A charley horse is a painful involuntary

cramp A cramp is a sudden, involuntary, painful skeletal muscle contraction or overshortening associated with electrical activity; while generally temporary and non-damaging, they can cause significant pain and a paralysis-like immobility of the aff ...

in the

legs A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element ...

and/or foot, lasting anywhere from a few seconds to a day. The term formerly referred more commonly to bruising of the

quadriceps The quadriceps femoris muscle (, also called the quadriceps extensor, quadriceps or quads) is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the sole extensor muscle of the knee, forming a large ...

muscle of the anterior or lateral thigh, or

contusion A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur close ...

of the femur, that commonly results in a haematoma and sometimes several weeks of pain and disability. In this latter sense, such an injury is known as dead leg. Dead legs and charley horses are two different types of injuries: A charley horse involves the muscles contracting without warning, and can last from a few seconds to a few days. A dead leg often occurs in

contact sport Contact sports are sports that emphasize or require physical contact between players. Some sports, such as mixed martial arts, are scored on impacting an opponent, while others, including rugby football, gridiron football and Australian rules fo ...

s, such as football when an athlete suffers a knee (blunt trauma) to the lateral quadriceps causing a haematoma or temporary

paresis In medicine, paresis () is a condition typified by a weakness of voluntary movement, or by partial loss of voluntary movement or by impaired movement. When used without qualifiers, it usually refers to the limbs, but it can also be used to desc ...

and

antalgic gait An antalgic gait is a gait that develops as a way to avoid pain while walking ('' antalgic'' = ''anti-'' + '' alge'', "against pain"). It is a form of gait abnormality where the stance phase of gait is abnormally shortened relative to the swing pha ...

as a result of pain. Colloquially, taking a hit in the thigh area (thigh contusion) can also be referred to as a ''charley horse'' or even simply a ''charley.''

Cause

They have many possible causes directly resulting from high or low pH or substrate concentrations in the blood, including

hormonal imbalance Endocrine diseases are disorders of the endocrine system. The branch of medicine associated with endocrine disorders is known as endocrinology. Types of disease Broadly speaking, endocrine disorders may be subdivided into three groups: # Endocrin ...

dehydration In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...

, low levels of

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosphe ...

, or

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...

(evidence has been mixed), side effects of medication, or, more seriously, diseases such as

amyotrophic lateral sclerosis Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND) or Lou Gehrig's disease, is a neurodegenerative disease that results in the progressive loss of motor neurons that control voluntary muscles. ALS is the most comm ...

and

neuropathy Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or o ...

. They are also a common complaint during

pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ca ...

Treatment

Relief is given by massaging or stretching the leg or foot in the opposite direction of the cramp. Relief also comes from standing up, which serves to counter the muscle-tightening signal.

Notes

References

* * *

External links

* {{Nervous and musculoskeletal system symptoms and signs Muscular disorders Colloquial terms