Muscle spasms and cramps are spontaneous, often painful muscle
The rapid, uncontrolled muscle contraction, or spasm, happens
unexpectedly, with either no stimulation or some trivially small one. The
muscle contraction and
last for several minutes and then slowly ease. Cramps may affect any
muscle but are most common in the calves, feet, and hands. While painful,
they are harmless and, in most cases, not related to any underlying
disorder. Nonetheless, cramps and spasms can be manifestations of many
neurological or muscular diseases.
The terms cramp and spasm can be somewhat vague, and they are sometimes
used to include types of abnormal muscle activity other than sudden
painful contraction. These include stiffness at rest, slow muscle
relaxation, and spontaneous contractions of a muscle at rest
(fasciculation). Fasciculation is a type of painless muscle spasm, marked
by rapid, uncoordinated contraction of many small muscle fibers. A
critical part of diagnosis is distinguishing these different meanings and
allowing the patient to describe the problem as precisely as possible.
The exact incidence of muscle cramps and spasms is not known. They are
more likely to occur in older children and teenagers who are participating
in organized, competitive
and strenuous aerobic activities.
Causes and symptoms
Normal voluntary muscle contraction begins when electrical signals are
sent from the brain through the spinal cord along nerve cells called motor
neurons. These include both the upper motor neurons within the brain and
the lower motor neurons within the spinal cord and leading out to the
muscle. At the muscle, chemicals released by the motor neuron stimulate
the internal release of calcium ions from stores within the muscle cell.
These calcium ions then interact with muscle proteins within the cell,
causing the proteins (actin and myosin) to slide past one another. This
motion pulls their fixed ends closer, thereby shortening the cell and,
ultimately, the muscle itself. Recapture of calcium and unlinking of actin
and myosin allow the muscle fiber to relax.
Abnormal contraction may be caused by unusual activity at any stage in
this process. Certain mechanisms within the brain and the rest of the
central nervous system help regulate contraction. Interruption of these
mechanisms can cause spasm. Motor neurons that are
overly sensitive may fire below their normal thresholds. The muscle
membrane itself may be overly sensitive, causing contraction without
stimulation. Calcium ions may not be recaptured quickly enough, causing
Structural disorders such as flat feet, hyperextended knees (genu
recurvatum), and hypermobility syndrome (joints that can move beyond the
normal range of motion) may predispose a person to developing leg cramps.
Prolonged sitting, inappropriate leg positioning during sedentary
activity, or standing on concrete flooring for prolonged periods may be
associated with an increased incidence of leg cramps.
Interruption of brain mechanisms and overly sensitive motor neurons may
result from damage to the nerve pathways. Possible causes include
, multiple sclerosis,
, neurodegenerative diseases, trauma,
spinal cord injury
, and nervous system poisons such as strychnine,
, and certain insecticides. Nerve damage may lead to a prolonged or
permanent muscle shortening called contracture.
Changes in muscle responsiveness may be due to or associated with the
Fasciculation may be due to fatigue, cold, medications, metabolic
disorders, nerve damage, or neurodegenerative disease, including
amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig's
disease). Most people experience brief, mild fasciculation from time to
time, usually in the calves.
The pain of a muscle cramp is intense, localized, and often debilitating.
Coming on quickly, it may last for minutes and fade gradually.
Contractures develop more slowly, over days or weeks, and may be permanent
if untreated. Fasciculation may occur at rest or after muscle contraction
and may last several minutes.
Exercising in high temperatures can lead to dehydration. Dehydration
should be suspected if these symptoms are present: dry mouth or tongue,
increased or excessive thirst, few or no tears when crying, decreased
urination, dark yellow urine, irritability, low energy, lightheadedness or
fainting, severe weakness, and sunken abdomen, eyes and cheeks.
Prompt medical attention is required if the child has any of the symptoms
associated with dehydration, as listed above. Prompt medical attention
also is required if the child has a high fever— of 102°F or
38.9°C, or above. Parents also should call the child's
pediatrician if the following symptoms are present:
A usual bout of muscle cramps should not require a visit to the doctor.
However, medical treatment is essential if the child has any symptoms of
dehydration associated with the muscle cramps. In addition, any abnormal
contractions or frequent muscle cramps or spasms that cause concern should
be evaluated by a physician. Abnormal muscle contractions are diagnosed
through a careful medical history, as well as a physical and neurological
examination. In some cases when a structural abnormality is suspected, x
rays may be performed.
