Variability of a “force signature” during windmill softball pitching and relationship between discrete force variables and pitch velocity

This study assessed reliability of discrete ground reaction force (GRF) variables over multiple pitching trials, investigated the relationships between discrete GRF variables and pitch velocity (PV) and assessed the variability of the “force signature” or continuous force-time curve during the pitching motion of windmill softball pitchers. Intraclass correlation coefficient (ICC) for all discrete variables was high (0.86–0.99) while the coefficient of variance (CV) was low (1.4–5.2%). Two discrete variables were significantly correlated to PV; second vertical peak force (r(5) = 0.81, p = 0.03) and time between peak forces (r(5) = −0.79; p = 0.03). High ICCs and low CVs support the reliability of discrete GRF and PV variables over multiple trials and significant correlations indicate there is a relationship between the ability to produce force and the timing of this force production with PV. The mean of all pitchers’ curve-average standard deviation of their continuous force-time curves demonstrated low variability (CV = 4.4%) indicating a repeatable and identifiable “force signature” pattern during this motion. As such, the continuous force-time curve in addition to discrete GRF variables should be examined in future research as a potential method to monitor or explain changes in pitching performance.     

Increased forefoot loading is associated with an increased plantar flexion moment

The aim of this study was to identify the cascade of effects leading from alterations in force generation around the ankle joint to increased plantar pressures under the forefoot. Gait analysis including plantar pressure measurement was performed at an individually preferred and a standardized, imposed gait velocity in diabetic subjects with polyneuropathy (n = 94), without polyneuropathy (n = 39) and healthy elderly (n = 19). The plantar flexion moment at 40% of the stance phase was negatively correlated with the displacement rate of center of pressure (r = ?.749, p < .001 at the imposed, and r = ?.693, p < .001 at the preferred gait velocity). Displacement rate of center of pressure was strongly correlated with forefoot loading (r = ?.837, p < .001 at the imposed, and r = ?.731, p < .001 at the preferred gait velocity). People with a relatively high plantar flexion moment at 40% of the stance phase, have a faster forward transfer of center of pressure and consequently higher loading of the forefoot. This indicates that interventions aimed at increasing the control of the roll-off of the foot may contribute to a better plantar pressure distribution.     

The relationship between allometry and preferred transition speed in human locomotion

The purpose of this study was to explore the relationships between preferred transition speed (PTS) and anthropometric characteristics, body composition and different human body proportions in males. In a sample of 59 male students, we collected anthropometric and body composition data and determined individual PTS using increment protocol. The relationships between PTS and other variables were determined using Pearson correlation, stepwise linear and hierarchical regression. Body ratios were formed as quotient of two variables whereby at least one significantly correlated to PTS. Circular and transversal (except bitrochanteric diameter) body dimensions did not correlate with PTS. Moderate correlations were found between longitudinal leg dimensions (foot, leg and thigh length) and PTS, while the highest correlation was found for lower leg length (r = .488, p < .01). Two parameters related to body composition showed weak correlation with PTS: body fat mass (r = −.250, p < .05) and amount of lean leg mass scaled to body weight (r = .309, p < .05). Segmental body proportions correlated more significantly with PTS, where thigh/lower leg length ratio showed the highest correlation (r = .521, p < .01). Prediction model with individual variables (lower leg and foot length) have explained just 31% of PTS variability, while model with body proportions showed almost 20% better prediction (R² = .504). These results suggests that longitudinal leg dimensions have moderate influence on PTS and that segmental body proportions significantly more explain PTS than single anthropometric variables.     

