Overview of work-related musculoskeletal disorders

Related Diseases & Conditions

• Evaluation of back pain

  Summary

  The etiologies of back pain can be subdivided into 3 groups: mechanical, systemic, and referred. Mechanical back pain, defined as pain that is elicited with spinal motion and decreased with rest, is the most common type of back pain.[3]​ The most common cause of mechanical back pain is lumbar strain/sprain, which accounts for around 70% of cases of low back pain.[4] Patients presenting to primary care with nonspecific low back pain account for 90% to 95% of low back pain cases.[5]​
• Musculoskeletal lower back pain

  Summary

  Musculoskeletal lower back pain is pain, stiffness, and/or soreness of the lumbosacral region (underneath the twelfth rib and above the gluteal folds). Occupations requiring physical exertion have been associated with lower back pain. Lifting objects heavier than 11.4 kg (25 lb), pushing/pulling heavy objects, and prolonged periods of standing or walking is associated with a higher incidence of lower back pain, particularly in women.[6]​ These occupational activities result in lower back pain because of both acute injuries and cumulative stresses to the spinal anatomy.[7]
• Degenerative cervical spine disease

  Summary

  Cervical spondylosis (CS) is the specific term for osteoarthritis of the spine, which includes the spontaneous degeneration of either disc or facet joints. CS incidence increases with age. A population-based magnetic resonance imaging study showed that over 85% of adults ages >60 years have disc degeneration of at least one cervical level (commonly C5-C6).[8]​ The etiology of CS is underlying spontaneous joint degeneration. It is related to age, and to wear and tear.[9] [10]​ However, concordant twin studies note a significant genetic predisposition to development of cervical degeneration, in addition to occupational and activity-related factors.[11]
• Discogenic low back pain

  Summary

  Lumbar discogenic back pain is characterized by low back pain with or without the concurrence of radicular lower limb symptoms, in the presence of radiologically-confirmed degenerative disk disease. An association has been noted between occupation-related postures and stresses due to abnormal loading and lifting mechanics.[12] The use of vibrating equipment is considered particularly hazardous.[13] Degenerative disc disease is also associated with increasing age, smoking, the presence of facet joint tropism and arthritis, abnormal pelvic morphology, and changes in sagittal alignment.
• Spinal stenosis

  Summary

  In nearly all patients, spinal stenosis typically results from degenerative changes in the lumbar spine. Key factors include age over 40 years, previous back injury or surgery, and manual labor. People who perform heavy-duty work may develop degenerative changes in the spine earlier in life because of increased mechanical wear of the spine and higher risk of traumatic injury.
• Costochondritis

  Summary

  Costochondritis is inflammation of one or more costal cartilages. It is a self-limiting condition that presents with insidious onset of anterior chest-wall pain exacerbated by certain movements of the chest and deep inspiration. A history of unaccustomed repetitive upper-limb movement is commonly associated with constochondritis.[14]
• Evaluation of knee injury

  Summary

  Patient description of the mechanism of injury is an essential part of the history. For example, most anterior cruciate ligament tears are non-contact twisting injuries. Location of contact and pain, history of previous injury, and areas of anesthesia/dysaesthesia, should be investigated.
• Evaluation of neck pain

  Summary

  Neck pain is a common condition that causes significant disability. High body mass index, frequent neck extension during the working day, high initial pain intensity, and high psychological job demands are all predictors of chronic neck pain development in office workers.[15]
• Popliteal cyst

  Summary

  Popliteal (Baker) cyst is an accumulation of synovial fluid. It is usually the result of a knee joint abnormality, such as arthritis or a cartilage tear. One ultrasonographic study which investigated the prevalence of popliteal cysts in patients with knee pain identified the pathology in 102 (25.8%) patients; a positive association with features of osteoarthritis and joint effusion was also noted.[16]​ Trauma in the knee joint, specifically injury of the medial meniscus, chondral lesions, and tears of the anterior cruciate ligament, is a significant risk factor in the development of popliteal cysts.
• Evaluation of lower extremity mononeuropathy

  Summary

  Examples of mononeuropathies in the lower extremities caused by work tasks include common peroneal mononeuropathy (squatting for long periods - carpet layers, farm workers), mononeuropathy of the lateral cutaneous nerve of the thigh (wearing a heavy belt - carpenters), and sciatic mononeuropathy (sitting on a hard surface).[17]
• Iliotibial band syndrome

  Summary

  Iliotibial band syndrome (ITBS) results from repetitive friction of the iliotibial band sliding over the lateral femoral epicondyle, moving anterior to the epicondyle as the knee extends and posterior as the knee flexes, and remaining tense in both positions. ITBS may be observed in athletes participating in volleyball, tennis, soccer, skiing, weight lifting, and aerobics. More experienced runners may be less likely to develop ITBS.[18]​ It is unusual in nonathletes.
• Evaluation of upper extremity mononeuropathy

  Summary

  There are more than 10 individual nerves in the arm distal to the brachial plexus, so many different mononeuropathies can occur. Osteoarthritis, tendinitis, or repetitive strain symptoms are often confused with carpal tunnel syndrome and/or ulnar neuropathy, as the distribution of pain can be similar in these conditions. Electrophysiologic studies can help identify or rule out an associated mononeuropathy in these cases.
• Rotator cuff injury

