Muscular Activity during Masonry Work at Various Heights

Masons frequently work with their shoulders elevated and often complain of upper extremity pain. Little is known about the muscular effects of masonry work. The purpose of this study was to evaluate muscular activity while masons laid concrete block at various heights.

Sixteen experienced male masons constructed a 2.4 m wide and 1.4 m high wall using concrete block. Surface electromyography (EMG) was sampled from the extensor and flexor forearm, and the upper and low back via telemetry. EMG amplitude was determined for the first, third, and seventh courses of block. Analyses of variance were used to test for significance.

There were no significant differences in the courses for the forearm extensors, forearm flexors, and right low back EMG. Significant differences were found for the bilateral upper trapezius and left lower back, with higher amplitudes at course 7. In this study, masons were exposed to more load in the upper back while laying block at higher courses.