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Guidelines Part 4
Guidelines Part 4 - Ergonomics (MSI) requirements
G4.46 Definition of musculoskeletal injury (MSI)
Issued August 3, 2006
Regulatory excerpt
Section 4.46 of the OHS Regulation defines "musculoskeletal injury" or "MSI" as follows:
"musculoskeletal injury" or "MSI" means an injury or disorder of the muscles, tendons, ligaments, joints, nerves, blood vessels or related soft tissue including a sprain, strain and inflammation, that may be caused or aggravated by work.
Purpose of guideline
This guideline provides further information on the definition of MSI.
Conditions addressed by the definition
The definition of "musculoskeletal injury" includes reference to a sprain, strain, and inflammation that may be caused or aggravated by work.
A sprain is a joint injury in which some of the fibers of a supporting ligament are ruptured but the continuity of the ligament remains intact.
A strain is an overstretching or overexertion of some part of the musculature.
An inflammation is a localized response to injury or trauma that is marked by increased blood flow, redness, heat, pain, swelling, and often a loss of function.
The Ergonomics Requirements are intended to help address the risk of overexertion injuries of the back as well as strain and sprain injuries to other parts of the body. They are also intended to address the risk of injuries or conditions such as tenosynovitis, tendonitis, bursitis, hand arm vibration syndrome, epicondylitis, carpal tunnel syndrome, cubital tunnel syndrome, radial tunnel syndrome, thoracic outlet syndrome, and trigger finger.
G4.47 Risk identification
Issued August 3, 2006; Revised December 1, 2006
Regulatory excerpt
Section 4.47 of the OHS Regulation ("Regulation") states:
The employer must identify factors in the workplace that may expose workers to a risk of musculoskeletal injury (MSI).
Purpose of guideline
This guideline provides information on the context of section 4.47 and how to identify risk factors.
The context of section 4.47
Risk factor identification is the first step in a process involving identification, assessment, control, and evaluation.
Section 4.49 lists factors that must be considered during the risk identification process. In some cases other factors such as illumination or vibration may be involved, which are addressed respectively in sections 4.64 - 4.69 and 7.10 - 7.16 of the Regulation.
Risk identification will be conducted by persons who are knowledgeable of work procedures, and the associated MSI risk factors. The risk identification process can be a part of a workplace inspection carried out under sections 3.5 to 3.8 of the Regulation.
Note: Section 4.53 requires that the joint occupational health and safety committee or worker health and safety representative, as applicable, must be consulted on risk identification.
How are risk factors identified?
In identifying risk factors, the employer should give priority to jobs which have a high risk of MSI.
The employer should check past workplace records for evidence of MSI, including first aid records and claims history. The records should be examined for a sufficient period of time to ensure that any occurrences are identified, and where possible, that any patterns are clear. To achieve both objectives it is recommended that records be kept for at least several years.
Other sources of information include
- Interviews with workers and supervisors
- Trends in the employer's industry
- MSI statistics in similar operations where available
In addition to reviewing records, risk factors can be identified through direct observation of the work activities. For this purpose, the employer has the option of using the MSI Risk Factor Identification Worksheet A which can be found via the Ergonomics portal on the WorkSafeBC website. The Worksheet covers a number of factors to consider and includes links to documents that address several others.
Generally, there will be more than one risk factor identified for a given work activity. This may occur because of the nature of the activity but may also be attributable to the personal characteristics of different workers doing the job, for example, their height.
Notes of the records reviewed, priorities established, and risk factors identified for work activities will be of assistance to the employer in following through on risk assessment and control.
G4.48 Risk assessment
Issued August 3, 2006: Revised December 1, 2006
Regulatory excerpt
Section 4.48 of the OHS Regulation states:
When factors that may expose workers to a risk of MSI have been identified, the employer must ensure that the risk to workers is assessed.
Purpose of guideline
This guideline outlines objectives for the risk assessment, and provides information on who should conduct it and how it can be performed.
