{"id":5018,"date":"2019-06-24T16:48:24","date_gmt":"2019-06-24T16:48:24","guid":{"rendered":"https:\/\/pressbooks.ccconline.org\/acchumanbio\/chapter\/14-6-disorders-of-the-muscular-system-3\/"},"modified":"2023-11-30T23:06:27","modified_gmt":"2023-11-30T23:06:27","slug":"14-6-disorders-of-the-muscular-system-3","status":"publish","type":"chapter","link":"https:\/\/pressbooks.ccconline.org\/acchumanbio\/chapter\/14-6-disorders-of-the-muscular-system-3\/","title":{"raw":"12.6\u00a0Disorders of the Muscular System","rendered":"12.6\u00a0Disorders of the Muscular System"},"content":{"raw":" \r\n\r\n[caption id=\"attachment_4252\" align=\"aligncenter\" width=\"333\"]\"12.6.1 Figure 12.6.1 Devices can be a pain in the neck - literally.<\/em>[\/caption]\r\n\r\nPain in the Neck<\/span>\r\n\r\nSpending hours each day looking down at hand-held devices is a pain in the neck \u2014 literally. The\u00a0weight\u00a0of the head bending forward can put a lot of strain on neck\u00a0muscles, and muscle injuries can be very painful. Neck pain is one of the most common of all complaints that bring people to the doctor\u2019s office. In any given year, about one in five adults will suffer from neck pain. That\u2019s a lot of pains in the neck! Not all of them are due to muscular disorders, but many of them are. Muscular disorders, in turn, generally fall into two general categories: [pb_glossary id=\"4253\"]musculoskeletal disorders[\/pb_glossary]\u00a0and [pb_glossary id=\"4254\"]neuromuscular disorders[\/pb_glossary].\r\n
\r\n

Musculoskeletal Disorders<\/h1>\r\n<\/div>\r\n[pb_glossary id=\"4253\"]Musculoskeletal disorders[\/pb_glossary]<\/strong> are injuries that occur in muscles or associated tissues (such as [pb_glossary id=\"4166\"]tendons[\/pb_glossary]) because of biomechanical stresses. They may be caused by sudden exertion, over-exertion, repetitive motions, or long periods of maintaining awkward positions. Musculoskeletal disorders are often work- or sports-related, and generally just one or a few muscles are affected. They can often be treated successfully, and full recovery can be very likely. The disorders include muscle strains, tendinitis, and carpal tunnel syndrome.\r\n

Muscle Strain<\/h2>\r\n[caption id=\"attachment_4256\" align=\"alignright\" width=\"462\"]\"12.6 Figure 12.6.2 Bleeding in muscle tissue may cause a muscle strain to produce a bruise over the affected muscle, as in this hamstring bruise. The photos show two images of the same leg, both taken four days after the injury occurred.<\/em>[\/caption]\r\n\r\nA\u00a0[pb_glossary id=\"4255\"]muscle strain[\/pb_glossary]<\/strong> is an injury in which muscle fibres tear as a result of overstretching. A muscle strain is also commonly called a pulled muscle or torn muscle. (Strains are often confused with sprains, which are similar injuries to ligaments.) Depending on the degree of injury to muscle fibres, a muscle strain can range from mildly to extremely painful. Besides pain, typical symptoms include stiffness and bruising in the area of the strained muscle. The photo here shows a large bruise caused by a hamstring muscle strain. Hamstring strains are very common in track and field athletes. In sprinters, for example, about one third of injuries are hamstring injuries. Having a previous hamstring injury puts an athlete at increased risk for having another one.\r\n\r\nProper first aid for a muscle strain includes five steps, which are represented by the acronym PRICE. The PRICE steps should be followed for several days after the injury. The five steps are:\r\n
    \r\n \t
  1. Protection:<\/strong>\u00a0Apply soft padding to the strained muscle to minimize impact with objects that might cause further damage.<\/li>\r\n \t
  2. Rest:<\/strong>\u00a0Rest the muscle to accelerate healing and reduce the potential for re-injury.<\/li>\r\n \t
  3. Ice:<\/strong>\u00a0Apply ice for 20 minutes at a time every two hours to reduce swelling and pain.<\/li>\r\n \t
  4. Compression:<\/strong>\u00a0Apply a stretchy bandage to the strained muscle to reduce swelling.<\/li>\r\n \t
  5. Elevation<\/strong>:<\/strong>\u00a0Keep the strained muscle elevated to reduce the chance of\u00a0blood\u00a0pooling in the muscle.<\/li>\r\n<\/ol>\r\nNon-steroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen) can help reduce inflammation and relieve pain. Because such drugs interfere with\u00a0blood\u00a0clotting, however, they should be taken only after bleeding in the muscle has stopped \u2014 not immediately after the injury occurs. For severe muscle strains, professional medical care may be needed.\r\n

