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Muscle Case Study

Muscle Case Study

Skeletal muscles are the organs of the muscular system and are made up of skeletal muscle tissue, nervous tissue, connective tissue and blood. The human body is approximately made up of 600 skeletal muscles. The basic functions of the skeletal muscles are to provide movement of the bones, maintain posture, and produce heat.

Sometimes a muscle or a group of muscles can become injured due to overuse, the most common injury affecting baseball pitchers. Jason is a college pitcher who began to experience soreness of his right pitching arm. The twenty year old pitcher noticed a decline in duration as well as pitching abilities. The symptoms developed during the season are due to a decrease in conditioning and an increase of duration and intensity while in training season. Once Jason felt his conditioning was met, the main focus turned toward pitching alone. When the season began, the patient had already started to wear down the rotator cuff muscles by pitching entire games and using more force. With time, the depletion in performance was evident and resulted in a choice of using a different pitching method rather than resting the tired arm. Eventually, Jason was sent to see a team physician to be evaluated. The physician suspected the rotator cuff was the root of the problem. The rotator cuff consists of 4 tendons that belong to the subscapularis, supraspinatus, infraspinatus, and the teres minor muscles. These muscles encircle and stabilize the shoulder joint and deltoid. Pitchers usually are associated with this particular kind of injury because of the overhand throwing motion, known as circumduction, and repetitive use. Through a physical examination, the results support the doctor’s diagnosis. The MRI revealed inflammation of muscles in the right shoulder and arm.

MRIs are the most commonly used over an x-ray because if a tear in the muscles or tissues were present, the MRI is able to distinguish between the soft tissues. As for x-rays, it focuses more on broken bones, disabling the detection of any soft tissue contrast. The right arms range of motion revealed that it was reduced and guarded, meaning the arm was drawn unusually close to body. The ROM test consists of internal and external rotation as well as abduction of shoulder. Muscle force test is also performed to help measure muscle strength.

There are three different scales that may be used to measure strength; however the numerical scale was used in this particular case. The numerical scale ranges from one, for “no contraction”, through five, “normal contraction strength”; to further differentiate strength, a negative or a positive may be added to the number grade.

The purpose is to focus on each individual muscle and determine the strength and ability against resistance. Jason’s strength test, of the rotator cuff muscles, received a grade of 4-, which is considered a “normal” contraction grade. As for the visual examination, the right shoulder drooped and lacked free movement, in addition to the arm being drawn closely to his body. If the injury affected the rotator cuff nerve supply it would have affected the brachial plexuses nerves that consist of the lower subscapular nerves (subscapularis), suprascapular nerve (supraspinatus/infraspinatus), and the axillary nerve (teres minor). (Quintana, 2001)

Joyce had broken her femur in a skiing accident and her leg was in a cast for several weeks. After the cast was removed, she began to see a physical therapist to help her test and regain muscle strength in that area. The therapist asked Joyce to extend her leg at the knee from a sitting position to test the quadriceps femoris muscle.

Quadriceps consists of four muscles of the thigh that aid in the extension of the knee; rectus femoris, vastus intermedius, vastus lateralis, and vastus medialis. Since the patient is capable of extension, this exhibits the ability of the leg against gravity. The following procedure was to push down on Joyce’s shin while asking her to resist the downward force. The resistance that is applied, tests the muscle’s capability to work against an externally applied force. Tests such as these, help to determine loss of strength that had taken place due to lack of movement and healing process of femur bone. (Ryan, 1991)

Adam had been experiencing fever, lethargy, muscle swelling and tenderness, and a rash on his face, chest, and eyelids. After a number of blood test and treatments with various anti-inflammatory agents, the symptoms were not alleviated, and seemed to be getting worse. The strength of Adam’s upper limb muscles were measured at significantly below normal (3-) on both sides of his body. The strength of muscles is a manual test based on a scale from one to five; one being “no contraction”, three through five being “normal”. Based on these symptoms his physician ordered a muscle biopsy. Myositis is the prime suspicion; however there are three types to choose from, polymyositis, dermatomyositis, and trichinosis. Myositis can be caused by a viral, bacterial, or parasitic infection and cause inflammation of muscles and associated connective tissue (often it is severe enough to induce necrosis and destroy muscle fibers). Polymyositis is the inflammation of multiple muscles at one time and when sometimes accompanied by skin lesions and is then called dermatomyositis. The physician can ask a few questions that help aid his diagnosis, such as how long have you had these symptoms? Have you had any fevers? How is your diet? Is it more difficult to lift objects now than before? Are simple tasks more a challenge (i.e. lifting a gallon of milk)? Do you feel burning sensations in your arm and if you do how long does it last? Are you tired- all of the time, or sometimes? Do you fall, and if so, is it difficult to get up? Along with these questions a biopsy should be performed to help determine if there are atrophied muscle fascicles and large numbers of inflammatory cells surrounding the blood vessels. Muscle biopsy can also detect both of the diseases better because of the ability to show patchy distribution that would have been missed elsewhere. (Myositis, 2002)

Trichinosis is foodborne disease caused by a parasitic round worm called trichinella spiralis. It can be consumed by humans from eating an infected animal such as pigs, boar, fox, and bear. The parasite is harbored in the animal’s muscle tissue and when the animal is not properly cooked, can be ingested and imbedded in the small intestines of a human. The larvae turn to adults in the small intestines and reproduce more larvae that enter the blood stream and eventually travel to the muscles, possibly invading the heart, diaphragm, lungs, and brain. Once the parasite has reached the muscle, it begins to mature into an infective larvae invading muscle tissue (this forms a myositis). Muscle pain involves soft tissue, such as connective, ligaments, tendons, and fascia (thick bands of tendons), surrounding the muscles. (Arnold, 2001)

A patient who has drooping upper eyelids and unable to raise the lid is diagnosed with ptosis (aka blepharoptosis). The two types of ptosis are acquired, result of aging, and congenital, born with defected eyelid muscles. Ptosis may be acquired through weakness in eyelid muscles, occurring in some rare muscle condition; problem with the nerve which controls the eyelid muscle; or with a mechanical defect caused by anything that increases the weight of the lid (i.e. cyst, swelling). The muscle that is affected by this disease is the levator palpebrae superioris. The levator palpebrae superioris fibers arise from the roof of the orbit and are inserted in the connective tissue of the upper lid, when these fibers contract, the upper lids are raised, and the eye opens. The LPS is innervated by the oculomotor nerve, which is part of the cranial nerve III, which arises from the midbrain and passes into the orbits of the eyes. (Cohen, 2001)

John, a 25 year-old construction worker, severely injured his left forearm. The injury occurred when John’s arm got caught between a wall and steel beams that had fallen due to a building collapsing. His arm appears swollen and the lab tests revealed elevated concentrations of serum CK, LDH, and aldolase. The hospital staff should be alert for dark, reddish urine. The breakup of muscle cells release myoglobin into the urine causing a condition known as myoglobinuria. Rhabdomyolysis, a severe destruction of muscle cells, is commonly affiliated with myoglobinuria. The most severe form is crush syndrome, usually caused by major trauma such as John’s case. The release of enough myoglobin can block kidney tubules and cause death. At times, limb injuries begin to accumulate fluid causing edema (swelling). Edema may then cause more pressure and may compress the blood vessels, reducing blood flow, ending the life of the cell. Contracture is the abnormal shortening of the muscle and is a result of dead muscular tissue being replaced by scar tissue. (Koren, 2001)

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