# Presentation: 565949

## 2002 Joint National Conference
Joseph A. Holmes Safety Association
And Mine Safety Institute of America
June 4-6, 2002

**2002 Joint National Conference**
**Joseph A. Holmes Safety Association**
**And Mine Safety Institute of America**
**June 4-6, 2002**

**Health and Safety Risk Factors**

**NIOSH - PRL**
**Fred Turin, Ergonomist**

**Notes:**
Welcome to the Health and Safety Risk Factor Talk.

Introduction:  I am ___________________________. 

## Defining Risk Factor

- Common Examples:
- Lifting very heavy object
- Slippery floor or work surface
- Highly repetitive bending or twisting

***An action or condition found to contribute to worker discomfort or injury***

**Notes:**
A risk factor is an action or condition known to contribute to injury.

These are common examples of risk factors.

We will be talking more about different kinds of risk factors later.

## Ergonomics - What is it?

**Most people look like this...**

**Some designers must think that people look like this...**

**Notes:**
You can see here that the way people design equipment is not always with the consideration of the people using it.

This would be a pretty funny looking person if he were to have the characteristics to use this equipment without stretching, reaching or bending. –  My cousin Todd

A lot of times, you are put into situations where your tools and equipment are designed so that you must get in awkward positions or reach and bend a lot.

## Ergonomics is...

- Scientific study of human work.
- Considers physical and mental capabilities of workers as they interact with tools, equipment, work methods, tasks, and working environment.
- Goal – to reduce work related injuries by adapting work to fit people *instead of* forcing people to adapt to work

**Notes:**
Basically,  the idea behind ergonomics is to adapt the workplace to fit the workers.

In order to do that we need to use what we know about the limitations and capabilities of people.  Then we need to make sure the work people are doing  does not require them to work outside of these capabilities or stretch them beyond their limits.

When the work is too much, we need to change the work area, the tools people use or the way that people do their jobs.

## Ergonomics is ...

**not only the design of jobs, tools and equipment, but**** ..how people use them**

**Notes:**
Demonstration of inline vs. pistol grip screw driver.  Ask which they think is more ergonomically designed and why.  Show an example of when to use an in-line and when to use the pistol.

## Targeting Injuries

**Reactive**

**Notes:**
Normally people wait until they have an injury or a lot of injuries before they take notice.  If you wait that long, it is too late.  Someone has paid the price.  This is called being reactive. 

## Targeting Risk Factors

***Injury***

***Risk Factors***

**Reactive**

**Notes:**
We want to change your way of thinking about injuries – we want you to stop being reactive and start being proactive.

To do this, you must understand the causes of injuries, what signals are there to tell you when one might occur and prevent them from happening.

Avoid waiting for the injuries to occur.  

We want you to be able to identify the risk factors for your job tasks and equipment you use.

## Work-Related Injuries

***Acute injuries*** –
- Occur instantly
- Examples:  fractures, cuts, bruises
***Cumulative injuries*** –
- Develop gradually
- Examples:  sprains/ strains, herniated discs, tendonitis, carpal tunnel syndrome

**Notes:**
You are probably more familiar with acute injuries – these are the ones most frequently reported since they are easy to identify.
They occur instantly.  Types of acute injuries include fractures, cuts and bruises.  

Cumulative injuries occur over time.
Some examples include sprains/strains, herniated discs, tendonitis, and carpal tunnel syndrome.
These injuries affect:  muscles, nerves, tendons, ligaments

Today, we will be focusing on cumulative injuries, their causes, and how to reduce your risk of developing them since they are the most difficult to identify.

## Targeting Signs

***Injury***

- decreased grip strength
- loss of muscle function
- decreased range of motion deformity
- swelling

**Notes:**
How do you know that you may be developing a cumulative trauma injury?  There are certain signs to watch for.

## Targeting Symptoms

***Injury***

***Signs***

***pain***

**muscle tightness**

**fatigue**

***achiness***

**burning**

***numbness***

**tingling**

**cramping**

**Notes:**
Any one or combination of these may be an early indicator that there is a problem.  

Symptoms that are ignored can progress to signs.

The key is to recognize symptoms early, before they progress to a sign or injury.  

It is important to know that symptoms may occur at ANY time – not just while you are working.

You may experience symptoms when you are sleeping, watching TV, or if you are in a cold environment.

## Cumulative Injury Progression

- Loss of Function

- Continuous Pain

- Pain Comes and Goes

- Fatigue/ Stiffness

**Notes:**
This is one possible progression for a cumulative injury.

Early symptoms such as fatigue or stiffness can progress to pain.
You may not feel the pain all the time, but instead it could come and go.