Inbreeding depression and IQ in a study of 72 countries

In this ecological study, a robust negative correlation of r = ? .62 (P < .01) is reported between national IQs and consanguinity as measured by the log₁₀ transformed percentage of consanguineous marriages for 72 countries. This correlation is reduced in magnitude, when IQ is controlled for GDP per capita (r = ? .41, P < .01); education index (r = ? .40, P < .01); and democracy index (r = ? .42, P < .01). Multiple regression analysis revealed that in the absence of the democracy index; percentage consanguineous marriages, education index and GDP per capita all exhibited stable final standardized β coefficients, however consanguinity had the least impact (β = 0, P > .05) whereas GDP per capita had the highest (β = .35, P > .01). This result is interpreted in light of cultural feedback theory, whereby it is suggested that consanguinity could subtly influence IQ at larger scales as a result of small IQ handicaps bought about through inbreeding being amplified into much larger differences through their effect on factors that maximize IQ such as access to education and adequate nutrition. Finally, consideration is given to future potential research directions.     

Personality and physical activity: A systematic review and meta-analysis

Whether personality determines physical activity or its outcomes is relevant for theory and public health but has been understudied. We estimated the population correlations between Big-Five personality factors and physical activity and examined whether they varied according to sample characteristics and study features. Database searches were conducted according to PRISMA guidelines, for articles published in the English language prior to November 1st, 2013. Sixty-four studies including a total of 88,400 participants yielded effects (k) for Extraversion (88), Neuroticism (82), Conscientiousness (69), Openness (51) and Agreeableness (52). Significant mean r was found for Extraversion (r = .1076), Neuroticism (r = −.0710), Conscientiousness (r = .1037) and Openness (r = .0344), but not Agreeableness (r = .0020). Effects were moderately heterogeneous (I² range = 44–65%) and varied by sample characteristics (e.g., age, gender, or clinical status) and/or study features (e.g., measure quality or item format). This analysis expands results of previous reviews and provides new support for a relationship between physical activity and Openness. Future studies should use better measures of physical activity and prospective designs, adjust for statistical artifacts, and consider advances in the conceptualization of personality.     

Facial width-to-height ratio and celebrity endorsements

This study hypothesized that the facial WHR of celebrity endorsers is associated with their endorsement income. Our sample consisted of the top 100 male and female celebrity endorsers (male = 50 and female = 50) in Seoul. The average annual total endorsement income of celebrity endorsers in 2012 was $1,691,924 for male endorsers and $1,684,474 for female endorsers. A statistical analysis demonstrated a significant negative correlation between celebrity endorsers’ facial WHR and their endorsement income in 2012 among male (r = −.390, p = .007, n = 47) but not among female (r = .166, p = . 248, n = 50) endorsers. Our findings imply that males with narrower faces are more popular among the media as well as among advertisers. Our study is the first to explore the relationship between physical features, such as facial WHR and monetary income in the entertainment industry.     

The relationship between hip,knee and ankle muscle mechanical characteristics and gait transition speed

The purpose of the present study was to explore the relationship between mechanical characteristics of hip, knee and ankle extensor and flexor muscle groups and gait transition speed. The sample included 29 physically active male adults homogenized regarding their anthropometric dimensions. Isokinetic and isometric leg muscle mechanical characteristics were assessed by an isokinetic dynamometer, while individual walk-to-run (WRT) and run-to-walk transition speeds (RWT) were determined using the standard increment protocol. The relationship between transition speeds and mechanical variables scaled to body size was determined using Pearson correlation and stepwise linear regression. The highest correlations were found for isokinetic power of ankle dorsal flexors and WRT (r = .468, p < .01) and the power of hip extensors and RWT (r = .442, p < .05). These variables were also the best predictors of WRT and RWT revealing approximately 20% of explained variance. Under the isometric conditions, the maximal force and rate of force development of hip flexors and ankle plantar flexors were moderately related with WRT and RWT (ranged from r = .340 to .427). The only knee muscle mechanical variable that correlated with WRT was low velocity knee flexor torque (r = .366, p < .05). The results generally suggest that the muscle mechanical properties, such as the power of ankle dorsal flexors and hip extensors, influence values of WRT and RWT.     

