Chap 2

• Musculoskeletal disorder (MSD) defined as an injury or disease of the musculoskeletal system, including sprains, strains, back injuries, joint and bone injuries, nerve injuries, muscular and vascular disorders, soft tissue hernias, and chronic pain
• MSDs occur in two ways: gradual wear and tear caused by repeated use of body parts and sudden damage caused by strenuous activity or unexpected movements
• Hazardous manual task defined as a task involving lifting, lowering, pushing, pulling, carrying, or moving that includes repetitive or sustained force, high or sudden force, repetitive movement, sustained or awkward posture, and exposure to vibration
• Primary duty to ensure health and safety risks are managed falls on the person conducting a business or undertaking
• Designers, manufacturers, importers, and suppliers have a duty to eliminate or minimize risks associated with hazardous manual tasks
• Officers, such as company directors, have a duty to ensure compliance with health and safety regulations
• Workers have a duty to take care of their own health and safety and not adversely affect others, complying with instructions and procedures
• To manage the risk of musculoskeletal disorders, duty holders must identify hazards, eliminate or minimize risks, implement control measures, maintain effectiveness, and review and revise control measures
• Consultation with workers is necessary at each step of the risk management process
• Identifying hazardous manual tasks involves consulting workers, reviewing available information, looking for trends, observing manual tasks, and recording findings on a hazard identification worksheet
• Characteristics of hazardous manual tasks include repetitive force, sustained force, and high force
• Repetitive force examples: lifting and stacking goods, gripping and handling bricks, pressing components, therapeutic massage, and removing splinting material
• Sustained force examples: pushing or pulling a trolley, holding down a trigger, supporting a plaster sheet, carrying objects over long distances, and supporting or stabilizing a patient's limb
• High force examples: lifting, lowering, pushing, pulling, or carrying tasks that exert force on muscles or joints
• High force tasks include:

  • Tasks described as very demanding physically by workers
  • Tasks requiring help due to the effort it requires
  • Tasks needing a stronger person or two persons to complete
  • Carrying a heavy object
  • Lifting, lowering, or carrying an object that cannot be positioned close to the body
  • Pushing or pulling an object that is hard to move or stop
  • Restraining a person or animal
• Examples of high force using the hands and fingers:

  • Using a finger-grip, a pinch-grip, or an open-handed grip to handle a heavy or large load
  • Operating hand tools with tight squeeze grips
  • Gripping small instruments with high force, like a dental hygienist cleaning teeth
• Sudden force tasks include:

  • Impact recoil of a large nail gun
  • Throwing or catching objects
  • Cutting reinforcement steel with large bolt cutters
  • Carrying an unbalanced or unstable load that suddenly moves
• Force is the amount of muscular effort required to perform a movement or task

  • Forceful muscular exertions overload muscles, tendons, joints, and discs and are associated with most MSDs
  • Handling frightened or resistant animals
  • Handling patients who suddenly resist or no longer assist during the handling procedure
• Repetitive movement involves using the same parts of the body to repeat similar movements over a period of time

  • Examples include painting, lifting goods from a conveyor belt and packing them in a carton, typing, and other keyboard tasks
• An ideal posture is one where the trunk and head are upright and forward facing, the arms are by the side of the body, the forearms are either hanging straight or at right angles to the upper arm, and the hand is in the handshake position

  • Postures that are both awkward and sustained are particularly hazardous
  • Sustained posture involves keeping part of or the whole body in the same position for a prolonged period
  • Awkward posture involves any part of the body being in an uncomfortable or unnatural position
• Whole body vibration occurs when vibration is transmitted through the whole body, usually via a supporting surface like a seat or the floor in heavy vehicles or machinery

  • Hand-arm vibration occurs when vibration is transferred through a vibrating tool, steering wheel, or controls in heavy machinery to the hand and arm
• A risk assessment involves examining the characteristics of hazardous manual tasks in more detail to assess whether the forces, movements, and postures are undertaken in a way that gives rise to the risk of MSDs

  • Risk assessments should be conducted for hazardous manual tasks unless the risk is well-known and controllable
  • Identifying postures, movements, and forces that pose a risk and determining why they occur and what needs to be fixed is essential
• How to do a risk assessment for hazardous manual tasks:

  • Identify participants for the risk assessment
  • Describe the task and area where the manual task is performed
  • Note body parts likely at risk of injury
  • Work through the assessment together to determine risk factors and why the risk exists
• Risk factors include:

  • Repetitive movement
  • Sustained or awkward postures
  • Repetitive or sustained forces
• Examples of postures and movements that pose a risk if they are repetitive or sustained:

  • Bending the back or head forwards or sideways more than 20 degrees
  • Bending the back or head backwards more than 5 degrees or looking up
  • Twisting the back or neck more than 20 degrees
  • Working with one or both hands above shoulder height
  • Reaching forward or sideways more than 30cm from the body
  • Reaching behind the body
  • Standing with most of the body’s weight on one leg
• • Twisting, turning, grabbing, picking, or wringing actions with the fingers, hands, or arms that include excessive bending of the wrist
  • Working with the fingers close together or wide apart
  • Squatting, kneeling, crawling, lying, semi-lying, or jumping
  • Very fast movements, for example, packing bottles from a fast-moving process line