Muscle fatigue induced by exercise simulating the work rate of competitive soccer

Fatigue represents a reduction in the capability of muscle to generate force. The aim of the present study was to establish the effects of exercise that simulates the work rate of competitive soccer players on the strength of the knee extensors and knee flexors. Thirteen amateur soccer players (age 23.3+/-3.9 years, height 1.78+/-0.05 m, body mass 74.8+/-3.6 kg; mean+/-s) were tested during the 2000-2001 soccer season. Muscle strength of the quadriceps and hamstrings was measured on an isokinetic dynamometer. A 90 min soccer-specific intermittent exercise protocol, incorporating a 15 min half-time intermission, was developed to provide fatiguing exercise corresponding in work rate to a game of soccer. The exercise protocol, performed on a programmable motorized treadmill, consisted of the different intensities observed during soccer match-play (e.g. walking, jogging, running, sprinting). Muscle strength was assessed before exercise, at half-time and immediately after exercise. A repeated-measures analysis of variance showed significant reductions (P < 0.001) in peak torque for both the quadriceps and hamstrings at all angular velocities (concentric: 1.05, 2.09, 5.23 rad x s(-1); eccentric: 2.09 rad x s(-1)). The peak torque of the knee extensors (KE) and knee flexors (KF) was greater before exercise [KE: 232+/-37, 182+/-34, 129+/-27, 219+/-41 N x m at 1.05, 2.09 and 5.23 rad x s(-1) (concentric) and 2.09 rad x s(-1) (eccentric), respectively; KF: 126+/-20, 112+/-19, 101+/-16, 137+/-23 N x m] than at half-time (KE: 209+/-45, 177+/-35, 125+/-36, 214+/-43 N x m; KF: 114+/-31, 102+/-20, 92+/-15, 125+/-25 N x m) and greater at half-time than after exercise (KE: 196+/-43, 167+/-35, 118+/-24, 204+/-43 N x m; KF: 104+/-25, 95+/-21, 87+/-13, 114+/-27 N x m). For the hamstrings:quadriceps ratio, significant changes were found (P < 0.05) for both legs, the ratio being greater before than after exercise. For fast:slow speed and left:right ratios, no significant changes were found. We conclude that there is a progressive reduction in muscle strength that applies across a range of functional characteristics during exercise that mimics the work rate in soccer.     

Analysis of Personality,Suicide, and Self‐Injury in Emerging Adulthood

Nonsuicidal self‐injury (NSSI) is a maladaptive coping strategy that is of significant clinical concern for behavioral health professionals in college settings. Relationships between NSSI, acquired capability for suicide, interpersonal cognitions, and five‐factor model personality traits were assessed in a survey‐based study that included 192 young adults in a college setting. Results indicated that those with an affirmative suicide attempt history, greater acquired capability for suicide, and elevated neuroticism had an increased likelihood of lifetime NSSI.     

Emotional eavesdropping: infants selectively respond to indirect emotional signals

Two experiments examined whether 18-month-olds learn from emotions directed to a third party. Infants watched an adult perform actions on objects, and an Emoter expressed Anger or Neutral affect toward the adult in response to her actions. The Emoter then became neutral and infants were given access to the objects. Infants' actions were influenced by their memory of the Emoter's affect. Moreover, infants' actions varied as a function of whether they were currently in the Emoter's visual field. If the previously angry Emoter was absent (Experiment 1) or turned her back (Experiment 2), infants did not use the prior emotion to regulate their behavior. Infants learn from emotional eavesdropping, and their subsequent behavior depends on the Emoter's orientation toward them.     

Analogue equivalents in number processing of simple arithmetic sums

This study had two aims. The first was to test the postulate of analogical equivalents in number processing using a stimulus set based on the differences between pairs of numbers, and second, to look for IQ-dependent differences in this processing. Participants were asked to make judgments concerning the differences between pairs of numbers—each number pair being defined according to overall numerical size and level of difference—and to draw the magnitude of the differences using a free-hand line. In agreement with previous findings, results indicated that the magnitude of participants' responses was dependent on the sizes and levels of the differences within the number pairs. In particular, participants' responses to a difference of nine units at the highest level were based on unit lengths smaller in magnitude compared with other number pairs. In contrast, participants' responses to a second test requiring them to estimate the length of a line using an independent number scale showed remarkable accuracy across all lengths. The results of the two tests did not, however, indicate any difference in responses based on IQ. The results gave support to the idea that transformation of numerical quantities to their analogical equivalents occurs during simple arithmetic sums, and that this transformation was flawed as suggested by the number size effect.     

Elite wheelchair rugby: a quantitative analysis of chair configuration in Australia

Limited recommendations of wheelchair configurations for court sports have been identified in the published literature. To accommodate the wide range of impairments in wheelchair rugby, players are given a point score that reflects their impairment. Players have regularly been grouped as high-, mid-, or low-point players in research, with high-point players having greater levels of muscle function compared with other classifications. This research documented the wheelchair configurations of elite Australian wheelchair rugby players across classification groups. Significant differences (p < 0.05) were found for increased seat height and decreased seat depth for high-point players compared with low- and mid-point groups, respectively. Low-point players displayed reduced wheelchair mass compared with high- and mid-point players, as well as increased frame length. Camber angles showed no significant differences across the classification groups. The incorporation of anthropometric measures, such as the elbow angle at the top dead center, was also investigated. While elbow angle showed no significant differences, seat height-to-total arm length ratio was higher for high-point players. Participants also completed surveys detailing their perception of the effect of altering wheelchair configurations. It is suggested that wheelchair configurations should consider an individual’s anthropometrics, impairment, training history, and court role to promote optimal performance, with predictive modeling having the potential to reduce the associated time and cost.     

Child maltreatment related injuries: incidence, hospital charges, and correlates of hospitalization

OBJECTIVE: This study was undertaken to determine the incidence, hospital charges, and correlates associated with inpatient treatment of child maltreatment related injuries. METHODS: The data were based on the 1995 Pennsylvania Hospital Discharge Data which included all Pennsylvania acute care hospitals that reported child maltreatment discharges. Per capita hospital discharge rates were computed for children discharged with child maltreatment related injuries according to selected variables. Odds ratios for child maltreatment related injury hospitalizations were also computed. RESULTS: A total of 348 maltreated injured children ages 0-19 years were discharged from Pennsylvania hospitals in 1995, representing an incidence rate of 10.8 per 100,000 persons. The total hospital charges for child maltreatment related injury discharges amounted to over $5.4 million, of which Medicaid alone paid for 45%. Compared to a random sample of non-maltreated injured children (n = 1052), maltreated injured children were found to be significantly younger, more likely to be females, and more likely to be Black. Child maltreatment related injury hospitalizations were more likely to be urgent and via physician referral or transfer from other health care facility. Maltreated injured children were three times as likely to die as other children. CONCLUSIONS: These findings indicate that injury from child maltreatment is a major cause of hospitalization of young children 5 years and younger and represents a significant cost to publicly financed health care. While hospital discharge data can be used for population-based surveillance of child maltreatment related trauma, there is need for improvement in the surveillance of these injuries.