    Tendinitis<\/h2>\r\n[pb_glossary id=\"4257\"]Tendinitis[\/pb_glossary]<\/strong>\u00a0is inflammation of a tendon that occurs when it is over-extended or worked too hard without rest. Tendons that are commonly affected include those in the ankle, knee, shoulder, and elbow.\u00a0The affected tendon\u00a0depends on the type of use that causes the inflammation. Rock climbers tend to develop tendinitis in their fingers, while basketball players are more likely to develop tendinitis in the knees, to name a few examples.\r\n\r\nSymptoms of tendinitis may include aching, sharp pain, a burning sensation, or joint stiffness. In some cases, swelling occurs around the inflamed tendon, and the area feels hot and looks red. Treatment includes the PRICE guidelines listed above,\u00a0as well as\u00a0the use of NSAIDs to further reduce inflammation and pain. Although symptoms should show improvement within a few days of treatment, full recovery may take several months. A gradual return to\u00a0exercise\u00a0or other use of the affected tendon is recommended. Physical or occupational therapy may\u00a0speed\u00a0the return to normal activity levels.\r\n

    Carpal Tunnel Syndrome<\/h2>\r\n[pb_glossary id=\"4258\"]Carpal tunnel syndrome[\/pb_glossary]<\/strong> is a common biomechanical problem that occurs in the wrist when the median nerve becomes compressed between carpal bones (see Figure 12.6.3). This may occur due to repetitive use of the wrist, a tumor, or trauma to the wrist. Two-thirds of cases are work-related. Computer work, work with vibrating tools, and work that requires a strong grip all increase one's risk of developing this problem. Carpal tunnel syndrome occurs more often in women than men. Other risk factors include obesity, pregnancy, and arthritis. Genetics may also play a role.\r\n\r\n[caption id=\"attachment_4259\" align=\"aligncenter\" width=\"546\"]\"12.6 Figure 12.6.3 Carpal tunnel syndrome occurs when the median nerve in the wrist becomes compressed.<\/em>[\/caption]\r\n\r\nCompression of the median nerve results in inadequate nervous stimulation of the\u00a0muscles\u00a0in the thumb and first two fingers of the hand. The main symptoms are pain, numbness, and tingling in these digits. Sometimes, symptoms can be improved by wearing a wrist splint or receiving corticosteroid injections. Surgery to cut the carpal ligament reduces pressure on the median nerve and is generally more effective than nonsurgical treatment. Recurrence of carpal tunnel syndrome after surgery is rare. Without treatment, on the other hand, the lack of nervous stimulation by the median nerve may eventually cause the affected muscles of the hand to weaken and waste away.\r\n
    \r\n

    Neuromuscular Disorders<\/h2>\r\n<\/div>\r\n[pb_glossary id=\"4254\"]Neuromuscular disorders[\/pb_glossary]<\/strong>\u00a0are systemic disorders that occur because of problems with the nervous control of muscle contractions, or with the muscle\u00a0cells\u00a0themselves. These disorders are often due to faulty genes and not due to biomechanical stresses. Other system-wide problems, such as abnormal [pb_glossary id=\"4242\"]immune system[\/pb_glossary] responses, may also be involved in neuromuscular disorders.\r\n\r\nUnlike musculoskeletal disorders, neuromuscular disorders generally affect most or all of the muscles in the body. The disorders also tend to be progressive and incurable. However, in most cases, treatment is available to slow the disease progression or to lessen the symptoms. Examples of neuromuscular disorders include muscular dystrophy, myasthenia gravis, and Parkinson\u2019s disease.\r\n

