Neuropathic arthropathy (or neuropathic osteoarthropathy), also known as Charcot joint (often Charcot foot) after the first to describe it, Jean-Martin Charcot, refers to progressive degeneration of a weight-bearing joint, a process marked by bony destruction, bone resorption, and eventual deformity due to loss of sensation. Onset is usually insidious. If this pathological process continues unchecked, it can result in joint deformity, ulceration and/or superinfection, loss of function, and in the worst-case scenario, amputation or death. Early identification of joint changes is the best way to limit morbidity. Symptoms and signs
The clinical presentation varies depending on the stage of the disease from mild swelling to severe swelling and moderate deformity. Inflammation, erythema, pain and increased skin temperature (3–7 degrees Celsius) around the joint may be noticeable on examination. X-rays may reveal bone resorption and degenerative changes in the joint. These findings in the presence of intact skin and loss of protective sensation are pathognomonic of acute Charcot arthropathy. Roughly 75% of patients experience pain, but it is less than what would be expected based on the severity of the clinical and radiographic findings. Pathogenesis
Any condition resulting in decreased peripheral sensation, proprioception, and fine motor control:

Diabetes mellitus neuropathy (the most common in the U.S. today, resulting in destruction of foot and ankle joints), with Charcot joints in 1/600-700 diabetics; related to long-term high blood glucose levels.
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.