Accuracy in the estimation of body weight: an alternate test of the motivated-distortion hypothesis

OBJECTIVE: Inaccuracies in self-reported weight are believed to represent a motivated distortion, but cognitive or perceptual biases have not been excluded. We examined the ability of participants to estimate the weight of a target person as a means of distinguishing between motivated distortions and perceptual biases. METHOD: Participants (restrained eaters and unrestrained eaters; women and men) estimated the weight of a target individual, which was compared with the actual weight of the target individual. RESULTS: Restrained and unrestrained eaters did not differ in their estimates of the target's weight, and men underestimated the target's weight to a greater extent than did women. DISCUSSION: The pattern of inaccuracies observed does not parallel those found in research on self-reported weight. This observation suggests that perceptual biases do not explain inaccuracies in self-reported weight and that such inaccuracies may be the result of motivated distortions. Issues regarding data analysis and presentation are also discussed.     

Subtalar Pronation Does Not Influence Impact Forces or Rate of Loading During a Single-Leg Landing

OBJECTIVE: To identify the influence of static subtalar pronation (as measured by weight-bearing navicular drop [ND]) on ground impact forces and rate of loading during a single-leg landing. DESIGN AND SETTING: Subjects were grouped (n = 16 per group) on the basis of weight-bearing ND scores (supinators, <5 mm; neutral, 5-10 mm; pronators, >10 mm). Subjects performed 5 single-leg landings, dropping from a 0.3-m height onto a force platform. An electrogoniometer simultaneously recorded sagittal knee range of motion during the landing task. SUBJECTS: Forty-eight healthy volunteers participated. MEASUREMENTS: Peak vertical force was defined as the highest force recorded in the F(z) direction during landing. Rate of loading was defined as the peak vertical force divided by the time to reach the peak vertical force. Knee-flexion excursion was defined as the change in knee-flexion range from initial contact to peak vertical force. RESULTS: Peak vertical force (P =.769) and rate of loading (P =.703) did not differ among groups. Although secondary analyses identified significant negative correlations between peak force and rate of loading with knee excursion, the amount of knee excursion was similar among groups (P =.744). CONCLUSIONS: Our results de-emphasize the influence of static anatomical foot alignment on impact forces and absorption during a single-leg drop landing and provide further support for the role of knee flexion in dissipation of landing forces. Further investigations are needed to fully elucidate the role of subtalar pronation and other lower extremity alignment factors in force dissipation during dynamic functional activities.     

Chronic Ankle Instability Does Not Affect Lower Extremity Functional Performance

OBJECTIVE: To determine if functional performance is impaired in individuals with self-reported chronic ankle instability. DESIGN AND SETTING: We used a between-groups design to assess 3 functional variables. All data were collected at a Division III college and a military academy. Before testing, all subjects performed a 5-minute warm-up, followed by a series of stretches for the lower extremity muscles. Subjects then performed cocontraction, shuttle run, and agility hop tests in a counterbalanced fashion. Three trials for each functional test were completed and averaged for analysis. SUBJECTS: Twenty men with a history of at least 1 significant ankle sprain and episodes of at least 1 repeated ankle injury or feelings of instability or "giving way" were compared with 20 men with no prior history of ankle injury. Subjects were matched by age, height, weight, and activity level. MEASUREMENTS: Time to completion was measured in seconds for the cocontraction and the shuttle run tests. The agility hop test was measured on an error point scale. RESULTS: Using 3 separate, independent, 2-tailed t tests, we found no significant difference between groups for the cocontraction (P =.452), shuttle run (P =.680), or agility hop (P =.902) tests. CONCLUSIONS: Chronic ankle instability is a subjectively reported phenomenon defined as the tendency to "give way" during normal activity. Although athletes commonly complain of subjective symptoms associated with chronic ankle instability, our findings suggest that these symptoms do not negatively influence actual functional performance. Future researchers should evaluate other, more demanding functional-performance tests to further substantiate these findings.     

