MSI 5-94

[Audio] Workers need to be trained in the multiple principles of good body mechanics so they are able to select the safest lifting technique for a given task, and to judge whether the task is safe to perform in the first place..

[Audio] Body mechanics refers to the way in which your muscles and joints interact to help you move in your daily activities. Proper body mechanics produces safe, energy efficient and controlled movements. Good body mechanics involves: Keeping your balance Keeping the elbows in, close to your sides Using the larger muscles to do the heaviest work Maintaining a neutral S-shape spine Incorporate these principles when performing your work tasks..

[Audio] Neutral posture is when joints are in their resting position. The back is in neutral posture when the three spinal curves – cervical, thoracic and lumbar - are maintained. In this position, the spine is under the least amount of stress, and muscles are their strongest. The same is true for the remaining joints. When they are in their neutral positions, their supporting tissues (e.g. ligaments, tendons, muscles) are neither stretched nor shortened resulting in minimal physical strain and optimal blood flow. Good blood flow plays an important role in the prevention of MSIs. When blood flows properly in and out of muscles, fatigue and discomfort are minimized. When a joint or body part moves away from neutral posture, extra stress is placed on tissues that surround and support those areas. For example, a twisted or bent back posture increases stress on the back tissues and increases the risk of injury..

[Audio] Your core muscles are not just your abdominals. They are the muscles that surround your trunk (your abs, sides and back and buttocks). You should practice firming up your core so it becomes a natural thing you do even when walking, and certainly before handling a load, so that the spine is supported. Creating tension in the core helps maintain a neutral S-shape spine and supports and protects the spine. For normal MMH tasks of daily living, the level of intensity of firming up only needs to be modest – about 10 percent or less of maximal tensioning. When handling heavier loads, or if you have back problems, the intensity of firming up should be increased, all the while still breathing normally..

[Audio] When attempting to lower your body to pick up an object or set an object down, be sure to bend at your hips first. The large muscles around your hips are designed to generate power, unlike the small muscles in your back. Bending at the hips helps maintain a neutral spine and allows the soft tissues to support the spine. Just as you would use a toilet, gently push your buttocks out behind you and lower your body by bending your hips and legs. To return to an upright position, pull your hips forward, straightening your hips and knees..

[Audio] During the handling of a load avoid moving the spine – keep it stiff by keeping the core tight..

[Audio] Twisting the lumbar spine wears down the spinal discs, resulting in reduced ability to bear loads. Pivot technique Turn the leading foot 90 degrees in the direction you want to turn, rotating about the hip. Bring the lagging foot next to the leading foot..

[Audio] For loads of unevenly distributed weight, keep the heaviest part of the load closest to your body..

[Audio] Good balance requires ensuring your centre of gravity remains inside your base of support. Increasing your base of support generally leads to a more stable lifting position. Place your feet shoulder-width apart or slightly wider. You should be able to place one foot on each side of the load and keep a neutral spine while lifting. Choose one of the following stances: A. Place one foot forward and to the side of the load between your knees; or B. Position your feet on both sides of the load with the load between your knees. Keep your feet flat on the floor and push down through your heels..

[Audio] The forces from rapid, jerky motions greatly increase injury risk. Handle loads in a smooth, deliberate manner..

Module 6. Workstation Set-up.

Workstation Setup. Determines the postures that must be taken and sustained by the worker when performing tasks and how the far one must reach to retrieve the necessary tools/equipment. Workstations could be composed of chair, assembly/factory lines, delivery systems, tables, vehicles, elevated work platforms, etc. Improper setup can cause excessive stress on the body with each movement..

Workstation Setup. An improper workstation setup may include: Chairs/tables is too high/low No lumbar, thoracic, or arm supports Work-table is not positioned properly Lighting is inadequate for the task Edges of tables/work surfaces are sharp/uncomfortable Ventilation makes the workspace cold Work environment is damp and cold Extended reach to use tools/equipment.

Posture. Improper workstation setup leads to many harmful postures when performing various tasks. Harmful/awkward postures put pressure on nerves and blood vessels, cause excessive strain on muscles, decrease circulation, and cause wear and tear on the joint structures..

