Mixed Factorial Analysis Of Variance Research Articles

An experimental evaluation of the benefits and costs of providing fertility information to adolescents and emerging adults.

STUDY QUESTIONDoes the provision of fertility (compared to control) information affect fertility-related knowledge, perceived threat of infertility, anxiety, physical stress and fertility plans in adolescents and emerging adults?SUMMARY ANSWERThe provision of fertility information was associated with increased fertility knowledge (emerging adults) and greater infertility threat (adolescents and emerging adults).WHAT IS KNOWN ALREADYAccording to fertility education research, adolescents and emerging adults know less than they should know about fertility topics. Fertility knowledge can be improved through the provision of information in older adults.STUDY DESIGN, SIZE, DURATIONExperimental design. Secondary and university students completed pre-information questionnaires, were randomly assigned via computer to an experimental group, read either fertility (FertiEduc group) or healthy pregnancy information (Control group), and completed post-information questionnaires. Data were collected in group sessions via an online portal.PARTICIPANTS/MATERIALS, SETTING, METHODSEligible participants were aged 16–18 (adolescents) or 21–24 years (emerging adults), childless, not currently pregnant (for men, partner not pregnant) or trying to conceive, presumed fertile and intending to have a child in the future. Of the 255 invited, 208 (n = 93 adolescents, n = 115 emerging adults) participated. The FertiEduc group received ‘A Guide to Fertility’, four online pages of information about fertility topics (e.g. ‘When are men and women most fertile?’) and the Control group received four online pages from the National Health Service (NHS) pregnancy booklet ‘Baby Bump and Beyond’. Participants completed a questionnaire (fertility knowledge, perceived threat of infertility, anxiety, physical stress and fertility plans, moderators) prior to and after the provision of information. Mixed factorial analysis of variance was used to examine the effects of information provision and hierarchical multiple regression to assess potential moderators of knowledge.MAIN RESULTS AND THE ROLE OF CHANCEThe FertiEduc and Control groups were equivalent on age, gender, disability, relationship status and orientation at baseline. Results showed that fertility information significantly increased fertility knowledge for emerging adults only (P < 0.001) and threat of infertility for emerging adults and adolescents (P = 0.05). The moderators were not significant. Participation in the study was associated with an increase in feelings of anxiety but a decrease in physical stress reactions. Adolescents had more optimal fertility plans compared to emerging adults due to being younger.LIMITATIONS, REASONS FOR CAUTIONThis was an experimental study on a self-selected sample of men and women from selected educational institutions and only short term effects of information were studied.WIDER IMPLICATIONS OF THE FINDINGSProvision of fertility information can have benefits (increased fertility knowledge) but also costs (increase potential threat of infertility). Adolescents find fertility information positive but do not learn from it. Fertility education should be tailored according to age groups and created to minimise negative effects. Longitudinal examination of the effects of fertility information in multi-centre studies is warranted and should include measures of perceived threat of infertility.STUDY FUNDING/COMPETING INTEREST(S)Cardiff University funded this research. All authors have no conflicts of interest to declare.

Knee strength ratios in competitive female athletes.

Knee strength ratios are related to the movement patterns, sport-specific training and knee injuries in athletes. The purpose of this study was to determine the ratios in the concentric isokinetic strength of the hamstrings and quadriceps and the isometric strength of the knee extensors. In female basketball players (n = 14) and female volleyball players (n = 12) were evaluated: the hamstrings to quadriceps peak torque ratio (H/Q) and side-to-side peak torque ratio (TR) for hamstrings and quadriceps; the ratio of the maximal bilateral strength to the summed maximal unilateral strength (B/U) and side-to-side maximal strength ratio (SR) for knee extensors. For the H/Q values, a 2 × 2 × 3 mixed-factorial analysis of variance and Bonferroni post hoc test were computed. The H/Q values increased from 48.0 (3.9)% at 60°/s to 70.4 (7.9)% at 300°/s. Furthermore, there were significant differences in the H/Q values between 300°/s and 180°/s, 300°/s and 60°/s in basketball and volleyball athletes, and between 180°/s and 60°/s only in basketball athletes (p < .05). Significantly higher H/Q results at 60°/s demonstrated basketball players than volleyball players (p < .05). Differences in the TR and SR mean values ranged from 4.4% to 8.6% and indicated no significant side-to-side strength deficits (p > .05). In both groups, greater isometric strength developed bilaterally was found (B/U > 100%). The findings revealed the magnitude of knee strength ratios in female athletes determined by sport-specific movements in basketball and volleyball. This study highlighted the importance of the bilateral strength deficit and muscular balance between the hamstrings and quadriceps in basketball and volleyball athletes in activities related to their movement patterns and specific training.

