The rhythmic action of rubbing the soles or sides of the feet together is a widely observed, often unconscious behavior that occurs primarily during periods of rest. People commonly engage in this movement, sometimes described as “scissoring” or “friction,” when winding down or attempting to fall asleep. This action is a form of self-regulation, found in both children and adults as a means of comfort. Understanding the terminology and underlying reasons for this repetitive foot movement helps differentiate a harmless habit from a potential medical condition.
Classification of Repetitive Foot Movements
The casual term for rubbing the feet together, particularly before or during sleep, is often called “cricketing” or “cricket feet,” named for the sound the action can produce. This rhythmic movement is a type of motor stereotype, a broader behavioral term for any repetitive, patterned, non-functional movement. Stereotypies are self-regulatory mechanisms that provide sensory input or emotional relief.
When this movement occurs during the transition into sleep or while asleep, it falls under the clinical category of a sleep-related movement. In sleep medicine, the behavior is an example of Rhythmic Movement Disorder (RMD). RMD is a neurological disorder characterized by repetitive, stereotyped movements of large muscle groups that happen when a person is drowsy or asleep.
While RMD most commonly involves head movements, such as head-banging or head-rolling, rhythmic feet movements (RFM) are a specific manifestation. This foot-rubbing action consists of oscillating movements of the feet or toes, often occurring in short bursts lasting between 10 and 15 seconds. RMD differs from Restless Legs Syndrome (RLS) because the movement is not driven by an unpleasant urge or sensation requiring relief.
Behavioral and Sensory Origins
The primary drive behind rubbing the feet together stems from a need for self-soothing and self-regulation. The predictable, rhythmic quality of the movement is inherently calming, functioning similarly to other repetitive actions like rocking or hair-twirling. Engaging in the motion helps quiet the mind and signals the body to relax and prepare for sleep.
The movement also serves as a source of sensory input, providing proprioceptive and tactile feedback. Proprioception is the body’s sense of its own position and movement, and the friction offers a grounding, physical sensation. This stimulation is helpful for individuals who are overstimulated, as it helps shift focus away from external distractions or internal worries.
The behavior is common during early developmental stages, with many infants and toddlers exhibiting the action as they learn to self-soothe to sleep. For older individuals, foot rubbing may become a learned habit that persists, often serving as a coping mechanism for anxiety or stress. The repetitive motion helps regulate emotional states, which is why it may be observed more frequently during moments of high tension or when attempting to fall asleep.
Assessing Severity and When to Consult a Doctor
For the majority of people, rhythmic foot rubbing is a benign, self-limiting habit that is not a cause for concern. It is often considered a normal, quasi-physiological phenomenon that helps with the sleep-wake transition. However, specific indicators suggest the need for professional consultation with a healthcare provider or a sleep specialist.
One indicator is if the movement becomes intense enough to cause physical harm, such as skin breakdown, persistent sores, or pain. Another concern arises if the action significantly disrupts sleep for the individual or a bed partner, leading to daytime drowsiness, poor concentration, or mood changes. The lack of restful sleep is a primary reason to seek an evaluation.
The onset or persistence of aggressive foot rubbing into older childhood or adulthood, especially if associated with other symptoms, warrants a medical opinion. Physicians will evaluate for other movement disorders like RLS, which is characterized by a distinct, unpleasant sensation relieved by movement. Consulting a professional helps determine if the behavior is a simple habit, a form of stereotypy, or a manifestation of Rhythmic Movement Disorder requiring management.