    Muscular Dystrophy<\/h2>\r\n[pb_glossary id=\"4260\"]Muscular dystrophy[\/pb_glossary]<\/strong> is a genetic disorder caused by defective proteins in muscle cells. It is characterized by progressive skeletal muscle weakness and death of muscle cells and tissues. Muscles become increasingly unable to contract in response to nervous stimulation.\u00a0 Approximately 50,000 Canadians suffer from muscular dystrophy.\r\n\r\nThere are at least nine major types of muscular dystrophy caused by different gene\u00a0mutations. Some of the mutations cause autosomal [pb_glossary id=\"2479\"]recessive[\/pb_glossary] or autosomal [pb_glossary id=\"5973\"]dominant[\/pb_glossary] disorders, and some cause [pb_glossary id=\"2517\"]X-linked[\/pb_glossary] disorders. The most common type of\u00a0childhood\u00a0muscular dystrophy is Duchenne muscular dystrophy<\/a>, which is due to a\u00a0mutation\u00a0in a recessive gene on the X chromosome. As an X-linked recessive disorder, Duchenne muscular dystrophy occurs almost exclusively in males.\r\n\r\nDifferent types of muscular dystrophy affect different major muscle groups. In Duchenne muscular dystrophy, the lower limbs are affected. Signs of the disorder usually become apparent when a child starts walking. Difficulty walking becomes progressively worse through childhood. By the time a child is ten, braces may be needed for walking \u2014 and walking may no longer even by possible by age 12. The lifespan of someone with muscular dystrophy is likely to be shorter than normal because of the disease, ranging from 15 to 45 years.\r\n\r\nIn some cases, physical therapy, drug therapy, or orthopedic surgery may improve some of the signs and symptoms of muscular dystrophy. However, at present, there is no known cure for the disorder. Research is ongoing to find a cure, with financial support provided by such sources as Muscular Dystrophy Canada (MDC) (see Figure 12.6.4). MDC is a non-profit organization dedicated to curing muscular dystrophy by funding worldwide research.\r\n\r\n[caption id=\"attachment_4261\" align=\"aligncenter\" width=\"400\"]\"12.6 Figure 12.6.4 Canadian firefighters have been supporting neuromuscular disorder research and care through fundraising and awareness campaigns for over 65 years.\u00a0 More than 600 Fire Departments and Associations across Canada raise more than $3 Million annually in support of MDC. Each year, career and volunteer Fire Fighters give their time and help \u201cFill the Boot\u201d by organizing various events like boot drives, rooftop campouts, stair climbs, ladder sits, car washes, raffles, sporting events and truck pulls in support of more than 50,000 Canadians who are impacted by neuromuscular disorders.<\/em>[\/caption]\r\n

    Myasthenia Gravis<\/h2>\r\n[pb_glossary id=\"4262\"]Myasthenia gravis[\/pb_glossary]<\/strong> is a genetic neuromuscular disorder characterized by fluctuating muscle weakness and fatigue. It occurs more commonly in women, and generally begins between the ages of 20 and 40. The initial symptom of myasthenia gravis is painless muscle weakness, generally in muscles around the eye (see photos in Figure 12.6.5). The disease then progresses to muscles elsewhere in the body, eventually involving most of the muscles. Swallowing and chewing may become difficult as the disease progresses, and speech may become slow and slurred. In more advanced cases, myasthenia crises may occur, during which the muscles that control breathing may be affected. Emergency medical care to provide assisted ventilation is required to sustain life. A myasthenia gravis crisis may be triggered by various stressors, such as infection, fever, or stress.\r\n\r\n[caption id=\"attachment_4263\" align=\"aligncenter\" width=\"1024\"]\"12.6 Figure 12.6.5 The photograph on the left shows a myasthenia gravis patient with a drooping eye lid, one of the most common signs of the disease because of weakening of muscles around the eye. The photo on the right shows the same patient after administration of a drug that blocks the breakdown of acetylcholine.<\/em>[\/caption]\r\n\r\nMost commonly, myasthenia gravis is caused by immune system antibodies blocking [pb_glossary id=\"5871\"]acetylcholine[\/pb_glossary] receptors on muscle cells, as well as the actual loss of acetylcholine receptors. Acetylcholine is the main neurotransmitter used by [pb_glossary id=\"3031\"]motor neurons[\/pb_glossary] to carry their signals to the [pb_glossary id=\"4156\"]muscle fibres[\/pb_glossary] they control. With acetylcholine blocked or the receptors lost, muscle cells fail to receive nervous stimulation to contract. Treatment of myasthenia gravis may include medications to counter the effects of the mutant gene or to suppress the immune system.\r\n

    Parkinson\u2019s Disease<\/h2>\r\n[pb_glossary id=\"4264\"]Parkinson\u2019s disease[\/pb_glossary]<\/strong>\u00a0is a degenerative disorder of the\u00a0central nervous system\u00a0that mainly affects the muscular system and movement. Four motor signs and symptoms are considered defining in Parkinson\u2019s disease: muscle tremor (shaking), muscle rigidity, slowness of movement, and postural instability. Tremor is the most common and obvious symptom, and it most often occurs in a limb that is at rest, so it disappears during sleep or when the patient moves the limb voluntarily. Difficulty walking eventually develops, and dementia is common in the advanced stages of the disease. Depression is common, as well.\r\n\r\nSee the video \"Neurology - Topic 14 - Parkinsons disease - examining a patient\" by UCD Medicine, of a physician examining a patient living with advanced Parkinson's disease:\r\n\r\nhttps:\/\/youtu.be\/sJqKvajUC3k\r\n
    \r\n