Posture. Examples of improper/awkward postures include: Working with neck flexed/tilted to one side Shoulders elevated Side bending to left or right Excessive twisting Forward bending/overreaching at waist Shoulders flexed and abducted (chicken winged) Elbows flexed greater than 90 degrees Wrists flexed/deviated in grasping Thumb hyperextension.

Module 7. Applying Ergonomics to the Workplace.

Working with Good Posture. Always try and maintain an erect posture. Minimize bending and leaning over. Keep feet flat to the floor to promote neutral or anterior tilt to your pelvis – this keeps the back aligned. Use an adjustable chair with lumbar, thoracic and arm support. Look for features such as adjustable height, width, tilt, backrest, seat pan, and arm rest..

Working with Good Posture. Adjust the height of your chair/table to a comfortable level. If your chair/table is too low and the work area is too high, this causes you to elevate your shoulders and can lead to neck problems and pinched nerves. If your chair is too high and the work surface is too low, you’ll have to flex your neck down and bend your wrists back which can lead to neck and hand problems. Remember the 90-degree rule – keep elbows at 90-degree angle with your wrists straight and shoulders relaxed..

Working With Good Posture. Work close to your body. 90 degree angle rule: have elbows, hips, knees, and ankles forming 90 degree angles. Reaching far beyond these angles too often means you should adjust your position..

[Audio] Facilitator Instructions: Start with the feet Adjust seat pan height so feet are firmly supported by the floor or a footrest Adjust seat pan tilt so thighs are parallel to the floor or positioned slightly downward with knees lower than the hips. Adjust seat pan depth to allow space (about 5 cm) between the edge of seat pan and back of legs (fit a clenched fist behind knees) Position lumbar support against the lumbar spine curve. It should fit snug against the curve of the lower back. The individual will feel a sense of relief/comfort once it is positioned properly. Adjust backrest angle so the hip (torso to thigh) angle is within 90 to 120 degrees, preferably slightly reclined (approximately 110 degrees). Adjust armrests: Rest arms by the body sides with the shoulders relaxed and elbows at about 90 degrees. Position armrests under the forearms so forearms settle onto the armrests. Once you are seated in a neutral posture, it is then time to introduce yourself to your work surface and make any required adjustments..

Working with Good Posture. Minimize excessive wrist movements. Try to maintain neutral position - palms facing each other, shoulder width apart with wrists straight. Avoid excessive finger movements. Use your shoulders and arms to position your hands rather than making the small forceful movements with your fingers. Alternate work positions between sitting, standing, walking Allows muscles to relax while shifting stress to other muscles and increasing circulation..

Improving Work Practices. Rotate between tasks Administrative tasks, manual handling, and other activities. Switch between positions throughout the day. Shift stress into different muscles, increase your circulation, and lessen the amount of fatigue from your work. (E.g., Sitting/standing)..

Equipment Layout. Equipment/tools used most often should be kept within the normal work area. 22-26 inches for most people is considered a “comfortable distance”. Frequently used items should kept within “normal horizontal reach” and less frequently used items should be placed within the “maximal horizontal reach” which is created with the arm is fully extended..

Module 8. The Role of Exercise in Preventing or Minimizing the Risk of MSI’s.

Types of Exercise. Exercises that increase fitness levels are divided into the following categories: Aerobic Exercises – total body fitness Stretching Exercises – Improve range of motion Strengthening Exercises – Increase muscular size.

Aerobic Exercise. Sometimes known as “cardio” exercises Concentrates on improving oxygen transport by increasing blood flow to the tissues and thereby increasing their efficiency. A contributing factor to MSI’s is decreased flow of nutrients and oxygen to muscles..

Aerobic Exercise. Examples include: Walking Running Performing intervals on an elliptical machine Jump rope Resistance training circuit that has little to no rest between exercises.

Aerobic Exercise. Warm up 10 minutes of total body movement and stretches Exercise period Intensity: 70% of heart rate maximum (HRMax = 220-age) Duration 20-30 minutes Frequency: 3-4 times a week Cool down 5-10 minutes of total body movement and stretching.

