Hip and knee pain: role of occupational factors

Many people rely economically on occupations involving high loading of the hip or knee joints for lengthy periods, possibly placing them at increased risk of developing chronic pain in these joints. There is a growing body of evidence from large longitudinal cohort studies, case-control studies and population-based surveys that certain occupations, or having work involving considerable heavy lifting, kneeling or squatting, may be associated with increased risk of symptomatic hip or knee osteoarthritis and joint replacement surgery. Only a few studies have evaluated the effectiveness of specific workplace strategies to reduce this risk. Identifying modifiable workplace risk factors and implementing feasible and accessible preventative strategies will be of great public health significance in the next decade.     

Challenges in aerospace medicine education

Aerospace medicine training and research represents a dream for many and a challenge for most. In Canada, although some opportunities exist for the pursuit of education and research in the aerospace medicine field, they are limited despite the importance of this field for enabling safe human space exploration. In this commentary, we aim to identify some of the challenges facing individuals wishing to get involved in the field as well as the causal factors for these challenges. We also explore strategies to mitigate against these.     

Number reading in pure alexia--a review

It is commonly assumed that number reading can be intact in patients with pure alexia, and that this dissociation between letter/word recognition and number reading strongly constrains theories of visual word processing. A truly selective deficit in letter/word processing would strongly support the hypothesis that there is a specialized system or area dedicated to the processing of written words. To date, however, there has not been a systematic review of studies investigating number reading in pure alexia and so the status of this assumed dissociation is unclear. We review the literature on pure alexia from 1892 to 2010, and find no well-documented classical dissociation between intact number reading and impaired letter identification in a patient with pure alexia. A few studies report strong dissociations, with number reading less impaired than letter reading, but when we apply rigorous statistical criteria to evaluate these dissociations, the difference in performance across domains is not statistically significant. There is a trend in many cases of pure alexia, however, for number reading to be less affected than letter identification and word reading. We shed new light on this asymmetry by showing that, under conditions of brief exposure, normal participants are also better at identifying digits than letters. We suggest that the difference observed in some pure alexic patients may possibly reflect an amplification of this normal difference in the processing of letters and digits, and we relate this asymmetry to intrinsic differences between the two types of symbols.     

Do Women Understand Urogynecologic Terminology?

OBJECTIVES: The aims of this study were to describe women's stated knowledge of the primary urogynecologic diagnostic terms (urinary incontinence, pelvic floor disorder, and pelvic organ prolapse) and to assess factors associated with knowledge. METHODS: Before any education about pelvic floor disorders, 376 women presenting to primary care-level gynecologic clinics were asked whether they knew what the terms urinary incontinence, pelvic organ prolapse, and pelvic floor disorder meant. χ(2) and t tests were used to compare characteristics of women with complete knowledge versus partial or no knowledge of terms. P < 0.05 was considered significant. RESULTS: Of all women, 25% knew all 3 terms and 18% knew none. Moreover, 80%, 52%, and 27% of women reported that they knew the meaning of the terms urinary incontinence, pelvic organ prolapse, and pelvic floor disorder, respectively. Of women with stress urinary incontinence symptoms, 88% knew the term urinary incontinence compared with 78% without stress urinary incontinence (P = 0.07). Of 41 women, 31 (76%) with the symptom of vaginal bulge knew the term pelvic organ prolapse compared with 49% without (P = 0.001). Only higher education and symptom of vaginal bulge were associated with complete knowledge of the 3 terms; 30% of women who completed college or higher reported complete knowledge compared with 18% who did not (P = 0.013). CONCLUSIONS: Public health campaigns using terms pelvic organ prolapse or pelvic floor disorders are unlikely to reach most women. Further education and research are needed to improve women's health literacy in urogynecology.     

Assessment of Subjective Perceived Exertion at the Anaerobic Threshold with the Borg CR-10 Scale

The purpose of this study was to evaluate the anaerobic threshold (AT) with a graphic visual method for estimating the intensity of ventilatory and metabolic exertion and to determine the ratings of perceived exertion (RPE) on the Borg CR-10 scale during a continuous ramp type exercise test (CT-R). Forty healthy, physically active and sedentary young women (age 23.1 ± 3.52 years) were divided into two groups according to their fitness level: active group (AG) and sedentary group (SG) and were submitted to a CT-R on a cycloergometer with 20 to 25 W/min increments. Shortly before the end of each one-minute period, the subjects were asked to rate dyspnea (RPE-D) and leg fatigue (RPE-L) on the Borg CR-10 scale. After the AT was determined with the graphic visual method, the score that the volunteers gave on the Borg CR10 scale was verified. Data were analyzed using the Mann-Whitney and Spearman correlation tests with the significance level set at 5%. The mean ratings of RPE-L and RPE-D at the AT level were not significantly different between groups (p > 0.05). Significant correlations were found between VO₂, heart rate (HR), power output and RPE for both groups. The muscular and respiratory RPE, according to the Borg CR-10 scale, were correlated with the AT, suggesting that scores close to 5, which correspond to a “strong” perception, may be used as parameters for quantifying aerobic exercise intensity for active and sedentary individuals. The similar perception of exercise intensity, which corresponded to the AT of different individuals, makes it possible to prescribe exercise at an intensity equivalent to the AT by means of the RPE.

Key points

• Interest in quantitative and systematic determination of the AT is growing, however, qualitative studies measure the AT by perceived exertion, are still unsubstantial.
• Borg CR-10 scale is a category scale with ratio properties consisting of numbers related to verbal expressions, which allows rate comparison between intensities as well as a determination of intensity levels.
• Scores close to 5 expressed on the Borg CR-10 scale, which correspond to a “strong” perception, may be used as parameters for quantifying the aerobic exercise intensity of both active and sedentary women.

Key words: Rating of perceived exertion, anaerobic threshold, exercise test