The medical history helps the physician evaluate the presence of other
conditions or disorders that might contribute to or cause the abnormal
contractions. Records of previous diagnoses, surgeries, and treatments are
reviewed. The child's
medical history is evaluated to determine if there is a history of
muscular or neurological disorders.
Questions about the child's medical history may include:
The physical and neurological exams may include an evaluation of the
child's motor reflexes including muscle tone, mobility, strength,
balance, and endurance; heart and lung function; cranial nerve function;
and an examination of the child's abdomen, spine, throat, and ears.
The child's height and weight and blood pressure also are checked
When a neurological cause is suspected, a multi-disciplinary team may be
consulted to provide an accurate diagnosis, so the proper treatment can be
planned. Occupational and physical therapy evaluations may be helpful to
determine upper and lower extremity movement patterns and passive range of
In some cases, nerve conduction studies with electromyography of the
affected muscles may be performed to evaluate an underlying neuromuscular
disorder. These tests are useful in evaluating a child's muscular
activity and provide a comprehensive
of nerve and muscle function.
In both tests, the examiner uses a computer, monitor, amplifier,
loudspeaker, stimulator, and high-tech filters to see and hear how the
muscles and nerves are responding during the test. In the nerve conduction
study, small electrodes are placed on the skin over the muscles to be
examined. A stimulator delivers a very small electrical current (that does
not cause damage to the body) through the electrodes, causing the nerves
to fire. In the electromyogram, a very thin, sterilized needle is inserted
into various muscles, usually those affected most by
symptoms. The needle is attached by wires to a recording machine. The
patient is asked to relax and contract the muscles being examined. The
electrical signals produced by the nerves and muscles during these tests
are measured and recorded by a computer and displayed as electrical waves
on the monitor. The test results are interpreted by a specially trained
—Spontaneous; produced by active efforts. Active range of motion
exercises are those that are performed by the patient without
—Based on the same traditional Chinese medical foundation as
acupressure, acupuncture uses sterile needles inserted at specific
points to treat certain conditions or relieve pain.
—Lack of oxygen.
—A condition marked by impaired muscular coordination, most
frequently resulting from disorders in the brain or spinal cord.
—A training technique that enables an individual to gain some
element of control over involuntary or automatic body functions.
Central nervous system
—Part of the nervous system consisting of the brain, cranial
nerves, and spinal cord. The brain is the center of higher processes,
such as thought and emotion and is responsible for the coordination and
control of bodily activities and the interpretation of information from
the senses. The cranial nerves and spinal cord link the brain to the
peripheral nervous system, that is the nerves present in the rest of
—A nonprogressive movement disability caused by abnormal
development of or damage to motor control centers of the brain.
—Referring to clonus, a series of muscle contractions and partial
relaxations that alternate in some nervous diseases in the form of
—A tightening of the uterus during pregnancy. Contractions may or
may not be painful and may or may not indicate labor.
—A tightening or shortening of muscles that prevents normal
movement of the associated limb or other body part.
—Painful involuntary muscle cramps or spasms.
—Small involuntary muscle contractions visible under the skin.
—Hyperextension of the knee.
—Reflexes that persist too long and may be too strong. For
example, a hyperactive grasp reflex may cause the hand to stay clenched
in a tight fist.
—Unusual flexibility of the joints, allowing them to be bent or
moved beyond their normal range of motion.
—Having excessive muscular tone or strength.
—Refers to a disease or condition of unknown origin.
—A nerve cell that specifically controls and stimulates voluntary
—A progressive, autoimmune disease of the central nervous system
characterized by damage to the myelin sheath that covers nerves. The
disease, which causes progressive paralysis, is marked by periods of
exacerbation and remission.
—Localized muscle contraction that occurs when the brain signals
the muscle to contract.
—Involuntary contractions of a muscle or an interrelated group of
muscles. Also known as myoclonic seizures.
—A doctor who specializes in disorders of the nervous system,
including the brain, spinal cord, and nerves.
—Physician who performs surgery on the nervous system.
Nocturnal leg cramps
—Cramps that may be related to exertion and awaken a person
—A healthcare provider who specializes in adapting the physical
environment to meet a patient's needs. An occupational therapist
also assists patients and caregivers with activities of daily living and
provide instructions on wheelchair use or other adaptive equipment.
—A doctor specializing in treatment of the musculoskeletal
—Movement that occurs under the power of an outside source such
as a clinician. There is no voluntary muscular contraction by the
individual who is being passively moved.
Periodic limb movement disorder
—A disorder characterized by involuntary flexion of leg muscles,
causing twitching and leg extension or kicking during sleep.
—Nerves outside the brain and spinal cord that provide the link
between the body and the central nervous system.