If you continue to perform tasks that cause the problem, the pain eventually may become continuous until finally you have loss of function.

I don’t know about you, but I think loss of function in a body part is serious stuff.

## Spinal Movement

**Notes:**
Let’s take a look at how the back and wrist work to understand how cumulative injuries develop.  First the back...
The vertebrae are the bones of the spine. Their function is to provide support and protection to the spinal cord.   Between each vertebrae is a disc.  The disk is actually a large, round ligament that connects the vertebrae together.

Start video.

The disk is subjected to different types of stress as we use our backs each day. The disk generally acts like a shock absorber. Bending over results in compression of the disk, and may also cause the disk to bulge. 

Twisting and bending together is perhaps the greatest stress on the parts of the spine - especially the disk.

## Herniated Disc

**Notes:**
Degeneration occurs when wear and tear causes deterioration (like when your favorite jeans get old and begin to fray).

Repeated lifting, combined with bending and twisting, can eventually lead to injury and degeneration of the disk. 

Start video.

One of the most dramatic injuries to the spine is the herniated disc.   In this injury, a tear in the ligament allows the center of the disc to squeeze into the spinal canal. If the nerve root is compressed by the disk material, there is pain, numbness, and weakness in the areas supplied by the nerve. 

## Wrist Anatomy

**Notes:**
Now, let’s take a look at the wrist. 

The carpal bones in the wrist and the transverse carpal ligament form a ‘tunnel’ through which the median nerve and the tendons that move the fingers pass into the hand. 

Looking at a cross section of the wrist, we can see the anatomy of this opening called the carpal tunnel.

## Tendon Movement

**Notes:**
Through this carpal tunnel opening, the median nerve (yellow) and the flexor tendons (white) run into the hand. 
Start video
The sheath (blue) that covers the tendons is very slippery, and allows the tendons to glide against each other as the hand is used to grasp objects.  
Any condition that irritates the tendons, such as bending the wrist and applying force, can result in swelling and thickening of the sheath
Inflammation of tendons and the sheath can cause discomfort or tendonitis.

You can see here how the blue sheaths have become reddened and inflamed.

However, if this condition gets to a point that increased swelling and pressure squeezes the median nerve against the ligament, 
Carpal Tunnel Syndrome develops.  This can result in numbness, tingling and pain in the hand(s).  

Symptoms are often most acute while sleeping.  Advanced cases may result in weakness and clumsiness of the hand.

## Take Action!

**Take Action!**

**Report concerns to:**
** **
**Safety personnel?**
**Supervisors?**

***As soon as you are aware of early warning signals***

***Early action may prevent loss of function and serious injury!***

**Notes:**
It is important that you learn to recognize early warning signs and take the right action.  What is the right action?

Don’t assume that fatigue or discomfort is just ‘part of the job’.

When an acute injury occurs it usually leads to automatic action,
but it is important that workers are involved in the solution!

Improvements made to a job may prevent an injury!!

## Risk Factors

***Actions or conditions found to contribute to worker discomfort or injury***
- Risk implies
- 	-	Probability:  What is the chance something      	could happen?
- 	-	Severity:  How bad could it be?

**Notes:**
Finally we return to the title of this work shop.

Risk factors are actions or conditions known to contribute to injury.

The big questions are:
  What is the chance something could happen? – Could risk be zero?
  How bad could it be?

## Risk Factor Effects

***Who*** is doing the work
***How many*** risk factors there are
***How much*** there is of each risk factor
***How often*** the work is done

**Are hard to predict, they depend on:**

**Notes:**
Although risk factor effects are hard to predict, it is generally known that over time they will have some effect on any worker.

Their effect depends on:
*Who    *How many    *How much of each    *How often(days/wk & times/day)

Early effects are more likely if:
- A worker is exposed to extreme levels 
- Multiple risk factors are in play – bend & twist while lift
 A worker has a pre-existing weakness due to heredity
 or previous injury or illness

## Targeting Risk Factors

***Injury***

***Symptoms***

***Signs***

**Notes:**
Now we are targeting risk factors to show you the types of actions and conditions that can lead to discomfort or injury.

This slide is key... as it suggests that we need to focus on risk factors... that’s the target!

We want to be able to identify those actions and conditions that could contribute to symptoms, signs, and injury.  

