Lotta Löfqvist

Ergonomic evaluation of long-shafted tools used in horse stables: the effects of shaft length variation and work technique on working posture

This study examined the physical demands involved in manual manure handling in horse stables when using two different long-shafted work tools, a shavings fork and a manure fork, and investigated how variations in shaft length affected the physical workloads of the user. The methods used were generic task specification (GTS) and the Jack human simulation system (JACK). In general, adding 10 cm to the 125 cm length of the existing manure fork shaft gave the highest reduction in load on the back, especially regarding compression forces, irrespective of body height, sub-task and work technique. Simulations with the shavings fork (length 150 cm) showed that correcting user work technique considerably reduced the load on the back. Thus, it is important to consider both the shaft length of a tool and the work technique when attempting to reduce the physical work load for users.

An analytical ergonomic risk evaluation of body postures during daily cleaning tasks in horse stables

BACKGROUND Musculoskeletal disorders (MSDs) are a common reason for health problems and sick leave in many professions. A work arena where MSDs have not been sufficiently studied is stable work. Here many heavy and repetitive work tasks are performed manually with old-fashioned working tools. OBJECTIVE The aim of this study was to use an analytical approach to identify, evaluate and grade ergonomic problems in physical work performed during daily activities in horse stables and relate these to MSDs among the workers and to the design of the tools. METHODS Three common work tasks were studied to identify, evaluate and grade ergonomic problems; mucking out, sweeping and bedding replacement. Used methods were Hierarchical Task Analysis, Heuristic Evaluation and Rapid Entire Body Assessment. RESULTS Several high-risk operations were found in mucking out boxes and disposal of bedding material. The problems consisted of awkward working postures such as a twisted and bent back, arms in an elevated position, wrists in extreme joint positions and handling of heavy loads. CONCLUSIONS By using an analytical approach it is possible to identify presumptive ergonomic problems without extensive empirical research. In most high-risk operations, long-shafted tools or a wheelbarrow were used, which emphasize a need to develop tools with better ergonomic design to improve the working situation. The limitation is that the ergonomics problems found are not finally validated. The results show where deeper empirical research is needed, both regarding how MSDs occur and how tools and environment contribute to physical problems.