Objectives-To determine which factors measured at baseline and during the course of treatment influence time to return to work after a first compensated episode ofback pain. Methods-The design is a treatment inception cohort including 305 compensated workers out of 402 eligible ones presenting at two rehabilitation centres for conventional treatment. Crude and adjusted rate ratios (RRs) along with 95% confidence intervals (95% CIs) were estimated with the Cox's proportional hazards regression.

No abstract

The purpose of this study, carried out on handlers in the distribution centre of a large transport company, was to identify the techniques used for handling objects other than boxes. Thirty-one workers, with experience varying from one month to 17 years, were each filmed during one shift. A grid with 36 variables allowed the successive operations to be described: the type of grip, the nature and the direction of the efforts by the upper limbs, the use of the back and the lower limbs, and the displacement of the object. Nine hundred and forty-four handlings carried out in 3217 distinct movements were analysed. These observations revealed the complexity of the handling techniques and the tendency to favour some of them. Seventy-nine per cent of the handlings observed included pre-transfer and/or post-placement phases in addition to the transfer itself. Essentially horizontal phases (pulling, pushing) are more frequent than essentially vertical ones (lifting, lowering); asymmetry is generalized, whether it involves the back position (torsion), the direction and the type of effort, the position of the hands on the object, etc. More than half of the efforts are used to move an object resting on a surface (sliding, pivoting, turning, rolling); resistive efforts downwards (e.g., lowering) are avoided in favour of 'throwing' or 'dropping'.

The first objective of this paper is to compare the observation procedures proposed to characterize physical work. The second objective is to examine the following 3 methodological issues: reliability, observer training, and internal validity. Seventy-two papers were reviewed, 38 of which proposed a new or modified observation grid. The observation variables identified were broken down into 7 categories as follows: posture, exertion, load handled, work environment, use of feet, use of hands, and activities or tasks performed. The review revealed the variability of existing procedures. The examination of methodological issues showed that observation data can be reliable and can present an adequate internal validity. However, little information about the conditions necessary to achieve good reliability was available.

Training programmes in handling have been one of the most used means of preventing work-related backache. The effectiveness of these programmes has not yet been demonstrated however, since they have rarely been evaluated. The purpose of this study was precisely to assess one of these programmes in the hospital sector which specifically dealt with the handling of patients. A field study was conducted and handling methods used by 32 trained orderlies were characterized using an observational grid developed and validated specifically to describe patient handling operations. The extent to which these orderlies used the handling methods taught was determined, and the observed deviations from these methods were characterized and interpreted. The results show that the handling principles taught (working with a straight back using the legs) were not frequently used in the workplace. Furthermore, the use of training was closely related to the type of handling carried out. In handling operations in which the effort includes a horizontal component (mainly those carried out in bed) the training was hardly used, while in vertical handling operations the taught principles were more frequently used. These results suggest that actual training is not well adapted to the handling of patients, particularly to horizontal handling carried out in the bed. Two main deficiencies in the actual programmes are pointed out. First, it is shown that, for reasons of physical constraints, training could not always be applied; second, the rationale of the taught principles could also be questioned, particularly the emphasis given to the use of the legs.