, which is important to note when using ultrasound to evaluate children and geriatric patients. Muscle Nerve 47: 890–893, 2013     

Validity and reliability of nerve and muscle ultrasound

Introduction: Nerve and muscle ultrasound has been studied in several conditions, but validity and reliability have not been assessed systematically. Methods: Nerve cross‐sectional area and muscle thickness were measured ultrasonographically at several sites in 4 cadavers, which were then dissected, and actual measurements were obtained. To assess intrarater and interrater reliability, between 3 and 5 ultrasonographers, with varying experience levels, made repeated measurements on healthy volunteers. Results: Correlation coefficients for nerve and muscle validity were >0.968 (P < 0.001), and for intrarater reliability were >0.901 (P < 0.001) for still and real‐time images. Correlation coefficients for interrater reliability were more varied, but for still images they were all significant at the P < 0.001 (0.542–0.998) level, and for real‐time images they were significant at the P < 0.05 level for half the sites (0.243–0.981). Conclusion: Overall, nerve and muscle ultrasound is a valid and reliable diagnostic imaging technique. Muscle Nerve, 2013     

Measurement of the mechanical properties of soccer balls using digital image correlation method

There are some features for an approved soccer ball by Fédération Internationale de Football Association (FIFA), such as properties of the material, mass, pressure, stitches, etc. Many of these features up to now have been studied; nevertheless, the mechanical properties of the soccer balls to date have not been well reported. The chief purposes of the current research, hence, were to calculate the mechanical properties of the soccer balls, i.e., linear elastic, nonlinear hyperelastic, and viscoelastic, at two different sizes, including 4 and 5 which are using for football and futsal, respectively. To do this, compressive and stress-relaxation loading were applied to 38 approved soccer balls to quantify the stress–strain as well as reduced relaxation function of the balls. The strain/displacement of the balls was also measured via a high-speed camera using Digital Image Correlation (DIC) technique. The results revealed the mean elastic modulus of 66 and 67 kPa for the football and futsal balls, respectively. In addition, the maximum stresses of the football and futsal balls were 16 and 13 kPa, respectively. The nonlinear mechanical response of the soccer balls were analyzed using hyperelastic material models, i.e., Mooney-Rivlin and Ogden. A Finite Element (FE) model was also developed to verify the hyperelastic data compared to the experimental ones and, remarkably, the numerical data were in consistence with the experimental data. Finally, Prony- series was employed to quantify the viscoelastic properties of the balls. During the game, a soccer ball can reach to a speed of 210 km/h that can damage the human eye; however, the injury detail still has not been studied.     

Patient and Parent Perspectives of Adolescent Laparoscopic Adjustable Gastric Banding (LAGB)

Background

Adolescent obesity is a significant global health challenge and severely obese adolescents commonly experience serious medical and psychosocial challenges. Consequently, severe adolescent obesity is increasingly being treated surgically. The limited available research examining the effectiveness of adolescent bariatric surgery focuses primarily on bio-medical outcomes. There is a need for a more comprehensive understanding of the behavioural, emotional and social factors which affect adolescents’ and parents’ experience of weight loss surgery.

Methods

Patient and parents’ perspectives of adolescent LAGB were examined using a qualitative research methodology. Individual, semi-structured interviews were conducted with eight adolescent patients and five parents. Thematic analysis was used to identify key themes in the qualitative data.

Results

Patients and parents generally considered adolescent laparoscopic adjustable gastric banding (LAGB) to be a life-changing experience, resulting in physical and mental health benefits. Factors considered to facilitate weight loss following surgery included parental support and adherence to treatment guidelines. Many adolescents reported experiencing surgical weight loss stigma and challenging interpersonal outcomes after weight loss for which they felt unprepared.

Conclusions

Patients and parents perceived LAGB positively. There are opportunities to improve both the experience and outcomes of adolescent LAGB through parental education and enhancements to surgical aftercare programmes.

     

Measuring salivary cortisol in studies of child development: watch out--what goes in may not come out of saliva collection devices

Technical advances that enable the noninvasive measurement of biomarkers in saliva have spawned a generation of investigations that integrate biological variables into behavioral and developmental research. This study examines whether the collection of saliva, using common absorbent devices compromises the measurement of cortisol when saliva specimens have low sample volume. Within subjects (n = 20), saliva samples were prepared to experimentally represent a gradient of lower to higher sample volumes. One aliquot was immediately frozen (no treatment control) and the remaining aliquots were absorbed ("collected") using one of three collection techniques employed in studies of child development (e.g., braided cotton dental rope, Salivette cotton pledget, or hydrocellulose microsponge). The sample volume recovered from each device relative to the initial volume available to be absorbed, and cortisol level recovered from each device relative to the untreated-control condition were measured. Results reveal that for certain collection devices (1) the percent volume recovered is related to the initial volume available to be absorbed, (2) a substantial percentage of cortisol in saliva specimens can remain in absorbent material, and (3) the percent of cortisol recovered can be associated with the initial sample volume available to be absorbed. When research participants, such as young children, produce low volume saliva specimens, some absorbent devices may have the potential to introduce error variance in the measurement of salivary cortisol.     

Caffeine Transiently Affects Food Intake at Breakfast

Background

Caffeine is frequently added to dietary supplements with claims it facilitates weight loss.