Contextual effects on activity profiles of domestic field hockey during competition and training

Game context is widely accepted to influence performance but most data available is ‘categorical’ and addresses performance rather than activity. This study assessed direct effects of opposition and team ranking in field hockey to establish influences on activity. One hundred and eight (n = 108) female field hockey players (age 16–39 years) participated, giving 186 competition and 48 training analyses. Team average distance (mean ± SD) observed in a mid-ranked team during competition ranged from 5949 ± 611 to 7719 ± 257 m demonstrating an opposition rank effect (Pearson’s r = .71; adjusted R² = .42). However, multiple linear regression analysis demonstrated a stronger relationship in lower ranked teams (Pearson’s r = .99; adjusted R² = .97 through 3–9). In contrast, no team rank effect was observed during randomly monitored competition where team average distance ranged from 5177 ± 444 to 7316 ± 241 m (Pearson’s r = .15 and adjusted R² = .12). In training, however, a team rank effect was observed in distance-related performance indicators where team average distance during small-sided games ranged from 5877 ± 188 to 3551 ± 193 m drill (per 70 min) with Pearson’s r = .95 and adjusted R² = .87. The presence of contextual effects has significant practical implications for team sports where the training load assumed from competition may be overestimated.     

A comparison of self-other agreement in personal values versus the Big Five personality traits

Can we judge other people’s values accurately, or are values too subjective to assess? We compared self-other agreement in personal values with agreement in the Big Five personality traits. Self-other agreement in four higher-order values (median r = .47) and in six culture-specific value factors (median r = .50) was substantial and similar to that for the Big Five personality traits (median r = .51). When corrected for attenuation due to measurement error self-other agreement was high for all three scales (median rs > .65). The results suggest that people can assess values of others whom they know well with remarkable accuracy. Therefore, other-ratings of personal values can be used to validate and complement self-report value measures.     

Impact of the telephone motivational interviewing on the colorectal cancer screening participation. A randomized controlled study

IntroductionWhile high participation rates ensure the cost-effectiveness of colorectal cancer screening programs, it is well known that postal requests do not achieve acceptable levels of participation.ObjectiveThis randomized controlled study aimed to test the impact of individualized phone counseling to prompt people aged 50 to 74 to take a colorectal cancer test.MethodTwo phone strategies were compared. The first involved computer-aided individualized counseling while the second was based on motivational interviewing. A total of 49,972 people were randomly assigned to a control group (CG) and to the individualized counseling (IC) and motivational interviewing (MI) telephone groups.ResultsA simple call doubled the participation rate per protocol (19.2% > 9.2%; p < .001; r = .131; OR = 2.374), and tripled it when the interview was conducted (30.4% > 9.2%; p < .001; r = .219; OR = 4.321). In an intention-to-treat analysis, the benefit of calling by phone remained even higher than postal requests (10% > 9.2%; p < .01; r = .014; OR = 1.103). However, there was no impact of the type of interview on participation rates.ConclusionThe results are discussed for future research.     

High- compared to low-arched athletes exhibit smaller knee abduction moments in walking and running

High- (HA) and low-arched athletes (LA) experience distinct injury patterns. These injuries are the result of the interaction of structure and biomechanics. A suggested mechanism of patellofemoral pain pertains to frontal plane knee moments which may be exaggerated in LA athletes. We hypothesize that LA athletes will exhibit greater peak knee abduction moments than high-arched athletes.MethodsTwenty healthy female recreational athletes (10 HA and 10 LA) performed five over-ground barefoot walking and five barefoot running trials at a self-selected velocity while three-dimensional kinematics and ground reaction forces were recorded. Peak knee abduction moments and time-to-peak knee abduction moments were calculated using Visual 3D.ResultsHigh-arched athletes had smaller peak knee abduction moments compared to low-arched athletes during walking (KAM1: p = 0.019; KAM2: p = 0.015) and running (p = 0.010). No differences were observed in time-to-peak knee abduction moment during walking (KAM1: p = 0.360; KAM2: p = 0.085) or running (p = 0.359).ConclusionsThese findings demonstrate that foot type is associated with altered frontal plane knee kinetics which may contribute to patellofemoral pain. Future research should address the efficacy of clinical interventions including orthotics and rehabilitation programs in these athletes.     

