Tag: body posture

Body Posture Plays Significant Role in Ergonomic Design

Body posture affects the amount of force that must be exerted to move and maneuver industrial carts and equipment. The human musculoskeletal system functions like a complex system of mechanical levers. Posture determines the positioning of our joints which, in turn, determines the reach of each muscle and the force needed to exercise it. Ergonomic design seeks to produce maximum force from each exertion by optimizing body posture. In creating a more efficient piece of equipment, the goal of ergonomic design is to minimize wear and tear and the threat of injury to the human body.

Optimal body posture generally changes a piece of equipment is moved. The horizontal force necessary to put equipment in motion gives way to a more upright stance as less force is needed to keep it in motion. Handle placement can affect the amount of horizontal push a worker is able to supply. Any angle above or below the horizontal plane will diminish the amount of force a worker can produce. The greater the angle, the less direct force can applied to horizontal movement. Due to variations in worker size, adjustable handles or multiple handholds will allow optimal force production for a greater percentage of your workforce.

Foot positioning can also have a significant impact on the amount of force a worker can produce. The greatest push force is generated when the body is in a lunging posture with feet separated, one foot some distance ahead of the other. Because this position places the rear foot beyond the body’s center of gravity, it unbalances the body, placing workers at increased risk for falls and injury. The risk of serious injury increases if push force must be executed on either an incline or decline.

The use of electronic or motorized carts eliminates the burden of force and the risk of potential injury from your workforce. Equipment rather than the worker’s body provides the push force to necessary initiate and maintain movement. Optimal force can be applied regardless of worker size and strength, maximizing the efficient use of your workforce and optimizing task completion.

Ergonomic Wheel Design Improves Productivity

In our last post we talked about the importance of wheel design in reducing friction. But why is that important? The answer is that any design element that decreases the force that must be exerted by the operator to manipulate a piece of equipment increases efficiency and decreases the risk of potential injury. The result is greater productivity. This is the goal of ergonomic design both in the design of equipment and the environment in which it will be used.

When a wheeled piece of equipment is used, the operator must first overcome inertia and friction. The initial force necessary to start an object in motion is far greater than the sustained force necessary to keep it moving. Once in motion, optimum sustained, or rolling, force is achieved when a steady, constant velocity is achieved. Any need to decrease or increase velocity requires increased force to combat inertia. This is particularly noticeable during turning and maneuvering when significant force must be applied to change direction. Stopping a piece of wheeled equipment requires the same high level of force as starting it. As when accelerating, the operator must overcome high levels of inertia and friction to decelerate.

The four physical elements required to move a piece of wheeled equipment — starting, rolling, turning and stopping — can place tremendous stress on the operator’s musculoskeletal system. If performing these tasks manually, workers frequently overexert and strain muscles while applying the necessary force to start or stop a piece of equipment. Turning and positioning equipment can cause operators to assume asymmetric body postures during exertion which can cause musculoskeletal injury.

Ergonomically designed carts and tugs seek to achieve the optimal wheel size, type, placement and composition to decrease the force an operator must exert to move a piece of equipment.