Solution Summary: Standing Motorized Finishing Trowel
A standing motorized finishing trowel is an engineering control that minimizes stooped or kneeling postures. The trowel is operated from an upright position and features a variable speed trigger to control the speed of the rotating trowel.
The standing motorized finishing trowel weighs 14 lbs. and features an 11.5-inch head that has self-adjusting and replaceable blades. It is powered by a rechargeable V-28 lithium-ion battery. One hand operates the variable speed trigger while the other hand controls the trowel via a handle on the shaft.
Continuously stooped or kneeling postures can cause various musculoskeletal disorders (MSDs). Stooped postures can cause low back disorders, such as muscle strain or a disc herniation (“slipped disc”). Prolonged kneeling can cause prepatellar bursitis, which is swelling on the front of the kneecap. Prolong kneeling can also cause osteoarthritis of the knee (degenerative joint disease). A standing motorized finishing trowel reduces the risk of MSDs associated with continuously stooped or kneeling postures.
How Risks are Reduced:
Traditionally, finishing concrete in tight spaces (around pipe, for example) is performed using a hand trowel from a stooped or kneeling posture. A standing motorized finishing trowel is operated while standing.
The manufacturer believes that a standing motorized finishing trowel can reduce the risk of MSDs. The manufacturer states, “[a standing motorized finishing trowel] reduces fatigue…saves your back and knees.”
Safety and health experts agree that a standing motorized finishing trowel may reduce the incidence of MSDs associated with stooped and kneeling postures. Prolonged periods (> 2 hours) of kneeling place excessive forces to the knee, resulting in knee bursitis or osteoarthritis (Kivimaki, 1992; McMillan & Nichols, 2010; & Spielholz, Davis, & Griffith, 2006). Kneeling postures require stooped back postures, which may increase risk for the development of lumbar disc syndrome or muscular strains (Splittstoesser et al. 2007; Bernard 1997; & da Costa & Vieira, 2010). Additionally, back strength is reduced in the kneeling posture compared to standing, which may increase the risk of back injury (Gallagher, 2005).
Effects on Productivity:
A standing motorized finishing trowel can increase productivity on the worksite because it finishes concrete faster than a hand held trowel
Dan Anton, PT, PhD, ATC; Jesse Brouwer, SPT, and Kevin Wright, SPT – Eastern Washington University