WHAT ARE THE COMMON INJURIES RELATED TO COMPUTER WORKERS ?
A 6 A ) DEFINITION
1 Computer-aided ergonomics is an engineering discipline using computers to solve complex ergonomic problems involving interaction between the human body and its environment.
2 The human body holds a great complexity thus it can be beneficial to use computers to solve problems involving the human body and the environment that surrounds it.
3 Ergonomics traditionally involves many disciplines including biomechanics, anthropometry, mechanical engineering, industrial engineering, kinesiology, health sciences and physiology.
4 Due to the highly interdisciplinary and complex nature of ergonomics it is hard to get a full understanding of a situation.
5 As the human body is a complex system, thus it is beneficial to have a computer system that models the human body as a mechanical system.
6 The human body contains several parts that can be modeled as known mechanical systems, for example bones connected with joints and driven by actuators (muscles).
7 One example of a computer system that can be used as a computer-aided ergonomics system is that consider the human body as a dynamic multi-rigid-body system.
A ) The human model is a public domain model contains most of the bones, muscles and joints that are present in the human body.
B ) The model in total have more than 1000 muscle elements, and many muscle elements have been modeled with the most detailed muscle model theory described by Hill, A.V. in 1938.
C ) The muscle model contains information as physiological cross-sectional area, length, penation angle, ratio of red and white fibers and so on.
D ) The AnyBody modeling system is capable of modeling almost any human voluntary movement or static situation.
E ) One example of a model, could be a seated model, where the human body is placed in a chair, that have a seat, backrest, headrest, leg rest, footrest, and armrest.
F ) The model can then calculate the forces acting between the human body and the chair, as well as for example the forces between any given spinal vertebra.
G ) This could be used for finding the optimal seated posture for a person, who suffers from lower back pain, assuming that greater load on a vertebra result in greater pain.
ADVANTAGES
1 First of all computer aided ergonomics using for example a musculo-skeletal modeling system as The AnyBody Modeling system would be beneficial in physical ergonomics, which traditional combines aspects from the human anatomical, anthropometric, physiological and biomechanical characteristics related to some physical activity.
2 The model can provide a quantitative foundation for ergonomic design and recommendations.
3 Traditionally “Ergonomics” has been based on recommendations derived from empirical data from various working tasks; if many people get injured from working in a certain posture, it is recommended to avoid working in that posture.
A ) However, when applying the recommendations to another related working posture, the posture or the movement often does not match exactly.
B ) This means that the theory and recommendations does not apply to the new situation.
C ) In this case it could be beneficial to model the situation in order to find out how the reaction forces and muscle activities differ from the first situation, where the recommendations were based on empirical data.
D ) A combination of risk factors can be derived from the model output.
4 For example, when designing an office chair, one would like to design it to fulfill several demands; comfortable, relaxing, supporting and so on.
5 Some of the criteria related to the demands might be conflicting for example; comfort is often related to the shear force on the seat, which should be kept as low as possible.
6 The seat shear force could be removed by making a horizontal seat and rising the backrest to 90 degrees however this would not be relaxing.
7 Therefore, a combination of seat and backrest angles needs to be considered in order to find optimal seated postures related to only the two design variables.
8 Computer-aided ergonomics is an interdisciplinary field of work, that involve the use of a computer to solve complex problems that involve a person interacting with an environment.
B ) COMMON INJURIES RELATED TO COMPUTER WORKERS
1 Posterior cervical dorsal syndrome(“computer back”) -
A ) Its a very common postural syndrome in modern society involves excessive rearward curving of your lower, middle, and upper back; forward drawn head; rounded shoulders; and excessive forward curving of your upper neck.
B ) This syndrome has been given several names including sterno-symphyseal syndrome, posterior cervical-dorsal syndrome, or more commonly, computer back or student syndrome. It is a natural result of prolonged sitting work, especially with computers.
C ) These postural defects in turn can cause -
1 headaches
2 excessive muscle tension in your neck, chest, shoulders, arms and forearms, back, abdomen, hips, and thighs
3 legs strains
4 trigger points the above muscles and joint dysfunction and sprains in your neck, back, and ribs
5 increased loading on the intervertebral discs of your spine
6 impaired function of your breathing muscle (your diaphragm), causing the muscles lifting your upper ribs and shoulders to become overactive and subject to problems
7 To help prevent computer back try adopting the postural relief position every 20 minutes.
2 Mouse shoulder -
A ) Is a syndrome arising from prolonged elevation and bracing of the shoulder to accommodate an inappropriately positioned mouse, or performing short range movements of the mouse, or (usually) both.
B ) This syndrome results in severe shoulder and shoulder blade muscle spasm (in the trapezius, deltoid, and teres muscles) and trigger points with referred pain in the arm.
C ) If left untreated, this problem can develop into a much more serious rotator cuff injury.
3 Carpal tunnel syndrome -
A ) Carpal tunnel syndrome arises primarily from compression of the median nerve as it passes through the wrist.
B ) It is the most common nerve compression injury in the body and it is the most common and costly RSI.
C ) Typical symptoms include -
1 paresthesias (abnormal sensations) such as tingling and numbness in the thumb and index and middle fingers
2 night pain
3 weakness in grasping, thumb and index finger pinching, and other thumb movements
4 clumsiness, such as awkward hand movements and dropping things
4 Tennis elbow -
A ) Classic tennis elbow, or lateral epicondylitis, is another type of RSI.
B ) It is a tendonitis affecting the common extensor tendon at the lateral (outside) area of the elbow.
C ) Tennis elbow is a very common cause of elbow and forearm pain.
D ) It can cause mild to severe pain in the lateral elbow and may be aggravated by grasping and excessive finger motions.
E ) The pain may also radiate up the arm or down into the forearm.
5 Lumbar sprains and strains -
A ) Lumbar spine sprains (ligament or joint capsule tears) and strains (muscle or tendon tears) are common in office workers due to the high loads placed on the spine during sitting.
B ) Sprains and strains may cause back and hip pain as well as muscle swelling and tightness.
6 Disc injuries -
A ) Increased loading on the spine due to prolonged and faulty sitting postures may cause sprains of the outer (annular) fibers of the intervertebral discs. In more advanced cases the soft inner material (nucleus) of the disc may protrude into or even through the annular fibers of the disc, resulting in a herniated disc.
B ) Herniated discs may cause back pain, leg pain and altered sensation down to the foot, weakness, walking difficulties, or combination of these symptoms.