Letters to the editor

This study examines editorial photography in nine major erotica magazines to determine how pictures vary as a function of the social class, gender and sexual preference of the intended readership. The analysis reveals that upwardly‐mobile, heterosexual men are treated to idealized images, whereas working‐class, heterosexual men are presented with more mundane yet highly‐sexualized images. Heterosexual women are provided with photographs of nude males in a low‐sexual context. Magazines for homosexual men present images, except for gender, very similar to those created for upwardly‐mobile, heterosexual men. These patterns are discussed from a functionalist perspective to show how erotica magazines contribute to social‐order maintenance.     

A Comparison of Knowledge Obsolescence of Graduating Seniors and Practitioners in the Field of Physical Education

Abstract

The issue of defining and measuring professional obsolescence among physical educators is examined through a comparison of the current knowledge base of graduating physical education seniors and physical education practitioners in Pennsylvania. In a previous study, the “Inventory of Recent Knowledge in Physical Education,” a 260-item sample of current knowledge as defined by content experts was developed by the authors and administered by mail to the population of 2,737 male professional members of the public school districts' departments of physical education in Pennsylvania. In the present study, results from the first study were compared with those from an administration of the same instrument to 462 female and male physical education majors graduating from nine Pennsylvania higher education institutions. Both studies employed multiple-matrix procedures for item-person sampling and data analysis. An analysis of the results for both groups showed essentially similar performance profiles on the Inventory. Average scores of the two groups tended to be low and neither met preestablished minimum standards for defining up-to-date or nonobsolete performance. These results point to a clear conflict between what experts think up-to-date persons in the field of physical education should know and the knowledge performance of practitioners and students.     

Confounding compression: the effects of posture,sizing and garment type on measured interface pressure in sports compression clothing

The purpose of this investigation was to measure the interface pressure exerted by lower body sports compression garments, in order to assess the effect of garment type, size and posture in athletes. Twelve national-level boxers were fitted with sports compression garments (tights and leggings), each in three different sizes (undersized, recommended size and oversized). Interface pressure was assessed across six landmarks on the lower limb (ranging from medial malleolus to upper thigh) as athletes assumed sitting, standing and supine postures. Sports compression leggings exerted a significantly higher mean pressure than sports compression tights (P < 0.001). Oversized tights applied significantly less pressure than manufacturer-recommended size or undersized tights (P < 0.001), yet no significant differences were apparent between different-sized leggings. Standing posture resulted in significantly higher mean pressure application than a seated posture for both tights and leggings (P < 0.001 and P = 0.002, respectively). Pressure was different across landmarks, with analyses revealing a pressure profile that was neither strictly graduated nor progressive in nature. The pressure applied by sports compression garments is significantly affected by garment type, size and posture assumed by the wearer.     

Changes in kinematics and arm–leg coordination during a 100-m breaststroke swim

The purpose of this study was to compare arm–leg coordination and kinematics during 100 m breaststroke in 26 (8 female; 18 male) specialist breaststroke swimmers. Laps were recorded using three 50-Hz underwater cameras. Heart rate and blood lactate were measured pre- and post-swim. Arm–leg coordination was defined using coordination phases describing continuity between recovery and propulsive phases of upper and lower limbs: coordination phase 1 (time between end of leg kick and start of the arm pull phases); and coordination phase 2 (time between end of arm pull and start of leg kick phases). Duration of stroke phases, coordination phases, swim velocity, stroke length (SL), stroke rate (SR) and stroke index (SI) were analysed during the last three strokes of each lap that were unaffected by turning or finishing. Significant changes in velocity, SI and SL (P < 0.05) were found between laps. Both sexes showed significant increase (P < 0.05) in heart rate and blood lactate pre- to post-swim. Males had significantly (P < 0.01) faster swim velocities resulting from longer SLs (P = 0.016) with no difference in SR (P = 0.064). Sex differences in kinematic parameters can be explained by anthropometric differences providing males with increased propelling efficiency.     

