Diseases and Disorders of the Muscle System
Duchenne Muscular Dystrophy
Duchenne Muscular Dystrophy (DMD) is caused by the inability of the body to make dystrophin (a muscle protein). This causes the muscles to become weak as the person ages. This disease primarily affects boys. Signs and symptoms typically present before the age of six and may include a delay of motor milestones and progressive weakness in the lower extremities and pelvis. Since all muscles are affected, the person will eventually require a wheelchair and assistance with breathing (National Human Genome Research Institute, 2013). To learn more, please visit the Genetic and Rare Diseases Information Center’s web page on Duchenne Muscular Dystrophy.
Cerebral palsy (CP) is caused by an interruption to the normal development of a person’s brain leading to weakness with muscles. Depending on the area of the brain that is affected, signs and symptoms will vary in the type and severity between individuals. Balance and coordination are often challenging due to the inability to control muscles (Centers for Disease Control and Prevention, n.d.). To learn more, please visit the Centers for Disease Control and Prevention’s web page on cerebral palsy.
Carpal Tunnel Syndrome
Carpal tunnel syndrome may present with pain, numbness, or weakness to the hand(s) caused by pressure on the median nerve. Some causes for this pressure are repetitive movements, trauma or injury to the wrist, or fluid retention related to pregnancy or menopause (National Institute of Neurological Disorders and Stroke, 2020). To learn more, visit the National Institute of Neurological Disorders and Stroke web page on carpal tunnel.
Paralysis is the loss of strength and control of the muscles in parts of the body. Paralysis can be localized where it affects specific areas such as the face, feet, vocal cords, et cetera, or it can be generalized where it affects a larger area of the body. There are various types of generalized paralysis, including:
- Paresis – a partial paralysis wherein there is a moderate degree of muscular weakness
- Paraplegia – paralysis that affects the lower extremities and lower portions of the trunk
- Quadriplegia – affects all four limbs
- Hemiplegia – affects one side of the body. For example, the arm and leg on the same side of the body (National Library of Medicine, 2021)
To learn more about paralysis, please visit the Cleveland Clinic’s web page on paralysis.
Sprain and Strain
A sprain is an injury to a joint whereby a ligament is stretched or torn. Joints can be sprained as a result of falling, twisting, or being hit. Sprains most often occur in the ankle, although other joints can be affected. Signs and symptoms of a sprain include pain, swelling, bruising, and an inability to use the joint (National Institute of Arthritis and Musculoskeletal and Skin Diseases, n.d.).
A strain is an injury to a muscle or a tendon caused by stretching or tearing. Tendons or muscles can be strained as a result of an injury, lifting heavy objects incorrectly, or overstress, and they can develop suddenly or over time. Signs and symptoms of a strain include pain, muscle spasms, swelling, cramping, and difficulty moving the muscle (National Institute of Arthritis and Musculoskeletal and Skin Diseases, n.d.).
Medical Terminology in Context
Medical Specialties and Procedures Related to Muscular System
Orthopedic surgeons are medical doctors who have specialized training in the prevention, diagnosis, treatment, and surgery of disorders and diseases related to the musculoskeletal systems (Bureau of Labor Statistics, 2021). For more details, please visit the American College of Surgeons’ web page on orthopedic surgery.
Massage therapists manipulate muscles and other soft tissues through touch to relieve pain, aid the injury-healing process, and reduce stress. Massage therapists generally have a postsecondary degree, although requirements vary by state (Bureau of Labor Statistics, 2021b). To learn more about massage therapy, visit the American Massage Therapy Association’s web page.
Electromyography (EMG) is a procedure that assesses the electrical signals muscles send while at rest and when they are used. During the test, a needle electrode is placed into the muscle, and a machine records the muscle activity. EMG can be used to diagnose myasthenia gravis, muscular dystrophy, and other conditions affecting the muscles (MedlinePlus, 2021a). To learn more, please visit the Medline Plus web page on electromyography.
