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• Manual materials handling means moving or handling things by lifting, lowering, pushing, pulling, carrying, holding, or restraining. MMH is also the most common cause of occupational fatigue, low back pain and lower back injuries.
• It seems that every worker who lifts or does other manual handling tasks is at some risk for musculoskeletal injury.
• Low back injury is the most likely kind of injury.
• Methods of Evaluation of MMH

  • Epidemiological - Science of identifying incidence, distribution and causes of injury/illness
• • 80% of Americans will battle back pain at some point in their life

  • Back-pain costs more than $100 billion annually

  • Low back pain is number two reason for doctor visits
• Back pain costs $160,000,000 annually BC back study (2005)

  • LBP costs more than $3.3 billion annually Ontario’s study (2004)

  • LBP costs about $1 billion annually in claims and lost time
• • 25% of all occupational injuries and MSDs are back related

  • 20% of work force have back pain each year
• Methods for evaluation of MMH

  • Biomechanical - Science studying the effect and control of forces acting on or produced by human body
• There are approximately 642 skeletal muscles within the typical human, and almost every muscle constitutes one part of a pair of identical bilateral muscles, found on both sides, resulting in approximately 320 pairs of muscles
• A tendon is a fibrous connective tissue which attaches muscle to bone.
• A ligament is a fibrous connective tissue which attaches bone to bone
• Spine is a complex arrangement of bones, joints, muscles, ligaments, discs, a spinal cord and nerves.
• In a healthy spine the vertebrae, facet joints and discs are vertically stacked, held together by a system of ligaments that help support the alignment while allowing movement within a safe range.
• Ligaments are another tissue that may get damaged and be a source of pain
• A spinal disk has a soft, jellylike center (nucleus) encased in a tougher, rubbery exterior (annulus).
• Sometimes called a slipped disk or a ruptured disk, a herniated disk occurs when some of the nucleus pushes out through a tear in the annulus.
• Two types of back muscles

  • Extrinsic back muscles
  • Intrinsic back muscles
•  The extrinsic back muscles, which lie most superficially on the back. These muscles are divided into superficial and intermediate.
• The intrinsic back muscles, which are also called true back muscles. They are located deep to the extrinsic muscles, being separated from them by the thoracolumbar fascia. Their primary function is to produce movements of the vertebral column. These muscles are divided into superficial, deep, and deepest layers.
• Flexion - bending of a joint at the hip, knee, ankle, or wrist
• Hyperextension - Extending a joint beyond its normal range of motion.
• Lateral flexion to right
• For Infrequent or Short Duration Lifting in the zone shown, lifting 16kg or less is recommended.
• The Lifting TLV uses a grid system showing vertical height and reach, and each zone has a recommended maximum weight.
• Green lifting situations are clustered between “knees and nose” and close to the body.
• Orange lifting situations have a recommended weight of zero (lifting should be avoided or controlled). Note that these are seen for lifting from the floor, far from the body or above the shoulder.
• Yellow lifting situations should be further assessed. A floor level lift, even if close in to the body, is undesirable: recall the message “Store it off the floor”. Routine lifting should be avoided above shoulder height.
• Manual Handling Operations Regulations

  Employers must

   Avoid the need for manual handling where possible

   Assess the risk of injury

   Reduce the risk as far as is practical
• Common methods for evaluation of MMH

  • Psychophysical - Science that examines the relationship between human sensations and physical stimuli
• Disadvantage

  Data for Snook tables are based on a population of experienced industrial workers
• Disadvantage

  • A lot of estimating is done since the Snook values are not specific to each job

  • Tables do not account for lifting awkward shapes or asymmetric loads

  • The Snook table values have not been all tested and therefore extrapolation and interpolation was done in the development of the tables, this may result in an unreliable estimate
• Advantage

  Snook tables takes gender into account when finding out the load limits, different tables are used for males and females

  • Snook tables is very easy and efficient to use

  • Multipliers allow for good indicators of which parts of the job need changing

  • Snook tables are applicable to intermittent tasks common in industry
• Common Methods for evaluation of MMH

  • Physiological - Science of examining metabolic and circulatory responses to loading stress and fatigue
• Factors affecting MMH

  • Human variables
  • Task Variables
  • Environmental variables
• Human variables

  • Fitness levels
  • Age
  • Gender
  • Body Weight
  • Technique of lifting
  • Anthropometry
  • Experience
• Task Factors

  • Load
  • Frequency
  • Vertical location of load
  • Horizontal location of load
  • Load Handle-coupling
  • Asymmetry factor
• Environmental Factors

  • Temperature
  • Humidity
  • Noise
  • Light
  • Vibration
  • Height
• -        L5/S1 is number one most injured disc
• -        You need the bigger discs at the bottom because it is carrying more weight so it must support more which in turn is the reason it is much bigger than the vertebrae at the top.
• -        Lordosis is the lower curve in and the kyphosis is the curve at the top and scoliosis is just messed up lol