Objectives of the risk assessment
The objectives include
- Determining the extent of impact of various risk factors on the potential for MSI
- Where feasible, determining the relative risk of MSI among workers or groups of workers
Achieving these objectives will assist with establishing priorities for the control of risks.
Who performs the assessment?
The risk assessment will be completed by a person who has a good understanding of
- The work processes involved
- The physical demands of work tasks and the factors which influence them (see the booklet Preventing Musculoskeletal Injury (MSI) A Guide for Employers and Joint Committees
- The methods for performing a risk assessment such as those referred to in this guideline
Note: Section 4.53(1) requires that the joint occupational health and safety committee or worker health and safety representative, as applicable, must be consulted on the risk assessment. Also, section 4.53(2) requires that during a risk assessment, the employer must consult with the workers with signs or symptoms of MSI, and a representative sample of the workers who are required to carry out the work being assessed.
How is the assessment performed?
A risk assessment can be performed using a variety of methods. WorkSafeBC provides the MSI Risk Factor Assessment Worksheet B, which addresses a number of the factors to be considered. Other methods may be used as long as they ensure the proper identification and assessment of risks. Worksheet B can be found via the Ergonomics portal at the WorkSafeBC website.
Methods of assessment may include but are not limited to
- Observation of workers performing their tasks, including videotaping
- Still photographs of work postures, workstation layout, etc.
- Workstation measurements, using for example, a measuring tape, or weigh scales
- Measurement of handle size, weighing tools, measuring tool vibration, etc.
- Determination of characteristics of work surfaces such as slip resistance
- Measurement of exposures to heat, cold, vibration, noise, and lighting
- Biomechanical calculations, for example, the force required to accomplish a task or the pressure put on a spinal disk
- Physiological measures
- Worker surveys (for example, use of subjective force rating scales)
- Task analysis techniques (for example, NIOSH lifting equation, SNOOK push/pull tables - see The design of manual handling tasks: Revised table of maximum acceptable weights and forces in Ergonomics, Vol. 34, No. 9, 1991). Also, a Push/Pull/Carry Calculator is provided via the Ergonomics portal on the web site www.worksafebc.com
- Postural analysis techniques (for example, the Ovako Working Posture Analysis System (OWAS), Rapid Upper Limb Assessment (RULA), or WATBAK (a biomechanical modeling program from the University of Waterloo))
The person(s) performing the assessment and using any of these methods should understand the applications and limitations of the method being used.
G4.49 Risk factors
Issued August 3, 2006
Regulatory excerpt
Section 4.49 of the OHS Regulation states:
The following factors must be considered, where applicable, in the identification and assessment of the risk of MSI:
(a) The physical demands of work activities, including
(i) force required
(ii) repetition
(iii) duration
(iv) work postures
(v) local contact stresses
(b) Aspects of the layout and condition of the workplace or workstation, including
(i) working reaches
(ii) working heights
(iii) seating
(iv) floor surfaces
(c) The characteristics of objects handled, including
(i) size and shape
(ii) load condition and weight distribution
(iii) container, tool and equipment handles
(d) The environmental conditions, including cold temperature
(e) The following characteristics of the organization of work
(i) work-recovery cycles
(ii) task variability
(iii) work rate
Purpose of guideline
This guideline provides information on the risk factors outlined in section 4.49.
General information
Section 4.49 states that the listed factors must be considered "where applicable." This means that the factors must be considered where they are present. Not all tasks will have all risk factors present.
In addition, it is acceptable for the employer to give priority to considering the risk factors relevant to high risk tasks that have caused injuries in the past.
Information on risk factors listed in section 4.49
Each of the factors listed in 4.49 is discussed below. Though listed separately, these factors often act in combination.
