MUSCULOSKELETAL DISORDERS (MSDs), such as chronic back pain or shoulder problems, often take time to develop. Forceful exertion, awkward positions, hand-arm and whole-body vibration, contact stress, and repetitive tasks can add up over time to produce an MSD.
This statement comes courtesy of an Ontario Infrastructure Health and Safety Association (IHSA) pamphlet on musculoskeletal hazards and controls. Ergonomics experts and wood industry veterans both agree that MSDs contribute to shortened careers, time lost and poorer quality of life in general.
According to ergonomist Peter Vi at the IHSA, the permanent risk factors for MSD are awkward posture, high forces and repetition, as well as other such secondary risk factors as constant contact stress. “Whenever you are moving away from the natural posture it’s considered the awkward posture — bending, kneeling, squatting, for example — rather than the natural standing posture.
“On top of that if you are lifting heavy items such as anything more than 30 to 50 pounds,” says Vi, “that also increases the risk of injuries. Because the higher the weight, the more forces that our muscles need to work in order to counteract those forces that we need to actually do the work.”
The best way to control and reduce those kinds of risk factors is by reducing the repetition or the severity of the awkward posture and the muscular stress of those high forces. Controls could mean being able to take jobs and perform tasks that are away from the floor. “So, you could rotate between working on the floor versus other tasks,” says Vi. “You can also use a variety of mechanical assistance, such as carts or dollies.”
MATERIAL HANDLING PRIORITY
GCW Kitchens and Cabinetry of St. Thomas, Ont., with over 100 staff, recognizes the need to take a “load off” when it comes to handling materials. According to John Van Houwelingen, purchasing manager and steering chairman of the joint health and safety committee at GCW, notes that his company has carefully studied the day-to-day lifting component of its employees’ workflow on the shop floor and in the field.
“We have done a lot of work especially since we moved from our old building about four years ago,” says Van Houwelingen. “Ever since that time we have implemented more and more strategies here to help with repetitive strain injuries. Anything to do with heavy lifting, awkward lifting.” Van Houwelingen brings 15 years of health and safety experience at Magna, the automotive parts giant, where he was a training coordinator.
GCW has instituted a number of practices, machinery and systems to reduce the strain of handling materials repeatedly, from sheet goods to the finished cabinet assemblies.
Don Patten, ergonomics specialist, technical services, Workplace Safety and Prevention Services (WSPS) in Ontario, notes that the fitness of the worker plays a part in avoiding MSDs but doesn’t preclude risk of injury. “When you do (a task) continuously for a long period of time it doesn’t matter what shape you are in,” says Patten. “You experience fatigue and discomfort. We want our ‘work athletes’ to be performing at their peak and be in shape and take care of their bodies.
“In some cases, the longer that you do the work in a job you kind of become work-hardened in a way. You are building the muscles and the flexibility based on the actual doing of the work. At the same time if the work exceeds what we are able to do as people from a strength perspective that is when the injury occurs.”
Patten cautions against having the bigger and stronger employee lifting more on the job. “Our spines can only take so much compressible force or twisting. We want to make sure that although we encourage our employees to be healthy, we also want to ensure that we are looking at the ways in which we are doing our work. “And how the work is designed so that we can reduce some of these MSDs.”
At GCW, the knowledge that materials have to be handled over and over again led it to create workstations that are all at waist height. “We don’t have anybody putting stuff down on the floor and working bent over,” says Van Houwelingen. He remembers how much, at the old shop location, the amount of “manhandling” of the sheet goods that was necessary.
“Here we rarely have to lift a full sheet by hand on anything,” explains Houwelingen. “We have the storage retrieval system which picks it up with a vacuum system up and over the fence and puts it down in a location based on where we tell it in the computer. The guys at the CNC can call the storage retrieval system via computer and have it lift onto their conveyor. So no more manhandling and putting it on the CNC bed.”
The conveyor systems put in place at GCW play an important part in reducing the need for staff to handle materials.
“We used to take everything off by hand off of the CNC bed and put each individual part and lift it off of there and put it on a cart. Now we stack them up on a conveyor and we can conveyor everything from one end all the way to the other end before people actually have to lift and put them on a work bench and assemble them.”
The company has now reduced a number of manhandling chores using its conveyor system with all of the rollers, such as moving everything from its beam saw CNC over to an edge bander with a return system. “Part of the extra workload on an edge bander,” says Van Houwelingen, “involves the operator putting the part on the one end and having to walk all the way to the other end and catch it so it doesn’t fall off.”
With the return system on the edge bander, the operator can load up from one end and it will come out the other end and return to him and back to his work station. “It saves him a ton of walking back and forth. Of course, he doesn’t have to lift the parts off a cart, onto the edge bander and back onto a cart again. He just keeps it on a conveyor and stacks it up and rolls it over on the conveyor.”
GCW has just purchased a new edge bander and will be installing a return system on it as well, according to Van Houwelingen. “We have saved a lot of repetitive walking back and forth. If you think about it, you are doing twenty steps for every part. When you do 1,000 parts every day that is putting 10,000 steps on your Fitbit pretty quick!”
Another issue that occurs after finishing and components become assembled, is the creation of a lot of the awkward parts, according to Van Houwelingen. “A cabinet assembly requires two people to lift it on to a rolling table, so you are not carrying it from one station to the next. We have a number of those wooden tables with the wheels on them also at various heights actually depending on how big the piece of cabinetry is.
“For instance, a big (kitchen) island you don’t want to put that on a waist high rolling table. You put it on a low table otherwise you would be reaching way above your head to work on it.”
GCW has various types of rolling tables that fit the different products to work on and to roll them through the shop. “Once the cabinets are all built, we have anywhere from 25 to 40 cabinets,” says Van Houwelingen. “Our old practice was to lift them off the clamp and put them on the floor. Stack them up three or four high. Put them in a place then the shipping guys would unstack them one by one.”
CONVEYOR TO SKID
The company has created a conveyor system that transports the cabinets after they are built. The cabinets slide down on a conveyor system onto a wrapping station where skids are at the same height. “When the cabinet is done,” says Van Houwelingen, “and all wrapped up, we just slide it on to a 4 by 8 skid — so no lifting there.
“Now we can move the whole skid of eight to 10 cabinets with the pump cart all the way to the shipping area.” The process saves a lot of wear and tear on both the handlers and the cabinets, adding quality control to the process. “When you get to the shipping truck at the loading dock, they do have to lift them one by one into the truck.”
But when a repetitive strain injury does occur, employers should think about accommodations for the staff member, according to Patten. “In some cases, the employee needs to be accommodated at work in order to ensure that those muscles or injured areas are given time to heal.”
There are still opportunities for improvement, Van Houwelingen believes, some of which involve capital expenditure. One alternative would be to buy a much bigger truck that would accommodate much bigger skids, but company isn’t there yet. GCW has two trucks that are delivering kitchen cabinets to job sites all of the time, he says.
“Considering where we were four years ago, we have come leaps and bounds in handling our material,” adds Van Houwelingen.
“There were two practical purposes. One was to save our employees a lot of repetitive strain injuries and a lot of extra lifting. A lot of it was to save our product as well.”
Overall, for GCW, the effort seems to be paying off in both departments.