    Neurology - Topic 14 - Parkinsons disease - examining a patient, UCD Medicine, 2013.<\/p>\r\n\r\n<\/div>\r\nParkinson\u2019s disease is more common in older people, with most cases being diagnosed after the age of 50. Often, the disease occurs for no known reason.\u00a0Cases like this are\u00a0called primary Parkinson\u2019s disease. Sometimes, the disease has a known or suspected cause, such as exposure to toxins in pesticides, or repeated head trauma. In this case, it is called secondary Parkinson\u2019s disease.\r\n\r\nRegardless of the cause, the motor symptoms of the disease result from the death of [pb_glossary id=\"2984\"]neurons[\/pb_glossary]\u00a0in the midbrain. The cause of cell death is not fully understood, but it appears to involve the buildup in the brain of protein structures called [pb_glossary id=\"4265\"]Lewy bodies[\/pb_glossary]. Early in the course of the illness, medications can be prescribed to help reduce the motor disturbances. As the disease progresses, however, the medications become ineffective. They also cause a negative side effect of involuntary writhing movements.\r\n

    \r\n

    Feature: Human Biology in the News<\/h1>\r\n<\/div>\r\nOn June 3, 2016, media all over the world exploded with news of the death of Muhammad Ali at the age of 74. The world champion boxer and Olympic gold medalist died that day of complications of a respiratory infection, but the underlying cause was Parkinson\u2019s disease. Ali was diagnosed with Parkinson\u2019s in 1984 when he was only 42 years old. Doctors attributed his disease to repeated head trauma from boxing.\r\n\r\nIn the days following Ali\u2019s death, the news was full of stories and images from milestones in the athlete\u2019s life, both before and after his diagnosis with Parkinson\u2019s disease. Sadly, the news coverage also provided an overview of his gradual decline as the disease progressed. Ali was pictured in 1996 lighting the flame at the Summer Olympics in Atlanta; however, in 2012, Ali had to be helped to his feet by his wife just to stand before the flag\r\n\r\n[caption id=\"attachment_4266\" align=\"alignright\" width=\"284\"]\"12.6 Figure 12.6.6 Muhammad Ali (left) and Michael J. Fox (right) became unlikely allies in the fight against Parkinson's Disease, testifying together before a Senate Committee in 2002.<\/em>[\/caption]\r\n\r\nhe was supposed to carry into the stadium. He was unable to carry it because of the ravages of Parkinson\u2019s disease.\r\n\r\nMuhammad Ali retired from boxing in 1981 at the age of 39, but he didn\u2019t retire from fighting. Up until the final year of his life, Ali was a passionate activist for peace and justice, and against war and racism. In 1998, he joined Michael J. Fox, who also has Parkinson\u2019s disease, to raise awareness of and funding for research on Parkinson\u2019s disease. In 2002, Fox and Ali made a joint appearance before Congress to present their case (see Figure 12.6.6). In 2005, Ali received the Presidential Medal of Freedom for the many achievements and contributions he made throughout his amazing life, in spite of Parkinson\u2019s disease.\r\n\r\n \r\n
    \r\n
    \r\n

    12.6 Summary<\/span><\/h1>\r\n<\/header>\r\n
    \r\n
      \r\n \t
    • [pb_glossary id=\"4253\"]Musculoskeletal disorders[\/pb_glossary]\u00a0are injuries that occur in muscles or associated tissues (such as tendons) because of biomechanical stresses. The disorders may be caused by sudden exertion, over-exertion, repetitive motions, and similar stresses.<\/li>\r\n \t
    • A [pb_glossary id=\"4255\"]muscle strain[\/pb_glossary] is an injury in which muscle fibres tear as a result of overstretching. First aid for a muscle strain includes the five steps represented by the acronym PRICE (protection, rest, ice, compression, and elevation). Medications for inflammation and pain (such as NSAIDs) may also be used.<\/li>\r\n \t
    • [pb_glossary id=\"4257\"]Tendinitis[\/pb_glossary] is inflammation of a tendon that occurs when it is over-extended or worked too hard without rest. Tendinitis may also be treated with PRICE and NSAIDs.<\/li>\r\n \t
    • [pb_glossary id=\"4258\"]Carpal tunnel syndrome[\/pb_glossary] is a biomechanical problem that occurs in the wrist when the median nerve becomes compressed between carpal\u00a0bones. It may occur with repetitive use, a tumor, or trauma to the wrist. It may cause pain, numbness, and eventually, if untreated, muscle wasting in the thumb and first two fingers of the hand.<\/li>\r\n \t
    • [pb_glossary id=\"4254\"]Neuromuscular disorders[\/pb_glossary]\u00a0are systemic disorders that occur because of problems with the nervous control of muscle contractions, or with the muscle cells themselves.<\/li>\r\n \t
    • [pb_glossary id=\"4260\"]Muscular dystrophy[\/pb_glossary] is a genetic disorder caused by defective\u00a0proteins in muscle cells. It is characterized by progressive skeletal muscle weakness and death of muscle tissues.<\/li>\r\n \t
    • [pb_glossary id=\"4262\"]Myasthenia gravis[\/pb_glossary] is a genetic neuromuscular disorder characterized by fluctuating muscle weakness and fatigue. More muscles are affected, and muscles become increasingly weakened as the disorder progresses. Myasthenia gravis most often occurs because immune system antibodies block acetylcholine receptors on muscle cells, and also because acetylcholine receptors are lost.<\/li>\r\n \t
    • [pb_glossary id=\"4264\"]Parkinson\u2019s disease[\/pb_glossary] is a degenerative disorder of the\u00a0central nervous system\u00a0that mainly affects the muscular system and movement. It occurs because of the death of neurons in the midbrain. Characteristic signs of the disorder are muscle tremor, muscle rigidity, slowness of movement, and postural instability. Dementia and depression also often characterize advanced stages of the disease.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
      \r\n