Force required (Section 4.49(a)(i))
This refers to the effort a worker must exert to counteract a load. This load may be experienced in the body through tension (such as muscle tension), pressure (such as increased pressure in the carpal canal), or irritation (such as irritation of a peripheral nerve). The greater the magnitude/intensity of the force, the greater the risk of causing an MSI.
Repetition (Section 4.49(a)(ii))
This refers to the cyclical use of the same body tissues either as a repeated motion or as a repeated muscular effort without movement. If motions are repeated frequently or for long periods without sufficient time to return to a resting state for recovery, there is risk of developing MSI. Consideration should be given to the following:
- How often the same motion or muscular effort is performed within a certain period of time
- The amount of time during or between a given work cycle for the affected muscle or tendon group to return to the recovery state
Duration (Section 4.49(a)(iii))
This refers to the length of time a person is exposed to a particular risk. A person may be exposed to a task that continually uses the same muscles and tendons.
Work postures (Section 4.49(a)(iv))
This refers to postures that are awkward. This occurs where joints are held at or near the end of range of motion or where muscle tension is required to hold the posture without movement. Awkward postures place significant stress on tendons, muscles, and other soft tissues and decrease their strength and efficiency. Postures to watch for include
- Shoulder abduction or flexion
- Flexion or extension of the wrist
- Ulnar deviation of the wrist
- Squatting and stooping
- Flexion or extension of the neck
- Rotation or side bending of the neck
Local contact stress (Section 4.49(a)(v))
This refers to physical contact between body tissues (in a small localized area) and objects in the work environment such as tools, machinery, and products. Local contact stress, when applicable, usually involves the knee, shoulder, elbow, wrist, or hand. Point pressure may also occur at the sides of fingers. Pressure over these areas may inhibit nerve function and/or blood flow.
Working reaches (Section 4.49(b)(i))
This refers to the risks that can result from reaching behind the shoulder, forward, or across the body. This factor may cause MSI, either through a single incident or through a repetitive or cumulative process.
Working heights (Section 4.49(b)(ii))
This refers to the risks from having to accommodate to inappropriate work surface heights for an extended period of time.
Seating (Section 4.49(b)(iii))
This refers either to the physical properties of a chair or seat, or prolonged sitting required by some jobs. The Canadian Standards Association (CSA) has issued the standard CAN/CSA-Z412-M89 A Guideline on Office Ergonomics, and WorkSafeBC has produced the booklet How to Make Your Computer Workstation Fit You. These publications can assist with an understanding of this factor. WorkSafeBC publications on ergonomics are available at the WorkSafeBC website.
Floor surfaces (Section 4.49(b)(iv))
This refers to the physical characteristics of a floor, including grade, surface texture and material, unevenness, and slip resistance. Examples of risk factors associated with floor surfaces include
- Sloped surfaces and ramps, which can result in an increased effort to carry, push, pull, or manipulate loads
- Hard surfaces, which can cause increased fatigue and back discomfort to workers who have to stand on them for an extended period of time
- Uneven work surfaces, which can increase the force needed to move objects
- Floors that are slippery, which can cause an increased risk of falling or slipping
Size and shape (Section 4.49(c)(i))
This refers to the size and shape of an object and how it influences physical demands on the body. A large bulky object requires greater energy, puts greater stress on the spine, and increases difficulty in gripping. Large loads may restrict vision or require the use of an awkward posture to see around them. If the outside corners of a deep box are not within reach when the top of the box is at waist height, a good grip will be difficult.
Load condition and weight distribution (Section 4.49(c)(ii))
The condition and weight of a load will determine how workers handle it. For inanimate objects, the term "condition" typically refers to factors such as whether the load is slippery, sharp, fragile, hot or cold, rigid, or liquid. For example, to handle fragile loads, workers may have to use awkward or static postures. On the other hand, rigid loads facilitate a good grip and smooth predictable movements.