Magnetic Resonance Imaging (MRI) is a test that uses radio waves and a magnetic field to view internal organs and structures. MRI tests are used to diagnose a variety of conditions, such as torn ligaments or tumors. They are also used to view the brain and spinal cord (Medline Plus, 2021b).
Range of Motion Testing is a diagnostic procedure used to determine the amount of movement around a specific joint.
Practice Terms Related to the Muscular System
Muscular System Vocabulary
In opposition to each other.
Condition of slow movement.
Involuntary and found only in the heart. Highly coordinated contractions pump blood into the vessels of the circulatory system.
Abnormal involuntary movements of the extremities, trunk, or jaw.
Record of the electricity of the muscle.
Recording of muscle electrical activity in response to a nerve’s stimulation of the muscle.
A common nonarticular rheumatic syndrome characterized by muscle pain.
Paralysis on one side of the body.
The process by which the body seals a ruptured blood vessel to prevent further blood loss.
Excessive movement of muscles of the body as a whole.
The enlargement of muscles.
Magnetic Resonance Imaging (MRI)
A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body.
A general term for the group of inherited myopathies that are characterized by wasting and weakness of the skeletal muscle.
Pain in a muscle or group of muscles.
A disease in which antibodies made by a person’s immune system prevent certain nerve-muscle interactions, causing weakness in the arms and legs, vision problems, and drooping eyelids or head.
Cancer that arises in plasma cells.
Paralysis that affects both legs and lower part of the body.
Partial paralysis wherein there is still some control of the muscles.
An inflammatory disease of the muscles closest to the center of the body.
Paralysis of all four limbs.
Necrosis or disintegration of skeletal muscle.
The muscles responsible for voluntary muscle movement; also called striated muscle.
The muscles responsible for involuntary muscle movement; also called visceral muscle.
The stretching or tearing of the supporting ligaments.
An overstretching or overexertion of a muscle or tendon.
Inflammation of the tendon.
Bureau of Labor Statistics. (2021a). Physicians and surgeons. In Occupational outlook handbook. U.S. Department of Labor. https://www.bls.gov/ooh/healthcare/physicians-and-surgeons.htm
Bureau of Labor Statistics. (2021b). Massage therapists. In Occupational outlook handbook. U.S. Department of Labor. https://www.bls.gov/ooh/healthcare/massage-therapists.htm
Centers for Disease Control and Prevention. (n.d.). What is cerebral palsy? https://www.cdc.gov/ncbddd/cp/facts.html
CrashCourse. (2015, July 15). Muscles, part 2 – organismal level: Crash course A&P #22 [Video]. YouTube. https://youtu.be/I80Xx7pA9hQ
National Library of Medicine. (2021). Medical Subject Headings database. National Institutes of Health, U.S. Department of Health and Human Services. https://www.nlm.nih.gov/mesh/meshhome.html
MedlinePlus. (2021a). Electromyography (EMG) and nerve conduction studies. U.S. National Library of Medicine. https://medlineplus.gov/lab-tests/electromyography-emg-and-nerve-conduction-studies
MedlinePlus. (2021b). MRI scans. U.S. National Library of Medicine, U.S. Department of Health and Human Services. https://medlineplus.gov/mriscans.html
National Human Genome Research Institute (2013). About Duchenne Muscular Dystrophy. National Institutes of Health, U.S. Department of Health and Human Services. https://www.genome.gov/Genetic-Disorders/Duchenne-Muscular-Dystrophy
National Institute of Arthritis and Musculoskeletal and Skin Diseases. (n.d.). Sprain vs. strain. National Institutes of Health, U.S. Department of Health and Human Services. https://www.niams.nih.gov/health-topics/sprains-and-strains#tab-symptoms
National Institute of Neurological Disorders and Stroke. (2020). Carpal tunnel syndrome fact sheet. National Institutes of Health, U.S. Department of Health and Human Services. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Carpal-Tunnel-Syndrome-Fact-Sheet
Science Reference Section. (2019). What is the strongest muscle in the human body? Library of Congress. https://www.loc.gov/everyday-mysteries/biology-and-human-anatomy/item/what-is-the-strongest-muscle-in-the-human-body/