      12.6 Review Questions<\/span><\/h1>\r\n<\/header>\r\n
      \r\n
        \r\n \t
      1. What are musculoskeletal disorders? What causes them?<\/li>\r\n \t
      2. How does a muscle strain occur?<\/li>\r\n \t
      3. Define tendinitis. Why does it occur?<\/li>\r\n \t
      4. Identify first-aid steps for treating musculoskeletal disorders, such as muscle strains and tendinitis.<\/li>\r\n \t
      5. Describe carpal tunnel syndrome and how it may be treated.<\/li>\r\n \t
      6. Define neuromuscular disorders.<\/li>\r\n \t
      7. Identify the cause and symptoms of muscular dystrophy.<\/li>\r\n \t
      8. Outline the cause and progression of myasthenia gravis.<\/li>\r\n \t
      9. What is Parkinson\u2019s disease? List four characteristic signs of the disorder.<\/li>\r\n \t
      10. [h5p id=\"605\"]<\/li>\r\n \t
      11. What are the main differences between musculoskeletal disorders and neuromuscular disorders?<\/li>\r\n \t
      12. Why is padding of a strained muscle part of the typical treatment?<\/li>\r\n \t
      13. What are two tissues \u2014 other than muscle tissue \u2014 that can experience problems that result in muscular system disorders?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
        \r\n

        12.6 Explore More<\/span><\/h1>\r\n<\/header>\r\n
        \r\n\r\nhttps:\/\/www.youtube.com\/watch?time_continue=3&v=BZcZenvWBlg&feature=emb_logo\r\n

        TEDxAmericanRiviera - Dr. Eric Goodman - The Unexpected Physical Consequences Of Technology, TEDx Talks, 2011.<\/p>\r\nhttps:\/\/www.youtube.com\/watch?v=MEBdXbZ5CDM&feature=emb_logo\r\n

        Deep Brain Stimulation Surgery to treat Parkinson's Disease at Mount Sinai Hospital,\r\nMount Sinai Health System, 2013.<\/p>\r\nhttps:\/\/www.youtube.com\/watch?v=wUEl8KrMz14\r\n

        Why sitting is bad for you - Murat Dalkilin\u00e7, TED-Ed, 2015.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\nAttributions<\/span>\r\n\r\nFigure 12.6.1<\/strong>\r\n\r\n<\/div>\r\nTexting by derick-anies-hDJT_ERrB-w<\/a> [photo] by Derick Anies<\/a> on Unsplash<\/a> is used under the Unsplash License<\/a> (https:\/\/unsplash.com\/license).\r\n\r\nFigure 12.6.2<\/strong>\r\n\r\npulled_hamstring<\/a> by Daniel.Cardenas<\/a> on Wikimedia Commons is used under a CC BY 3.0<\/a> (https:\/\/creativecommons.org\/licenses\/by\/3.0) license.\r\n\r\nFigure 12.6.3<\/strong>\r\n\r\nBlausen Carpal_Tunnel_Syndrome<\/a> by BruceBlaus<\/a> on Wikimedia Commons is used under a CC BY 3.0<\/a> (https:\/\/creativecommons.org\/licenses\/by\/3.0) license.\r\n\r\nFigure 12.6.4<\/strong>\r\n\r\nFirefighters fundraise for muscular dystrophy<\/a> by Sombilon Studios<\/a>\u00a0on Flickr<\/a> is used under a CC BY-ND 2.0<\/a> (https:\/\/creativecommons.org\/licenses\/by-nd\/2.0\/) license.\r\n\r\nFigure 12.6.5<\/strong>\r\n\r\nMyasthenia_gravis_ptosis_reversal<\/a> by Kurukumbi, M., Weir, R.L., Kalyanam, J.\u00a0et al.<\/i><\/a>\u00a0 on Wikimedia Commons is used under a CC BY 2.0<\/a> (https:\/\/creativecommons.org\/licenses\/by\/2.0) license.\r\n\r\nFigure 12.6.6<\/strong>\r\n\r\nAli and Fox Parkinsons Disease<\/a> from the Office of Senator Debbie Stabenow<\/a> is in the public domain<\/a> <\/i>(https:\/\/en.wikipedia.org\/wiki\/Public_domain).\r\n

