Solution Summary: Mortar Stand
A mortar stand is an engineering control that can reduce musculoskeletal disorders from stooped postures and manual material handling. It is a welded tubular steel base that supports a board or pan to hold mortar near the waist level.
Mortar stands benefit construction workers by providing a level, sturdy base to mix mortar materials at a comfortable level (near waist height). Placing work surfaces and heavy materials near waist level, instead of on the floor, reduces physical strain and the incidence of musculoskeletal disorders due to stooped postures (back injuries).
Figure 1. Mortar Stand (Photo courtesy of CPWR)
Stooped postures can cause low back disorders, such as muscle strain or a disc herniation (“slipped disc”), which is bulging of disc material possibly pressing on the spinal cord or nerves that go into the leg. The mortar stand can help reduce stooped posture by raising mortar bins off the ground to a more comfortable working height.
How Risks are Reduced:
Placing the work surface near the workers' waist level reduces or eliminates the need for stooped postures and lifting from floor level. This reduces back, knee, and shoulder stress.
There have not been independent published studies measuring the effect of a Mortar Stand on reducing musculoskeletal disorders. Regardless, safety and health experts believe that the use of mortar stands reduces the risk of developing musculoskeletal disorders. It is estimated that bricklayers spend 75% of their work time in 30 degrees or more of back flexion. This position increase compressive and shear forces in the low back. By moving the work surface to waist level, time spent in this bent position is minimized.
Effects on Productivity:
Mortar stands would actually reduce the amount of effort needed to perform a given amount of work since the lifting motion from the feet to the waist is eliminated. This reduced effort could be converted into an increase in repetitiion of the shorter motion and this an increase in productivity while at the same time reducing physical stress.
Dan Anton, PT, PhD, ATC – Eastern Washington University, and Carlos Sanchez-Marin, DDS, MS – University of Iowa