Background

Because pain often signals the occurrence of potential tissue damage, a nociceptive stimulus has the capacity to involuntarily capture attention and take priority over other sensory inputs. Whether distraction by nociception actually occurs may depend upon the cognitive characteristics of the ongoing activities. The present study tested the role of working memory in controlling the attentional capture by nociception.

Methodology and Principal Findings

Participants performed visual discrimination and matching tasks in which visual targets were shortly preceded by a tactile distracter. The two tasks were chosen because of the different effects the involvement of working memory produces on performance, in order to dissociate the specific role of working memory in the control of attention from the effect of general resource demands. Occasionally (i.e. 17% of the trials), tactile distracters were replaced by a novel nociceptive stimulus in order to distract participants from the visual tasks. Indeed, in the control conditions (no working memory), reaction times to visual targets were increased when the target was preceded by a novel nociceptive distracter as compared to the target preceded by a frequent tactile distracter, suggesting attentional capture by the novel nociceptive stimulus. However, when the task required an active rehearsal of the visual target in working memory, the novel nociceptive stimulus no longer induced a lengthening of reaction times to visual targets, indicating a reduction of the distraction produced by the novel nociceptive stimulus. This effect was independent of the overall task demands.

Conclusion and Significance

Loading working memory with pain-unrelated information may reduce the ability of nociceptive input to involuntarily capture attention, and shields cognitive processing from nociceptive distraction. An efficient control of attention over pain is best guaranteed by the ability to maintain active goal priorities during achievement of cognitive activities and to keep pain-related information out of task settings.

Background

Previous studies have indicated that gait patterns in older people may be affected by concern about falling. The aim of this study was to examine the effects of concern about falling and physiological falls risk on gait performance using a paradigm in which concern about falling was experimentally induced.

Methods

Forty-four community-living older adults (17 men, 27 women) with a mean age of 76.8 (standard deviation = 5.2) years walked at self-selected speeds on the floor and on a 60-cm elevated walkway in normal and dim lighting conditions. Temporal and spatial gait parameters, muscle activity, measures of physiological arousal, physiological falls risk, and concern about falls were assessed.

Results

Physiological falls risk was associated with slower walking speeds in all conditions including the optimal (floor) condition (p = .029). In the elevated walkway conditions, concern about falls (both self-report and as indicated by physiological arousal) was increased and participants walked more slowly, took shorter steps, decreased their cadence, and spent more time in double support (p < .005). Disproportionately large reductions in walking speed were evident in participants with greater concern about falling (p = .018).

Conclusions

These findings suggest that walking performance is influenced by both physiological and psychological factors. Physiological falls risk appears to determine walking speed under optimal conditions, whereas concern about falling elicits greater (possibly excessive) gait adjustments under conditions of postural threat.

Background

In the working population, back disorders are an important reason for sick leave and permanent work inability. In the context of fitting the job to the worker, one of the primary tasks of the occupational health physician is to evaluate the balance between work-related and individual variables. Since this evaluation of work capacity often consists of a physical examination of the back, the objective of this study was to investigate whether a physical examination of the low back, which is routinely performed in occupational medicine, predicts the development of low back pain (LBP).

Methods

This study is part of the Belgian Low Back Cohort (BelCoBack) Study, a prospective study to identify risk factors for the development of low back disorders in occupational settings. The study population for this paper were 692 young healthcare or distribution workers (mean age of 26 years) with no or limited back antecedents in the year before inclusion. At baseline, these workers underwent a standardised physical examination of the low back. One year later, they completed a questionnaire on the occurrence of LBP and some of its characteristics. To study the respective role of predictors at baseline on the occurrence of LBP, we opted for Cox regression with a constant risk period. Analyses were performed separately for workers without any back antecedents in the year before inclusion ('asymptomatic' workers) and for workers with limited back antecedents in the year before inclusion ('mildly symptomatic' workers).

Results

In the group of 'asymptomatic' workers, obese workers showed a more than twofold-increased risk on the development of LBP as compared to non-obese colleagues (RR 2.57, 95%CI: 1.09 – 6.09). In the group of 'mildly symptomatic' workers, the self-reports of pain before the examination turned out to be most predictive (RR 3.89, 95%CI: 1.20 – 12.64).

Conclusion

This study showed that, in a population of young workers wh no or limited antecedents of LBP at baseline, physical examinations, as routinely assessed in occupational medicine, are not useful to predict workers at risk for the development of back disorders one year later.

BACKGROUND:

In adults, it is well known that high levels of pain catastrophizing are related to increased pain and disability as well as to heightened anxiety and depression. However, due to the lack of a measure of pain catastrophizing adapted for francophone adolescents, little is known about the role of catastrophizing in this population.

OBJECTIVES:

To adapt the French version of the Pain Catastrophizing Scale (PCS) and to examine the psychometric properties and factorial structure of the PCS for Francophone Adolescents (PCS-Ado).

METHODS:

The French version of the PCS was modified by a group of experts. The format of the questions was modified to be appropriate for adolescents aged between 12 and 18 years. To assess the psychometric properties of the PCS-Ado, 345 adolescents completed the PCS-Ado and questionnaires measuring depression, anxiety and intensity of pain. Twelve to 16 weeks later, participants completed the questionnaires again to examine the test-retest reliability of the PCS-Ado.

RESULTS:

Results revealed a three-factor solution similar to the original PCS. In addition, results revealed that PCS-Ado had good internal consistency (PCS-Ado total: 0.85; rumination: 0.72; magnification: 0.66; helplessness: 0.74), and high test-retest reliability (r=0.73). Finally, significant correlations among catastrophizing, depression, anxiety and pain intensity support the construct validity of the PCS-Ado.

CONCLUSIONS:

The results suggest that the PCS-Ado is valid and reliable with francophone adolescents. Further research is required to assess the validity of the PCS-Ado in clinical settings.