The influence of materialism and ideal body internalization on body‐dissatisfaction and body‐shaping behaviors of young men and women: Support for the Consumer Culture Impact Model

Exposure to media images of the ‘body‐perfect’ ideal has been partly blamed for the pursuit of thinness among women and muscularity among men. Research has largely overlooked the materialistic messages frequently associated with these images. We present findings from two studies with Icelandic students aged 18–21, one focusing on young women (n = 303) and one on young men (n = 226), which test associations of materialistic and body‐perfect ideals with body dissatisfaction and excessive body shaping behaviors. In both studies, the internalization of materialistic values is strongly linked to the internalization of body‐perfect ideals: the thin‐ideal for young women, and the muscular‐ideal for young men. A materialist value orientation also predicted body dissatisfaction in both studies, and was linked to body shaping behaviors, albeit differently for young women and men. Thus, the research identifies materialism as a further correlate of both body dissatisfaction and excessive body‐shaping behaviors. The findings support Dittmar's ( 2008 ) Consumer Culture Impact Model, which proposes that the body‐perfect and ‘material good life’ ideals jointly impact well‐being.     

Comparison of trunk muscle reflex activation patterns between active and passive trunk flexion–extension loading conditions

The aim of the present study was to determine the effects of trunk flexion–extension loading on the neuromuscular reflexive latencies and amplitude responses of the trunk musculature. Eighteen male and female subjects (18–27 yrs) participated in active and passive trunk flexion extension, performed ∼7 days apart. Subjects performed 60 trunk flexion–extension repetitions. Surface electromyography (EMG) was collected bilaterally from paraspinal and abdominal muscles. In the active condition, subjects volitionally moved their trunks, while in the passive condition the dynamometer controlled the movements. The trunk was perturbed before and immediately after 30 repetitions. Latency of muscle onset, latency of first peak, latency of maximum peak, and peak EMG amplitude were evaluated. No differences between conditions, sides, or perturbation session were apparent. Overall latencies were shorter in females (p < .05) and abdominal muscles compared to paraspinals (p < .05). Thoracic paraspinal muscle amplitudes were greater than all other muscles (p < .05). Based upon the present results, the neuromuscular system engages trunk flexor muscles prior to the paraspinals in order to provide possible stabilization of the trunk when flexor moments are generated. Overall, the results indicate no difference in response of the neuromuscular system to active or passive repetitive loading.     

Modulation of motor variability related to experimental muscle pain during elbow-flexion contractions

Experimental muscle pain typically reorganizes the motor control. The pain effects may decrease when the three-dimensional force components are voluntarily adjusted, but it is not known if this could have negative consequences on other structures of the motor system. The present study assessed the effects of acute pain on the force variability during sustained elbow flexion when controlling task-related (one-dimensional) and all (three-dimensional) contraction force components via visual feedback. Experimental muscle pain was induced by bolus injection of hypertonic saline into m. biceps brachii, and isotonic saline was used as control. Twelve subjects performed sustained elbow flexion at different levels of the maximal voluntary contraction (5–30% MVC) before, during, and after the injections. Three-dimensional force components were measured simultaneously with surface electromyography (EMG) from elbow flexors and auxiliary muscles. Results showed that force variability was increased during pain compared to baseline for contractions using one-dimensional feedback (P < .05), but no significant differences were found for three-dimensional feedback. During painful contractions (1) EMG activity from m. trapezius was increased during contractions using both one-dimensional and three-dimensional feedback (P < .05), and (2) the complexity of EMG from m. triceps brachii and m. deltoid was higher for the three-dimensional feedback (P < .05). In conclusion, the three-dimensional feedback reduced the pain-related functional distortion at the cost of a more complex control of synergistic muscles.     

Muscle strength and functional performance is markedly impaired at the recommended time point for sport return after anterior cruciate ligament reconstruction in recreational athletes

PurposeTo examine potential deficits in muscle strength or functional capacity when comparing (1) an ACL reconstructed group to matched healthy controls, (2) the ACL reconstructed leg to the non-injured leg and (3) the non-injured leg to matched healthy controls, at the time-point of recommended sport return 9–12 months post-surgery.MethodsSixteen patients (male-female ratio: 9:7) 9–12 months post ACL reconstruction and sixteen age and sex matched healthy controls were included. Outcome measures included maximal knee extensor (KE) and knee flexor (KF) dynamometry, including measurement of rate of force development, functional capacity (counter movement jump (CMJ) and single distance hop (SDH)) and the Lysholm score.ResultsCompared to the control group, maximal KE and KF muscle strength were impaired in the ACL reconstructed leg by 27–39% and 16–35%, respectively (p < .001). Also, impairments of both CMJ (38%) and SDH (33%) were observed (p < .001). Rate of force development for KE were reduced in the ACL group compared to the control group (p < .001). Similarly, the KE and KF muscle strength, CMJ and SDH of the ACL reconstructed leg were impaired, when compared to the non-injured leg by 15–23%, 8–20%, 23% and 20%, respectively (p < .05).ConclusionMuscle strength and functional capacity are markedly impaired in the ACL reconstructed leg of recreationally active people 9–12 months post-surgery when compared to healthy matched controls and to their non-injured leg. This suggests that objective criteria rather than “time-since-surgery” criteria should guide return to sport.     