Investigation of alpha band of the electroencephalogram before and after a task of proprioceptive neuromuscular facilitation.

The proprioceptive neuromuscular facilitation (PNF) sets up a feature of treatment developed with the objective to facilitate and improve the motor performance. The aim of this study was to investigate in healthy female individuals the effects of electrophysiological of a diagonal of the PNF upper limb. The sample consisted of 30 female participants aged between 18 to 28 years, randomly divided into 3 groups (G1, G2, and G3). The three groups had 2 moments of electroencephalographic signal detection, before and after the task. The statistical neurophysiological design allowed the analysis of the relative power of alpha band in three leads (Fz, F7, and F8). Thus, a three-way mixed factorial analysis of variance (ANOVA) was performed to investigate the factor inter subjects (groups) and intrasubjects (areas and moments), a two-way ANOVA to investigate the interactions between the three factors, and a one-way ANOVA to analyze separately the factors time and area. A P≤0.05 was considered as significance level. The results showed significant increase of alpha band in the three groups analyzed, being more evident to the G2 group. Therefore, the PNF can be considered favorable also in relation to the cortical behavior, reinforcing its use in rehabilitation processes, especially in the clinical practice of physiotherapy.

The effect of television watching and portion size on intake during a meal

Watching television while eating and eating from larger portion sizes of food are factors that have been found to independently increase food intake. When combined, these factors may further enhance consumption. This investigation, using a 4 × 2 × 2 mixed factorial design, with a between-subjects factor of order of conditions and within-subjects factors of television watching (NO TV and TV) and portion size (SMALL and LARGE), tested the independent effects and interaction of these factors in seventeen women and three men (21.6 ± 2.3 kg/m2, 22.3 ± 3.7 years, 80% white and 95% non-Hispanic). In each condition, participants had 30 min to eat a meal containing macaroni and cheese and salad with dressing. For NO TV, participants sat for 30 min while eating, while for TV, participants viewed a 30-min show containing no food cues while eating. In SMALL the meal provided 1083 kcal, while in LARGE the meal provided 200% of SMALL. Mixed factorial analysis of variance revealed a significant main effect of portion size on grams and energy consumed of the total meal. Participants consumed more grams (577.9 ± 150.5 g vs. 453.1 ± 96.6 g; p < 0.001) and energy (903.9 ± 270.4 kcal vs. 734.6 ± 187.1 kcal; p < 0.001) in LARGE as compared to SMALL. No significant effect of television watching or interaction of television watching and portion size was found. Results of this study suggest that to assist with reducing intake, smaller portion sizes should be implemented in all types of eating situations.

Effects of a Periodized Training Program and a Traditional Military Training Program on Functional Movement and Y-Balance Tests in ROTC Cadets

Background: Functional movement screening (FMS) and Y-balance test (YBT) are assessment procedures used to examine the ‘quality’ of movement patterns and identify individuals that might have specific limitations or asymmetries. Low FMS and YBT scores have been linked with a higher risk of injury among athletic populations. Since FMS and YBT are becoming more widely used screening tools, it is important to examine the various training programs that could improve FMS and YBT scores. Purpose: This pilot study examined the effects of a 10-week periodized and traditional military training program on FMS, and upper and lower quadrant YBT scores of Reserve Officers Training Corps (ROTC) Cadets. Methods: Subjects consisted of 36 Army and Air Force ROTC cadets (male=24, female=12), Age 19.7(yrs)±5.96, Height (cm)=175.7±9.28, Weight(kg)=75.70±13.41. The periodized, intervention group (IG n=24) trained for 1 hour/day, 4 days/week and the control group (CG n=12) participated in traditional ROTC training protocol for 1 hour/day, 3 days/week. A 2×2 mixed factorial analysis of variance (ANOVA) was used to compare mean change values of the FMS, upper, and lower quadrant YBT scores for intervention and control groups. Results: A significant interaction (p≤0.05) was observed for FMS scores. The control group had a much lower initial FMS score and demonstrated more improvement than the intervention group. Both groups demonstrated a significant increase in left side YBT upper (p=0.03) and lower (p=0.02) quadrant scores after 10-weeks of training. Conclusions: Since FMS and YBT scores are being used more frequently as screening tools for risk of injury, it is important to study methods that will improve FMS and YBT scores in diverse athletic populations. This study found larger improvements in FMS scores in ROTC cadets participating in a traditional military training program compared to cadets participating in a periodized strength training program. Scores in the left side of the YBT upper and lower quadrants were improved in both groups suggesting multiple training programs can improve function in non-dominant sides or asymmetries. Future studies are warranted and should address certain limitations that this study encountered (sample size and length of training period). Further exploration of FMS and YBT scores and mechanisms of improvement in tactical athletic populations would be beneficial.

