Work load and musculoskeletal disease

A factor or set of factors operating in the work environment (the work itself or the work environment) can cause the emergence of a disease (occupational disease). With increased work load on the musculoskeletal system, diseases of tendons (tendinitis, tendosynovitis, tendovaginitis), tendon attachments ( enthesopathy ), joints ( arthrosis ), damage to menisci, bursitis ( bursitis), peripheral nerve diseases (compressive - ischemic neuropathy) occur.

Characteristics of noxy
These are exposures to one-sided long-term excessive load, which is objectified by a hygiene investigation at the workplace. Applies to:


 * long-term criterion : Applies when an accident event is excluded,
 * excessiveness criterion : It is evaluated according to the amount of muscle force exerted, the duration of its action, the frequency of work movements per time unit and according to the basic working position or the position of the limbs. It is met when the average full-shift force exceeds the F max limit of 10% during static work and 30%F max during dynamic work.
 * unilaterality criterion : Fulfilled when overloading the same muscle group for more than 50% of the working time.

Etiopathogenesis
One-sided long-term excessive load causes alteration of the overloaded tissue, which progresses faster than its repair.

Clinical manifestations
First pain, swelling, dysfunction, later more serious manifestations (e.g. joint deformities).

Special Precautions
The aim is to prevent excessive workload and include technical and technological measures (e.g. production automation), ergonomic, organizational (adjustment of e.g. work and rest regime), entrance and periodic preventive inspections.

Tendinitis, tendosynovitis, tendovaginitis
It is an aseptic inflammation of the tendons and tendon sheaths caused by minor traumas that arise as a result of their mutual friction during an excessive number of movements in forced positions. Subsequently, degenerative changes can develop – thickening of the fibrous sheath – and narrowing of the tendon passages ( stenosing tendovaginitis ). Morbus de Quervain is a term for tendosynovitis of the tendons of the abductor pollicis longus and extensor pollicis brevis muscles.

Clinical manifestations [ edit | edit source ]
Swelling, pain on movement and palpation, possibly crepitation.

Preventive measures [ edit | edit source ]
Limit the number of unusual movements in forced fixed positions.

Enthesopathy
It is a disease of tendon attachments. These include (among others) elbow joint disease – radial, ulnar epicondylitis – and rotator cuff disease and impingement syndrome. These are often occupational diseases.

Epicondylitis - radial and ulnar
When working with long-handled tools and when working with excessive elbow movements under excessive load, microtraumas, aseptic inflammation and degenerative dystrophic changes (increase in cartilage tissue, defibrillation of Sharpey's fibers, erosion with subsequent fibrosis and new bone formation - periosteal calcification) will occur. Impairment of the attachments of the extensors on the radial epicondyle of the humerus is called tennis elbow, while the flexors on the ulnar epicondyle are called javelin or golfer's elbow.

Clinical manifestations [ edit | edit source ]
Both resting and exertional pain propagating distally along the muscle, palpable soreness. Pain during extension (especially of the 3rd finger) / flexion against resistance is characteristic.

Preventive measures [ edit | edit source ]
Use of epicondylar tapes and elbow braces.

Rotator cuff syndrome, impingement syndrome, rotator cuff rupture
Dystrophic changes in the tendons of the rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis) when the shoulder joint is overloaded. Impingment syndrome is caused by mechanical compression of the supraspinatus tendon between the tubercle majus humeri and the acromion. The highest degree of damage is a rotator cuff tear.

Clinical picture [ edit | edit source ]
Pain at night and during tension maneuvers on the supraspinatus muscle. In impingement syndrome, there is a positive symptom of a painful arc – when abducting above a certain limit (usually 60°), pain appears, which disappears with the next abduction (above 110°–120°). In more severe conditions of fibrotization and contracture with subsequent limitation of abduction.

Osteoarthritis from overuse
It does not differ from ordinary arthrosis. It arises after many years of stress (average 15-20 years). The most common location is the elbow and knee joint.

Compressive – ischemic neuropathy
It is a disease of the peripheral nerves of the limbs from long-term excessive unilateral overloading or from pressure, traction, torsion. Nerve compression occurs in predilection places: Carpal tunnel ( n. medianus ), supinator tunnel ( n. radialis ), pronator tunnel (n. medianus), n. ulnaris in sulcus ulnaris, tarsal tunnel (n. tibialis), fossa poplitea ( n. tibialis), retrofibular space (n. peroneus communis). Movements lead to narrowing of tunnel spaces and compression of the nerve. The situation can be worsened by accessory influences (leakage during tendovaginitis, endocrinological factors such as climax and pregnancy, configuration after an injury such as after a Colles fracture ).

Clinical picture [ edit | edit source ]
stages:


 * 1) irritant – paresthesia, dysesthesia, causalgia, hyperesthesia
 * 2) extinction − hypoesthesia and paretic manifestations appear

Bursitis
They are aseptic inflammations of pressure bags. The most common are bursitis prepatelaris, olecrani, subacromialis.

See the Bursitis page for more detailed information .

Meniscus damage
These are ruptures of the medial meniscus - as a result of its less mobility.