The Systems of the Body
The Muscular System
Back to the Basics - Our Body
by Patrick O’Brien, MD
March 2010
OverviewThe body’s muscular system. It’s a weighty issue. Why? Because the muscular system accounts for half your total body weight. That’s why people often gain weight rather than lose it when they begin an exercise routine, particularly one that involves strength training (which all exercise routines should include!).
The primary function of the muscular system is to make the body move. Our muscles link our bones together and work in groups to respond to involuntary and voluntary nerve impulses.
There are three different types of muscles in the human body:
SKELETAL MUSCLES get their name from the fact that they are attached to our bones. They work in pairs to control bone movement. For example, one muscle moves a bone to the right; the other moves the bone back to the left. The number of skeletal muscles in the body totals more than 630, which tells you how much we move. Skeletal muscles are voluntary, which means we think about the movement we want to make. Our thoughts are messages that we send to our nervous system. Our nervous system then tells the appropriate muscles to move, or contract.
SMOOTH MUSCLES are in our body’s organs, such as our lungs, digestive system and bladder (to name a few). As part of these organs, they help us breathe, digest food and eliminate waste. Smooth muscles are involuntary, which means we don’t have to think about using them. The nervous system automatically controls them.
CARDIAC MUSCLES are in the heart. Cardiac muscles have characteristics of both smooth and skeletal muscles. They stretch like smooth muscles and contract like skeletal muscles. Fortunately for all of us, cardiac muscles are involuntary, so we don’t have to think about making our hearts beat!
Muscles themselves are made of fibers, which are elongated cells tightly packed together. The fibers are different in each type of muscle—skeletal, smooth and cardiac—and are held together by connective tissue.
In order to stretch and contract, the muscles need fuel—oxygen and nutrients. They get that fuel from capillaries. Capillaries are tiny blood vessels that penetrate the connective tissue to deliver oxygen and nutrients to the muscles.
Common Muscle IssuesMUSCLE SPRAIN Sprains are among the most common muscle problems. A sprain occurs when a ligament (connective tissue between the bones of the joints) is stretched or torn, most often as a result of a fall or twist. We see more ankle and wrist sprains than any other type. Typical symptoms of sprains include pain, tenderness when pressure is applied, swelling, bruising and even stiffness.
MUSCLE STRAIN People often confuse sprains and strains. In contrast to a sprain, a strain is a torn or stretched muscle or tendon. Tendons connect muscle to bone. Ligaments also connect bones but they do so at joints (ankles, wrists, knees, elbows and shoulders). Strains are often caused by twisting and/or pulling. Back and hamstring strains are the most common. People who suffer strains often experience muscle spasms, swelling and the inability to move the impacted muscle.
TENDONITIS When a tendon or tendons become inflamed, tendonitis occurs. Tendonitis can result from injury, repetitive motion and even rheumatoid arthritis. Pain and tenderness in the shoulders, knees, hips, heels, wrists or elbows are typical symptoms.
Diagnosis & TreatmentIt is important to see your doctor if you think you have a sprain, strain or tendonitis. They share common symptoms, but they may call for different treatment. Whether it involves physical therapy or simply rest, the right treatment is vital to making a full recovery.
TREATING SPRAINS & STRAINS Sprains and strains require similar treatment. RICE—rest, ice, compression and elevation—is the first course of action. Begin this treatment as soon as you can after the injury and make an appointment to see your physician. Your physician or physician-referred physical therapist will assess your condition and determine how much longer you need to perform RICE and when you can resume activity. Muscle-strengthening exercises may be recommended to support the area that has been sprained or strained.
TREATING TENDONITIS Treatment for tendonitis varies depending on the amount of inflammation and how well the affected area responds to treatment. In some cases, ice, rest and anti-inflammatory medications (i.e. ibuprofen) are all that are needed. In most cases, your doctor will refer you for physical therapy. Steroid injections and even surgery may also be necessary.
In order to make a full recovery from a sprain, a strain or tendonitis, it is important to follow your physician’s and/or your physical therapist’s instructions both in the therapy setting and at home. Progress is often slow and can be frustrating. But realize that an acute issue can become chronic if you do not follow your treatment plan. A big part of that is continuing to follow up with your physician or your physical therapist if your doctor orders physical therapy for you. Unfortunately, we often see patients who do not complete their recovery plan and must undergo more intense therapy or surgery. Make the commitment to following the full course of treatment the first time. You will thank yourself in the long run.
Patrick O’Brien, MD is a Physical Medicine/Rehabilitation Specialist at WakeMed Rehabilitation.