Task values and self‐efficacy beliefs of undergraduate psychology students

ObjectivePsychological literacy has been proposed as an outcome for psychology graduates, which requires an understanding of and integration between theory, research, and practice. Using the expectancy‐value theory, the current study aimed to examine psychology students’ values and self‐efficacy towards these domains.MethodThree hundred and nineteen psychology students (Mage = 26.25, SD = 10.26) reported on their social influences, task values, and self‐efficacy beliefs for theory, research, and practice.ResultsUsing 3 (Year) × 3 (Domain) mixed factorial analyses of variance (ANOVAs), it was shown that students have poorer task values and lower self‐efficacy towards research than theory or practice. A consistent effect of year was not found for task values, but students’ self‐efficacy beliefs showed an effect of training, with first years reporting poorer self‐efficacy than middle and fourth‐year students. Results indicated that students hold contrasting views of what they perceive friends and family to value compared to their perception of what academic staff value.ConclusionsIt was recommended that the undergraduate curriculum promote equal values across theory, research, and practice by integrating education in the three domains. Utility interventions are discussed as a cost‐effective way to improve task values and performance in learning domains that are not well‐valued by students.

Age-Related Reductions in Muscle Quality Influence the Relative Differences in Strength and Power

Recent studies have demonstrated that age-related changes in the relative differences in isokinetic strength and power may reflect fast twitch fiber alterations. It is possible skeletal muscle ultrasound (US) imaging may reflect these changes. PURPOSE: The purpose of this study was to examine the influence of muscle quality on the relative differences in strength and power in younger and older adults. METHODS: Twenty young (20.1±1.5 yrs) and 20 older (69.5±3.1 yrs) healthy, recreationally active men performed two plantar flexion maximal voluntary isometric actions (MVCs) and three maximal isokinetic actions on a calibrated isokinetic dynamometer. Panoramic brightness-mode US images of the medial and lateral gastrocnemius were taken to determine subcutaneous fat corrected echo intensity (EI) to represent muscle quality. Isokinetic peak torque (PT), mean power (MP), and peak power (PP) at 0.52 rad·s-1 and 2.09 rad · s-1 were normalized as %MVC. Six separate 2-way mixed factorial analyses of variance were used to evaluate absolute and normalized PT, MP, and PP. Independent samples t-tests were used to compare isometric PT, EI, %decrease in PT and %increase in MP and PP between the younger and older men. Pearson’s correlation coefficients were used to examine the relationship between EI and the %decrease in PT, %increase in MP, and %increase in PP. An alpha of P≤0.05 was used to determine statistical significance. RESULTS: The younger men exhibited greater absolute isometric PT, isokinetic PT, MP, and PP at 0.52 rad·s-1 and 2.09 rad·s-1 (P=0.001-0.003). After normalizing to isometric PT, age-related differences were eliminated. The older men exhibited higher EI (P<0.001), greater %decrease in PT (43.6% vs. 38.9%; P=0.006), and lower %increase in MP (167.5% vs. 186.3%; P=0.049) and PP (125.5% vs. 144.5%; P = 0.006). Echo intensity was significantly related with the %decrease in PT (r=0.605; P<0.001), %increase in MP (r=-0.419; P=0.009), and %increase in PP (r=-0.605; P<0.001) from 0.52 rad·s-1 to 2.09 rad·s-1. CONCLUSIONS: The absolute age-related reductions in isokinetic strength and power are eliminated with normalization. However, the relative differences from slow to fast velocities may reflect the age-related decreases in fast-twitch fiber and subsequent alterations in muscle quality.

