Solution Summary: Bucket Clamp
A bucket clamp is an engineering control that may help reduce stressful hand and wrist activity, awkward postures, and mixer accidents. A bucket clamp allows masons to mix materials while standing upright without having to straddle and squeeze the bucket. To use a bucket clamp, a five-gallon bucket is placed in the clamp and the worker steps on the adjacent foot plates to stabilize the bucket. The mason can then mix the cement or mortar with a hand held mixer while standing upright.
The bucket clamp is a narrow rectangular sheet of aluminum with a central base plate for the 5 gallon bucket and adjacent foot plates. Around the central base plate is a clamp system that compresses the bucket to stabilize it (Figure 1).
Figure 1. The Spin Resistant Bucket Clamp
A bucket clamp can accommodate most 3.5 and 5 gallon buckets. The worker’s weight on the foot plates activates the clamp system which stabilizes the base of the bucket with approximately 220-250 lb/in2 of compression on the bucket (Figure 2.).
Figure 2. The Spin Resistant Bucket Clamp
Exposure to stooped postures and continuous gripping to stabilize the bucket can lead to musculoskeletal disorders (MSDs) of the back or arms. Prolonged stooping can lead to back MSDs such as disc herniation or strain. Gripping the bucket with one hand while mixing requires forceful hand exertions, which can lead to MSDs such as wrist tendonitis. Additionally, straddling and squeezing the bucket may not provide sufficient stabilization. A loss of control of the bucket while operating a hand held mixer could result in cuts or bruises.
How Risks are Reduced:
A bucket clamp minimizes the duration of stooped postures because once the bucket is in place, the mixer can be operated from a upright position. The worker does not need to stoop and secure the bucket while simultaneously attempting to operate the mixer. Additionally, a bucket clamp eliminates the continuous activation of leg muscles to squeeze and stabilize the bucket. The risk of losing control of the mixer or bucket is eliminated because the bucket clamp provides sufficient force to stabilize the bucket.
The manufacturer claims that a bucket clamp will reduce the risk of MSDs by ”Keeping the worker’s body straight with the bucket. The [bucket clamp] distributes equal pressure to the bucket while relieving stress off the workers lower back, giving the worker full control of the working area.”
Safety and health experts believe that a bucket clamp reduces demand on the mason because it eliminates strain on the operator's back, legs, and arms. While there is no research on the bucket clamp specifically, research has shown that workers who spend more time in stooped posture or other awkward back postures are at a higher risk for developing low back problems. Studies have reported a decrease in low back pain and stress among those working with materials kept at or near waist height (Hoogendoorn et al., 2000). A bucket clamp can stabilize the bucket without stooping to secure the bucket while simultaneously operating the mixer.
In addition, research has concluded that holding static muscle contractions (such as using leg musculature to squeeze and secure a bucket) can lead to fatigue and MSDs (Bernard, 1997). A bucket clamp eliminates continuous muscle activation of the legs by using the mason’s weight on the foot plates to activate the clamp system which provides compression that stabilizes the base of the bucket.
Effects on Productivity:
A bucket clamp increases productivity on the worksite.
A bucket clamp increases the stability of the bucket, which reduces the risk of losing control of the mixer or bucket. Accidental contact with a powered mixer can lead to cuts or bruises.
Dan Anton, PT, PhD, ATC; and Kevin Wright, SPT – Eastern Washington University