repetitive stress injuries - american cheese societyrepetitive stress injuries: understanding your...

Repetitive Stress Injuries: Understanding Your Pain, Prevention, & Treatment

Lauren Plum, PT, DPT, [email protected]

What I hope you learn how to do• Describe the variables involved in proper body

mechanics• Demonstrate proper body mechanics for common

occupation-related tasks• Recognize the symptoms of common

musculoskeletal disorders• Describe ways of preventing or treating

musculoskeletal disorders, i.e. fixing yourself• Know when and how to seek additional help

Decrease the frequency and severity of injuries and pain

Why is this important?• Affects 83-90% of dairy workers • More common than in nurse’s assistants • 76-80% of parlor milkers – highest injury rate • Milkers: Highest rate of chronic shoulder pain• Female machine milkers: Wrist and hand • 55% of sheep farmers: Carpal tunnel

Time Out• Everyone has had pain, or you wouldn’t be here!

(And you wouldn’t be normal!)• Groups of 2-3• One minute• Kindly introduce yourself:

• Where ya’ from?• What’s your job title(s)?• Where do you have pain? Don’t be shy!

• Participation is always optional but encouraged

This means YOU get to do something!

So, where do you hurt?

Low back (25%)

Shoulders

Wrists

Hands/fingers

Knees

Neck

Head/face(13%)

Chest(11%)

• It’s not necessarily anything you did wrong.• Parlor milking: 50-55% of injuries• Small farms: Low back, knee, and shoulder pain• Livestock management: 24% to head/face/chest• Milking: 27% to wrist, hand, and fingers • Cheesemongers and repetitive forward bending• Inefficiencies

Why do you hurt?

This means this might be a practical solution!

What is it about milking?• Majority of workload• Not perceived as

strenuous• Traditional vs. modern• 39% modify workload• Majority could have

worked 10-15 more years

How to Save Your Body 101

• Maximizing safety and efficiency of equipment and workspaces

• Mats, adjustable-height flooring, lighter equipment• Lack of publications from OSHA, CDC• Lack of research on dairy operations

Ergonomics

Take 30 seconds or so and jot down YOUR definition of ergonomics.

• It is your job to make your job fit you.• Farmers who receive education: Fewer injuries• Not a “one size fits all” approach• Consider:

• Type of workstation set-up• Height of workstation• Size of work or product • Worker height• Distance between worker and work

• Some job demands we can’t ergo our way out of.

Ergonomics

: Surface or support

• Includes surfaces beneath/behind you…Concrete, dirt, hay, metal, wood, lumbar support

• …and your footwearSteel-toed boots, athletic shoes, boots, flip-flops

Depends on How You “S.A.T.”

: Angle

• The angle that a joint is making

• Each joint has a normal range of motion that is comfortable

• Does your joint angle exceed this?

The “S.A.T.” Principle

: Time

• Duration: How long are you in one position?• Repetition: How many times do you have to do a

particular task in one day? • Alternate high-repetition and low-repetition

tasks.

The “S.A.T.” Principle

• Time for some self-reflection• One minute• Apply the S.A.T. principle to your own work

1) What surface are you standing or sitting on most often?2) What kind of footwear do you wear most often?3) What kind of body positions are you in for extended

periods?4) What body positions or motions do you have to do

repetitively?5) What is the one part of your job that you repeat the

most often throughout the day?

Time Out

• Among the most common positions in dairy work

• Surface: Anti-fatigue mats

• Angles:• Leg width• Back and hip position• Foot position

Standing

• Cheesemongers may ignore this• Surfaces:

• Hard-backed chair• Stool with no back support• Crate? Overturned bucket?

• Angles:• Hip: 85-100°• Knee: 85-110°• Ankle• Back: Lumbar support • Neck

Sitting

• Bending 20x PER HOUR = excessive

• Avoid prolonged stooping over

• If you have to work close to the ground:

• Alternate stooping with standing or walking

• Sit on a stool

Repetitive Forward Bending

• Assumption: Brett is right-handed• If he faces the cheese and bends

down and to the right to use the wire slicer even 20 times a shift…

• Isn’t that a lot of stress and strain on his back?

• Repetitiveness/velocity = fish and computers

• 36° per second• Muscle force:

low to moderate • Depends on distance

from milker to udder• 6.5lbs. for every foot

away from udder

Let’s come back to milking

• Most strenuous• Time: 12 second/animal• Rest time: 1.0-1.4%• End-range wrist

positions 10% of time• Wrist positions >50% of

max• Get closer, use

lightest cluster possible

Attachment Disorders

True or False:For every 10 pounds you lift, it’s 100 pounds of pressure on your back.

