Work-related upper disorders of the limb
Work-related Upper Limb Disorders (WRULDs) is basically an umbrella term that refers to a variety of work-related injuries to the muscles, nerve, tendons and other soft body tissues. The most effected areas include the hand, wrist, arm, shoulder and spine.
In other words, the WRULDs are the impairments caused to the bodily structures such as muscles, joints, tendons, ligaments, nerves, bones and the localized blood circulation system. The WRULDs are also known as sprains and strains, repetitive strain injuries and cumulative trauma disorders.
The most common conditions in this category include:
Carpal Tunnel Syndrome Tendonitis Tenosynovitis de Quervain’s Syndrome Tennis Elbow Thoracic Outlet Syndrome
Incidence and Trends
The WRULDs primarily occur in the following workers who,
Maintain one position for a long time with little or no movement Repeat the same movement Feel stressed
The main working groups at a high risk of the development of WRULDs belong to the following industries:
Agriculture, forestry and fisheries Manufacturing and mining Machine operators Tailors, craft workers Construction Wholesale, retail and repairs Hotels, restaurants and catering Secretaries, typists Loaders, unloaders
There is also evidence to show that the WRULDs affect women more than men, owing to the nature of work they do.
Symptoms associated to WRULDs usually develop over a long period of time. The most prominent set of symptoms include:
Discomfort Numbness Tingling sensations Swelling in joints Decreased mobility or grip strength Change in color of hands or fingers
There are three broad groups of risk factors that contribute to the development of the Work-related Upper Limb Disorders. Here we briefly discuss each of them, along with suitable examples.
Static muscle loading
Static muscle loading describes muscular activity which involves holding an object or maintaining a certain posture or position, with little or no activity at all.
The key problem associated with this kind of activity is related to the muscle structure and the basic way in which the muscles work. Keeping the muscles in a static position for long reduces the supply of blood to these muscles. This in turn hinders their natural action of contraction, eventually leading to muscle fatigue, which is felt as an ache or discomfort.
The most prominent example of this form of activity is computer-related work.
Overuse and repetition
Overuse of certain specific muscles and repetition of certain activities might carry the risk of straining tissues beyond their normal capacity.
The basic underlying cause is that any repetitive task performed continuously without sufficient breaks or modifications places demands on specific structures and can result in a risk of injury. However, the way these activities are performed determines their influence.
For instance, if an individual types or uses the mouse keeping the wrists in a neutral position, he/she is less likely to suffer from a WRULD, even if extensive use is there.
Stress, along with other psychological factors can play a major role in the development of WRULDs. Stress and anxiety considerably increase muscle tension and sensitize the nervous system, which further leads to an increased perception of pain.
Other causes of WRULDs include:
Poor posture Highly repetitive movements Forceful hand applications Hand-arm vibration Direct mechanical pressure on the body tissues Cold work environments How work is organized How workers perceive the work organization
Specific Activities and WRULDs
Certain activities lead to the development of WRULDs in specific body parts. Here we list the most common activities and the possible WRULDs associated with them.
In neck and shoulders
Working in positions where the weight of parts of the body has to be supported or objects have to be held Prolonged work in static postures, involving strain on the same group of muscles, such as working with a microscope Repeated lifting of arms or turning the head to the side
In elbow, wrists and hands
Use of great muscular force to handle objects, such as grasping with a large grip Working with wrists in deviated postures, e.g. turned inwards or outwards Repeating the same wrist movements
The following measures can be adopted at the workplace to ensure prevention and avoid recurrence of WRULDs.
Improve the workplace layout Use ergonomically designed work tools Plan and delegate work more efficiently Implement safer systems of work Ensure more job rotation Promote workplace health