        References<\/h2>\r\n

        Blausen.com Staff. (2014). Medical gallery of Blausen Medical 2014. WikiJournal of Medicine 1<\/em> (2). DOI:10.15347\/wjm\/2014.010. ISSN 2002-4436.<\/p>\r\n

        Kurukumbi, M., Weir, R.L., Kalyanam, J., Nasim, M., Jayam-Trouth, A. (2008, 25 July). Rare association of thymoma, myasthenia gravis and sarcoidosis : a case report. Journal of Medical Case Reports,\u00a0<\/i>2<\/span><\/em>:245. doi:10.1186\/1752-1947-2-245<\/span><\/p>\r\n

        TED-Ed. (2015, March 5). Why sitting is bad for you - Murat Dalkilin\u00e7. YouTube. https:\/\/www.youtube.com\/watch?v=wUEl8KrMz14&feature=youtu.be<\/p>\r\n

        TEDx Talks. (2011, December 3).\u00a0 TEDxAmericanRiviera - Dr. Eric Goodman - The unexpected physical consequences of technology. YouTube. https:\/\/www.youtube.com\/watch?v=BZcZenvWBlg&feature=youtu.be<\/p>\r\n

        UCD Medicine. (2013, January 10). Neurology - Topic 14 - Parkinsons disease - examining a patient. YouTube. https:\/\/www.youtube.com\/watch?v=sJqKvajUC3k&feature=youtu.be<\/p>","rendered":"

         <\/p>\n

        \"12.6.1
        Figure 12.6.1 Devices can be a pain in the neck – literally.<\/em><\/figcaption><\/figure>\n

        Pain in the Neck<\/span><\/p>\n

        Spending hours each day looking down at hand-held devices is a pain in the neck \u2014 literally. The\u00a0weight\u00a0of the head bending forward can put a lot of strain on neck\u00a0muscles, and muscle injuries can be very painful. Neck pain is one of the most common of all complaints that bring people to the doctor\u2019s office. In any given year, about one in five adults will suffer from neck pain. That\u2019s a lot of pains in the neck! Not all of them are due to muscular disorders, but many of them are. Muscular disorders, in turn, generally fall into two general categories: musculoskeletal disorders<\/a>\u00a0and neuromuscular disorders<\/a>.<\/p>\n

        \n

        Musculoskeletal Disorders<\/h1>\n<\/div>\n

        Musculoskeletal disorders<\/a><\/strong> are injuries that occur in muscles or associated tissues (such as tendons<\/a>) because of biomechanical stresses. They may be caused by sudden exertion, over-exertion, repetitive motions, or long periods of maintaining awkward positions. Musculoskeletal disorders are often work- or sports-related, and generally just one or a few muscles are affected. They can often be treated successfully, and full recovery can be very likely. The disorders include muscle strains, tendinitis, and carpal tunnel syndrome.<\/p>\n

        Muscle Strain<\/h2>\n
        \"12.6
        Figure 12.6.2 Bleeding in muscle tissue may cause a muscle strain to produce a bruise over the affected muscle, as in this hamstring bruise. The photos show two images of the same leg, both taken four days after the injury occurred.<\/em><\/figcaption><\/figure>\n

        A\u00a0muscle strain<\/a><\/strong> is an injury in which muscle fibres tear as a result of overstretching. A muscle strain is also commonly called a pulled muscle or torn muscle. (Strains are often confused with sprains, which are similar injuries to ligaments.) Depending on the degree of injury to muscle fibres, a muscle strain can range from mildly to extremely painful. Besides pain, typical symptoms include stiffness and bruising in the area of the strained muscle. The photo here shows a large bruise caused by a hamstring muscle strain. Hamstring strains are very common in track and field athletes. In sprinters, for example, about one third of injuries are hamstring injuries. Having a previous hamstring injury puts an athlete at increased risk for having another one.<\/p>\n