Investigation of the Concussion Goggle™ Education Program with Secondary School Athletic Teams: A Pilot Study

Background: Researchers have investigated different types of concussion education programs within various populations with mixed results. To date, no research has been published using the Concussion Goggles™ educational program Objective: To compare secondary school student-athletes’ knowledge about concussions before and after attending a concussion education program using the Concussion Goggles™. Design: Pre- posttest. Setting: Public secondary school. Patients or Other Participants: 41 secondary school students (14 girls soccer players, 14 boys basketball players, and 13 girls basketball players) with a mean age of 15.37 ± 1.22 years. Intervention(s): Participants completed the Concussion Goggles™ concussion educational program consisting of PowerPoint slides with 3 activities and short video segments within the presentation. Participants completed a test developed by the manufacturers of the Concussion Goggles™ educational program prior to and following the intervention to measure change in concussion knowledge. Main Outcome Measure(s): A 3-way mixed factorial analysis of variance (sport x grade level x gender) for repeated measures was utilized to determine statistical significance. Results: A statistically significant difference between the overall pretest (9.37 ± 1.20) and posttest (9.63 ± 1.04) scores was not found (p = 0.28). Repeated measures analysis did not indicate significant interaction effects for test score x grade (p = 0.18), test score x sport (p = 0.63), nor test score x grade x sport (p = 0.96). Conclusion: The Concussion Goggle™ education program did not affect participant knowledge of concussions in the posttest. In its current form, the Concussion Goggle™ program may not be an effective concussion education program. Word Count: 251

Remote assessment of verbal memory in MS patients using the California Verbal Learning Test

We used the California Verbal Learning Test, Second Edition (CVLT-II), one component of the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS), to determine feasibility of a remote assessment protocol. We compared telephone-administered CVLT-II data from MS patients to data acquired in person from an independent sample of patients and healthy controls. Mixed factor analyses of variance (ANOVAs) showed no significant differences between patient groups, but between-group effects comparing patients and healthy controls were significant. In this study, CVLT-II assessment by conventional in-person and remote telephone assessment yielded indistinguishable results. The findings indicate that telephone-administered CVLT-II is feasible. Further validation studies are underway.

Paradoxical Effects of Worrisome Thoughts Suppression: the Influence of Depressive Mood

Thought suppression increases the persistence of unwanted idiosyncratic worrisome thoughts when individuals try to suppress them. The failure of suppression may contribute to the development and maintenance of emotional disorders. Depressive people seem particularly prone to engage in unsuccessful mental control strategies such as thought suppression. Worry has been reported to be elevated in depressed individuals and a dysphoric mood may also contribute to the failure of suppression. No studies examine, however, the suppression of worrisome thoughts in individuals with depressive symptoms. To investigate the suppression effects of worrisome thoughts, 46 participants were selected according to the cut-off score of a depressive symptomatology scale, and they were divided in two groups (subclinical and nonclinical group). All of the individuals took part in an experimental paradigm of thought suppression. The results of the mixed factorial analysis of variance revealed an increased frequency of worrisome thoughts during the suppression phase, depending on the depressive symptoms. These findings confirm that a depressive mood can reduce the success of suppression.

Effect of Adding Online Social Support Tools to an Adult Walking Program: A Pilot Randomized Controlled Trial.

This pilot study examined the efficacy of providing access to online social support tools on adults' step counts during a technology-mediated walking intervention. Sixty-three insufficiently active adults were randomized to a 12-week walking intervention with (SUPPORT) or without (NO SUPPORT) access to online social support tools. Both groups received a pedometer, step goals, and access to relevant websites. The SUPPORT group also received access to online social support tools. A mixed-factor analysis of variance was conducted to examine within- and between-group differences in measures of daily steps, psychosocial indicators, and health. Both groups significantly (p < .05) increased their daily steps over time from baseline by 1,401 (SUPPORT) and 2,461 (NO SUPPORT), with no significant differences between groups. Psychosocial and health improvements were no greater for SUPPORT versus NO SUPPORT. The SUPPORT group's use of the online social support tools was low. Results suggest that giving adults access to online social support tools during a technology-mediated walking program did not lead to an enhanced increase in daily steps versus an identical program without these tools; however, the low use of these tools may have weakened their effect. Future studies should examine SUPPORT versus NO SUPPORT among groups with preexisting social ties.