Parent-daughter transmission of the androgen receptor gene as an explanation of the effect of father absence on age of menarche

Based on an evolutionary theory of socialization, Belsky and colleagues proposed that girls exposed to a stressful environment, especially when due to father absence in the first 7 years of life, showed an early onset of puberty, precocious sexuality, and unstable relationships as adults. The authors of this article examined an alternative explanation that a variant X-linked androgen receptor (AR) gene, predisposing the father to behaviors that include family abandonment, may be passed to their daughters causing early puberty, precocious sexuality, and behavior problems. The results of a study of 121 White males and 164 White females showed a significant association of the short alleles of the GGC repeat polymorphism of the AR gene with a range of measures of aggression and impulsivity, increased number of sexual partners, sexual compulsivity, and lifetime number of sex partners in males; and paternal divorce, father absence, and early age of menarche in females. These findings support a genetic explanation of the Belsky psychosocial evolutionary hypothesis regarding the association of fathers' absence and parental stress with early age of onset of menarche and early sexual activity in their daughters. A genetic explanation of the father absence effect is proposed in which fathers carrying the AR alleles are more likely to abandon a marriage (father absence) and pass those alleles to their daughters in whom they produce an earlier age of menarche and behavioral problems.     

Bias among Professionals Who Erroneously Declare Students Eligible for Special Services

A computer simulation program was developed for the purpose of studying the processes diagnostic personnel in the schools engage in when making psychoeducational decisions about students. Initially, the program collected demographic data on 159 participants and assessed their knowledge base in assessment. Bogus referral information for one of sixteen “cases” was then provided and subjects were instructed that they were to make eligibility and classification decisions for the child. They were told that scores and other information (e.g., observations) were available to them on a variety of tests from among seven domains. Although the referral data indicated the student might be evidencing academic or behavior problems, all assessment data indicated a normal or average performance. Fiftytwo percent of the subjects (i.e., 83) declared the “average” child eligible for special education services; their classification decisions were further analyzed. Decisions about the 16 different children were found to be more a function of referral information than child performance data. The outcomes are discussed with regard to implications for the practice of psychoeducational assessment.     

Educational Testing in America: What's Right,What's Wrong? A Criterion-Referenced Perspective

What is a criterion-referenced test? What are the good and bad points of authentic assessment, criterion-referenced testing, and Item Response Theory?     

An evaluation of inertial sensor technology in the discrimination of human gait

Abstract

Inertial sensors may provide the opportunity for broader and more cost effective gait analysis; however some questions remain over their potential use in this capacity. The aim of the study was to determine whether an inertial sensor could discriminate between normal walking, fast walking, and running. A single group crossover design was used to compare acceleration profiles between three gait conditions: normal walking, fast walking, and running. An inertial sensor was placed on the sacrum of 12 participants (6 male, 6 female) who performed 3 trials of each gait condition on both overground and treadmill settings. A significant difference (P < 0.001) in the occurrence of heel strike in the gait cycle was found between running and both walking conditions. No differences were seen between overground and treadmill in any condition or variable. The results indicate that a single sacral mounted inertial sensor can differentiate running from normal walking and fast walking using temporal gait event measures. This study indicates that inertial sensors can differentiate walking from running gait in healthy individuals which may have potential for application in the quantification of physical activity in the health and exercise industry.     

Predicting vertical ground reaction force during running using novel piezoresponsive sensors and accelerometry

ABSTRACT

Running is a common exercise with numerous health benefits. Vertical ground reaction force (vGRF) influences running injury risk and running performance. Measurement of vGRF during running is now primarily constrained to a laboratory setting. The purpose of this study was to evaluate a new approach to measuring vGRF during running. This approach can be used outside of the laboratory and involves running shoes instrumented with novel piezoresponsive sensors and a standard accelerometer. Thirty-one individuals ran at three different speeds on a force-instrumented treadmill while wearing the instrumented running shoes. vGRF was predicted using data collected from the instrumented shoes, and predicted vGRF were compared to vGRF measured via the treadmill. Per cent error of the resulting predictions varied depending upon the predicted vGRF characteristic. Per cent error was relatively low for predicted vGRF impulse (2–7%), active peak vGRF (3–7%), and ground contact time (3–6%), but relatively high for predicted vGRF load rates (22–29%). These errors should decrease with future iterations of the instrumented shoes and collection of additional data from a more diverse sample. The novel technology described herein might become a feasible way to collect large amounts of vGRF data outside of the traditional biomechanics laboratory.