Industrial Safety and Health for Goods and Materials Services - Chapter 17 potx

17
Lifting
It is probably safe to assume that workers in retail, wholesale, and warehousing
perform a large number of lifting tasks as an integral part of their job duties some of
which could be both heavy and at times awkward. Employers in these industry
sectors should lift carefully since overexertion and back injuries are the leading
causes of injuries. It should not be a foregone conclusion that back injuries are an
acceptable part of doing business. Efforts should be directed toward prevention
although many employers as well as workers view lifting as a natural activity that
everyone knows how to do correctly. This has proven to be a false belief.
17.1 BACK INJURIES
Back disorders can develop gradually as a result of microtrauma brought about by
repetitive activity over time or can be caused by a single traumatic event. Because of
the slow and progressive onset of this internal injury, the condition is often ignored
until the symp toms become acute, often resulting in disabling injury. Acute back
injuries can be the immediate result of improper lifting techniques and=or lifting
loads that are too heavy for the back to support. While the acute injury may seem to
be caused by a single well-defined incident, the real cause is often a combined
interaction of the observed stressor coupled with years of weakening of the musculo-
skeletal support mechanism by repetitive microtrauma. Injuries can arise in muscle,
ligament, vertebrae, and disks, either singly or in combination.
Although back injuries account for no work-related deaths, they do account for a
significant amount of human suffering, loss of productivity, and economic burden
Lifting is an integral part of goods and material handling.
ß 2008 by Taylor & Francis Group, LLC.
on compensation systems. Back disorders are one of the leading causes of disability
for people in their working years and afflict over 600,000 employees each year
with a cost of about $50 billion annually in 1991 according to National Institute
for Occupational Safety and Health (NIOSH). The frequency and economic
impact of back injuries and disorders on the workforce are expected to increase
over the next several decades as the average age of the workforce increases and

medical costs go up.
17.2 BACK DISORDERS
17.2.1 F
ACTORS ASSOCIATED WITH BACK DISORDERS
Back disorders result from exceeding the capability of the muscles, tendons, disks, or
the cumulative effect of several contributors:
.
Reaching while lifting
.
Poor posture—how one sits or stands (Figure 17.1)
.
Stressful living and working activities—staying in one posit ion for too long
.
Bad body mechanics—how one lifts, pushes, pulls, or carries objects
.
Poor physical condition — losing the strength and endurance to perform
physical tasks without strain
.
Poor design of job or workstation
.
Repetitive lifting of awkward items, equipment, or (in health care facilities)
patients
Awkward postures
FIGURE 17.1 Stretching and poor posture can cause back injuries. (Courtesy of the
Occupational Safety and Health Administration.)
ß 2008 by Taylor & Francis Group, LLC.
.
Twisting whi le liftin g
.
Bending while liftin g

.
Maintain ing bent postures
.
Heavy liftin g
.
Fatigue
.
Poor footi ng such as slippery floors or const rained postu re
.
Lifting with forcef ul movem ent
.
Vibration, such as with lift truck drive rs, delivery drive rs, etc.
17.2.2 BEFORE A L IFT
Before a lift is perfor med some a ctions need to be taken to assur e the lift is a safe
one. The se are as follow s:
.
Checking the object before a lift is attempt ed by testing every load before
lifting by pushing the object with your hands or feet to see how easil y it
moves. Thi s gives an idea of how heavy it is. Remem ber, a smal l size does
not always mean a ligh t load.
.
Check to make sure the load is packed correctly. Make sure the weight is
balanced and packed so it would not move around. Loose pieces inside a
box can cause accide nts if the box becomes unbala nced.
.
Check to see if the load can be gripped easil y. Be sure that you have a tigh t
grip before lif ting. Objects wi th handle s can be lifted in a safer manne r.
.
Check to see if the load is withi n easy reach. An injury can occur if the back
is arched when lifting a load. To prevent a ba ck injury use a ladder when

lifting some thing over h ead level .
.
Determine that the best way to pick up an object is being used. Use slow
and smoo th movement s. Hurried, jerky movem ents can strain musc les in
the back. Keep the bod y facin g the object while lifting . Twis ting while
lifting can injure the back. Keep the load close to the body. Having to reach
and carry an object may hurt the back. Lifting with the legs should be done
only when the load can be straddled. To lift with the legs, bend the knees
while keeping the back straight. Try to carry the load in the space between
the shoulder and the waist. This puts less strain on the back muscles.
.
Follow the steps sugges ted in Figure 1 7.2 to make a safe lift.
17.3 SYMPTOMS AND CONTRIBUTORS TO INJURIES
Signs and symptoms include pain when attempting to assume normal posture,
decreased mobility, and pain when standing or rising from a seated position.
At times the following are contributors to work-related back injuries:
.
Congenital defects of the spine
.
Increase in static standing or sitting tasks
.
An aging workforce
.
Decreases in physical conditioning and exercise
ß 2008 by Taylor & Francis Group, LLC.
.
Lack of awareness of workplace hazards
.
Job dissatisfaction
Manual materials handling is the principal source of compensable injuries in

the American workforce, and four out of five of these injuries will affect the
lower back.
Good lifting techniques
When lifting, remember to
Avoid overloading
Stop and look at the load’s
1. Weight
2. Size
3. Shape
Do not twist
1. Move foot in direction
of turn
2. Move entire body
Re-position the load
1. Tense stomach muscles
2. Keep load close to body
3. Place feet around load
4. Grip corners
Tense stomach muscles Straighten back
Bend at knees Lift with le
g
s
Bend at hips
FIGURE 17.2 Steps to follow in making a safe lift.
ß 2008 by Taylor & Francis Group, LLC.
17.4 RECORDS REVIEW: OSHA 300 LOG
Note when back or other musculoskeletal disorders appear excessive from lost work
day injury and illness (LWDII) rate calculations. Understand that excessiveness is
relative, since there is no set limit that delineates safe from unsafe. A better measure
is to look for trends of escalating number of injuries or of increasing severity of