Note that patient handling is an important issue in the prevention of MSI in the health care sector. Factors such as patient size and condition are significant considerations for the safety of both the worker and the patient. The condition of the patient may affect the degree of effort needed to move the patient safely, and the precautions necessary to help ensure the move does not involve unexpected risks.
Containers, tool and equipment handles (Section 4.49(c)(iii))
Objects without handles are more difficult to handle and require more forceful gripping, which can result in an awkward posture. Important considerations in handle design include size, shape, texture, and location.
| Size | Improper handle size increases fatigue; handles should accommodate gloves |
| Shape | Sharp edges, grooves, seams may cause contact stress |
| Texture | Slippery handles may cause dropping |
| Location | Improperly placed handles may force an awkward posture of wrists or arms. Asymmetrical placement may cause hazards of tipping of an unstable load |
Environmental conditions, including cold temperature (Section 4.49(d))
Cold temperatures may have a direct adverse effect on the tissue through vascular constriction. Cold temperatures are related to increased forceful exertions and increased gripping forces.
Poor lighting and glare can adversely affect postures as well as cause eyestrain. This is addressed in sections 4.64 - 4.69 of the OHS Regulation on illumination.
Hand/arm vibration is linked to conditions such as carpal tunnel syndrome, and vibration white finger disease. Sections 7.10 - 7.16 of the OHS Regulation and associated OHS Guidelines deal specifically with vibration.
Work-recovery cycles (Section 4.49(e)(i))
This refers to the availability and distribution of breaks in a particular activity to allow the tissue to return to a resting state for recovery. Breaks can be achieved in various ways, including job rotation or use of different body parts to perform a task, for example alternate use of the right and left hands.
Task variability (Section 4.49(e)(ii))
The longer the time a task remains unchanged, unvaried, or uninterrupted, the less likely are the affected tissues to return to a resting state for recovery.
Work rate (Section 4.49(e)(iii))
This refers to the speed at which the tasks are being carried out. Individual workers may vary somewhat in the rates at which they can safely perform the same task. In some cases work rate may be associated with non-optimal work techniques that could add to the risk of injury. The more critical or physically demanding the task, the more appropriate it is to ensure the pace is properly set for the worker. Planning the work rate will also involve consideration of work recovery cycles, task variability, and staffing schedules.
G4.50 Risk control
Issued August 3, 2006
Regulatory excerpt
Section 4.50 of the OHS Regulation states:
(1) The employer must eliminate or, if that is not practicable, minimize the risk of MSI to workers.
(2) Personal protective equipment may only be used as a substitute for engineering or administrative controls if it is used in circumstances in which those controls are not practicable.
(3) The employer must, without delay, implement interim control measures when the introduction of permanent control measures will be delayed.
Purpose of guideline
This guideline provides information on the application of section 4.50(1), and discusses the hierarchy of controls and interim controls under sections 4.50(2) & (3).
Section 4.50(1) - General requirement for control of risk
The employer will eliminate or minimize the risks by creating control mechanisms for the risk factors found during the risk assessment.
In some cases, the control of ergonomic risk involves matters covered in other sections of the OHS Regulation, or in the Workers Compensation Act. Examples include lighting, vibration, unsafe work practices, and training.
Risk factors must be eliminated where practicable. "Practicable" is defined in section 1.1 of the OHS Regulation as "that which is reasonably capable of being done."
In determining if elimination is "practicable," the relevant considerations include
- Degree of risk to the worker arising from risk factors
- Extent of available information on the risk and the means of controlling it
- Availability and suitability of control measures
- Frequency of performing tasks that contain risk factors
- Resources needed to control the risk
Where elimination is not practicable, the specific risk factors identified in the risk assessment should be reduced to the lowest practicable level. Typically this means minimizing the duration, magnitude, and/or frequency of the relevant risk factor. Care should be taken to ensure that the reduction of risk of MSI from one factor does not increase the risk from another.
As a general rule, risk factors for tasks which are performed most of the time should be considered first. The primary risk factors to consider normally include awkward postures, force required, and repetition.
