Rigor – Causes, Treatment & Help


Rigor is a muscular stiffness that is controlled by the central nervous system and is caused by the simultaneous activation of muscles and their opponents. Rigor is the symptom of extrapyramidal or pyramidal lesions in the CNS and may be associated with Parkinson’s disease, for example. The therapy mainly consists of physiotherapy and occupational therapy.

What is rigor?

The muscles have a basic tension, which is also referred to as the resting tone. So, at rest, skeletal muscles are neither contracted nor fully relaxed. In a so-called rigor, the basic tension of the skeletal muscles is increased. The result is muscle rigidity or muscle stiffness. Rigor is based on a centrally controlled and simultaneous activation of the individual muscles and their antagonists.

The opponents of individual skeletal muscles are designated as such. Muscle activation during rigor thus corresponds to agonist-antagonist co-activation. In addition to a feeling of stiffness, patients with rigidity often describe pulling discomfort in the affected area. A special form of rigor is the so-called cogwheel phenomenon, in which the muscles of a passively moved extremity give way with a jerk. The cogwheel phenomenon indicates disorders in the extrapyramidal system of the central nervous system.


The causes for all forms of rigor are to be found in the central nervous system. Muscles have a certain basic tension that is regulated by different areas of the central nervous system. In addition to the pyramidal system, the extrapyramidal system is involved in this regulation.

All muscle information for the contraction of the muscles and muscle groups migrate to the target organs via the cerebral cortex-spinal cord pathways. These orbits correspond to the pyramidal orbits, which are summarized in the pyramidal system. Movement information can also be routed extrapyramidally and thus reach the spinal cord in a different way. The pyramidal and extrapyramidal systems interact with each other.

In most cases, rigor is preceded by dysfunction in the extrapyramidal system. The cogwheel phenomenon, for example, is often based on a lack of dopamine and the resulting disorders, such as those that occur in the context of Parkinson’s disease .

Patients with rigidity suffer from the main symptom of muscular rigidity. In the case of the cog wheel phenomenon, this rigidity only affects passive movements. Other forms of rigor involve active movement only. The muscle rigidity ultimately leads to movement disorders and sometimes to coordination problems . One of the earliest signs of rigidity is reduced arm movement when walking.

In some cases, there is pain and discomfort in addition to rigidity . The discomfort is often due to the compression of sensitive nerves in the muscles. The movement disorders can promote a tendency to fall in individual cases. Some patients develop camptocormia during the course of the rigor. Medicine understands this postural anomaly as an involuntary active forward bending movement of the trunk area.

The cause of this phenomenon is the dystonic involuntary tightening of the trunk flexor muscles. This contraction is particularly strong when the body is upright, so that camptocormia usually occurs when standing. All other symptoms depend on the particular cause of the rigor. In the context of Parkinson’s, for example, resting tremor and akinesia are among the most relevant symptoms.

diseases with this symptom

Diagnosis & History

Rigor is diagnosed by measuring resting tone. For example, an EMG can be used for the measurement , which makes the state of tension objectifiable. A neurological examination is also carried out as part of the diagnosis. In this examination, the rigor is demonstrated with the patient lying or sitting. This proof is particularly successful with the gear wheel phenomenon.

The doctor passively moves each joint and asks the patient to relax the muscles. With a rigor or cogwheel phenomenon, the doctor feels the waxy rigidity of the musculature in the form of an evenly tough resistance. Unlike spastic phenomena, resistance does not depend on the speed of movement.

If the patient actively moves the limb on the other side, the resistance on the passively moved side increases. In the case of the cog wheel phenomenon, the rigor in this study is characterized by interruptions. In order to identify the primary cause of the rigor, the doctor then arranges imaging procedures, among other things. The prognosis depends on the cause of the rigors.


Muscle stiffness or rigidity occurs primarily in the context of Parkinson’s disease. Another possible complication of Parkinson’s is the so-called freezing, in which the affected person freezes in the middle of the movement. On the contrary, it can also lead to excessive, unwanted movements of the arms and legs or the trunk (hyperkinesia), which increases the risk of injury to those affected and those around them.

Furthermore, circulatory disorders can occur in Parkinson’s patients, which can lead to severe dizziness and even loss of consciousness from lying down to getting up. In addition, the affected person can experience weakness in the bladder or rectum, resulting in incontinence and the need for care.