Effects of whole body vibration on muscle contractile properties in exercise induced muscle damaged females

Determining muscle contractile properties following exercise is critical in understanding neuromuscular function. Following high intensity training, individuals often experience exercise induced muscle damage (EIMD). The purpose of this investigation was to determine the effect of whole-body vibration (WBV) on muscle contractile properties following EIMD. Twenty-seven females volunteered for 7 sessions and were randomly assigned to a treatment or control group. Muscle contractile properties were assessed via voluntary torque (VT), peak twitch torque (TT), time to reach peak torque, half relaxation time of twitch torque, percent activation (%ACT), rate of rise (RR), rate of decline (RD), mean and peak electromyography during maximum voluntary isometric contraction. Two testing sets were collected each day, consisting of pre measures followed by WBV or control and post measures. A mixed factor analysis of variance was conducted for each variable. %ACT measures found baseline being less than day 1 in both measures in the control group. TT was found to be greater in the control group compared to WBV group. TT and VT baseline measures were greater than all other time points. RR showed control group had higher values than WBV group. These results indicate that WBV following EIMD had some positive effects on muscle contractile properties.

Effects of a DVD-delivered exercise program on patterns of sedentary behavior in older adults: a randomized controlled trial.

IntroductionIn the present study, we examined the influence of a home-based, DVD-delivered exercise intervention on daily sedentary time and breaks in sedentary time in older adults.MethodsBetween 2010 and 2012, older adults (i.e., aged 65 or older) residing in Illinois (N = 307) were randomized into a 6-month home-based, DVD-delivered exercise program (i.e., FlexToBa; FTB) or a waitlist control. Participants completed measurements prior to the first week (baseline), following the intervention period (month 6), and after a 6 month no-contact follow-up (month 12). Sedentary behavior was measured objectively using accelerometers for 7 consecutive days at each time point. Differences in daily sedentary time and breaks between groups and across the three time points were examined using mixed-factor analysis of variance (mixed ANOVA) and analysis of covariance (ANCOVA).ResultsMixed ANOVA models revealed that daily minutes of sedentary time did not differ by group or time. The FTB condition, however, demonstrated a greater number of daily breaks in sedentary time relative to the control condition (p = .02). ANCOVA models revealed a non-significant effect favoring FTB at month 6, and a significant difference between groups at month 12 (p = .02).ConclusionsWhile overall sedentary time did not differ between groups, the DVD-delivered exercise intervention was effective for maintaining a greater number of breaks when compared with the control condition. Given the accumulating evidence emphasizing the importance of breaking up sedentary time, these findings have important implications for the design of future health behavior interventions.

A randomised controlled trial of 'clockwise' ultrasound for low back pain.

AimsTo examine how the choice of words explaining ultrasound (US) may influence the outcome of physiotherapy treatment for low back pain (LBP).MethodsSixty-seven patients with LBP < 3 months were randomly allocated to one of three groups – traditional education about US (control group [CG]), inflated education about US (experimental group [EG]) or extra-inflated education about US (extra-experimental group [EEG]). Each patient received the exact same application of US that has shown clinical efficacy for LBP (1.5 Watts/cm2 for 10 minutes at 1 Megahertz, pulsed 20% over a 20 cm2 area), but received different explanations (CG, EG or EEG). Before and immediately after US, measurements of LBP and leg pain (numeric rating scale), lumbar flexion (distance to floor) and straight leg raise (SLR) (inclinometer) were taken. Statistical analysis consisted of mixed-factorial analyses of variance and chi-square analyses to measure differences between the three groups, as well as meeting or exceeding minimal detectable changes (MDCs) for pain, lumbar flexion and SLR.ResultsBoth EG and EEG groups showed a statistically significant improvement for SLR (p < 0.0001), while the CG did not. The EEG group participants were 4.4 times (95% confidence interval: 1.1 to 17.5) more likely to improve beyond the MDC than the CG. No significant differences were found between the groups for LBP, leg pain or lumbar flexion.ConclusionThe choice of words when applying a treatment in physiotherapy can alter the efficacy of the treatment.