False.18 inches away from your body:• 738lbs. of force• 2,234lbs. of

compression

30-pound box:3 x 100lbs = 300lbs

• Bring the load as close to you as possible:• Avoid lifting objects off the floor whenever possible• Avoid lifting objects above shoulder height• Don’t use round containers or crates

• Put handles on things whenever possible• Use a utility cart or dolly for carrying more than a

few feet

Lifting

Here’s what good posture looks like

Looking Down with Poor Posture

• 60 pounds of force from looking down already

• Plus apron pulling neck forward

• Get out of static and end-range positions frequently• Look, really look, at the flow of your work:

• Draw a flow chart of the sequence of a task• Ask an impartial 3rd party for help• Identify inefficiencies:

• Static positions• Unnecessary repetition• Unnecessary height changes• Reaching farther than needed

Final Notes About Ergonomics

• Most common location• 55% of sheep farmers• 17% of parlor milkers• 3.6% of non-milkers• Symptoms:

• Pain on inside of forearm, wrist, palm

• Numbness/tingling in middle, index, thumb

Carpal Tunnel Syndrome

• High velocity = more force

• Maximum end-range wrist positions

• Exposure to excessive vibration

• Genetic component?

Carpal Tunnel Syndrome Causes

• X-rays/MRI/CT• EMG (electromyography) study

Carpal Tunnel SyndromeMaking the Diagnosis

DO’s:• Research online• Try self-treatment• Be specific/journal• Ask questions/discuss• Request PT or OT• Respect opinions• Seek 2nd opinions

DON’Ts:• Read complainer forums• Demand to see a

specialist right away• Demand imaging right

away• Demand surgery before

trying conservative treatment

How to Navigate the Medical Field

Trying to avoid surgery?• Improve body mechanics

• Get out of static and extreme wrist positions

• Stretch before/after work

• Wear a splint• Try PT or OT• Rule out other causes of

numbness/tingling


• Many states have some form of “direct access”• Many clinics still require a referral1) Make an appointment with your doctor2) Request PT or OT3) Take referral to clinic or call

• Realize all practitioners treat differently• No such thing as a “cookie-cutter” approach• Do your homework, research, and exercises• Give your therapist feedback

Getting in to PT or OT

• Many doctors don’t know the difference• Lots of gray area

Physical Therapy vs. Occupational Therapy

OT PTWhat do they treat? Upper extremity Whole bodyTreatment Techniques

•Fine motor skills•Dexterity•Hands-on therapy•Exercises•Taping•Modalities

•Big functional movements

•Hands-on therapy•Exercises•Taping•Modalities

Common Tools Adaptive equipment Assistive devices

Consult a doctor or orthopedic surgeon when….• Conservative PT/OT fails to provide relief• Numbness/tingling is constant and affecting sleep• Muscles in hand start to atrophy• Losing grip strength• Dropping objects


• Tennis elbow, lateral epicondylitis, golfer’s elbow• Symptoms:

• Sharp pain on outside of elbow with grip• Milking• Stirring• Slicing cheese

• Can extend down forearm• Possible swelling• Possible elbow stiffness• NO numbness/tingling

Cheesemonger’s Elbow

Causes• Repetitive or sustained grip + extension or rotation• Using tools that are not ergonomically designed• Poor elbow positioning• Milking in a traditional setting• 3 most difficult tasks in milking:

1) Attaching milking unit2) Holding milking cluster in place3) Sanitizing/drying udder


Even more causes:• Ladling cheese curd • Slicing cheese• Stirring cheese • Packaging


An ounce of prevention….Remember: Education and training actually does reduce injuries!


Making the Diagnosis• Fairly easy to diagnose based on:

• Pain location• Symptoms• 3rd finger test

• Can be confused with a common nerve compression syndrome

• If so, EMG


: Protect (ergonomics!)

: Rest

: Ice

: Compress

: Elevate

PRICE Principles

Counterforce brace to offset work of wrist extensor muscles

• Avoid wrist deviation• Choose a design with a handle that bends up so

your wrist can be straight• Make sure handles are long enough• Objects >10lbs. should have a handle

Improving Your Ergonomics

Improving Your Ergonomics• Ideal grip diameter: 1.25 – 2in.• Grips should be curved and contoured to the palm

of your hand• Grips should be padded and non-slip but should

not have finger cut-outs or ridges

Consult a doctor or orthopedic surgeon when….• Conservative PT/OT fails to provide relief• Pain is constant and is affecting everyday life

Other interventions may include:• Injections• Surgery: Many different types, all experimental


• Many different sources…• Tendonitis • Collar bone injury• Bursitis • AC joint injury• Tendonosis • Frozen shoulder• Impingement • Referred pain – neck • Rotator cuff tear • Cardiac pain

• …so self-diagnosis or treatment is not recommended for this particular problem

Shoulder Pain

• 4 muscles:• Supraspinatus• Infraspinatus• Teres minor• Subscapularis

• Many functions:• Suction-cup shoulder onto trunk• Lift arm• Rotate arm• Throwing

The Rotator Cuff

• Dull or sharp pain in upper arm

• Can extend farther down • Loss of shoulder motion• NO numbness or tingling• Difficulty lifting or

sleeping on affected side

Shoulder Pain Symptoms

• Overhead reaching/lifting• Reaching or lifting outside your base of support• Milkers: highest rate of chronic shoulder pain• 25% of max shoulder strength required in machine

milking

Causes of Shoulder Pain

True or False: Each of these weights weighs 20 pounds.