Note: The employer is required under section 4.53 to consult with the joint occupational health and safety committee or worker health and safety representative, as applicable, on the implementation of controls.
Section 4.50(2) Hierarchy of controls/personal protective equipment
Under section 4.50(2) engineering or administrative controls must, where practicable, be used in preference to personal protective equipment (PPE) for eliminating or reducing the risk of MSI.
Section 1.1 of the OHS Regulation states that "engineering controls" means the "physical arrangement, design or alteration of workstations, equipment, materials, production facilities or other aspects of the physical work environment, for the purpose of controlling risk."
Section 1.1 defines "administrative controls" to mean the "provision, use and scheduling of work activities and resources in the workplace, including planning, organizing, staffing and coordinating, for the purpose of controlling risk."
PPE for MSI includes, but is not limited to the following:
- Gloves (for example, vibration dampening gloves, friction gloves)
- Footwear (for example, safe, cushioned footwear with a comfortable toe box, and proper-fitting, low profile heels)
- Devices to protect against contact stress (for example, knee pads and wrist rests on computer keyboards)
WorkSafeBC provides Ergonomics Commentary sheets on topics such as the computer mouse, wrist braces, and back belts. These can be accessed via the Ergonomics portal at the WorkSafeBC website.
Section 4.50(3) Interim controls
This section permits the use of interim controls if the introduction of permanent controls will be delayed.
"Delayed" in this context means putting off the introduction of permanent control measures for reasons related to practicability. For example, the cost of, or time required to develop control measures, may require that they be phased in over a period of time.
Section 4.50(3) requires that "interim control measures" be applied to minimize risk while more effective or long term solutions are being developed. The section does not authorize the employer to delay the introduction of practicable control measures for other reasons.
G4.51 Education and training
Issued August 3, 2006
Regulatory excerpt
Section 4.51 of the OHS Regulation states:
(1) The employer must ensure that a worker who may be exposed to a risk of MSI is educated in risk identification related to the work, including the recognition of early signs and symptoms of MSIs and their potential health effects.
(2) The employer must ensure that a worker to be assigned to work which requires specific measures to control the risk of MSI is trained in the use of those measures, including, where applicable, work procedures, mechanical aids and personal protective equipment.
Purpose of guideline
This guideline provides information to assist with understanding terms in section 4.51(1) and on what is meant by "trained" in section 4.51(2).
Section 4.51(1)
This provision requires that workers be educated as to the risk factors which have been identified during the risk identification process under section 4.47 for a work activity that they perform. The education needs to be sufficient so the workers are aware of the applicable risk factors and their potential impact on the body.
Because all work has a physical component to it (i.e. from lifting a box to sitting behind a desk) risk factors are likely to be identified in the majority of jobs. Therefore, most workers will need education under this provision.
The early signs and symptoms of MSI include but are not limited to the following:
- Pain or discomfort
- Reduced range of motion at a joint
- Swelling
- Tingling, numbness
- Weakness when trying to perform a natural action like grasping
See OHS Guideline G4.46 for more information on the medical conditions addressed by the Ergonomics Requirements. WorkSafeBC has also produced the booklet Understanding the Risks of Musculoskeletal Injury (MSI) to help employers with the requirements of section 4.51(1) to educate workers in risk identification, signs and symptoms of MSI, and their potential health effects. These can be accessed via the Ergonomics portal at the WorkSafeBC website.
Section 4.51(2)
In this provision, "trained" refers to the provision of practical information so that the workers affected understand why a control measure is in place and are able to effectively apply the control measures in their work.
Workers should be able to demonstrate an understanding of the education and training. To check this, it may be useful to ask workers about the risk factors present in their job and if there are specific procedures or equipment they use to reduce the risk. Sample questions for the worker could include
- What are some early signs and symptoms of MSI, and what could happen if they are ignored?
- Who should you report any signs and symptoms of MSI to?