Intelligence and semen quality are positively correlated

Human cognitive abilities inter-correlate to form a positive matrix, from which a large first factor, called ‘Spearman's g’ or general intelligence, can be extracted. General intelligence itself is correlated with many important health outcomes including cardio-vascular function and longevity. However, the important evolutionary question of whether intelligence is a fitness-related trait has not been tested directly, let alone answered. If the correlations among cognitive abilities are part of a larger matrix of positive associations among fitness-related traits, then intelligence ought to correlate with seemingly unrelated traits that affect fitness—such as semen quality. We found significant positive correlations between intelligence and 3 key indices of semen quality: log sperm concentration (r = .15, p = .002), log sperm count (r = .19, p < .001), and sperm motility (r = .14, p = .002) in a large sample of US Army Veterans. None was mediated by age, body mass index, days of sexual abstinence, service in Vietnam, or use of alcohol, tobacco, marijuana, or hard drugs. These results suggest that a phenotype-wide fitness factor may contribute to the association between intelligence and health. Clarifying whether a fitness factor exists is important theoretically for understanding the genomic architecture of fitness-related traits, and practically for understanding patterns of human physical and psychological health.     

The role of motion platform on postural instability and head vibration exposure at driving simulators

This paper explains the effect of a motion platform for driving simulators on postural instability and head vibration exposure. The sensed head level-vehicle (visual cues) level longitudinal and lateral accelerations (a_x,sensed = a_{x_head} and a_y,sensed = a_{y_head}, a_yv = a_{y_veh} and a_yv = a_{y_veh}) were saved by using a motion tracking sensor and a simulation software respectively. Then, associated vibration dose values (VDVs) were computed at head level during the driving sessions. Furthermore, the postural instabilities of the participants were measured as longitudinal and lateral subject body centre of pressure (X_CP and Y_CP, respectively) displacements just after each driving session via a balance platform. The results revealed that the optic-head inertial level longitudinal accelerations indicated a negative non-significant correlation (r = −.203, p = .154 > .05) for the static case, whereas the optic-head inertial longitudinal accelerations depicted a so small negative non-significant correlation (r = −.066, p = .643 > .05) that can be negligible for the dynamic condition. The X_CP for the dynamic case indicated a significant higher value than the static situation (t(47), p < .0001). The VDV_x for the dynamic case yielded a significant higher value than the static situation (U(47), p < .0001). The optic-head inertial lateral accelerations resulted a negative significant correlation (r = −.376, p = .007 < .05) for the static platform, whereas the optic-head inertial lateral accelerations showed a positive significant correlation (r = .418, p = .002 < .05) at dynamic platform condition. The VDV_y for the static case indicated a significant higher value rather than the dynamic situation (U(47), p < .0001). The Y_CP for the static case yielded significantly higher than the dynamic situation (t(47), p = .001 < 0.05).     

Imaging intelligence with proton magnetic resonance spectroscopy

Proton magnetic resonance spectroscopy (¹H-MRS) is a technique for the assay of brain neurochemistry in vivo. N-acetylaspartate (NAA), the most prominent metabolite visible within the ¹H-MRS spectrum, is found primarily within neurons. The current study was designed to further elucidate NAA–cognition relationships, particularly whether such relationships are moderated by sex, or tissue type (gray or white matter). We administered standard measures of intelligence to 63 young, healthy subjects and obtained spectroscopic imaging data within a slab of tissue superior to the lateral ventricles. We found that lower NAA within right anterior gray matter predicted better performance VIQ (F = 6.83, p = .011, r² = .10), while higher NAA within the right posterior gray matter region predicted better PIQ (F = 8.175, p = .006, r² = .12). These findings add to the small but growing body of literature linking brain biochemistry to intelligence in normal healthy subjects using ¹H-MRSI.     