β-Hydroxy-β-methylbutyrate attenuates cytokine response during sustained military training

This study tested the hypothesis that of 23 days of β-hydroxy-β-methylbutyrate (HMB) supplementation can maintain muscle mass and attenuate the immune and inflammatory response in combat soldiers during highly intense military training. Soldiers were randomly assigned to either a HMB (n = 6) or placebo (PL; n = 7) group and provided with 3 g · day−1 of either HMB or PL. During the final week of supplementation soldiers participated in extreme physical training, which included night navigation of 6–8 hours across difficult terrain carrying heavy loads combined with sleep deprivation (3.8 ± 3.0 h per night). Blood draws were performed prior to and following the supplementation period. Magnetic resonance imaging, which included diffusion tensor imaging sequence, was used for muscle fiber tracking analysis. Data was analyzed using a two-way mixed factorial analysis of variance. Magnitude-based inferences were used to provide inferences on the true effects that HMB may have had on the dependent variables compared to PL, calculated from 90% confidence intervals. Changes in tumor necrosis factor–α for HMB (−3.9 ± 8.2 pg · mL−1) were significantly lower (P = .043) compared to the change in PL (+4.0 ± 3.7 pg · mL−1). HMB ingestion was also very likely (92%-95% Likelihood) to lower granulocyte colony-stimulating factor and interleukin 10 compared to PL. In addition, HMB supplementation was likely (78%-87% likelihood) to reduce interferon-γ, interleukin 8, CX3CL1, and increase muscle volume for the adductor magnus (77% likelihood) compared to PL. In summary, the results of this study provides evidence that HMB supplementation may attenuate the inflammatory response to high intense military training, and maintain muscle quality.

Effect of body mass and midsole hardness on kinetic and perceptual variables during basketball landing manoeuvres

This study investigated the effects of body mass and shoe midsole hardness on kinetic and perceptual variables during the performance of three basketball movements: (1) the first and landing steps of layup, (2) shot-blocking landing and (3) drop landing. Thirty male basketball players, assigned into “heavy” (n = 15, mass 82.7 ± 4.3 kg) or “light” (n = 15, mass 63.1 ± 2.8 kg) groups, performed five trials of each movement in three identical shoes of varying midsole hardness (soft, medium, hard). Vertical ground reaction force (VGRF) during landing was sampled using multiple wooden-top force plates. Perceptual responses on five variables (forefoot cushioning, rearfoot cushioning, forefoot stability, rearfoot stability and overall comfort) were rated after each movement condition using a 150-mm Visual Analogue Scale (VAS). A mixed factorial analysis of variance (ANOVA) (Body Mass × Shoe) was applied to all kinetic and perceptual variables. During the first step of the layup, the loading rate associated with rearfoot contact was 40.7% higher in the “heavy” than “light” groups (P = .014) and 12.4% higher in hard compared with soft shoes (P = .011). Forefoot peak VGRF in a soft shoe was higher (P = .011) than in a hard shoe during shot-block landing. Both “heavy” and “light” groups preferred softer to harder shoes. Overall, body mass had little effect on kinetic or perceptual variables.

Catechol-O-methyltransferase genotype and response to Compensatory Cognitive Training in outpatients with schizophrenia.

The catechol-O-methyltransferase (COMT) ValMet polymorphism is associated with cognitive functioning in schizophrenia and may predict cognitive training outcomes. This study aimed to explore the contribution of COMT genotype in predicting improvement following Compensatory Cognitive Training (CCT). We conducted mixed factorial analysis of variance to examine COMT genotype as a predictor of response to CCT (i.e. improved cognitive performance) in 41 participants with schizophrenia-spectrum disorders. We also explored the effect of CCT treatment and COMT genotype on psychiatric symptom severity, functional capacity, and subjective quality of life. Met carrier status did not predict CCT treatment outcomes. COMT genotype may exert only modest effects on cognitive training response. Further research with larger samples is needed to establish genetic predictors of response to cognitive training.

Improving physical functional and quality of life in older adults with multiple sclerosis via a DVD-delivered exercise intervention: a study protocol

IntroductionThere is a need to identify innovative, low-cost and broad-reaching strategies for promoting exercise and improving physical function in older adults with multiple sclerosis (MS).Methods and analysisThis randomised controlled pilot...

Interaction of gender and body composition on rectus femoris morphology as measured with musculoskeletal ultrasound imaging.