injuries. Comparing your target population with Bureau of Labor Statistics (BLS)
data, other company rates, other lines, departments, wings, or occupational titles can
yield a meaningful measuring point to gauge excessiveness.
Back injuries should be treated as an injury on the OSHA (Occupational Safety
and Health Administration) 300 log regardless of whether the injury was the result of
an acute or chronic exposure. To determine if trends exist, at least several years of the
OSHA 300 log will have to be reviewed. Record or copy information, including
occupational titles, departments, dates of injury, or illness, from the OSHA 300 log
and pertinent OSHA 301 (or equivalent).
17.5 EVALUATING BACK INJURIES
The following techniques can be used to assess why back injuries occurred:
.
Use a walkaround.
.
Interview employees about their opini on on the difficulty of the task as well
as personal experiences of back pain.
.
Observe worker postures and lifting.
.
Determine weight of objects lifted.
.
Determine the frequency and duration of lifting tasks.
.
Measure the dimensions of the workplace and lift.
.
Videotapes should be taken of the work task for later review and for
evidence of recognized musculoskeletal hazards.
17.6 MANUAL LIFTING
Repetitive material handling increases the likelihood of a back disorder. Principal
variables in evaluating manual lifting tasks to determine how heavy a load can be lifted

are the horizontal distance from the load to the employee’s spine, the vertical distance
through which the load is handled, the amount of trunk twisting the employee utilized
during the lifting, the ability of the hand to grasp the load, and the frequency with
which the load is handled. Additional variables include floor and shoe traction, space
constraints, two-handed lifts, size, and stability of the load.
17.7 PREVENTION AND CONTROL
17.7.1 E
NGINEERING CONTROLS
Generally, the task can be altered to eliminate the hazardous motion and=or change the
position of the object in relation to the employee’sbody—such as adjusting the height of
ß 2008 by Taylor & Francis Group, LLC.
a pallet or shelf. Manual handling tasks should be designed to minimize the weight,
range of motion, and frequency of the activity. Work methods and stations should be
designed to minimize the distance between the person and the object being handled.
Platforms and conveyors should be built at about waist height to minimize awkward
postures. Conveyors or carts should be used for horizontal motion whenever possible.
Reduce the size or weight of the objects lifted. High-strength push–pull requirements are
undesirable, but pushing is better than pulling. Material handling equipment should be
easy to move, with handles that can be easily grasped in an upright posture (Figure 17.3).
Workbench or workstation configurations can force people to bend over. Cor-
rections should emphasize adjustments necessary for the employee to remain in a
relaxed upright stance or fully supported seated posture. Bending the upper body and
spine to reach into a bin or container is highl y undesirable. The bins shoul d be
elevated, tilted, or equipped with collapsible sides to improve access. Repetitive or
sustained twisting, stretching, or leaning to one side are undesirable. Corrections
could include repositioning bins and moving employees close r to parts and con-
veyors. Store heavy objects at waist level. Provide lift-assist devices and lift tables.
17.8 CONTROLS AND WORK PRACTICES
The following are controls and other methods that address the prevention of back
injuries at the workplace:

.
Engineering controls are the preferred mechanism to address interventions.
.
Worker training and education should include general principles of e rgo-
nomics, recognition of hazards and injuries, procedures for reporting haz-
ardous conditions, and methods and procedures for early reporting of
FIGURE 17.3 Use a handtruck to avoid lifting and carrying task. (Courtesy of the Occupa-
tional Safety and Health Administration.)
ß 2008 by Taylor & Francis Group, LLC.
injuries. Additionally, job-specific training should be given on safe work
practices, hazards, and controls. The training should include practical
sessions where workers are taught and practice safe lifting techniques
under expert supervision.
.
Strength and fitness training can reduce compensation costs.
.
Rotating of employees, providing a short break every hour, or using a two-
person lift may be helpful. Rotation is not simply a different job, but must
be a job that utilizes a completely different muscle group from the ones that
have been over-exerted.
.
Standing for extended periods places excessive strain on the back and legs.
Solutions include a footrest or rail, resilient floor mats, height-adjustable
chairs or stools, and opportunities for the employee to change position.
.
Where employees are seated the chairs or stools must be chosen properly.
Proper adjustable lumbar support must be provided.
.
Static seated postures with bending or reaching should be avoided.
17.9 SUMMARY

To review safe lifting, the legs should be used and not the back. To pick up a load stand
close to the load, bend the knees while maintaining the backs natural curve. Grip the
load firmly and push the body and load up slowly and smoothly with the legs.
To put down a load do not twist the body. Bend the knees to lower the load and
place the load on the edge of a surface, then slide it back.
At times two persons will be needed to lift. Put one person in charge to say when
to lift. Both individuals should lift at the same time while keeping the load level and
unload at the same time (Figure 17.4).
Liftin
g
bulky loads
FIGURE 17.4 Two person lifts reduce the strain of a single person lift. (Courtesy of the
Occupational Safety and Health Administration.)
ß 2008 by Taylor & Francis Group, LLC.
ß 2008 by Taylor & Francis Group, LLC.