Effect of the Physiological Angular Position of the Resting Knee on Pressure at the Heel/Surface Interface

Study Overview
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Brief Summary
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The main objective of this study is to evaluate the relationship between the angle of knee flexion in a supine position with joint relaxation (DDPD) and the maximum interface pressure at the heel area (PtAl).

Detailed Description
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The secondary objectives of this study are: A. To evaluate the relationship between the angle of flexion of the knee in DDPD and the average pressure throughout the heel area (Pmean). B. To evaluate the relationship between the angle of flexion of the knee in DDPD and the contact surface of the heel area (Stal) where the pressure is greater than 60 mm Hg. C. To evaluate the inter-operator concordance for the knee flexion angle measurement in DDPD via photos. D. To evaluate the inter-operator concordance for skin marks used to measure knee flexion angles in DDPD via photos (only one knee for 30 patients). E. To evaluate the inta-operator concordance (measures on 2 consecutive days) for skin marks used to measure knee flexion angles in DDPD via photos (for 30 patients).

Official Title
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Effect of the Physiological Angular Position of the Resting Knee on Pressure at the Heel/Surface Interface

Conditions
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Adult, Hospitalized

Intervention / Treatment
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* Other: Knee flexion measurement 1
* Other: Knee flexion measurement 2
* Other: Heel - interface pressure measurements


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The patient must have given his/her informed and signed consent The patient must be insured or beneficiary of a health insurance plan The patient is in a stable medical state (no complications within the past 10 days) Exclusion Criteria: The patient is participating in another study The patient is in an exclusion period determined by a previous study The patient is under judicial protection, under tutorship or curatorship The patient refuses to sign the consent It is impossible to correctly inform the patient The patient has had medical complications within the ten days preceding study inclusion The patient has a bed-sore or bandages on his/her heels The patient has had a lower-limb amputation

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| The study population<br>Only one group is included. See inclusion/exclusion criteria. Intervention: Knee flexion measurement 1 Intervention: Knee flexion measurement 2 Intervention: Heel - interface pressure measurements | Other: Knee flexion measurement 1<br>* The angle of knee flexion during resting, supine position is measured by a first person.<br>Other: Knee flexion measurement 2<br>* The angle of knee flexion during resting, supine position is measured by a second person.<br>Other: Heel - interface pressure measurements<br>* The pressure analysis system used is the X Sensor X3 model (Xsensor Technology Corporation, Calgary, Canada). The sensor mat is made up of transducer cells, each measuring 1.6 cm^2. The digital signal is transmitted to a PC via a USB port at a sampling frequency of 10Hz. Before each measurement, the sensor mat is calibrated from 10 to 220 mm Hg, according to the manufacturer's recommendations. The sheet of pressure sensors is disposed on the dedicated bed. The patient is then asked to take his/her usual position in the supine position and a latency of 5 minutes is observed. The recording time pressure is then performed for 90 seconds in the optical observing time to adapt to changes in media.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measurement 1: Measurement of the knee joint angle (degrees °) in a physiological relaxed position (supine)(via photos of first skin marks). |  | Day 0 | 
| Measurement 2: Measurement of the knee joint angle (degrees °) in a physiological relaxed position (supine)(via photos of first skin marks) |  | Day 0 | 
| Maximum pressure on the heel area (Ptal) |  | Day 0 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean pressure over the entire heel area (P mean) |  | Day 0 | 
| Measurement of the contact surface of the heel zone (Stal) having a pressure greater than 60 mmHg |  | Day 0 | 
| Concordance for measurements 1 & 2 for knee flexion angle in a relaxed supine position (via photos) |  | Day 0 | 
| Concordance for skin marks for knee flexion angles between 2 operators for 30 knees. | relaxed, decubitus dorsal position | Day 0 | 
| Intra-operator concordance for skin marks used for measuring knee flexion angle for 30 knees | Relaxed decubitus dorsal position | Day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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heel - mattress pressure interface, knee angular position, flexion