Ergonomics is the science of designing work environments and tasks to fit the capabilities and limitations of the human body, optimizing comfort and performance. When this fit is poor, physical factors create ergonomic hazards. These hazards are physical conditions that interact with the body’s anatomy, potentially leading to debilitating musculoskeletal injuries (MSIs). Protection begins with understanding these hazards and addressing the cumulative effects of a poorly designed workspace or work process.
Recognizing Common Ergonomic Risk Factors
Protection involves identifying physical factors that strain the body’s soft tissues, nerves, and joints. These factors are grouped into four main risk categories that increase the likelihood of developing an MSI.
Force refers to the physical effort required to perform a task, such as gripping a tool or pushing a heavy object. Higher force demands require greater muscle exertion and lead to quicker fatigue.
Repetition is performing the same motion repeatedly throughout the workday. If the cycle time is 30 seconds or less, it limits recovery time for involved muscles and tendons. Combining high repetition with high force significantly increases injury risk.
Awkward posture involves positioning the body outside its neutral range of motion. Examples include excessive wrist bending, reaching overhead, or prolonged leaning. Maintaining these non-neutral positions places stress on joints and compresses soft tissues.
Contact stress occurs when a hard object presses against a soft body part, creating localized pressure. Examples include resting forearms on a sharp desk edge or kneeling on a hard floor. This mechanical pressure can impede blood flow, irritate nerves, and damage tendons.
Modifying Your Workspace for Prevention
The most effective way to address ergonomic hazards is by adjusting the physical environment to promote a neutral posture. The chair is the foundation of a seated workspace. Adjust it so your feet rest flat on the floor or a footrest, and your thighs are parallel to the floor. The backrest should offer firm lumbar support, aligning with the natural curve of your lower spine. Armrests should gently support the weight of your arms, keeping shoulders relaxed and elbows close to your sides.
Correct monitor positioning helps maintain a neutral neck and head posture. The top of the screen should be set at or slightly below eye level to minimize tilting. Place the screen approximately an arm’s length away (20 to 40 inches) to reduce eye fatigue. If using dual monitors, position them in a slight V-shape, centered relative to your primary viewing area.
Input devices must be placed to maintain straight wrists and forearms. The keyboard and mouse should be situated directly in front of you, close to the body, and at elbow height. Keep the keyboard flat or slightly angled away from you, avoiding the use of the small prop feet.
When using a mouse, the wrist should remain neutral and in line with the forearm. Minimize reaching by placing the mouse immediately next to the keyboard and moving it from the elbow, not the wrist. If you frequently use the phone, a headset prevents the awkward posture of cradling the handset between your neck and shoulder.
Safe Movement and Material Handling
Ergonomic protection includes tasks involving physical movement, lifting, and prolonged standing. When handling materials, use the powerful muscles in your legs for lifting instead of bending at the waist. Keep the load as close to your body as possible, ideally between waist and shoulder height, to reduce back strain.
Secure a firm grip and avoid twisting your torso while lifting or carrying. To change direction, turn your whole body by moving your feet, keeping your shoulders aligned with your hips. When moving objects horizontally, pushing a load with your body weight is safer and easier than pulling it.
Prolonged standing exposes the body to static loading, restricting blood flow and causing muscle fatigue. Using an anti-fatigue mat provides cushioning and encourages subtle posture shifts, reducing pressure on the feet, knees, and lower back. Alternating foot position or resting one foot on a slight elevation helps distribute weight. Whenever possible, use mechanical assists like lift tables or hand trucks to minimize manual lifting and carrying.
Incorporating Essential Rest and Recovery
Even an adjusted workspace requires regular breaks, as static posture and repetition demand recovery time. Implementing micro-breaks is an effective strategy, involving short interruptions (30 to 60 seconds) every 20 minutes. These breaks relieve muscle tension and encourage movement before fatigue sets in.
For computer users, the 20-20-20 rule prevents eye strain: every 20 minutes, look away from the screen and focus on an object 20 feet away for at least 20 seconds. Longer breaks should include simple, targeted stretches for the neck, shoulders, and wrists.
A final control is task rotation, especially for highly repetitive tasks or those requiring sustained awkward postures. Switching between different types of tasks ensures varied muscle group use, preventing the overloading of the same tendons and joints. This scheduled variation allows different parts of the body to rest and recover during the work cycle.