The effect of gender, age, and lateral dominance on arch height and arch stiffness

BACKGROUND

Arch structure is known to vary widely. However, it may be linked to intrinsic factors such as gender, age, and lateral dominance. Understanding the association between these factors and arch structure may be useful in understanding injury biases that exist between individuals with different foot types.

METHODS

The foot structure of 145 subjects, 68 men and 77 women (18 to 65 years) was examined in this study. The arch height index, a measure of dorsal height normalized to foot length, and arch stiffness of both feet were measured in each subject. Comparisons of both arch height and arch stiffness were made between genders and between the dominant and nondominant feet. In addition, the relationship between both arch height and stiffness and age was examined.

RESULTS

There was no difference between the arch height index of men and women; however, the arches in women were significantly less stiff (p = 0.00). There were no statistically significant relationships between increasing age and either arch height index or stiffness. The within-subject comparisons showed that the dominant foot had a significantly higher arch height index than the nondominant foot (p = 0.00). However, arch stiffness was not different between sides. There was a significant, but weak, relationship between arch height index and arch stiffness (p = 0.00, R2 = 0.09) with a higher arch height index corresponding to a stiffer arch.

CONCLUSION

Understanding differences in arch structure may lend insight into the predilection for injury between genders, with increasing age, and between sides of a given subject.

The relationship between forefoot, midfoot, and rearfoot static alignment in pain-free individuals

STUDY DESIGN

Correlational study.

OBJECTIVES

To determine whether, and to what degree, a relationship exists between forefoot angle and weight-bearing midfoot and rearfoot position.

BACKGROUND

There have been conflicting reports with regard to the degree to which the structure of the foot may influence the function. The influence of forefoot structure on weight-bearing midfoot and rearfoot position has not been extensively investigated.

METHODS AND MEASURES

Fifty-one healthy subjects participated in this study (26 male and 25 female). Forefoot angle was measured in prone as varus (positive numbers), neutral (0), or valgus (negative numbers). Navicular drop was measured from subtalar joint neutral to unilateral standing relaxed. Rearfoot angle was measured in relaxed single-limb stance as the angle between a line that bisected the calcaneus and a line that bisected the lower third of the leg. The relationships between forefoot angle and navicular drop, and between forefoot angle and relaxed rearfoot angle, were investigated. The same relationships were also investigated in the neutral forefoot subgroup when the sample was divided in 3 subgroups based on 1 standard deviation of forefoot angle.

RESULTS

There is a significant relationship between forefoot angle and relaxed rearfoot angle (r = 0.52, P < .001), as well as between forefoot angle and navicular drop (r = 0.55, P < .001), in the whole sample (n = 51). Average degrees of forefoot angle in the neutral subgroup (between 1.0 degree and 8 degrees of varus) are not associated with predictable positions of relaxed rearfoot angle (r = 0.19, P = .24) or navicular drop (r = 0.01, P = .96).

CONCLUSIONS

Based on the results of this study, there is a significant relationship between forefoot angle and relaxed rearfoot angle, as well as between forefoot angle and navicular drop, in healthy subjects. These relationships were not found when forefoot varus values were within a standard deviation of the sample mean.

Differences in normal and perturbed walking kinematics between male and female athletes

OBJECTIVE

To identify differences in lower extremity kinematic movement patterns between genders during walking through the application of an expected perturbation.

DESIGN

Randomized limb kinematics were compared between healthy active males and females.

BACKGROUND

Lower extremity kinematics during jump landing and cutting have been implicated as a potential source of the discrepancy in anterior cruciate ligament injury rates between genders. Kinematic differences between genders have been identified during tasks that are not provocative of anterior cruciate ligament injury but do result in increased ligament strain. Repetition of movement patterns that increase anterior cruciate ligament strain may increase the likelihood they will be reproduced during athletic tasks that produce force loads that exceed anterior cruciate ligament tensile strength.

METHODS

Twenty subjects (10 women, 10 men) classified as a level I or II athlete underwent motion analyses while performing self-paced walking trials. Five trials were undisturbed, and five each with a platform translating either laterally or anteriorly at heel contact. Sagittal, frontal, and transverse hip angles as well as sagittal and frontal knee angles were collected during stance.

RESULTS

Excursions in the frontal and transverse planes were greater at the hip and knee for females compared to males in each walking condition. The rate of these excursions also occurred more rapidly for females than males. There was no difference for joint angles at initial contact between genders, and there was no difference in the amount of sagittal plane excursion for the hip and knee when comparing genders.

CONCLUSIONS

Females demonstrate characteristics during both normal and perturbed gait that may potentially contribute to increased anterior cruciate ligament strain. Repetition of these potentially harmful movement patterns during provocative athletic maneuvers may lead to anterior cruciate ligament injury.

RELEVANCE

Females exhibit lower extremity kinematic patterns that differ from males. Female kinematic patterns may contribute to an increased risk for anterior cruciate ligament injury.

