Inclusion Criteria:  Work for Liverpool University Hospital NHS Foundation Trust Participant is willing and able to give informed consent for participation in the study. Agree to have weight, height, chest and waist measurements taken Agree to the study protocol Aged 18 years or above.  Exclusion Criteria:  Presentation of skin lesions Absence of any limb Female participant who is pregnant Have a lower back problem Pain or injury in shoulders or arms History of conditions that would make it difficult to lie prone, such as pressure injury or surgery within six months leading up to the study Any conditions that significantly affect movement and sensation such as diabetes or mobility limitations