Stretching Exercises. Benefits of stretching: Increase blood flow to muscles Increase the production of joint synovial fluid Reduce the formation of trigger points Maintain normal joint range of motion Increase nutrient supply to vertebral disks Create a relaxation response in the central nervous system Warm up the muscle before beginning to work Identify tight structures that may be predisposed to injury.

Stretching Exercises. Perform a variety of stretches throughout the day A stretch maintained for 15-30 seconds slowly decreases the tension in the muscles. Stretch force should be slow, gentle and pain free. Each stretch can be done 2-3 times a day. Complete during breaks or at home..

Stretching Exercises. Scalene stretch – sit and hold the under surface of the chair with one hand, tuck the chin and side bend the neck to opposite side and rotate to the same side. With the other hand, apply gentle pressure on the head in the direction of the stretch. Stretch is felt on the side of the neck..

Stretching Exercises. Pectoralis Major stretch – Stand facing the corner of a wall two feet away from it with arms against the wall. Lean the entire body forward from the ankles with knees slightly bent until you feel a stretch on the front of your shoulder..

Stretching Exercises. Hand stretch Extension Stretch: This stretch is great for the wrist and elbow. Gently pull your fingers backwards (as shown) until you feel a stretch along the bottom of your arm and through your wrist. Flexion Stretch: This stretch is great for the wrist and elbow. It stretches most of the muscles running along the top of the arm. Bend your hand down towards the floor and grasp your fingers with the opposite hand and gently pull your fingers and wrist back towards the arm..

Stretching Exercises. Lateral Trunk stretching – Sit in the chair and bend to one side with opposite hand raised above head. Stretch is felt on the side of the trunk..

Stretching Exercises. Hip Flexor stretch – Stand with one leg forward and the other backward. Bend the front leg forward at the knee while maintaining the back leg straight with knee extended and the heel slightly raised. Shift the body weight on to the front leg. The stretch is felt over the anterior thigh..

Stretching Exercises. Hamstring stretch – Sit with the leg to be stretched extended across another chair and lean forwards towards the knees. Stretch is felt under the thigh and knee..

Stretching Exercises. Calf stretch – Stand on a slope and bend forward with straight spine. Stretch is felt on the back of the leg..

Strengthening Exercises. Strengthening exercises increase the power and endurance of a muscle. Exercises should be done smoothly and be pain free. Start with minimal load. 8-10 reps x 2-3 sets per day..

Strengthening Exercises. Shoulder Retractor strengthening Rows Step 1: Wrap a resistance band around a pole or stabilize it on the inside doorknob of a closed door. Stand about 2 feet away from the pole and hold one end of the band in each hand. Step 2: Slowly pull each end backward as though you are rowing the oars of a boat. As you do this, squeeze both shoulder blades down and back without letting your shoulders shrug. Your forearms should remain parallel to the ground as you complete this motion. Step 3: Hold this position for 1 to 2 seconds and then release the tension on the band..

Strengthening Exercises. Spinal Extensor strengthening Bridging – Lie on your back and place arms at sides. Lift the buttocks off the floor. Opposite Arm and Leg Raise - executed from an all-fours position. Before you start the exercise, make sure your hands are under your shoulders and knees are under your hips. Steadily raise your left arm straight in front of your body and extend your right leg straight behind you. After holding for a full second, lower your arm and leg and repeat on your other side..

Physical Activity. When you make your muscles work by being physically active, they grow stronger and healthier. Muscles that do not get used will get smaller and weaker – also known as atrophy. Strong muscles keep your joints in good shape and also help with balance. Activities that make your skeletal muscles strong will also keep your heart muscles strong..

Conclusion.

WorkplaceNL on MSI Prevention. WorkplaceNL has several documents and resources available on MSI prevention in the workplace. Website: http://www.workplacenl.ca/prevention/msi_prevention.whscc.

Take Away Message. Musculoskeletal Injuries can be serious and disabling for workers. It is important to be PROACTIVE and MINIMIZE the risks. A workplace injury does not just affect your work life; it affects your entire life..

[Audio] MSIs are disorders of soft tissue. They are the leading type of lost-time work-related injury in NL and affects workers, workplaces, families and communities. You now have the tools to identify MSI hazards in your own work and are able to take steps to control those hazards to create a healthy and safe workplace for you and your coworkers..

Questions or Comments?.