Postural control impairment is common in people with COPD (pwCOPD), which can increase the risk of falls and affect quality of life. However, the majority of existing studies examine this postural control in isolation, without taking into account the cognitive demands that occur during activities of daily living during which individuals are often required to perform a mental task while maintaining their balance. This research aims to fill this gap by studying how a cognitive task can influence postural control in pwCOPD. We hypothesized an impaired postural control in pwCOPD compared to healthy individuals, which would be exacerbated in presence of a cognitive task.

This observational study is based on the analyses of data (center of pressure displacement) recorded during the first visit of NEUROTIGUE study (NCT04028973).

Center of pressure (COP) displacement were recorded during 60s of static balance in four conditions (random order) :

• Eyes open without cognitive task
• Eyes open with cognitive task
• Eyes closed without cognitive task
• Eyes closed with cognitive task The cognitive task used was a working memory task : the 1-back task. COP displacement will be assess using a conjunction of parameters to provide a comprehensive understanding of postural control (e.g., amplitude, standard deviation, non-linear approaches).

Inclusion Criteria:

COPD patients :

• GOLD II - III or IV
• FEV1 <80% of predicted values
• Men and women aged 40 years and over
• French-speaking participant
• BMI <30 kg / m²
• Stable condition (i.e. without exacerbation) for more than 15 days
• Able to express their consent in writing prior to any participation in the study
• Affiliates or beneficiaries of a social security
• Minimum score of 26 on the MMSE questionnaire of 3 months or less

Healthy volunteers :

• Men and women aged 40 years and over
• French-speaking participant
• BMI <30 kg / m²
• No known chronic respiratory, cardiovascular, metabolic, renal or neuromuscular pathologies
• Able to express their consent in writing prior to any participation in the study
• Affiliates or beneficiaries of a social security
• Minimum score of 26 on the MMSE questionnaire of 3 months or less

For all participants :

-Subject who has not objected to the reuse of data collected

Exclusion Criteria:

• COPD patients :
• Alcoholism, i.e. > 21 glasses a week for men and >14 glasses a week for women
• Psychiatric pathologies or antecedent of behavioral disorders
• Patients treated with oral or systemic corticosteroids (> 0.5 mg / kg / day for > 7 days)
• Contraindication to the application of a magnetic field (i.e. right hip arthroplasty, pelvic / abdominal surgeries)
• Severe vision or hearing problems not corrected
• Patient oxygen dependent
• Patients in exclusion period from another research protocol
• Pregnant women (known pregnancy) or lactating women
• Patient deprived of liberty by a judicial or administrative decision
• Patient subject to a legal protection measure or unable to express their consent
• Patient who is not sufficiently fluent in reading and understanding the French language to be able to consent to participate in the study
• Patient unable to follow study procedures and to respect visits throughout the study period
• Person with a medical history that, in the opinion of the investigator, could interfere with the results of the study
• Any condition that, in the opinion of the investigator, could increase and compromise the safety of the person in the event that he / she participates in the study
• Any other reason that, in the opinion of the investigator, could interfere with the evaluation of the aims of the study

Healthy volunteers:

• Alcoholism, i.e. > 21 glasses a week for men and >14 glasses a week for women
• Psychiatric pathologies or antecedent of behavioral disorders
• Patients treated with oral or systemic corticosteroids (> 0.5 mg / kg / day for > 7 days)
• Contraindication to the application of a magnetic field (i.e. right hip arthroplasty, pelvic / abdominal surgeries)
• Severe vision or hearing problems not corrected
• Subjects in exclusion period from another research protocol
• Pregnant women (known pregnancy) or lactating women
• Regular physical activity with a frequency greater than 3 sessions per week
• Participant deprived of liberty by a judicial or administrative decision
• Participant subject to a legal protection measure or unable to express their consent
• Participant who is not sufficiently fluent in reading and understanding the French language to be able to consent to participate in the study
• Participant unable to follow study procedures and to respect visits throughout the study period
• Person with a medical history that, in the opinion of the investigator, could interfere with the results of the study
• Any condition that, in the opinion of the investigator, could increase and compromise the safety of the person in the event that he / she participates in the study
• Any other reason that, in the opinion of the investigator, could interfere with the evaluation of the aims of the study

Participants enrolled in NEUROTIGUE study (NCT04028973)