The impact of tool selection on back and wrist injury risk in tying steel reinforcement bars: a single case experiment

Abstract

The paper explores the risk of work-related musculoskeletal injury in tying steel reinforcement bars. Three tools are compared to determine the extent to which ergonomic tools can reduce the risk of injury to the back and wrist in steel-tying. A whole body system of wearable sensors was used to measure biomechanical risk in tying. Three tools were assessed to determine their impact on the risk of work-related musculoskeletal injury when used at different heights. These were: a conventional pincer-cutting tool; a power-driven tying tool, and a long handled stapler tool.
 No tool was found to work best in all situations. The long handled stapler tool significantly reduced trunk inclination when used from ground to shoulder height, but produced higher trunk extension (backward bending) when used above shoulder height. The power tying tool did not reduce the need to bend when working at lower work heights. The power-tying tool produced significantly lower peak wrist flexion values compared to the conventional pincer-cutter tool at all work heights except overhead. The power tying tool involved significantly lower levels of wrist rotation than the conventional pincer-cutter tool at all work heights above knee level.
 Many assessments of ergonomic risk factors in construction rely on observational methods. The use of small, lightweight wearable sensors permits the objective measurement of biomechanical risk factors for work-related musculoskeletal injury, as well as providing objective performance data that can be used in the design and selection of task-specific tools. Our analysis of work by height also provides insight into the way in which risk factors and reduction opportunities afforded by different tools vary depending on the height at which work is to be performed.

Identifying user requirements in order to digitally enable the off-site fabrication of steel reinforcement

“…Lower back injuries being the most prevalent musculoskeletal disorders experienced by rebar workers (Hunting et al 1999). Studies have found that rebar workers currently spend 37 -48% of the working time in a nonneutral trunk working posture (Burdorf et al 1991, Buchholz et al 2003, Forde and Buchholz 2004, Lingard et al 2019. As such, it follows that the manual process of rebar tying leads to a high risk of musculoskeletal disorders (Umer et al 2017).…”

“…This leads to a decrease in static trunk bending and thereby decreasing the peak and cumulative compressive forces on the lower back (Vi 2003). Lingard et al (2019) investigated the impact of tool selection on back and wrist injury risk during steelfixing, and found that no single tool (nips, hand-held automatic rebar tying power tool, and/or long-handled stapler tool) was best in all situations and that work at different heights (in relation to the worker's body) involves different levels of risk to the back and wrist. However, Badgujar et al (2019) reported that knots tied using automatic rebar-tying tools were less rigid and stiff than those done manually with nips.…”