Pneumatosis intestinalis and diarrhea in a child following renal transplantation

Pneumatosis intestinalis is an uncommon finding beyond the neonatal period, but it has been reported in immunocompromized pediatric patients. The association of pneumatosis intestinalis in children following renal transplantation has to the best of our knowledge been only reported once in children. We describe a 4-year-old female who developed intermittent emesis, weight loss, and intermittently loose bloody stools after cadaveric renal transplantation at age 3.5 years. An abdominal x-ray demonstrated extensive pneumatosis in the colon. The infectious work-up was negative. Histologically, she had increased eosinophils throughout the lamina propria in the rectum. A glucose breath test was suggestive of small bowel bacterial overgrowth. She was treated with 10 days of metronidazole with resolution of the diarrhea and occult blood in stools. One month after the treatment she had radiologic resolution of her pneumatosis. Based on this report, pneumatosis intestinalis should be considered in the differential diagnosis of children after organ transplant suffering from diarrhea, abdominal pain, or blood in the stool.

Perturbing nuclear transport in Drosophila eye imaginal discs causes specific cell adhesion and axon guidance defects

To study nucleocytoplasmic transport during multicellular development, we developed a sensitive nuclear protein import assay in living blastoderm embryos. We show that dominant negative truncations of the human nuclear transport receptor karyopherinbeta/Importinbeta (DNImpbeta) disrupt mRNA export and protein import in Drosophila. To test the sensitivity of different developmental processes to nuclear trafficking perturbations, we expressed DNImpbeta behind the morphogenetic furrow of the eye disc, at a time when photoreceptors are patterned and project their axons to the brain. DNImpbeta expression does not disrupt the correct specification of different photoreceptors, but causes a defect in cell adhesion that leads to some photoreceptors descending below the layer of ommatidia. The photoreceptors initially project their axons correctly to the posterior, but later their axons are unable to enter the optic stalk en route to the brain and continue to project an extensive network of misguided axons. The axon guidance and cell adhesion defects are both due to a disruption in the function of Ketel, the Drosophila ortholog of Importinbeta. We conclude that cell adhesion and axon guidance in the eye have specific requirements for nucleocytoplasmic transport, despite involving processes that occur primarily at the cell surface.

Small bristles, the Drosophila ortholog of NXF-1, is essential for mRNA export throughout development

We identified a temperature-sensitive allele of small bristles (sbr), the Drosophila ortholog of human TAP/NXF-1 and yeast Mex67, in a screen for mutants defective in mRNA export. We show that sbr is essential for the nuclear export of all mRNAs tested in a wide range of tissues and times in development. High resolution and sensitive in situ hybridization detect the rapid accumulation of individual mRNA species in sbr mutant nuclei in particles that are distinct from nascent transcript foci and resemble wild-type export intermediates. The particles become more numerous and intense with increasing time at the restrictive temperature and are exported very rapidly after shifting back to the permissive temperature. The mRNA export block is not due indirectly to a defect in splicing, nuclear protein import, or aberrant nuclear ultrastructure, suggesting that in sbr mutants, mRNA is competent for export but fails to dock or translocate through NPCs. We conclude that NXF-1 is an essential ubiquitous export factor for all mRNAs throughout development in higher eukaryotes.

small bristles is required for the morphogenesis of multiple tissues during Drosophila development

We found that mutations in small bristles (sbr) affect several tissues during the development of the fruit fly. In sbr embryos, neurons have defects in pathfinding and the body wall muscles have defective morphology. As adults, sbr flies have smaller and thinner bristles with a reduced diameter, suggesting a defective cytoskeleton within. The phenotypes we observe are consistent with defects in cell morphogenesis. We identified DmNXF1, the Drosophila homolog of a mRNA export protein that has been characterized in human (NXF1/TAP) and yeast (Mex67p) as the protein encoded by the small bristles locus. Given that a global decrease in mRNA export in these mutants is likely, the phenotypes we observe suggest that certain tissues are acutely sensitive to lower levels of cytoplasmic mRNA and the resultant decrease in protein synthesis during key stages of cellular morphogenesis.

Clinical role of F-18 fluorodeoxyglucose positron emission tomography for detection and management of renal cell carcinoma

PURPOSE

We evaluate the accuracy of F-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) for staging and management of renal cell carcinoma.

MATERIALS AND METHODS

FDG-PET was performed in 25 patients with known or suspected primary renal tumors and/or metastatic disease and compared with conventional imaging techniques, including computerized tomography (CT). Histopathological confirmation was obtained in 18 patients and confirmation of the disease was by followup in the remainder. The impact of FDG-PET on disease management was also assessed.

RESULTS

Of the 17 patients with known or suspected primary tumors FDG-PET was true positive in 15, true negative in 1 and false-negative in 1. Comparative CT was true positive in 16 patients and false-positive in 1. The accuracy of FDG-PET and CT was similar (94%). All patients would have undergone radical nephrectomy after conventional imaging findings but FDG-PET results altered treatment decisions for 6 (35%), of whom 3 underwent partial nephrectomy and 3 avoided surgery due to confirmation of benign pathology or detection of unsuspected metastatic disease. Of the 8 cases referred for evaluation of local recurrence and/or metastatic disease FDG-PET changed treatment decisions in 4 (50%), with disease up staged in 3 and recurrence excluded in 1. Compared with CT, FDG-PET was able to detect local recurrence and distant metastases more accurately and differentiated recurrence from radiation necrosis.

CONCLUSIONS

FDG-PET accurately detected local disease spread and metastatic disease in patients with renal cell carcinoma and altered treatment in 40%. FDG-PET may have a role in the diagnostic evaluation of patients with renal cell carcinoma preoperatively and staging of metastatic disease.