Four Basic Principles of Body Mechanics
Proper body mechanics are vital for prevention of injury and disability. According to the U.S. NAVY Military Sealift Command, poor body mechanics are a major contributor to preventable low back injuries. Integrate principles of good body mechanics into your everyday activities to lower your risk of preventable injury.
Maintain proper spinal alignment while sitting, standing and sleeping. The human spine is comprised of individual bones called vertebrae that are stacked on top of each other. Together, these vertebrae form a natural "S" curve when they are properly aligned. Sit with a small rolled towel behind your lower back to support your lumbar spine. Stand up straight with your ears, shoulders, hips and ankles in alignment with each other. Place one foot on a small footrest to rotate your pelvis to reduce pressure on your lower back when standing for long periods of time. Sleep on your back with a small pillow supporting your legs to reduce pressure on your lower spine. For side-sleeping, bend your knees and place a pillow between your legs to keep your spine straight.
Base of Support and Center of Gravity
Widen your base of support by placing your feet shoulder-width apart before lifting, pushing or pulling. Place one foot slightly in front of the other to improve balance and reduce the risk of injury. Keep your body centered over your feet to evenly distribute body weight. Carry objects close to your body to bring its center of gravity as close as possible to your center of gravity. For example, slide a box close to your body before lifting and carry it at your chest with elbows bent; do not try to lift or carry it with your arms extended.
Use larger muscle groups in your arms, legs and torso to accomplish tasks to reduce risk of injury. For example, to pick up a box from the floor, squat down and use your legs to bring yourself upright rather than bending over and lifting the box with your arms. Carry grocery bags over your forearm, close to your elbow rather than gripping handles in your hands. Push or pull objects to engage torso muscles rather than lifting with your arms and legs.
Use good form when lifting to protect your spine. Keep your back straight and squat down to the level of the object before lifting. Do not bend at the waist. Pull the object close to your body before standing and tighten your abdominal muscles as you stand. If bending cannot be avoided, use a "golfer's lift" -- straighten one leg and lift it backwards as you bend forward. This will prevent your spine from bending, reducing rick of injury. Use caution -- the golfer's lift requires the ability to stand on one leg without losing your balance.
- United States Department of Labor: Occupational & Health Administration: Hospital eTool: Ergonomics
- Mercer Community College: Body Mechanics
- Centers for Disease Control and Prevention: Safe Patient Handling Training for Schools of Nursing
- FoxGeri: Geriatric Education & Research Institute
- Texas Department of Insurance: Division of Workers' Compensation: Workplace Safety: Back Injury Prevention
- Agency for Healthcare and Research Quality: Healthcare and Utilization Project:Emergency Department Visits and Inpatient Stays Related to Back Problems, 2008
Aubrey Bailey has been writing health-related articles since 2009. Her articles have appeared in ADVANCE for Physical Therapy & Rehab Medicine. She holds a Bachelor of Science in physical therapy and Bachelor of Arts in psychology from the University at Buffalo, as well as a post-professional Doctor of Physical Therapy from Utica College. Dr. Bailey is also a certified hand therapist.