Efficacy of the Star Excursion Balance Tests in Detecting Reach Deficits in Subjects With Chronic Ankle Instability

OBJECTIVE: Chronic instability after lateral ankle sprain has been shown to cause balance deficits during quiet standing. Although static balance assessment in those with ankle instability has been thoroughly examined in the literature, few researchers have studied performance on more dynamic tasks. Our purpose was to determine if the Star Excursion Balance Tests (SEBTs), lower extremity reach tests, can detect deficits in subjects with chronic ankle instability. DESIGN AND SETTING: We performed all testing in a university athletic training facility. We tested lower extremity reach using the SEBTs, which incorporates single-leg stance with maximal reach of the contralateral leg. SUBJECTS: Twenty subjects with unilateral, chronic ankle instability (age = 19.8 +/- 1.4 years, height = 176.8 +/- 4.5 cm, mass = 82.9 +/- 21.2 kg) and 20 uninjured subjects matched by sex, sport, and position (age = 20.2 +/- 1.4 years, height = 178.7 +/- 4.1 cm, mass = 82.7 +/- 19.9 kg). MEASUREMENTS: We measured the reach distances in centimeters (cm) and averaged 3 reaches in each of the 8 directions while the subjects stood on each leg for data analysis. RESULTS: The group with chronic ankle instability demonstrated significantly decreased reach while standing on the injured limb compared with the matched limb of the uninjured group (78.6 cm versus 82.8 cm). Additionally, subjects with chronic ankle instability reached significantly less when standing on their injured limbs as compared with their uninjured limbs (78.6 cm versus 81.2 cm). CONCLUSIONS: The SEBTs appear to be an effective means for determining reach deficits both between and within subjects with unilateral chronic ankle instability.     

All-terrain vehicle rules and regulations: impact on pediatric mortality

Background/purpose: All-terrain vehicles (ATV) use by children leads to severe injury and death. Since the US Consumer Product Safety Commission consent decree expired in 1998, there has been little movement in regulating ATV use for children (<16 yr). The authors hypothesized that states with laws and regulations restricting pediatric ATV use may abrogate excess death compared with states without such restrictions.Methods: Pediatric mortality data reported to the consumer product safety commission from 1982 to 1998 were analyzed as well as state all-terrain vehicle requirements compiled by the Specialty Vehicle Institute of America in August 2001. The authors calculated ATV mortality rate by dividing ATV mortality frequency by 1980-2000 pediatric census results. They compared the top 26 states with the highest ATV mortality rates (TOP) with those of all other states (OTH) in terms of age, ATV type, ATV occupancy, and ATV laws. Chi-square analysis was performed.Results: There were 1,342 ATV pediatric deaths during the 16-year period. The TOP states averaged approximately a 2-fold increase in adjusted ATV mortality rate compared with the national ATV pediatric mortality rate. Ninety-two percent of TOP states have no licensing laws compared with 73% of the OTH states (P < .07). There is no difference between groups with regard to minimum age requirements and safety certification.Conclusions: Current legal and regulatory standards have low probability of decreasing ATV-related pediatric mortality. States should adopt laws that restrict the use of ATV’s for children less than 16 years of age and potentially prevent excess ATV-related pediatric mortality.     

Quantitation of film coating on Zantac 75 mg tablets and Epivir HBV 100 mg tablets by ICP-AES

PURPOSE: To present a selective analytical Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) method developed and validated for the quantitation of tablet film coatings containing titanium. METHODS: Tablet samples were decomposed by either digestion or dry ashing. The amount of film tablet coating was calculated based on titanium content of the sample. RESULTS: The reported ICP-AES method was accurate, precise, sensitive and linear for determination of titanium concentrations from 2.9 to 8.6 ppm. CONCLUSION: This method provides an accurate determination of the amount of coating on a tablet and has general applicability for a variety of coating formulations containing different elements.