Inclusion Criteria:

• Aged 18 and over
• Unable to transfer from lying to sitting independently
• Requiring technical assistance or the help or supervision of a third party
• Using a medical bed
• In-patient care for a minimum of 3 weeks in a medical or rehabilitation facility
• Having freely consented to participate
• Affiliated with a social security scheme or entitled to benefits

Exclusion Criteria:

• Non-consolidated spinal or pelvic fracture
• Degenerative shoulder
• Cardiovascular disorders caused by physical exertion
• Joint pain localized to dorsolumbar spine
• Behavioural disorders (opposition, agitation, dementia)
• Invalid patient (disability, low tonicity), agitated, not lucid (confused, disoriented) at risk of falling, requiring physical restraint with bed rails on medical prescription
• Functional inability to move independently
• Cognitive impairment affecting reliability of response to questionnaires
• Motor or algic incapacity of the 2 upper limbs not allowing the use of a technical aid (lifting frame or SAM) to ensure transfer from lying to sitting position in bed
• Patient less than 146 cm tall
• Patient weighing less than 30 kg or more than 200 kg
• Patient with a mattress incompatible with the OS'CARE device
• Mattress length less than 190 cm or greater than 200 cm, and width less than 85 cm or greater than 120 cm

In addition, vulnerable persons covered by articles L. 1121-5 to 8 and L. 1122-1-2 of the French Public Health Code are excluded from the study:

• Pregnant, parturient or breast-feeding women
• Persons deprived of their liberty by judicial decision (including guardianship, curatorship and safeguard of justice) or administrative decision
• Persons under psychiatric care or admitted to a health or social institution for purposes other than research.
• Person in an emergency situation unable to give prior consent