  Summary

  A common cause of shoulder pain, especially in older and active people. The spectrum of rotator cuff pathology is one of the most common groups of conditions affecting the adult shoulder. ​Rotator cuff pathology is the leading cause of shoulder-related disability seen by orthopedic surgeons in the US.[19] [20]​​ An episode of vigorous overhead activity, such as painting or overhead lifting, may incite subacromial bursitis or impingement symptoms, which can be prodromes to tearing and failure of the rotator cuff. Not all patients present with symptoms related to activity or injury; the onset of symptoms can be insidious.
• Carpal tunnel syndrome

  Summary

  A collection of symptoms and signs caused by compression of the median nerve in the carpal tunnel. With a prevalence of approximately 1 in 25, carpal tunnel syndrome is the most common entrapment neuropathy affecting the upper extremities.[21]​ Occupations involving exposure to repetitive bending or twisting of the hands or wrists, or the use of vibrating tools (e.g., construction or manufacturing), may cause damage to the median nerve over time and increase the likelihood of carpal tunnel syndrome.[21] [22]​
• Epicondylitis

  Summary

  Epicondylitis of the elbow is described as a history of activities contributing to overuse of the forearm muscles that originate at the elbow. Epicondylitis has a worldwide distribution. Prevalence rates for both lateral and medial epicondylitis are similar. Both medial and lateral epicondylitis have been associated with repetitive elbow and forearm activities, such as hammering, typing, meat-cutting, plumbing, and painting, as well as leisure activities including tennis and golf.
• Tenosynovitis of the hand and wrist

  Summary

  A group of entities with a common pathology involving the extrinsic tendons of the hand and wrist and their corresponding retinacular sheaths. Repetitive shear stress through the retinacular sheath causes irritation to the tendon and its synovial lining (tenosynovium), and subsequent inflammation followed by hypertrophy and fibrosis, which may lead to the development of trigger finger. The most common presentation is trigger finger, followed by de Quervain disease (thumb extensor tendonitis in the first dorsal compartment).
• Plantar fasciitis

  Summary

  This condition causes an acute or chronic pain in the inferior heel at the attachment of the medial band of the plantar fascia to the medial calcaneal tubercle. It is commonly seen in people who work in a standing position, especially those who are standing on a hard, unforgiving surface such as concrete (e.g., factory or postal workers).[23] [24] Other risk factors include running, obesity, presence of equinus, people ages between 40-60 years, and presence of pes planus or pes cavus. Plantar fasciitis is the most common cause of infracalcaneal pain and accounts for 11% to 15% of all foot complaints that require professional treatment.[25]​
• Inguinal hernia

  Summary

  A protrusion of abdominal or pelvic contents through a dilated internal inguinal ring or attenuated inguinal floor into the inguinal canal and usually out of the external inguinal ring, causing a visible bulge. Occurs because of a defect in the structure of the inguinal canal that may be either congenital or acquired. In England, 69,637 primary inguinal hernia repairs were performed in 2014-2015, and 92% of patients were male.[26]​ Patients with inguinal hernia have been shown to have abnormal collagen metabolism and decreased collagen levels.
• Bursitis

  Summary

  An acute or chronic inflammatory condition of a bursa - a jelly-like sac that usually contains a small amount of synovial fluid. Any occupation that causes repetitive mechanical stress over a bursa may result in bursitis. Symptoms and signs vary according to the anatomic site of the affected bursa, but localized swelling and fluctuance are usually present. In primary care, bursitis most commonly presents in the knee, and as subacromial (subdeltoid), trochanteric, retrocalcaneal, and olecranon bursae.
• Tendinopathy

  Summary

  Tendon degeneration characterized by a combination of pain, swelling, and impaired performance. The etiology is unclear, studies suggest it is an overuse condition leading to inadequate tendon repair that predisposes the tendon to microtears and degeneration. Tendinopathy affects millions of people in athletic and occupational settings as well as the general population.[27] [28] [29] Risk factors include: athletic training, poor athletic training technique, inappropriate equipment, hard and high-friction playing surface, poor flexibility, poor cardiovascular conditioning, imbalance in muscle use/training, and history of old tendon or muscle injury.​​​​
• Musculoskeletal sprains and strains

  Summary

  Strain is an injury to the muscle or musculotendinous junction, whereas sprain is an injury to the ligament. Around 30% to 50% of musculoskeletal (tendon/muscle/bone) injuries presenting to physicians are tendon and ligament injuries.[29] Muscle injuries can be caused by contusion, strain, or laceration.[30] [31]​​​ Predisposing factors are: type of muscle architecture (i.e., pennate muscle, type II fast twitch muscle fibers, and muscle-tendon units that span two joints), and previous injuries.
• Chronic pain syndromes

  Summary

  Pain persisting longer than 3 months is deemed to be chronic. Chronic pain is common and has a significant impact on quality of life. Prevalence increases with increasing age (especially for pain due to musculoskeletal causes), so the number of people living with chronic pain worldwide will increase as life expectancy increases.[32]​ High-risk occupations are healthcare workers (e.g., healthcare assistants, nurses, dentists, and chiropractors), construction workers, car mechanics, housekeepers/janitors, and hairstylists. Unemployment and previous job change due to pain are also risk factors for pain chronicity.
• Overview of musculoskeletal pain

  Summary

  Musculoskeletal pain refers to acute or chronic pain in the muscles, bones, tendons, and ligaments. It is very common and is a major cause of morbidity and occupational sickness absence.
• Overview of sport-related injuries

  Summary

  Sport-related injuries are generally categorized as acute or chronic. The range of medical conditions potentially resulting from sport- or exercise-related injuries is wide. More than 90% of all sport-related injuries are either contusions or strains.[30] Contact sports (e.g., soccer, hockey) may increase the risk of contusion, whereas sprinting and jumping are the most common activities associated with muscle strains.[31] [33]