The body is made up of muscles, tendons, ligaments, bones, joints, discs, and nerves known as the musculoskeletal system. Musculoskeletal disorders (MSDs) are injuries in this system due to a variety of factors. Prevention of these disorders can be achieved by creating a safe work environment, identifying MSD hazards, providing education on ergonomic principles and the training and use of appropriate equipment.
Safe lifting principles:
Prior to performing any lifting activities, a generalized warm up of walking or large body movements can prepare the muscles for work, lessening the likelihood of injury. The weight of the object to be lifted should be checked before lifting is attempted, ensuring the feet are shoulder width apart and appropriate, non-slip footwear is being worn. As the weight is lifted, it should be brought in close to the body and held between shoulder and thigh height, keeping the back straight and abdominal muscles tight. Avoid breath holding or carrying any objects that block vision. When possible, pick up and lower loads on a raised platform to avoid bending or squatting. If the weight is being lifted/lowered to/from a lower level, bend at the knees and stick the bum out, using both hands, grasping boxes at opposite corners if possible. Most importantly, get help for heavy, large or awkwardly shaped items from a coworker or by using a dolly or other assistive device. Never attempt to carry a load that is too heavy.
Pushing and pulling
Use carts whenever possible to transport items when moving an object, as pushing and pulling is much easier than lifting or carrying. Push rather than pull as this will protect the back, avoids twisting, provides better visibility and prevents the cart rolling over the top of feet/body. Make sure that the load is evenly distributed, wheels are aligned, and the cart is not overloaded. To get the cart moving, stagger the feet and weight shift to push/pull using legs and entire body not just the back and arms. Keep elbows by sides and the object close to the body with elbows bent at 90 degrees. Get directly behind the object and push in a direction that is straight ahead, avoid pushing to the side. Finally, slowly build the push force, rather than applying quick and abrupt force. Remember, the initial force required to get the object going is usually much greater than the continuous (sustained) force required to keep the object moving.
Avoiding reaching/bending/twisting:
When possible, raise height of the activity to waist level so no reaching or bending is required. If this is not possible, hinge at the hips, keeping back straight, and stick the bum out when bending. Make sure to use the support of the opposite hand to take pressure off back. Move the feet/body around large objects instead of reaching and stay close to the work, keeping the reach in front with elbows bent. If overhead, select longer handled tools to lessen or avoid reach or use a step stool to raise up to a height that allows for work to happen at chest height.
If working low to the ground cannot be avoided, instead of bending, squat for brief periods, keeping feet shoulder width apart, weight on heels, knees behind toes and head up. Kneeling briefly on one knee with the opposite foot in front, knee at 90 degrees and back straight is also acceptable. Another option is to use a golfer’s reach by placing one hand on a counter/chair/wall and tip forward from the hip on one foot while the non-weightbearing leg comes up behind.
Protecting against repetitive movements:
Repetitive movements can be hazardous when the same joints and muscles repeat the same movement too quickly and for too long without adequate rest. Maintaining a comfortable pace with regular breaks or changes in activity reduces the effort required, limiting the development of fatigue and the likelihood of injuries.
Avoiding the same position for long periods:
Standing or sitting in one position for extended periods can be a source of joint stiffness and muscular tightness, contributing to fatigue and discomfort. To reduce this, movement is recommended every 20 to 30 minutes or as needed. This encourages blood flow to muscles, reduces muscular tension and lessens the discomfort that is associated. This can be as simple as standing up from a sitting position or walking a few steps if standing in place to work. While walking is not always possible when working in a standing position, heel raises or bringing the heel to the buttock is. Rolling the shoulders, bending and straightening the fingers/wrists/elbows or rotating the neck can also be very helpful. A good ergonomic set-up is essential to preventing injury in addition to moving regularly throughout the day.
Please contact Heather Robinson, Injury Prevention Specialist at heather.robinson@wchospital.ca if you have any ergonomic questions or concerns.