Background:Quadriceps function is an important measure in patients recovering postoperatively. Traditionally, strength measures that require high levels of resistance are contraindicated during the early postoperative phase. Thus it may be helpful to evaluate the utilization of other tools, such as ultrasound imaging, that allow for assessment during a position of low resistance.Hypothesis:The rectus femoris cross-sectional area (CSA) is affected by sex and body composition in healthy subjects.Study Design:Cross-sectional study.Level of Evidence:Level 4.Methods:Thirty-two healthy subjects (16 women, 16 men), selected from a previously larger study, were chosen for analysis. All subjects underwent a maximal volitional isometric contraction protocol from 0° to 90° of knee motion controlled by an isokinetic dynamometer. In the contracted and resting positions, the rectus femoris CSA was measured at each angle using ultrasound imaging. The contractile index (contracted − resting CSA) was calculated at each position. Subjects were separated into 1 of 4 groups based on sex and fat percentage (low or high). These data were analyzed using mixed-factor analysis of variance (group × angle) for each variable, with a critical α level of 0.05.Results:A significant interaction was noted for the CSA of the rectus femoris at rest (P < 0.03) and during contraction (P < 0.02). For both variables, all groups performed similarly, with the exception of women with high body fat percentage. No statistically significant interaction existed for the contractile index; however, a main effect for angle (P < 0.01) was observed.Conclusion:Rectus femoris CSA appears to depend on sex as well as the body composition of individuals.Clinical Relevance:Traditional subjective assessment measures of quadriceps strength and function have low reliability and functional validity. With the improved feasibility of ultrasound imaging in the clinical setting, quadriceps size may be more accurately measured during the early postoperative stages.

The Influence of Aging on Interaural Asymmetries in Middle Latency Response Amplitude

Auditory-evoked potentials (EPs) provide a more objective assessment of central auditory nervous system (CANS) dysfunction when compared to behavioral measures because they do not require a behavioral response (Anderson and Kraus, 2010). In this regard, the middle latency response (MLR) has been considered an important component of CANS assessment (Jerger et al, 1988); however, its large within-group variability limits its usefulness (Musiek et al, 1999). It has been argued that performing intratest calculations on the MLR (e.g., difference in EP amplitude when stimulating the left ear versus the right ear) can reduce the within-group variability of the MLR and enhance its clinical usefulness (Musiek et al, 1999; Weihing et al, 2012). To date, it has not been investigated how well these MLR intratest measures reduce within-group variability in adults of various ages, nor has it been shown that these intratest measures are sensitive to aging-related changes in the CANS. The two primary goals of the present study were (1) to determine if calculating an intratest MLR measure, the difference in MLR Na-Pa peak-to-peak amplitude on left versus right ear stimulation (i.e., "ear effects"), will reduce within-group variability in adults of various ages; and (2) to determine if ear effect magnitude will change as a function of aging. Ear effects were measured in both quiet and in noise to determine if the addition of noise enhanced any age-related-effects. A cross-sectional study was conducted. The researchers studied 30 adults ranging in age from 20-80 yr with hearing sensitivity of 25 dB HL or better at the octave frequencies from 500-2000 Hz, and no history of neurologic issues. Adults were assigned to one of three age groups based on their chronological age, which were young adults, middle-aged adults, and older adults. MLRs were acquired using a Nicolet Spirit 2000 during a single laboratory visit. To determine if within-group variability decreased significantly with ear effects, variability for absolute amplitude measures was compared to ear effect variability using the Pitman t-test. To examine potential effects of background noise and aging, data were analyzed using a mixed-factorial analysis of variance with the within-subjects factor "background noise" and the between-subjects factor "age group." Within-group variability was significantly reduced by calculating ear effects for the youngest group only. Additionally, the oldest adults in the present sample showed significantly larger ear effects than younger and middle-aged adults. This effect did not appear to be a result of differences in peripheral hearing sensitivity. Finally, introducing noise into the paradigm did not influence the observed effects. Ear effects become larger in older adults possibly as a result of age-related changes in the subcortical and/or cortical generators of the MLR. Failure of the ear effect calculation to reduce within-group variability in the middle-aged and older adults suggests that interaural asymmetries in MLR amplitude become more variable across participants who are older than 50 yr. Information obtained from this measure may benefit the development of treatment plans for older adults with hearing difficulties.