Act 1974.  is the legislation in the UK that governs exposure to vibration and assists with preventing HAVS occurring. Good practice in industrial health and safety management requires that worker vibration exposure is assessed in terms of acceleration, amplitude, and duration. Using a tool that vibrates slightly for a long time can be as damaging as using a heavily vibrating tool for a short time. The duration of use of the tool is measured as trigger time, the period when the worker actually has their finger on the trigger to make the tool run, and is typically quoted in hours per day. Vibration amplitude is quoted in metres per second squared, and is measured by an accelerometer on the tool or given by the manufacturer. Amplitudes can vary significantly with tool design, condition and style of use, even for the same type of tool.In the UK, Health and Safety Executive gives the example of a hammer drill which can vary from 6 m/s² to 25 m/s². HSE publishes a list of typically observed vibration levels for various tools, and graphs of how long each day a worker can be exposed to particular vibration levels. This makes managing the risk relatively straightforward.
Osteosclerosis is a disorder that is characterized by abnormal hardening of bone and an elevation in bone density. It may predominantly affect the medullary portion and/or cortex of bone. Plain radiographs are a valuable tool for detecting and classifying osteosclerotic disorders. It can manifest in localized or generalized osteosclerosis. Localized osteosclerosis can be caused by Legg–Calvé–Perthes disease, sickle-cell disease and osteoarthritis among others. Osteosclerosis can be classified in accordance with the causative factor into acquired and hereditary. Types
Acquired osteosclerosis
Osteogenic bone metastasis caused by carcinoma of prostate and breast
Pagets disease of bone
Myelofibrosis (primary disorder or secondary to intoxication or malignancy)
Osteosclerosing types of chronic osteomyelitis
Hypervitaminosis D
hyperparathyroidism
Schnitzler syndrome
MastocytosisSkeletal fluorosis

Monoclonal IgM Kappa cryoglobulinemia
Hepatitis C.

Hereditary osteosclerosis
Malignant infantile osteopetrosis
Neuropathic infantile osteopetrosis
Infantile osteopetrosis with renal tubular acidosis
Infantile osteopetrosis with immunodeficiency
IO with leukocyte adhesion deficiency syndrome (LAD-III)
Intermediate osteopetrosis
Autosomal dominant osteopetrosis (Albers-Schonberg)
Pyknodysostosis (osteopetrosis acro-osteolytica)
Osteopoikilosis (Buschke–Ollendorff syndrome)
Osteopathia striata with cranial sclerosis
Mixed sclerosing bone dysplasia
Progressive diaphyseal dysplasia (Camurati–Engelmann disease)
SOST-related sclerosing bone dysplasias

Diagnosis
Osteosclerosis can be detected with a simple radiography. There are white portions of the bone which appear due to the increased number of bone trabeculae. Animals
In the animal kingdom, there also exists a non-pathological form of osteosclerosis, resulting in unusually solid bone structure with little to no marrow. It is often seen in aquatic vertebrates, especially those living in shallow waters, providing ballast as an adaptation for an aquatic lifestyle. It makes bones heavier, but also more fragile. In those animal groups, osteosclerosis often occurs together with bone thickening (pachyostosis). This joint occurrence is called pachyosteosclerosis. See also
Pachyostosis
Pachyosteosclerosis
Heinrich Albers-Schönberg

References


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