- What are the risks of MSI in your job?
- What can be done to reduce the risk of MSI in your job?
Note: Section 4.53 of the OHS Regulation requires that the joint occupational health and safety committee or worker health and safety representative, as applicable, must be consulted on the content and means of provision of education and training under section 4.51.
G4.52 Evaluation
Issued August 3, 2006
Regulatory excerpt
Section 4.52 of the OHS Regulation states:
(1) The employer must monitor the effectiveness of the measures taken to comply with the Ergonomics (MSI) Requirements and ensure they are reviewed at least annually.
(2) When the monitoring required by subsection (1) identifies deficiencies, they must be corrected without undue delay.
Purpose of guideline
This guideline provides information on what is meant by conducting a review under section 4.52(1) and some of the considerations when applying section 4.52(2).
Section 4.52(1) - Conducting a review
This section requires the employer to monitor the effectiveness of control measures and ensure they are reviewed at least once a year.
The review must cover all the measures taken under sections 4.47 to 4.51, including risk identification and assessment, the implementation of control measures, and the education and training of workers.
In reviewing the effectiveness of existing measures, employers will evaluate whether they have eliminated or minimized the degree of risk to workers. The information to be considered may include evidence on changes of exposure to risk factors, reports of worker discomfort, MSI records in the first aid book, and MSI claims.
Section 4.52(1) states that a review must be done at least annually. A review is also required when significant changes in circumstances occur, including when
- MSI of a different type is reported, or workers report signs and symptoms of MSI of a different type
- A request from a worker is received to identify a risk factor that has not previously been considered
- A new or changed piece of equipment is implemented
- When new work stations or work processes are initiated
Note: Section 4.53 requires that the joint occupational health and safety committee or worker health and safety representative, as applicable, must be consulted in the evaluation.
Section 4.52(2) - Effective control measures
If monitoring shows there has been no reduction in the level of risk to workers or reports of discomfort, the effectiveness of the measures taken will need to be considered, and a determination made of whether additional corrective action should be taken.
If any different injury or signs or symptoms are reported, or any new risk factors are identified during a review, these need to be assessed and appropriate risk control measures taken. Identification of new MSI or new risks means the priority for addressing MSI should be reviewed, and the overall MSI program adjusted as necessary to ensure the areas of highest risk are receiving appropriate action.
G4.53 Consultation
Issued August 3, 2006
Regulatory excerpt
Section 4.53 of the OHS Regulation states:
(1) The employer must consult with the joint committee, if any, or the worker health and safety representative, as applicable, with respect to the following when they are required by the Ergonomics (MSI) Requirements:
(a) Risk identification, assessment and control
(b) The content and provision of worker education and training
(c) The evaluation of the compliance measures taken
(2) The employer must, when performing a risk assessment, consult with
(a) Workers with signs or symptoms of MSI, and
(b) Representative sample of the workers who are required to carry out the work being assessed
Purpose of guideline
This guideline provides information on expectations for consultation under subsections (1) and (2) of this requirement. Consultation includes seeking the participation of the affected parties and asking for their input on measures taken under sections 4.47 to 4.52 of the OHS Regulation.
Section 4.53(1)
Section 4.53(1) requires the employer to consult with the joint occupational health and safety committee or worker health and safety representative, as applicable, regarding implementation of ergonomic requirements. It is expected that ergonomic requirements will be incorporated as part of the occupational health and safety program for the workplace.
Section 4.53(2)
This provision requires the employer to consult with the affected workers when a risk assessment is being done regarding tasks or functions performed by those workers. A "representative sample" under subsection (2)(b) means, in addition to workers with signs or symptoms, a cross section of workers, having regard to differences in age, shift schedule, gender, size (height, weight), and work location (climatic conditions can vary considerably, and clothing or icy surfaces may result in different levels of risk for similar tasks). The size of the sample will depend on how many applicable differences there are in the group.
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