## Examples of Acute Risk Factors

- Forceful work
- Pinch points
- Slipping or tripping hazards
- Working around moving equipment
- Falling or flying objects
- Electrical shock

**Notes:**
Although we have focused on cumulative injuries and their risk factors, it is very important to be aware of acute injury risk factors!!

## Cumulative Injury Risk Factors

**Forceful Work**:**  **A lot of physical effort
**Poor Posture**:  Poor positioning of the body
**Repetitive Work**:  Doing the same movements many times
**Vibration Exposure**:  Two types – hand-arm & whole body

**Four Main Risk Factors**

**Notes:**
This workshop focuses on cumulative injury risk factors

There has been a lot of ergonomics research done to identify workplace factors that can cause cumulative injury.

The four main cumulative injury risk factors are Force, Posture, Repetition, & Vibration.

## Examples of Forceful Work

- Heavy lifting
- Carrying heavy objects
- Forceful pushing or pulling
- Forceful gripping
- Shoveling damp or heavy materials

**Notes:**
Heavy lifting or carrying,  forceful pushing or pulling,  forceful gripping,
& shoveling are just a few examples of forceful work.

I am sure you can think of other forceful work you do as part of your own job.

The force needed to do a job depends on: the task your are trying to do,
       the weight & shape of objects being handled,
       the type of grip you are using,
      & your ability to get a good grip.

The man in the picture is using a forceful grip & the effort is extreme.
I hope this is not a regular job task.

## Examples of Poor Posture

- Elbows above shoulders
- Extended forward reaches
- Trunk bent over more than 20 degrees
- Extreme wrist bending
- Pinch grips
- Kneeling or squatting

**Notes:**
Elbows above shoulders,  extended forward reaches,  trunk bending,
extreme wrist bending,  pinch grips,  & kneeling or squatting are poor postures.

It is common for workers to use postures that put stress on their bodies.

In general, you should use several different but equally safe postures.

But what is a safe posture?
An ideal posture for the upper body would have arms at your sides, elbows bent, wrists straight, & your eyes looking straight ahead.

But we know work is active & your posture constantly changes.
Do ROBO Worker Here!

A good rule of thumb is to do work with your joints at about the mid-point of their range of motion.

For example, see the range of motion of my elbow.  It would be good to have the elbows around 90 or 100 degrees of bend like this.

## Examples of Repetitive Work

- Using equipment controls
- Machine paced assembly tasks
- Packing or unpacking items
- Computer keyboarding
- Manning a store check
-     out line

## Examples of Vibration Exposure

- Hand-Arm:
- 	Using vibrating tools.
- Whole Body:
- 	Sitting or standing on vibrating surfaces.

**Notes:**
Hand-arm & whole body vibration are the primary forms of vibration exposure.

Commonly used power tools like sanders & drills have moderate hand-arm vibration levels.

Tools like impact wrenches & jack hammers have high hand-arm vibration levels.

Whole body vibration is often caused from riding in mobile equipment like haul trucks or fork lifts.

Short term effects of too much vibration is reduced blood flow and loss of the ability to feel things like cold, hot, rough, or sharp.

## Identifying Risk Factor Root Causes

*Method* used or required to do the task
*Effort* or strength required
*Location* of parts, equipment, or tools
*Position* of parts, equipment, or tools
*Design* of parts, equipment, or tools
*Speed* or frequency of work
*Duration* or repetition of tasks
*Environment* factors (light, temp, noise...)

**Notes:**
To ID root causes you need to observe the work & take measurements in order
- to determine how much there is of each risk factor and
- to understand why things are done the way they are.

## Video Tape Examples	

- What is the risk factor(s)?
- What part(s) of the body is affected?
- What is causing the risk factor(s)?

**Three key questions:**

**Notes:**
Now that you are aware of what risk factors are, we are ready to do an exercise.

Hand out risk factor sheet!

We are handing out a summary page of common risk factors.
Although we have focused on cumulative injury risk factors we want you to be aware of acute injury risk factors as well.

In this exercise, we will watch someone performing a job.
We will decide which risk factors we see,
we will identify the part of the body that is affected by the risk factors,
and we will decide what might be causing the risk factors

We will help you through this first exercise.

## Stacking boxes

**Notes:**
Here, we see a person stacking boxes of potatoes.  He gets the boxes off the conveyor belt and stacks them on top of the other stacked boxes.

You might see someone doing something like this where you work in a receiving area.  They may be stacking or moving materials that you use in the mine or maintenance area.

What risk factors are present here?
What part of the body is affected?       
What is causing the risk factor?