Personality,intelligence and proof-reading

Two studies sought to determine personality and cognitive ability correlates of proof-reading. In both studies candidates were given 5 min to identify up to 55 errors in a 920 word, two page document. In Study 1, which tested 240 school children, fluid intelligence (as measured by the Baddeley Reasoning Test) was the highest correlate of proof-reading (r = .30). Eleven percent of the variance in total attempted scores was accounted for by intelligence, Introversion and low Conscientiousness. In the second study 70 undergraduates completed the same proof-reading test along with two intelligence tests (Baddeley Reasoning Test; Wonderlic Personnel Test) and a more robust personality measure (NEO-FFI). Proof-reading was correlated with both intelligence tests (Baddeley r = .45; Wonderlic r = .40). More of the variance was accounted for in the total attempted-score of errors than for a correct errors-detected score. When the two intelligence and five personality trait scores were regressed on to the proof-reading test score over a quarter of the variance (Adj R² = .28) was accounted for, but only the Baddeley test was a significant predictor (Beta = .39).     

Relationships between match activities and peak power output and Creatine Kinase responses to professional reserve team soccer match-play

The specific movement demands of soccer that are linked to post-match recovery and readiness to train are unclear. Therefore, we examined the relationship between Global Positioning System (GPS) variables and the change (Δ; from baseline) in Creatine Kinase (CK) concentrations and peak power output (PPO; during the countermovement jump) at 24 h and 48 h post-match. Fifteen English Premier League reserve team players were examined over 1–4 matches. Measurements of CK and PPO were taken before (24 h prior to match-play) and after (+24 h and +48 h) each game during which movement demands were quantified using 10 Hz GPS data. High intensity distance covered (r = 0.386, p = 0.029; r = −0.349; p = 0.050), high intensity distance covered⋅min⁻¹ (r = 0.365, p = 0.040; r = −0.364, p = 0.040), high speed running distance (r = 0.363, p = 0.041; r = −0.360, p = 0.043) and the number of sprints⋅min⁻¹ (r = 0.410, p = 0.020; r = −0.368, p = 0.038) were significantly related to ΔCK and ΔPPO at +24 h post-match, respectively. No relationships were observed between any match variables and ΔCK and ΔPPO after +48 h of recovery. These findings highlight that high intensity match activities are related to ΔCK and ΔPPO in the 24 h, but not 48 h, following soccer match-play. Such information is likely of interest to those responsible for the design of soccer player’s training schedules in the days following a match.     

Comparison of fetal and maternal heart rate measures using electrocardiographic and cardiotocographic methods

PurposeTo determine the reliability at term of: (1) two methods of measuring fetal heart rate (HR), electrocardiographic (ECG, the ‘gold standard’) and cardiotocographic (CTG) and (2) two ECG methods of measuring maternal HR variability over relatively brief periods of time (s–min).MethodsDuring 20 min of rest (N = 39) and during 2 min of auditory stimulation (mother's recorded voice, n = 19), fetal HR data were collected using an ECG (Monica AN24) and a Hewlett-Packard Model 1351A CTG. Simultaneously, maternal HR data (n = 37) were collected using the same ECG device (Monica AN24) and a second stand-alone cardiac monitor (Spacelab 514T cardiac monitor with a QRS detector).ResultsDuring 20 min of maternal rest, correlations of individual fetal CTG with ECG measures of HR at each second were moderate to high (r = .57–.97) for 77% of fetuses. Correlations of HR averaged over fetuses and over each of the 20 min were high (r = .93–.97); fetal HR averaged over 20 min varied between devices from 0.0 to 0.8 bpm. During 2 min of maternal voice presentation, correlations of fetal HR over each second were moderate to high (r = .54–.99) for 95% of fetuses and high (all rs = .99) when averaged across fetuses in 30 s or 2 min epochs. Average fetal HR between devices over the 2 min voice varied from 0.0 to 0.6 bpm. Correlations and/or % agreement between the two ECG methods of measuring maternal HR were high. Average maternal HR over 10 min showed 81% of pairs with a difference of ≤1 bpm; correlations for HR variability measures varied from r = .89 to .97.ConclusionsGood reliability was demonstrated between individual spontaneous and auditory induced fetal CTG and ECG with high correlations when HR data were averaged over fetuses or in 30–120 s epochs. High reliability of maternal HR measures was obtained using two ECG devices.     