        Proper first aid for a muscle strain includes five steps, which are represented by the acronym PRICE. The PRICE steps should be followed for several days after the injury. The five steps are:<\/p>\n

          \n
        1. Protection:<\/strong>\u00a0Apply soft padding to the strained muscle to minimize impact with objects that might cause further damage.<\/li>\n
        2. Rest:<\/strong>\u00a0Rest the muscle to accelerate healing and reduce the potential for re-injury.<\/li>\n
        3. Ice:<\/strong>\u00a0Apply ice for 20 minutes at a time every two hours to reduce swelling and pain.<\/li>\n
        4. Compression:<\/strong>\u00a0Apply a stretchy bandage to the strained muscle to reduce swelling.<\/li>\n
        5. Elevation<\/strong>:<\/strong>\u00a0Keep the strained muscle elevated to reduce the chance of\u00a0blood\u00a0pooling in the muscle.<\/li>\n<\/ol>\n

          Non-steroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen) can help reduce inflammation and relieve pain. Because such drugs interfere with\u00a0blood\u00a0clotting, however, they should be taken only after bleeding in the muscle has stopped \u2014 not immediately after the injury occurs. For severe muscle strains, professional medical care may be needed.<\/p>\n

          Tendinitis<\/h2>\n

          Tendinitis<\/a><\/strong>\u00a0is inflammation of a tendon that occurs when it is over-extended or worked too hard without rest. Tendons that are commonly affected include those in the ankle, knee, shoulder, and elbow.\u00a0The affected tendon\u00a0depends on the type of use that causes the inflammation. Rock climbers tend to develop tendinitis in their fingers, while basketball players are more likely to develop tendinitis in the knees, to name a few examples.<\/p>\n

          Symptoms of tendinitis may include aching, sharp pain, a burning sensation, or joint stiffness. In some cases, swelling occurs around the inflamed tendon, and the area feels hot and looks red. Treatment includes the PRICE guidelines listed above,\u00a0as well as\u00a0the use of NSAIDs to further reduce inflammation and pain. Although symptoms should show improvement within a few days of treatment, full recovery may take several months. A gradual return to\u00a0exercise\u00a0or other use of the affected tendon is recommended. Physical or occupational therapy may\u00a0speed\u00a0the return to normal activity levels.<\/p>\n

          Carpal Tunnel Syndrome<\/h2>\n

          Carpal tunnel syndrome<\/a><\/strong> is a common biomechanical problem that occurs in the wrist when the median nerve becomes compressed between carpal bones (see Figure 12.6.3). This may occur due to repetitive use of the wrist, a tumor, or trauma to the wrist. Two-thirds of cases are work-related. Computer work, work with vibrating tools, and work that requires a strong grip all increase one’s risk of developing this problem. Carpal tunnel syndrome occurs more often in women than men. Other risk factors include obesity, pregnancy, and arthritis. Genetics may also play a role.<\/p>\n

          \"12.6
          Figure 12.6.3 Carpal tunnel syndrome occurs when the median nerve in the wrist becomes compressed.<\/em><\/figcaption><\/figure>\n

          Compression of the median nerve results in inadequate nervous stimulation of the\u00a0muscles\u00a0in the thumb and first two fingers of the hand. The main symptoms are pain, numbness, and tingling in these digits. Sometimes, symptoms can be improved by wearing a wrist splint or receiving corticosteroid injections. Surgery to cut the carpal ligament reduces pressure on the median nerve and is generally more effective than nonsurgical treatment. Recurrence of carpal tunnel syndrome after surgery is rare. Without treatment, on the other hand, the lack of nervous stimulation by the median nerve may eventually cause the affected muscles of the hand to weaken and waste away.<\/p>\n

          \n

          Neuromuscular Disorders<\/h2>\n<\/div>\n

          Neuromuscular disorders<\/a><\/strong>\u00a0are systemic disorders that occur because of problems with the nervous control of muscle contractions, or with the muscle\u00a0cells\u00a0themselves. These disorders are often due to faulty genes and not due to biomechanical stresses. Other system-wide problems, such as abnormal immune system responses, may also be involved in neuromuscular disorders.<\/p>\n

          Unlike musculoskeletal disorders, neuromuscular disorders generally affect most or all of the muscles in the body. The disorders also tend to be progressive and incurable. However, in most cases, treatment is available to slow the disease progression or to lessen the symptoms. Examples of neuromuscular disorders include muscular dystrophy, myasthenia gravis, and Parkinson\u2019s disease.<\/p>\n

          Muscular Dystrophy<\/h2>\n

          Muscular dystrophy<\/a><\/strong> is a genetic disorder caused by defective proteins in muscle cells. It is characterized by progressive skeletal muscle weakness and death of muscle cells and tissues. Muscles become increasingly unable to contract in response to nervous stimulation.\u00a0 Approximately 50,000 Canadians suffer from muscular dystrophy.<\/p>\n