Reorganised motor control strategies of trunk muscles due to acute low back pain

This study assessed how the low back motor control strategies were affected by experimental pain. In twelve volunteers the right m. longissimus was injected by hypertonic and isotonic (control) saline. The pain intensity was assessed on a visual analog scale (VAS). Subjects were seated on a custom-designed chair including a 3-dimensional force sensor adjusted to the segmental height of T1. Electromyography (EMG) was recorded bilaterally from longissimus, multifidus, rectus abdominis, and external oblique muscles. Isometric trunk extensions were performed before, during, and after the saline injections at 5%, 10%, and 20% of maximum voluntary contraction force. Visual feedback of the extension force was provided whereas the tangential force components were recorded. Compared with isotonic saline, VAS scores were higher following hypertonic saline injections (P < .01). Experimental low back pain reduced the EMG activity bilaterally of the rectus abdominis muscles during contractions at 10% and 20% MVC (P < .01) although force accuracy and tangential force variability was not affected. Increased variability in the tangential force composition was found during pain compared with the non-painful condition (P < .05). The immediate adaptation to pain was sufficient to maintain the quality of the task performance; however the long-term consequence of such adaptation is unknown and may overload other structures.     

Contributions of Behavioral Systems Science to Leadership for a New Progressive Movement

We argue in this paper that we are in the midst of a period in which fundamental global change will be required if societies and many species, perhaps even our own, are to survive. The realities are inescapable, and the potential implications are likely to affect nearly every dimension of human life in the USA and globally. Current trends are discouraging and will be extraordinarily difficult to shift, given global structural realities. It is hard to imagine a time when effective leadership is more necessary or will be more challenging. Our thesis here is that behavioral systems science can contribute in meaningful ways to shaping and sustaining such leadership, leadership required to advance a new progressive movement.     

Does the Broaden-and-Build Theory Explain Reduction in Social Disruption After a Brief Relaxation Intervention for Women With Breast Cancer Undergoing Treatment?

Women with breast cancer experience social disruption during and after treatment. Brief cognitive-behavioral (CBT) and relaxation (RT) interventions may improve social disruption by increasing positive affect. Using the Broaden-and-Build Theory as a framework, this study examined whether short-term CBT- and RT-related increases in positive affect mediate long-term reductions in social disruption in women with breast cancer undergoing treatment (N = 183). This secondary analysis used latent change score and growth models to test 6- and 12-month intervention effects on positive affect and social disruption, respectively; a parallel-process model assessed mediation. RT demonstrated larger reductions in social disruption across 12 months compared to CBT and a health education control. Six-month latent change in positive affect was significant but not driven by condition. There was a significant direct effect linking the latent slopes of positive affect and social disruption but meditation was not observed. These preliminary findings hint at the value of promoting positive affect and inform the development of brief behavioral interventions that aim to augment social functioning among women surviving breast cancer.     

An evaluation of progressively increasing intertrial intervals on the acquisition and generalization of three social skills

We evaluated the effects of different intertrial intervals (ITIs; time between programmed learning opportunities) on the acquisition and generalization of 2 preschoolers' social skills. Independent and generalized skills were observed only when the daily ITI was gradually increased from short to progressively longer intervals.     

Immediate postsession feeding reduces operant responding in rats

Three experiments investigated the effects of immediate and delayed postsession feeding on progressive-ratio and variable-interval schedule performance in rats. During Experiments 1 and 2, immediate postsession feeding decreased the breakpoint, or largest completed ratio, under progressive-ratio schedules. Experiment 3 was conducted to extend the results of the first two experiments to responding maintained by variable-interval schedules with different session lengths (15 and 60 min). Response rates decreased in all 4 subjects when postsession feeding immediately followed a 15-min session and in 3 of 4 subjects when postsession feeding immediately followed a 60-min session. The implications of this research are twofold: (1) The functional context in which within-session reinforcers are embedded extends outside the experimental chamber, and (2) supplemental postsession feedings should be sufficiently delayed from the end of a session to avoid weakening operant behavior in the experimental sessions.