True. (That was not a trick question.)(That was just an easy question.)

True or False: It would take 20 pounds of force to lift one of these weights 20 inches in front of you.

False.It would take one of the rotator cuff muscles 20x that amount to lift that weight.20 pounds x 20 = 400lbs. of force

• Angles: • Below shoulder height• Within 17 inches

• “Light” workstation: • Women 37-39in. tall• Men 40-43in. tall

• “Heavy” workstation:• Women 33-35in. tall• Men 36-39in. tall

• Quick estimate

Reaching

• Not just about height, but space• Is it well-lit?• Do you have to lean forward to get adequate light?• Is it cluttered?• Is it too spread-out?

• Adequate knee/foot clearance• Transfer towards dominant hand

Reaching

Avoiding Shoulder Pain

• Unless you’ve had trauma or surgery, no sling• Avoid sleeping on affected side• Keep it moving to avoid frozen shoulder• Get motion back 1st, then strength• Personal bias: Get in to PT/OT

Self-Treating Shoulder Pain

Consult a doctor or orthopedic surgeon when….• Rest or conservative PT/OT fails to provide relief• Pain is constant • You can’t find a comfortable position• You are losing motion and strength in your arm • Pain is affecting sleep

Other treatments may include:• Injections• Surgery (many different types)

Shoulder Pain

• 25% of all farm injuries• Avoid self-diagnosing or treating• Symptoms:

• Pain in center of low back, across back, or on one side• Pain can also go down legs • May have numbness/tingling• Usually worse with standing activities

Low Back PainInsert ubiquitous

picture of a person clutching their low

back here

• Avoid stooping over – sit on a stool

• Stand with one foot resting on a stool

• Get out of sustained positions – go the opposite direction

• Avoid lifting off the floor• Lift 51lbs. max

Preventing Back Pain

• Pain down legs• Numbness and tingling• Different sensations• Legs weakness• Legs give way• Falls

Low Back PainConsult a doctor….

• Avoid self-diagnosing and self-treating• Symptoms:

• Pain in center of neck or on either side• Can also go down shoulder blades or arms• Neck stiffness/loss of motion• May have numbness/tingling• Usually worse with looking down

Neck Pain

• Sustained looking down• Awkward positions

• Side-bending• Rotation

• “Forward head” posture• Poor lifting techniques• Inadequate head/neck

support during sleep

Causes of Neck Pain

• Avoid looking down for long periods when possible• Get out of sustained positions – go the opposite

direction• Avoid sleeping with feather pillows• Side-sleepers: Use a thicker side-sleeper pillow

Preventing Neck Pain

• Constant pain• Pain going down arm• Numbness and tingling• Different sensations• Arm weakness• Dropping objects• Wry neck

Neck PainConsult a doctor….

• Increased risk of knee arthritis in dairy workers• Symptoms:

• Dull ache, occasional sharp pain• Front of knee most common but may also be in back of

knee, down shin, or in calf• Movie-goer’s sign: stiffness• May have swelling• May have mechanical noises• NO numbness/tingling• Possible giving way• Difficulty standing, walking, descending stairs, squatting,

kneeling, jumping

Knee Pain

• Repetitive or sustained squatting or kneeling• Stanchion milking system: More than 1/6th of time

spent in 110° or more• Parlor systems: Less than 1 min.

Causes of Knee Pain

• Avoid prolonged squatting or kneeling:• Get out of sustained postures every hour• Sit on a stool• Alternate with standing/walking activity• Wear a knee sleeve

• Use good body mechanics when squatting• Make sure your knee has full motion

Preventing Knee Pain

• One diagnosis, many different causes• Symptoms:

• Sharp pain in heel• Pain in arch of foot• Worse when 1st waking up• Worse with standing/walking

Plantar Fasciitis

• Prevent it: • Wear supportive shoes• Stretch your calves

• Treat it: roll out your feet

Plantar Fasciitis

Consult a doctor….• Conservative home treatment or PT has failed to

provide relief• Numbness/tingling• Different sensations• Atrophy of muscles in foot• Change in foot appearance (color, hair growth)• Temperature differences in foot

Plantar Fasciitis

Reality:• Our time together is nearing an end• Some injuries and pain may be unavoidableGood News:• You are now equipped with resources:

• Improved body mechanics and ergonomics• Increased recognition of common injuries• Tools for prevention

Good News/Bad News

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References

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