In addition, Parkinson’s can lead to depression due to the reduction in quality of life. This can lead to an increase in alcohol and drug consumption, and depressed people tend to have suicidal thoughts. A rare and feared complication of Parkinson’s disease is the akinetic crisis.

In this case, the symptoms worsen and the person affected suffers from total muscle stiffness or extreme rigidity. This can lead to a complete immobility, which can also affect the speaking and breathing muscles. This can also lead to overheating of the body.

When should you go to the doctor?

In order to receive a correct diagnosis, those affected should contact a doctor if they suspect rigor. Self-diagnosis using tests or checklists from the Internet is not sufficient. Patients usually first contact their general practitioner . If necessary, the family doctor can then issue a referral to a specialist.

If the symptom occurs again, patients suffering from Parkinson’s disease should also inform their treating specialist about the appearance of the rigor. This is usually a neurologist or psychiatrist .

In Germany, however, patients do not necessarily need a referral to see a neurologist. Depending on how good the medical care situation is on site, the waiting times for an appointment can vary greatly. An appointment with the general practitioner is often faster and can in some cases already enable an initial assessment of the symptoms.

In some cities there are also special outpatient clinics, which are often attached to a larger clinic. Some of these specialized treatment centers also make appointments for diagnosis and treatment of suspected Parkinson’s disease.

Since rigor is a core symptom of Parkinson’s, professional diagnosis by a doctor is always advisable.

Treatment & Therapy

The treatment of rigor also depends on the primary cause of the disorder. In any case, physiotherapeutic and ergotherapeutic steps are part of the therapy. A causal therapy cannot take place. All rigor has a central nervous system cause, and damage to the central nervous system is, to some extent, irreversible in most cases. Occupational therapy and physiotherapy are therefore not causal but symptomatic treatments.

Forms of therapy aim to at least alleviate the rigor or to help the patient deal with the symptom. In occupational therapy, for example, the patient learns how to use possible aids so that he can find his way through everyday life independently for as long as possible, even with severe rigor. Above all, everyday movements are trained as part of the therapy. Under certain circumstances, medicinal treatment steps that cause the central nervous system to reduce tonification can also be considered.

Outlook & Forecast

In the case of rigidity, the prognosis essentially depends on the cause of the muscle stiffness. If the rigor is due to Parkinson’s disease, the symptoms can be alleviated by physiotherapeutic and ergotherapeutic measures, but damage that has already occurred is in most cases irreversible. There is therefore no prospect of a complete recovery, but early action can at least alleviate further symptoms.

In the course of the disease, there are usually other symptoms such as a change in gait behavior, a lack of blinking or a decrease in voice volume, which can worsen the prognosis accordingly. Corresponding complaints continue to develop as the underlying Parkinson’s disease progresses and increase in intensity and spread until the patient finally becomes severely paralyzed and later dies.

Rigor is likely to be cured as a result of an injury or accident. Then, under certain circumstances, surgical interventions can restore the original muscle performance without resulting in subsequent symptoms. The first signs of rigor should be clarified promptly by a doctor due to the severity of the course.


Rigor is the symptom of pyramidal or extrapyramidal damage to the central nervous system. Rigor can thus only be prevented to the extent that lesions in the central nervous system can be prevented. For example, there are no preventive measures against diseases such as multiple sclerosis . For this reason, rigor can never be completely prevented.

You can do that yourself

In the case of a rigor, it can be helpful to carry out appropriate exercises outside of the physiotherapy sessions. The prerequisite for this, however, is that the exercises are carried out properly and that the therapist treating you is consulted beforehand. Otherwise there is a risk of aggravation of the symptoms or overloading. Only properly performed exercises are able to improve the everyday life of those affected.

Nonetheless, the opportunities to take action yourself in the event of a rigor are fairly limited. It is only possible to supplement or support existing treatment approaches. Since rigor is often associated with irreversible damage to the central nervous system, those affected have to adapt their everyday life to the illness. It is important to accept this. Everyday movements should be carried out despite the restrictions. If tools are to be used, they must be mastered.

In addition, psychological aspects must also be taken into account in the everyday life of those affected. After all, the diagnosis rigor brings with it numerous changes. Since these are mostly irreversible, the path of acceptance is usually the easiest. It is therefore advisable to mentally come to terms with the new circumstances. Consulting a psychologist or psychiatrist can help.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.