—A physician who specializes in physical medicine and
—A healthcare provider who teaches patients how to perform
therapeutic exercises to maintain maximum mobility and range of motion.
Range of motion (ROM)
—The range of motion of a joint from full extension to full
flexion (bending) measured in degrees like a circle.
Restless legs syndrome (RLS)
—A disorder in which the patient experiences crawling, aching, or
other disagreeable sensations in the calves that can be relieved by
movement. RLS is a frequent cause of difficulty falling asleep at night.
—A constant resistance to passive motion.
Spinal cord injury
—Injury to the spinal cord, via blunt or penetrating trauma.
—Interruption of blood flow to a part of the brain with
consequent brain damage. A stroke may be caused by a blood clot or by
hemorrhage due to a burst blood vessel. Also known as a cerebrovascular
Alternative and complementary therapies include approaches that are
considered to be outside the mainstream of traditional health care. In
adults, alternative treatments for cramps include gingko (
) or Japanese quince (
). Supplements of vitamin E, niacin, calcium, and magnesium may also help
to relieve the likelihood of night cramps, especially when taken at
bedtime. Indications for these treatments in children have not been
There are several alternative therapies that can be useful when treating
. Among the therapies that may be helpful are acupuncture, homeopathy,
touch therapies, postural alignment therapies, and biofeedback. The
progress made will depend on the individual and his/her condition.
Biofeedback training may be used to teach older children how to
consciously reduce muscle tension. Biofeedback uses an electrical signal
that indicates when a spastic muscle relaxes. The patient may be able to
use biofeedback to learn how to consciously reduce muscle tension and
possibly reduce symptoms.
Before learning or practicing any particular technique, it is important
for the parent or caregiver and child to learn about the therapy, its
safety and effectiveness, potential side effects, and the expertise and
qualifications of the practitioner. Although some practices are
beneficial, others may be harmful to certain patients. Alternative
therapies should not be used as a substitute for medical therapies
prescribed by a doctor. Parents should discuss these alternative
treatments with the child's doctor to determine the techniques and
remedies that may be beneficial for the child.
Occasional cramps are common and have no special medical significance.
The likelihood of developing cramps may be reduced with regular exercise
to build up energy reserves in the muscles. Avoiding exercising in extreme
heat helps prevent heat cramps. Heat cramps can also be avoided by
drinking plenty of water before and during exercise in extreme heat.
Practicing proper body mechanics while sitting (sitting with both feet on
the floor, back straight and legs uncrossed) can help prevent the
development of leg cramps. Taking a warm bath before bedtime may increase
circulation to the legs and reduce the incidence of nighttime leg cramps.
The likelihood of developing cramps may be reduced by eating a
well-balanced, healthy diet with appropriate levels of minerals. A
registered dietitian can work with parents to identify a child's
specific calorie needs and develop an individualized meal plan.
Fluids should be encouraged during all strenuous activities, especially in
warm weather. People should aim for two to four eight-ounce glasses of
fluid per hour of activity.
If an underlying neurological disorder has been identified, dietary
guidelines are individualized, based on the child's age, diagnosis,
overall health, caloric and energy needs, and level of functioning. Early
identification, treatment, and correction of specific feeding problems
will improve the health and nutritional status of the patient.
Occasional muscle cramps are common. The most important concern is
preventing dehydration, especially when the child is exercising in high or
humid temperatures. Make sure the child drinks enough fluids before,
during, and after sports and other activities. Pack a water bottle and/or
sports drink for the child to have at sports practices, games, and other
physical activities. Make
sure the coach provides time out for water breaks. After the activity,
encourage the child to continue drinking water to replace lost fluids.
If a movement disorder has been diagnosed, parents should work closely
with the child's therapists and doctors to create an effective
treatment plan. It is important for parents to communicate their treatment
goals with the health care team. Parents should take an active role in the
child's exercise program.
Raising a child with a movement disorder can be challenging. There are
several support groups available to provide information and assistance.
Bradley, Walter G., et al.
Neurology in Clinical Practice
,4th ed. Woburn, MA: Butterworth-Heinemann, 2003.
Martini, Frederic H.
Fundamentals of Anatomy and Physiology
, 6th ed. Englewood Cliffs, NJ: Prentice Hall, 2002.
National Institute of Neurological Disorders and Stroke
National Institutes of Health. PO Box 5801, Bethesda, MD 20824. Web site:
National Rehabilitation Information Center (NARIC).
4200 Forbes Blvd., Ste. 202, Lanham, MD 20700. Web site: