(Unknown Author)

Pain in the Workplace

Work can cause pain. Any strong effort exerted over a long time usually causes some degree of pain, or at least discomfort. This is natural. Usually the tissues strengthen with mild overuse. This was first noted in bone by J.Wolff and reported in 1872. Now it is referred to as Wolff's Law. But we also know that too much overuse, e.g., repeatedly bending a bone, can cause stress fractures. The same is true of all tissues. Muscles and tendons become thicker and stronger with use, but if those same stresses that cause them to become stronger are applied to excess, the tissues break down, and now we have an injury. Such an injury is often called a repetitive strain injury (RSI) or cumulative trauma disorder (CTD).

How Much is Too Much?

No one really knows for sure. Guidelines are at this very moment being worked out....in the midst of great debate. But at least we can agree that certain conditions at work may present risk of injury to susceptible individuals. These are called "Risk Factors".

Unfavourable Working Conditions and Their Potential Effects. These health effects are based upon epidemiologic studies and the presence of the risk factor increases the risk of an individual developing a chronic work-related musculoskeletal injury. All potential health effects depend on the length of exposure to the conditions, the magnitude or size of the stressor, and the variation of the exposure.

Risk Factors Possible Tissue Changes Example Diagnoses
High Forces/Moments Strain in tendons or muscles. High forces for short duration may lead to tissue disruption. Moderate forces for long durations may lead to creep in tendons or muscle fatigue. Tendinitis

Muscle strain

Exertion of force in non-optimal postures Increased fatigue Muscle pain
Extreme Posture Compression of blood vessels or nerves Carpal Tunnel Syndrome
Overhead work Increased intramuscular pressure in supraspinatus with reduction in blood flow Myalgia of the trapezius and/or supraspinatus and supraspinatus tendinitis
Whole Body Vibration Increased shrinkage of intervertebral disks Low back pain
Hand/Arm Vibration Increased grip force to maintain control of object

Damage to nervous tissue

Increased fatigue and muscle pain

Carpal Tunnel Syndrome

Raynaud's Disease

Immobile Posture Static contraction of muscles Myalgia/Tension Neck syndrome
High Frequency Movements High velocity of tendon sliding combined with static contraction of more proximal muscles Tenosynovitis

Myalgia/Tension Neck syndrome