Solution Summary: Kneeling Creepers
A kneeling creeper is an engineering control used to relieve the pressure on the knees joints while kneeling on hard surfaces. It also minimizes the need to get in and out of kneeling and squatting postures during work activities. A kneeling creeper is a mobile platform with knee cushions on the surface will swivel wheels beneath. Some models offer removable seats and chest supports.
Many construction tasks require frequent kneeling, squatting, or stooping because the work is close to the foor. Kneeling on a hard surface puts a lot of direct pressure on your knee, while squatting puts stress on the tendons, ligaments, and cartilage of the knee joint. Working in either position often or for long periods of time can lead to knee problems, including knee osteoarthritis.
If you work in a stooped position, there is stress on your lower back as well as your knees, possibly leading to back pain and even a serious back injury.
There are several types of wheeled kneelers available, such as the Racatac™ and MasterRac™. These models have removable seats and cushioned knee supports. They are very low and have 2-3 inch casters. The MasterRac™ knee supports are only 3/4 inch above the foor. The cushioned knee supports reduce the pressure on your knees, just as ordinary knee pads do.
These models are available with an adjustable cushioned chest support (optional on the Racatac™, but standard on the MasterRac™). It is useful when doing prolonged foor-level jobs like tile setting and concrete patching. It helps support your weight, reducing back strain and some of the pressure on your knees.
Risks Addressed:When the job requires kneeling or squatting to work at foor level, these devices will reduce the stress to your knees, ankles, and lower back. These devices also can reduce stooping, since they make kneeling at floor level more comfortable
How Risks are Reduced:
Wheeled kneelers provide support when work must be done in awkward and stressful positions. They reduce stress on the knees and lower back, and can help prevent serious muscle and joint problems.
Biomechanical research shows that high compression forces occur in the spine while stooping, and that sustained or repeated flexion of the spine may decrease the stability of the lower back and increase the risk of fatigue, leaving the back more vulnerable to injury.
While there is considerable research shows that working in stooped, kneeling and squatting postures causes low back disorders, the research mostly focuses on those postures in combination with other risk factors such as bending or twisting or heavy loads. The literature combining stooped, squatting or kneeling postures with load handling shows rapid and severe spinal damage. There is much less in the literature regarding the health effects of these postures in an unloaded situation - that is, stooping without lifting.
However, safety and health experts believe that it is importnat to avoid prolonged and repeat forward bending of the back (stooping) even in the absence of the other risk factors for low back disorders.
Effects on Productivity:
Since floor level work can be done with less discomfort and pain, productivity may increase.
Wheeled kneelers also allow workers to move around more easily and quickly. Many models also have an area where tools can be conveniently placed. Both factors may increase productivity.
Terrence Roach, MPA - CPWR The Center for Construction Research and Training