Musculoskeletal disorder

Musculoskeletal disorders (MSDs) are injuries or pain in the human musculoskeletal system, including the joints, ligaments, muscles, nerves, tendons, and structures that support limbs, neck and back. MSDs can arise from a sudden exertion (e.g., lifting a heavy object), or they can arise from making the same motions repeatedly repetitive strain, or from repeated exposure to force, vibration, or awkward posture. Injuries and pain in the musculoskeletal system caused by acute traumatic events like a car accident or fall are not considered musculoskeletal disorders. MSDs can affect many different parts of the body including upper and lower back, neck, shoulders and extremities (arms, legs, feet, and hands). Examples of MSDs include carpal tunnel syndrome, epicondylitis, tendinitis, back pain, tension neck syndrome, and hand-arm vibration syndrome. Musculoskeletal disorders (MSDs) are injuries or pain in the human musculoskeletal system, including the joints, ligaments, muscles, nerves, tendons, and structures that support limbs, neck and back. MSDs can arise from a sudden exertion (e.g., lifting a heavy object), or they can arise from making the same motions repeatedly repetitive strain, or from repeated exposure to force, vibration, or awkward posture. Injuries and pain in the musculoskeletal system caused by acute traumatic events like a car accident or fall are not considered musculoskeletal disorders. MSDs can affect many different parts of the body including upper and lower back, neck, shoulders and extremities (arms, legs, feet, and hands). Examples of MSDs include carpal tunnel syndrome, epicondylitis, tendinitis, back pain, tension neck syndrome, and hand-arm vibration syndrome. MSDs can arise from the interaction of physical factors with ergonomic, psychological, social, and occupational factors. MSDs are caused by biomechanical load which is the force that must be applied to do tasks, the duration of the force applied, and the frequency with which tasks are performed. Activities involving heavy loads can result in acute injury, but most occupation-related MSDs are from motions that are repetitive, or from maintaining a static position. Even activities that do not require a lot of force can result in muscle damage if the activity is repeated often enough at short intervals. MSD risk factors involve doing tasks with heavy force, repetition, or maintaining a nonneutral posture. Of particular concern is the combination of heavy load with repetition. Although poor posture is often blamed for lower back pain, a systematic review of the literature failed to find a consistent connection. People vary in their tendency to get MSDs. Gender is a factor, with women having a higher incidence of MSDs than men. Obesity is also a factor, with overweight individuals having a higher risk of some MSDs, specifically of the lower back. There is a growing consensus that psychosocial factors are another cause of some MSDs. Some theories for this causal relationship found by many researchers include increased muscle tension, increased blood and fluid pressure, reduction of growth functions, pain sensitivity reduction, pupil dilation, body remaining at heightened state of sensitivity. Although there is no consensus at this time, some of the workplace stressors found to be associated with MSDs in the workplace include high job demands, low social support, and overall job strain. Researchers have consistently identified causal relationships between job dissatisfaction and MSDs. For example, improving job satisfaction can reduce 17-69 per cent of work-related back disorders and improving job control can reduce 37-84 per cent of work-related wrist disorders. Because workers maintain the same posture over long work days and often several years, even natural postures like standing can lead to MSDs like low back pain. Postures which are less natural, such as twisting of or tension in the upper body, are typically contributors to the development of MSDs due to the unnatural biomechanical load of these postures. There is evidence that posture contributes to MSDs of the neck, shoulder, and back. Repeated motion is another risk factor for MSDs of occupational origin because workers can perform the same movements repeatedly over long periods of time (e.g. typing leading to carpal tunnel syndrome), which can wear on the joints and muscles involved in the motion in question. Workers doing repetitive motions at a high pace of work with little recovery time and workers with little to no control over the timing of motions (e.g. workers on assembly lines) are also prone to MSDs due to the motion of their work. Force needed to perform actions on the job can also be associated with higher MSD risk in workers, because movements which require more force can fatigue muscles quicker which can lead to injury and/or pain. Additionally, exposure to vibration (experienced by truck drivers or construction workers, for example) and extreme hot or cold temperatures can affect a worker's ability to judge force and strength, which can lead to development of MSDs. Vibration exposure is also associated with hand-arm vibration syndrome, which has symptoms of lack of blood circulation to the fingers, nerve compression, tingling, and/or numbness. Assessment of MSDs is based on self-reports of symptoms and pain as well as physical examination by a doctor. Doctors rely on medical history, recreational and occupational hazards, intensity of pain, a physical exam to locate the source of the pain, and sometimes lab tests, X-rays, or an MRI Doctors look for specific criteria to diagnose each different musculoskeletal disorder, based on location, type, and intensity of pain, as well as what kind of restricted or painful movement a patient is experiencing. A popular measure of MSDs is the Nordic Questionnaire that has a picture of the body with various areas labeled and asks the individual to indicate in which areas they have experienced pain, and in which areas has the pain interfered with normal activity. Prevention of MSDs relies upon identification of risk factors, either by self-report, observation on the job, or measurement of posture which could lead to MSDs. Once risk factors have been determined, there are several intervention methods which could be used to prevent the development of MSDs. The target of MSD prevention efforts is often the workplace in order to identify incidence rates of both disorders and exposure to unsafe conditions. Groups who are at particular risk can be identified, and modifications to the physical and psychosocial environment can be made. Approaches to prevention in workplace settings include matching the person's physical abilities to the tasks, increasing the person's capabilities, changing how tasks are performed, or changing the tasks. Employers can also utilize engineering controls and administrative controls to prevent injury happening on the job. Implementation of engineering controls is the process of designing or redesigning the workplace to account for strengths, weaknesses, and needs of the working population- examples would be workstation layout changes to be more efficient or reducing bending over, or moving necessary tools within shorter reach of the worker's station. Employers may also utilize administrative controls like reducing number of hours in a certain position, limiting overtime, or including more breaks during shifts in order to reduce amount of time at risk for each worker.