University of São Paulo: Chronic or acute sleep deprivation affects walking control
An analysis conducted by the Biomechatronics Laboratory of the Polytechnic School of USP, coordinated by Professor Arturo Forner-Cordero, monitored the sleep patterns of 30 university students. After being submitted to a motor coordination test, it was found that sleep deprivation affected gait control, responsible for people’s balance during walking. These results can guide the role of clinical practice in physical therapy processes and in the identification of fatigue symptoms, among other medical interventions. An article on the subject was published in the scientific journal Science Reports , and is available at this link .
Lack of sleep can impair control of body movements
The work was conceived after researchers at the laboratory, which specializes in the study of motor control and exoskeleton development, noticed that students who volunteered for coordination tests had very poor results at the end of the semester, and the lack of sleep was cited as one of the possible reasons.
The tests were carried out as follows: the volunteers spent two weeks using an actimeter (equipment used to monitor sleep patterns) and then were divided into three groups. As all students suffered from some degree of daily sleep deprivation, the control group consisted of students who, although not getting enough sleep throughout the week, made up for this loss on the weekend. Students who did not catch up on lost sleep on days off, on the other hand, formed the “chronic sleep deprivation” group. Finally, part of the volunteers was instructed to spend a sleepless night right before the test, to serve as a group with “acute sleep deprivation”.
In the test, researchers asked the volunteers to walk in sync with a beep produced by a machine. The frequency of the beep varied a few milliseconds gradually, to represent the imperceptible microadjustments we make while walking normally.
When trying to follow the beep, the group with chronic sleep deprivation was unable to maintain rhythm stability. And the acute sleep deprivation group was even worse, completely out of sync.
“The elderly population has a high prevalence of hospitalizations for falls and a poorer quality of sleep, on average. Noticing a relationship between these two phenomena can have several practical implications for therapeutic purposes, such as turning care strategies to sleep in order to improve step control and avoid this type of accident.”
These results have important implications for clinical practice, explains Guilherme Umemura, first author of the article: “For example, the elderly population has a high prevalence of hospitalizations for falls and a poorer quality of sleep, on average. Noticing a relationship between these two phenomena can have several practical implications for therapeutic purposes, such as turning care strategies to sleep in order to improve step control and avoid this type of accident”.
The opposite is also possible, according to him: “Perhaps, in the future, it will be possible to develop systems to monitor people’s walking patterns and use this to identify individuals suffering from fatigue, something relevant in work safety, among other contexts.”
The volunteers’ walk was recorded by sensors in the laboratory and rhythm stability was analyzed using a computer system/ Images provided by the researcher
Umemura received funding from the Coordination for the Improvement of Higher Education Personnel (Capes) and the project received funding from the Office of Naval Research Global, the US government’s international research funding institute. In addition to him and the Forner-Cordero coordinator, the article had the collaboration of João Pedro Pinho, also from Poli, and Jacques Duysens and Hermano Igo Krebs, from the Catholic University of Leuven and the Massachusetts Institute of Technology.