This condition is caused by highly repetitive work in extreme positions, in combination with high force development. The median nerve, which runs through the space in the wrist called the carpal tunnel, gets pinched due to increased pressure. This leads to numbness, tingling, decreased function and weakness in the area around the nerve, and the fingers that are affected by the median nerve (the thumb and three middle fingers). Similar symptoms can be had for radial and ulnar nerves. Treatment of CTS depends on the severity, but non- surgical treatment usually includes wearing a supportive wrist splint to prevent the wrist from bending.
Tendon inflammation is a condition where movement Of the wrist and fingers is painful due to a sense of pressure and swelling at the knuckles. It is the result of irritation in the tendons’ sheaths, caused either by highly repetitive finger work Or sharp edgeson hand tools.
One symptom, known as “trigger finger syndrome”, is an inability to flex and extend the thumb and Forefinger in one smooth movement instead, the movement is hindered until It “snaps”into position. Medical language distinguishes between tendonitis (inflame tendon) and tenosynovitis (inflamed tendon sheath).
“White fingers” is a condition with numb, tingling fingers, where blood flow is so decreased that the fingertips turn white. The condition may be hereditary, in which case it is called “Raynaud’s Syndrome” (therefore, it is important to determine the individual’s medical history) or it may be the result of a MSD caused by hand-arm vibration. The greatest risk for contracting this injury occurs at frequencies between 50 and 150 Hz. When caused by work, it is also called vibration white finger (VWF), hand-arm vibration syndrome (HAVS) or dead finger. However, it is sometimes hard to distinguish from Raynaud’s syndrome, where the characteristic white fingers appear due to biological or non-work- related causes. Symptoms include: discoloured, pale white fingertips, especially in cold temperatures; numbness and prickling sensations in the fingers; and a decreased motor function and sense of touch.
• The human body is a very complex structure made up of bones, muscles and joints; if loaded in the wrong way it can easily get injured.
• Combined, the skeleton, muscles and joints enable the body to turn chemical energy into motion, withstand forces and perform physical work.
• With the knowledge of basic physical anatomy and how certain structures move and respond to loading, it is possible for engineers to design healthy workplaces with reduced risk for injury.
• Wor k- related injuries resulting from repetitive static tasks and heavy loading are unfortunately Quite a common occurrence, with the highest impact on employees taking sick leave in Europe.
• To avoid pain, discomfort, fatigue or injury the body should be used in its natural position, as close to neutral as possible.
• Most skeletal muscles are attached to the skeleton and enable humans to transfer loads and torques, while protecting the skeleton. Their strength is dependent on age, gender, genetic heritage and training.
• There are two types of muscle fibres: fast twitch and slow twitch. Fast twitch are suited to short fast explosive contractions while slow twitch is better for sustained longer exertions.
• An adult skeleton is made up of 206 bones of varying size and function.
• Joints are structures positioned at the point where different bones connect; they can enable movement in up to three different dimensions.
• Joints are the most complex of the three structures and can take years to heal if injured, or
in some cases never fully heal.
• The back is one of the most common areas affected by WMSDs. The spine is made up of a series of stacked vertebrae and discs.
• When sitting or standing the back is being loaded and the discs between vertebrae com press. Excessive or uneven loading can cause discs to rupture, resulting in severe pain or numbness.
• The neck and shoulder complex are also a common area affected by WMSDs. Frequent or static bending of the neck resulting from looking at screens is a common injury trigger.
• The hands and wrists are crucial for carrying out high-precision work tasks, and an injury here has serious implications as it hinders humans from most forms of work.
• The hand and wrist can move in a number of different directions; however, working with them as close to the functional resting position as possible enables the best performance conditions for high strength and good precision.