Environmental, Health and Safety Services

Express

The "Express" element of the ERGO model focuses on communication between employees, supervisors, EHSS and other Virginia Tech entities.

Responsibilities

  • Employees are responsible to report signs and symptoms of musculoskeletal disorders to supervisors.
  • Supervisors (including Deans, Directors, and Department heads) are responsible for promoting a climate that fosters communication about ergonomic issues. This includes listening and responding to employee reports of signs and symptoms of musculoskeletal disorders and forwarding concerns to EHSS.
  • EHSS is responsible to prioritize and address reported ergonomic issues and coordinate distribution of awareness resources to supervisors and employees.

What are Musculoskeletal Disorders (MSDs)?

MSDs are injuries and illnesses that affect muscles, nerves, tendons, ligaments, joints or spinal discs. A healthcare provider might diagnose the following common MSDs.

  • Carpal tunnel syndrome
  • Rotator cuff syndrome
  • Trigger finger
  • Sciatica
  • Tendinitis
  • Raynaud's phenomenon
  • Herniated spinal disc
  • Low back pain
  • Tension neck syndrome
  • De Quervain's disease
  • Epicondylitis
  • Carpet layers' knee
  • Hand-arm Vibration Syndrome

Symptoms of MSDs

Employees suffering from MSDs may experience less strength for gripping, less range of motion, loss of muscle function and inability to do everyday tasks.

Common symptoms include:

  • Painful joints
  • Pain in wrists, shoulders, forearms, knees
  • Pain, tingling or numbness in hands or feet
  • Fingers or toes turning white
  • Shooting or stabbing pains in arms or legs
  • Back or neck pain
  • Swelling or inflammation
  • Stiffness
  • Burning sensation

What causes MSDs?

According to the scientific literature, the following are recognized as important risk factors for musculoskeletal disorders, especially when occurring at high levels and in combination. Figure 1 provides illustrations of some of these risk factor conditions. In general, knowledge of the relationships between risk factors and the level of risk is still incomplete. Also, individuals vary in their capacity to adjust to the same job demands. Some may be more affected than others.

Workplace MSDs are caused by exposure to the following risk factors:

Repetitive motions

Doing the same motions over and over again places stress on the muscles and tendons. The severity of risk depends on how often the action is repeated, the speed of the movement, the number of muscles involved and the required force.

If motions are repeated frequently (e.g., every few seconds) and for prolonged periods such as an 8-hour shift, fatigue and muscle-tendon strain can accumulate. Tendons and muscles can often recover from the effects of stretching or forceful exertions if sufficient time is allotted between exertions. Effects of repetitive motions from performing the same work activities are increased when awkward postures and forceful exertions are involved. Repetitive actions as a risk factor can also depend on the body area and specific act being performed.

Awkward postures

Examples of various awkward postures Body postures determine which joints and muscles are used in an activity and the amount of force or stresses that are generated or tolerated. Awkward postures include repeated or prolonged reaching, twisting, bending, kneeling, squatting, working overhead with your hands or arms, or holding fixed positions.For example, more stress is placed on the spinal discs when lifting, lowering, or handling objects with the back bent or twisted, compared with when the back is straight. Manipulative or other tasks requiring repeated or sustained bending or twisting of the wrists, knees, hips, or shoulders also impose increased stresses on these joints. Activities requiring frequent or prolonged work over shoulder height can be particularly stressful.

Contact stresses

Pressing the body against a hard or sharp edge can result in placing too much pressure on nerves, tendons and blood vessels. For example, using the palm of your hand as a hammer can increase your risk of suffering an MSD.

Repeated or continuous contact with hard or sharp objects such as non-rounded desk edges or unpadded, narrow tool handles may create pressure over one area of the body (e.g., the forearm or sides of the fingers) that can inhibit nerve function and blood flow.

Vibration

Exposure to local vibration occurs when a specific part of the body comes in contact with a vibrating object, such as a power handtool. Exposure to whole-body vibration can occur while standing or sitting in vibrating environments or objects, such as when operating heavy-duty vehicles or large machinery.

Forceful exertions (including lifting, pushing, and pulling)

Force is the amount of physical effort required to perform a task (such as heavy lifting) or to maintain control of equipment or tools. The amount of force depends on the type of grip, the weight of an object, body posture, the type of activity and the duration of the task.

Tasks that require forceful exertions place higher loads on the muscles, tendons, ligaments, and joints. Increasing force means increasing body demands such as greater muscle exertion along with other physiological changes necessary to sustain an increased effort. Prolonged or recurrent experiences of this type can give rise to not only feelings of fatigue but may also lead to musculoskeletal problems when there is inadequate time for rest or recovery. Force requirements may increase with:

  • increased weight of a load handled or lifted,
  • increased bulkiness of the load handled or lifted,
  • use of an awkward posture,
  • the speeding up of movements, increased slipperiness of the objects handled (requiring increased grip force),
  • the presence of vibration (e.g., localized vibration from power handtools leads to use of an increased grip force),
  • use of the index finger and thumb to forcefully grip an object (i.e., a pinch grip compared with gripping the object with your whole hand), and
  • use of small or narrow tool handles that lessen grip capacity.

Duration

Duration refers to the amount of time a person is continually exposed to a risk factor. Job tasks that require use of the same muscles or motions for long durations increase the likelihood of both localized and general fatigue. In general, the longer the period of continuous work (e.g., tasks requiring sustained muscle contraction), the longer the recovery or rest time required. In cases of high force requirements, sufficient recovery time may be longer than the task itself.

Other conditions

Workplace conditions that can influence the presence and magnitude of the risk factors for MSDs can include:

  • cold temperatures,
  • insufficient pauses and rest breaks for recovery,
  • machine paced work, and
  • unfamiliar or unaccustomed work.

Signs of musculoskeletal disorders

Musculoskeletal System

Some background information on the musculoskeletal system will provide framework to "express" ergonomic concerns.

The arm musculoskeletal system of the armThe musculoskeletal system is made up of the soft tissue and bones in the body. These are the parts of the musculoskeletal system:

Bones: the load-bearing structure of the body.
Muscles: tissues that contract to create movement.
Tendons: tissue that connects muscles to bones.
Ligaments: tissue that connects bones to bones.
Cartilage: tissue that provides cushioning and reduces friction between bones.
Nerves: the communication system that links muscles, tendons and other tissue with the brain.
Blood vessels: tubes that circulate nutrients throughout the body.

Ergonomics is the science of fitting jobs to the people who work in them. The goal of the Virginia Tech Workplace Ergonomics Program is to reduce work-related musculoskeletal disorders (MSDs) employees may develop when a major part of their jobs involve ergonomic risk factors such as reaching, bending over, lifting heavy objects, using continuous force, working with vibrating equipment and doing repetitive motions.