What do you think about the back belt?  (if this hasn’t already come up)
Do you think it helps?
It is important if a lifting tasks may cause injury that the task be redesigned instead of giving the worker a back belt.
In the example, the worker is at risk whether he is wearing the belt or not.

## Job Evaluation Form

**Risk Factors Observed**

**Body Parts Affected**

**Job Evaluation Form**

**Job Name:  ****Box Stacking**

**Notes:**
Here is a filled out form that shows what an observer might identify for the box stacking task.

## Job Evaluation Form (cont’d)

**Root Causes Identified **

- Method:  Box stacks start at floor level and go to above shoulder
- Effort:     Boxes weigh 50 lbs and must be carried across the room
- Location of parts:  Boxes are stored all around the conveyor
- Position of parts:
- Design of parts:  Box size and shape makes it hard to carry &
- 	             weight of boxes is too much
- Speed or frequency:   Conveyor moves quickly setting a quick work pace
- Duration or repetition: Conveyor pace causes very repetitive job
- Environment factors:
- Other:

## Operating Hydraulic Pit Station

**Notes:**
This is a hydraulic pit station operator at a phosphate mine.  She works in this pit station all day (12 hrs).  She is responsible for mixing the phosphate with water so it can be piped back to the processing plant.  

Even though this job is not at your mine, this type of job would be similar to any job that requires a person to use controls.

What risk factors are present here?    Ask several people what they
What part of the body is affected?               See as risk factors
What is causing the risk factor?     

## Job Evaluation Form

**Risk Factors Observed**

**Body Parts Affected**

**Job Evaluation Form**

**Job Name:  ****Hydraulic Pit Operation**

**Notes:**
Here is a filled out form that shows what an observer might identify for the hydraulic pit operation task.

## Job Evaluation Form (cont’d)

**Root Causes Identified **

- Method:  Type of control causes frequent & exaggerated movements
- Effort required:
- Location of parts, equipment or tools: Control positioning causes leaning in 				   and reaching
- Position of parts, equipment or tools:  Control table flat not angled properly 				   for operator
- Design of parts, equipment or tools: Round control top causes hand pressure 				points & Sharp edge on table
- Speed or frequency:   Pace of work controlled by dragline production
- Duration or repetition: Task requires constant control use
- Environment factors:
- Other: Poor seat with no arm support
- Other: Long shift with few breaks

## Preventing Injuries

- <date/time>

**Preventing Injuries**

**Engineering Controls**

**Work       Practices**

**PPE **

**Changes made to workers to reduce hazards**

***Rest Breaks***

***Exercise***

**Changes to procedures associated with our work**

**Changes to workstation, tools, and equipment**

**Notes:**
This is our job improvement pyramid.  There are three types of controls or job improvement categories that most changes fall into:

Personal Protective Equipment a “band-aid” fix to a larger problem.  For instance, hearing protection is used because a machine or tool makes loud  noises that could damage your hearing.  
Work practices changes to work procedures.  An example would be daily or weekly job rotation so that one person does not get excessive exposure to a particularly difficult or hazardous job.
That brings us to Engineering Controls.  These are the changes that we like to do but are sometimes costly and take a lot of time.  At NIOSH, we try to help with developing these types of solutions. 
Rest breaks fall into the category of changes to work practices and they should be scheduled into any procedure, especially ones that are physically demanding.
Also, Exercise, which is a change a person makes to themselves, can go a long way to improving an individual’s health and safety both on and off the job.

As you look at this pyramid, think of the food pyramid where the top of the pyramid represents something that is necessary but should be kept in small amounts.
As you go down the pyramid you are doing more substantial things that take more time and effort to digest and put into use but may provide a better long term solution.

## Take Action!

**Take Action!**

***As soon as you are aware of risk factors***

***Early action may prevent loss of function and serious injury!***

**Notes:**
Again we stress that it is important that you learn to recognize risk factors and early warning signs and take action.

Don’t assume that fatigue, discomfort, or difficult working conditions are  just ‘part of the job’.

Improvements made to a job can prevent injury!!

## Targeting Risk Factors

***Injury***

***Symptoms***

***Signs***

***Risk Factors***

**Notes:**
The pro-active approach to reducing injuries at work and in your personal lives is to zero in on the risk factors.  

Avoid waiting for injuries to occur.  

Now  you should be able to identify the risk factors on your job and the equipment you use as well as any new jobs and new equipment in the future.

When the time comes to decide how to improve a job you should be ready to take an active role.

## Thank You!Questions?

**Thank You!****Questions?**

**Notes:**
Thank you for your attention!   Do you have any questions?