2 Back safety Learning goals: Understand anatomy and balance (how your back works)Learn safe body mechanics (lifting, standing, sitting, lying)Get your back in shape (exercises for strength, flexibility)A. Understand anatomy and balance (how your back works)1. Your back is strong enough to support the weight of your head and body2. Your back is flexible enough to allow you to walk, sit, move3. The secret to its suppleness and strength is in its balance of curves4. Knowing how the back works can help you avoid any strain or injuryB. Learn safe body mechanics (lifting, standing, sitting, lying)1. We are constantly using our backs to hold ourselves upright, sit, bend, we use our backs even when we are lying down2. Poor posture can cause back problems3. The back is most vulnerable to injury during any liftingC. Get your back in shape (exercises for strength, flexibility)1. We often do “back-breaking” activities without any proper preparationD. Exercise can1. Prepare muscles for work (cold muscles are prone to injury)3. Keep bones and muscles strong, supple and aligned4. Ease back pain5. Rehabilitate injured backs
3 Back safety Definitions Manual handling: force exerted to lift, lower, push, pull, carry or otherwise move, hold or restrain somethingManual handling injury: sprains, strains or fractures to muscles, tendons, ligaments and joints
4 Common causes of back injury/pain Traumatic injury (auto, industrial or sports accident)A. Traumatic injury (auto, industrial or sports accident)B. Poor posture and alignment1. Any posture that compromises the natural curve of the spine puts strain on the supporting back muscles and weakens them2. Without proper support, the vertebrae are forced to carry weight they are not meant to carry: premature spinal degeneration3. Also makes movement difficult and awkward, increasing the chances of injuryPoor posture and alignment: makes movement difficult and awkward
5 Common causes of back injury/pain Overexertion: failure to ease off activity or change positionC. Overexertion1. Failure to ease off strenuous activities2. Failure to change position for long periods of time3. Ignore the twinges.4. Strain or muscle discomfort is a warning sign!D. Cumulative strain1. Excess body weight, repetitive movements, working in awkward positions, age (wear and tear)2. Happens over time, not all at onceCumulative strain: excess body weight, repetitive movements, working in awkward positions, age (wear and tear)
6 Common causes of back injury/pain Emotional stress and muscle tensionEmotional stress and muscle tension1. Stress causes the muscles to contract2. Contracted muscles stop circulation of blood and oxygen: atrophy
7 Back anatomySpineMade of 24 moveable bones (vertebrae) “stacked” in three flexible curvesSupports head and trunk, protects spinal cord, provides flexibility to bend/rotateSpine1. Primary component of your back2. Supports head and trunk, protects spinal cord, provides flexibility to bend/rotate3. Made of 24 moveable bones (vertebrae) “stacked” in three flexible curvesa. Cervical vertebrae1. Support head and neck2. Smaller and more flexible than other vertebraeb. Thoracic vertebrae: support ribs forming chest cavityc. Lumbar vertebrae (lower back)1. Largest and carries most of body’s weight (“workhorse” of the spine)2. Area most prone to injuryd. Sacrum: five fused vertebraee. Coccyx: tailboneMost of body weight falls on lumbar region, making it prone to injury
8 Back anatomyDiscsFlexible spacers between the vertebrae allow smooth movementAct as spinal “shock absorbers”Compress and release, like springs“Slipped” disc occurs when jelly-like center squeezes out of the discDiscs1. Each vertebrae is separated from its neighbor by a cartilage cushion2. Discs allow smooth movement; act as hydraulic “shock absorbers”3. Compress and release, like springs4. Disc anatomya. Dense outer ring of criss-crossed fiber, like a radial tireb. Interior is soft and squishy, like thick jelly1. 1/3 rd of height of spine is made up of discs2. when lying down, they soak up nutrients and water from blood, making average person taller in the morning (up to 2 inches)5. Disc injuriesa. “Slipped” disc1. Occurs when outer ring wears out like worn tire tread2. Jelly-like center squeezes out and presses on a nerve (severe pain)b. Disc degeneration1. Disc loses moisture, narrows2. Bones grind together, irritating nerves (nerve damage)
9 “Slipped disk”jelly-like center squeezes out and presses on a nerve
10 Back anatomy Spinal Cord Central nervous system (with brain) Pair of spinal nerves exit below each vertebraeCervical nerves go to the arms; lumbar area to the legsSpinal Cord1. With brain forms the central nervous system2. Pair of spinal nerves exit below each vertebrae3. Cervical nerves go to the arms: pinched nerve in neck4. Nerves in lumbar area go to the legs: sciatic nerve from tailbone down legs