Propulsion strategy in the gait of primary school children; the effect of age and speed

The strategy used to generate power for forward propulsion in walking and running has recently been highlighted as a marker of gait maturation and elastic energy recycling. This study investigated ankle and hip power generation as a propulsion strategy (PS) during the late stance/early swing phases of walking and running in typically developing (TD) children (15: six to nine years; 17: nine to 13 years) using three-dimensional gait analysis. Peak ankle power generation at push-off (peakA2), peak hip power generation in early swing (peakH3) and propulsion strategy (PS) [peakA2/(peakA2 + peakH3)] were calculated to provide the relative contribution of ankle power to total propulsion. Mean PS values decreased as speed increased for comfortable walking (p < 0.001), fast walking (p < 0.001) and fast running (p < 0.001), and less consistently during jogging (p = 0.054). PS varied with age (p < 0.001) only during fast walking. At any speed of fast walking, older children generated more peakA2 (p = 0.001) and less peakH3 (p = 0.001) than younger children. While the kinetics of running propulsion appear to be developed by age six years, the skills of fast walking appeared to require additional neuromuscular maturity. These findings support the concept that running is a skill that matures early for TD children.     

Walking impairs cognitive performance among people with multiple sclerosis but not controls

People with multiple sclerosis (MS) complain of problems completing two tasks simultaneously; sometimes called ‘dual-tasking’ (DT). Previous research in DT among people with MS has focused on how adding a cognitive task interferes with gait and few have measured how adding a motor task could interfere with cognition. We aimed to determine the extent to which walking affects a concurrent working memory task in people with MS compared to healthy controls. We recruited MS participants (n = 13) and controls (n = 10) matched by age (±3 years), education (±3 years) and gender. Participants first completed the cognitive task (subtracting 7’s from the previous number) and then again while walking on an instrumented walkway. Although there were no baseline differences in cognition or walking between MS participants and controls, MS participants demonstrated a 52% decrease in number of correct answers during DT (p < 0.001). Mental Tracking Rate (% correct answers/min) correlated strongly with MS-related disability measured using the Expanded Disability Status Scale (EDSS; r(11) = −0.68, p < 0.01). We propose that compromised mental tracking during walking could be related to limited neural resource capacity and could be a potentially useful outcome measure to detect ecologically valid dual tasking impairments.     

When is received social support related to perceived support and well-being? When it is needed

How do perceptions of being supported relate to the amount of social support received? Received and perceived support have generally been found to be only moderately related. Previous research has however focused on the amount of support received regardless of whether it was needed. We hypothesized that a measure of support received when needed would predict perceived support and well-being better than would an unqualified measure of received support. Study 1 found that correlations between received support and perceived support measures were, on average, twice as high when received support was measured as the proportion of times support was received when needed (average r = .54) than when it was measured as the number of times support was received (average r = .28). Similar results were found for correlations between received support and mental health which rose from r = .04 to r = .31 when need for support was considered. Study 2 replicated the strong relationship between support received when needed and both perceived support and mental health. Received support measures should be adapted to take the need for support into consideration in future investigation of these relationships. Social support interventions may only be beneficial if the recipient’s support needs are not already being met.