          There are at least nine major types of muscular dystrophy caused by different gene\u00a0mutations. Some of the mutations cause autosomal recessive<\/a> or autosomal dominant<\/a> disorders, and some cause X-linked<\/a> disorders. The most common type of\u00a0childhood\u00a0muscular dystrophy is Duchenne muscular dystrophy<\/a>, which is due to a\u00a0mutation\u00a0in a recessive gene on the X chromosome. As an X-linked recessive disorder, Duchenne muscular dystrophy occurs almost exclusively in males.<\/p>\n

          Different types of muscular dystrophy affect different major muscle groups. In Duchenne muscular dystrophy, the lower limbs are affected. Signs of the disorder usually become apparent when a child starts walking. Difficulty walking becomes progressively worse through childhood. By the time a child is ten, braces may be needed for walking \u2014 and walking may no longer even by possible by age 12. The lifespan of someone with muscular dystrophy is likely to be shorter than normal because of the disease, ranging from 15 to 45 years.<\/p>\n

          In some cases, physical therapy, drug therapy, or orthopedic surgery may improve some of the signs and symptoms of muscular dystrophy. However, at present, there is no known cure for the disorder. Research is ongoing to find a cure, with financial support provided by such sources as Muscular Dystrophy Canada (MDC) (see Figure 12.6.4). MDC is a non-profit organization dedicated to curing muscular dystrophy by funding worldwide research.<\/p>\n

          \"12.6
          Figure 12.6.4 Canadian firefighters have been supporting neuromuscular disorder research and care through fundraising and awareness campaigns for over 65 years.\u00a0 More than 600 Fire Departments and Associations across Canada raise more than $3 Million annually in support of MDC. Each year, career and volunteer Fire Fighters give their time and help \u201cFill the Boot\u201d by organizing various events like boot drives, rooftop campouts, stair climbs, ladder sits, car washes, raffles, sporting events and truck pulls in support of more than 50,000 Canadians who are impacted by neuromuscular disorders.<\/em><\/figcaption><\/figure>\n

          Myasthenia Gravis<\/h2>\n

          Myasthenia gravis<\/a><\/strong> is a genetic neuromuscular disorder characterized by fluctuating muscle weakness and fatigue. It occurs more commonly in women, and generally begins between the ages of 20 and 40. The initial symptom of myasthenia gravis is painless muscle weakness, generally in muscles around the eye (see photos in Figure 12.6.5). The disease then progresses to muscles elsewhere in the body, eventually involving most of the muscles. Swallowing and chewing may become difficult as the disease progresses, and speech may become slow and slurred. In more advanced cases, myasthenia crises may occur, during which the muscles that control breathing may be affected. Emergency medical care to provide assisted ventilation is required to sustain life. A myasthenia gravis crisis may be triggered by various stressors, such as infection, fever, or stress.<\/p>\n

          \"12.6
          Figure 12.6.5 The photograph on the left shows a myasthenia gravis patient with a drooping eye lid, one of the most common signs of the disease because of weakening of muscles around the eye. The photo on the right shows the same patient after administration of a drug that blocks the breakdown of acetylcholine.<\/em><\/figcaption><\/figure>\n

          Most commonly, myasthenia gravis is caused by immune system antibodies blocking acetylcholine<\/a> receptors on muscle cells, as well as the actual loss of acetylcholine receptors. Acetylcholine is the main neurotransmitter used by motor neurons<\/a> to carry their signals to the muscle fibres<\/a> they control. With acetylcholine blocked or the receptors lost, muscle cells fail to receive nervous stimulation to contract. Treatment of myasthenia gravis may include medications to counter the effects of the mutant gene or to suppress the immune system.<\/p>\n

          Parkinson\u2019s Disease<\/h2>\n

          Parkinson\u2019s disease<\/a><\/strong>\u00a0is a degenerative disorder of the\u00a0central nervous system\u00a0that mainly affects the muscular system and movement. Four motor signs and symptoms are considered defining in Parkinson\u2019s disease: muscle tremor (shaking), muscle rigidity, slowness of movement, and postural instability. Tremor is the most common and obvious symptom, and it most often occurs in a limb that is at rest, so it disappears during sleep or when the patient moves the limb voluntarily. Difficulty walking eventually develops, and dementia is common in the advanced stages of the disease. Depression is common, as well.<\/p>\n

          See the video “Neurology – Topic 14 – Parkinsons disease – examining a patient” by UCD Medicine, of a physician examining a patient living with advanced Parkinson’s disease:<\/p>\n