11 Back anatomyMusclesSpinal (back) muscles: stabilize spine- not made for liftingButtock and thigh muscles: strong and durableStomach muscles: also used in lifting1. Spinal (back) musclesa. Stabilize the spine: very strong because they support bodyb. But they are not made for lifting!2. Buttock and thigh muscles: strongest in body and very durable3. Stomach musclesa. Used in liftingb. When stomach muscles weaken, back muscles tighten (increasing chance of injury)
12 Muscles Dynamic muscle work: Static muscle work Involves muscle contraction and movementBlood flushes out lactic acid which causes muscle fatigue (can work for lengthy periods)Lifting and stacking boxes an exampleStatic muscle workMuscles hold the body without movementSustained contraction halts blood flow to muscles: lactic acid builds up, causes fatigueBending over workbench, sitting at computer are examples4. Dynamic muscle worka. Involves muscle contraction and movementb. Blood flushes out lactic acid which causes muscle fatigue (can work for lengthy periods)c. Lifting and stacking boxes an example5. Static muscle worka. Muscles hold the body without movementb. Sustained contraction halts blood flow to muscles: lactic acid builds up, causes fatiguec. Bending over workbench, sitting at computer are examples
13 Spinal balance Posture is important. Spine is aligned in three “S” shaped curvesBalanced to keep weight evenly distributed on spineProper balance places least amount of stress on spineVertebrae pushed out of line causes pain, invites injuryA. Spinal balance1. Spine is aligned in three “S” shaped curves2. Column of curves is balanced to keep weight evenly distributed3. In proper balance, the spine and all its structures are under the least amount of stress and muscles are at their strongest4. Spine is out of balance when it loses its three natural curves5. Good posture is important: simplest way to help keep back healthy and pain-freeB. Laying down1. Lay on side with knees slightly bent toward chest2. Lay on back with a pillow beneath kneesPosture is important.
14 PostureStanding“Stack” ears, shoulders, hips, knees and ankles in a straight lineTuck in chinShoulders back and downSuck in gut: a pot belly can act as a load and pull spine out of balancea. Standing1. “Stack” ears, shoulders, hips, knees and ankles in a straight line2. Tuck in chin3. Shoulders back and down4. Suck in gut: pot belly can act as a load and pull spine out of balance5. Elevate one foot to reduce stress in lower back
15 PostureIf standing for long periods, elevate one foot to reduce stress in lower back
16 PostureSittingSit with ankles, knees, thighs and elbows at right anglesKeep head balanced over shouldersKeep shoulders relaxed (not hunched)Sit back in chair for supportb. Sitting1. Sit with ankles, knees, thighs and elbows at right angles2. Keep head balanced over shoulders3. Keep shoulders relaxed (not hunched)4. Sit back in chair for support
17 Safe body mechanicsBody mechanics:The relationship between your posture and your movementGood body mechanics avoids putting undue strain on your back
18 Safe body mechanicsPrinciples of levers: A weight, a short distance from the fulcrum requires less effort to move than the same weight a farther distance from the fulcrum1. A weight, a short distance from the fulcrum requires less effort to move than the same weight a farther distance from the fulcrum
19 Principles of leversThe worst lifting situation occurs when the body is used like a lever and extended over the loadIf the load is further away, there will be a greater strain on the person doing the lifting
20 Principles of leversThe further the load, the greater the strain on the person doing the handlingIf the load is further away, the greater the strain on the person doing the lifting
21 Principles of leversThe lower back becomes a fulcrum supporting the weight of the body plus the loadThe worst lifting situation occurs when the body is used like a lever and extended over the loadIf you bend at your waist and extend your upper body to lift an object, the lower back becomes a fulcrum supporting the weight of the body plus the load.this situation is called “overload”
22 Techniques for safe lifting Get a firm footing: keep feet shoulder width apart, toes out, distribute weight evenly on soles of both feeta. Keep feet shoulder width apart, toes outb. This adds stability and reduces stress on musclesc. Distribute weight evenly on soles of both feetThis stance adds stability and reduces stress on muscles
23 Techniques for safe lifting Bend your knees: not your waista. Bending at the waist puts tremendous pressure on the vertebraeb. The legs serve as a shock absorber for the bodyc. When the knees are bent, the weight comes first into the thighs and hips instead of the spineWhen the knees are bent, the weight come first onto the thighs and hips, not the spine
24 Techniques for safe lifting Bending at the waist puts tremendous pressure on the vertebrae
25 Techniques for safe lifting You can also lower your body down on one knee and glide the object up into your body to get a good grip before pushing your body upward.
