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Coal mines are continuously seeking to determine the performance of entries with different ground control products and installation methods. There are many factors that impact how an entry will perform which include but are not limited to geology, overburden, bolting type and pattern, and mine design. At the National Institute for Occupational Safety and Health (NIOSH), research has been instituted to examine the relationship of the parts of a coal mine entry as a system and not as individual components. To study this relationship, the first step in this study was to create a numeric rating system that accurately reflects visual observations of the mine entry and is easy to implement. NIOSH researchers devised this rating system to improve upon previous ideas, offering increased flexibility which can be incorporated into an overall entry condition that offers different levels of confidence based on the user’s time devoted to the inspection. This new entry rating system was implemented at three different mines over varying periods of time to evaluate the ground response to the geology, bolt installation pattern, stress changes by mining, overburden, and time dependency.

Bolting large sheets of wire mesh screen (WMS) to the roof of underground mines prevents injuries due to rock falls. However, WMS can be heavy and awkward to lift and transport, and may result in significant spinal loading. Accordingly, six male subjects (mean age = 45.8 years + 7.5 SD) were recruited to lift WMS in a laboratory investigation of the biomechanical demands. Biomechanical modeling was used to estimate external moments about L5–S1 for sixteen lifting tasks, using two sizes of WMS. Full-size WMS involved a two-person lift, while half-size WMS involved a one-person lift. Lifts were performed under 168 cm and 213 cm vertical space. Restriction in vertical space increased the maximum L5–S1 extensor moment from 254 to 274 Nm and right lateral bending moment from 195 to 251 Nm. Lifting full sheets of screen (as opposed to half sheets) resulted in an average 33 Nm increase in L5–S1 extensor moment. The L5–S1 extensor moment was increased by an average of 44 Nm (18%) when lifting screens positioned flat on the floor compared to an upright position. Relevance to industry Large flexible materials are commonly lifted in industrial work environments, and may involve the efforts of two or more workers. The current study examines the low back loading associated with lifting large flexible screens and presents recommendations to reduce spine loading.

Roof screen is often bolted to the mine ceiling to help control hazardous rock falls in coal mines. While the screen prevents rock fall injuries, its installation may expose the miner to musculoskeletal stress. The purpose of this study was to evaluate methods of handling roof screen. Subjects performed installation tasks under a normal and intervention condition while trunk kinematics and muscle activity data were collected. Trunk kinematics were not affected by the intervention but were significantly higher in the morning than in the afternoon. Muscle activity did not differ significantly with seam height but was significantly reduced by the intervention. Overall, this study showed that musculoskeletal stressors during screen installation were reduced by the proposed intervention.