27 Techniques for safe lifting Tighten stomach muscles: they support spine when lifting, reducing force of the loadGet a good grip: use both hands“Hug” the load: hold it as close as possible to your body; the closer it is to your spine, the less force it exerts on your back3. Tighten stomach musclesa. They support the spine when lifting, reducing force of the loadb. Keep center of gravity in the abdominal cavity4. Get a good grip: lifting with one hand throws you off balance4. “Hug” the loada. Hold it as close as possible to your bodyb. The closer it is to your spine, the less force it exerts on your back
28 Techniques for safe lifting Lift with your legsGradually straighten to a standing positionLift steadily and smoothly without jerkinga. Gradually straighten to a standing positionb. Lift steadily and smoothly without jerking
29 CarryingKeep back straight: to help shift weight onto the legs
30 Techniques for safe lifting Avoid twisting Twisting can overload the spine and cause injury to the feet, knees and torso.Your feet knees and torso should always be in the same direction
31 Techniques for safe lifting Pivot with your feet, not your back.
32 Techniques for safe lifting Use the same technique to set down the load.
33 Lifting awkward loads Reaching into a bin or car trunk: Stand with feet shoulder distance apartSlightly bend knees and squat, bending at hip joints, not waistSlide the load as close to your body as possibleRaise yourself with leg and hip musclesIf possible, rest knees against edge for support
34 Hard to reach loadsDo not reach above the shoulders: use a stepstool or ladderTest the weight before removing from shelfSlide it toward you and hug it close to your bodyLifting above your shoulders is hard on your arms and back.If possible, reduce the amount of weight being lifted by removing some of the contents of the box or container.Try using a step stool or ladder to get closer to the target area, instead of lifting above your shoulders. If possible, place the item on a lower shelf.
35 Hard to reach loads Place item on lower shelf Don’t reach above shouldersPlace item on lower shelf
36 Two person loads (Team lifting) - Both persons should be about the same height.- One person should charge of the lift, so that you are working together not against each other.- Lift together, walk in step and lower the load together.
37 Two-person long load Shoulder on the same side Keep load level Walk in step
38 Loading truck or shelfPut the load on the edge and push it into place.
39 Awkward location Don’t force your body to conform to the workspace Use the golfer’s lift to pick up light, small loads when you can’t bend your knees or get close to the object.Swing one leg straight out behind you.Keep your back straight while your body leans forward.To help support your body, place one hand on your knee or on a nearby solid object.
40 Awkward loadsInstead of lifting, push a loadPush, don’t pull!
41 Repetitive lifting If you must lift many items: Design workspace so items to lift are in your safe lift zone
43 Safe liftingDon’t:Lift anything that exceeds 1/3 - 1/2 your body weightLift from the floor if possibleTwist and liftLift with one hand (unbalanced)Lift loads across or over obstaclesLift while reaching or stretchingLift from an uncomfortable postureFight to recover a dropped object
44 Exercise Benefits: Muscle strength helps maintain natural curves Keeps back strong and suppleWarm muscles increase ease of movementBenefits of back exercises1. Healthy backs require strong supporting musclesa. Muscle strength helps maintain natural curvesb. Keeps backs strong and supple2. Greater flexibilitya. Joint flexibility lets you move freely and easilyb. Warm muscles increase ease of movement
45 ExerciseMore energy: increased blood and oxygen flow flushes out lactic acidCool down exercises decrease potential stiffness3. More energy: increases blood and oxygen flow, flushes out wastes like lactic acid4. Balanced workout: some muscles get overworked while others “sleep in”5. Cool down stretches decrease potential stiffness
46 Exercise “dos” Change your posture/position often Stretch frequently throughout the dayKeep body flexible (not rigid or fixed)Warm up before any strenuous work or liftingMove slowly and gentlyStop if there is any discomfort
47 Exercise Wall slides to strengthen back, hip, and leg muscles Stand with your back against a wall and feet shoulder-width apart. Slide down into a crouch with knees bent to about 90 degrees. Count to five and slide back up the wall. Repeat 5 times.
48 Exercise Leg raises to strengthen back and hip muscles. Lie on your stomach. Tighten the muscles in one leg and raise it from the floor. Hold your leg up for a count of 10 and return it to the floor. Do the same with the other leg. Repeat five times with each leg.
49 Exercise Leg raises to strengthen stomach and hip muscles Lie on your back with your arms at your sides. Lift one leg off the floor. Hold your leg up for a count of 10 and return it to the floor. Do the same with the other leg. Repeat five times with each leg. If that is too difficult, keep one knee bent and the foot flat on the ground while raising the leg.
50 Exercise Partial sit-up to strengthen stomach muscles Lie on your back with knees bent and feet flat on floor. Slowly raise your head and shoulders off the floor and reach with both hands toward your knees. Count to 10. Repeat five times.
51 Exercise Back leg swing to strengthen hip and back muscles Stand behind a chair with your hands on the back of the chair. Lift one leg back and up while keeping the knee straight. Return slowly. Raise other leg and return. Repeat five times with each leg.
52 ExerciseStretchStand with your feet slightly apart. Place your hands in the small of your back. Keep your knees straight. Bend backwards at the waist as far as possible and hold the position for one or two seconds.Give participants the Back Exercise handout and explain it contains exercises to warm up, relieve pain, and exercises for people who sit a lot.