Knee Indentation for Soft Tissues Mechanical Characterization and Modeling (KneeDent)

Indentation for the Mechanical Characterization of Soft Tissues in Contact With a Knee Orthosis: Towards Simulation of the Leg-Orthosis Interface.

Knee osteoarthritis is a common cause of disability, affecting more than 650 million people aged 40 and over worldwide in 2020. To relieve pain and improve mobility, some patients use knee orthoses . However, the effectiveness of these devices is not universally agreed upon, and users report widely varying levels of satisfaction.

This study aims to understand how the body responds to these orthoses from a biomechanical perspective, and in particular to quantify the interactions with soft tissues (skin, adipose tissue and muscles). To better understand this interaction, the authors propose to characterize soft tissue behavior on an individual basis using an indentation technique. In practice, this involves pressing on the soft tissues with an ultrasound probe to measure their stiffness at the interface between the leg and the orthosis.

Study Overview

• Status: Completed
• Conditions: Soft Tissue Characterization of the Knee Region
• Intervention / Treatment: Other: Knee indentation

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Ille-et-Vilaine
    • Bruz, Ille-et-Vilaine, France, 35170
      • Ens Rennes

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria

Participant whose skin is intact on at least one of the two legs, in the tested area.

Participant able to understand simple instructions, conditioning guidelines, and to provide informed consent.

Adult over the age of 50, not under guardianship. Participant having signed the study participation consent form.

Non-inclusion Criteria

Persons covered by articles L. 1121-5 to L. 1121-8 and L. 1122-1-2 (minors, protected adults, etc.) Skin lesions, inflammation, or acute local pain on the tested leg. Neuromuscular pathology preventing controlled muscle contraction. Joint pain preventing the performance of everyday activities (e.g., walking, rising from a chair, climbing stairs…).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Knee indentation; under different level of thigh and shank muscles contraction, we indent specific zones of the knee region to assess its stiffness and define a mechanical model of response for knee orthosis design	Other: Knee indentation; we push the soft tissue in the indentation zone with an instrumented elastographic probe, allowing to assess force vs tissue thickness.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
force-displacement curves	Using the force below and displacement below, this a construction of the relative displacement with regard to the applied force	through study completion, an average of 1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Indentation force (N)	Force being applied by the indenter on the zone to be indented	through study completion, an average of 1 year
Displacement (mm)	using motion capture, this is the assessment of the relative displacement of the probe with regard to the resting position during an indentation	through study completion, an average of 1 year
Height (m)	Height of the subject, measured with a standard ruler	through study completion, an average of 1 year
Weight (kg)	measured with a standard scale	through study completion, an average of 1 year
Muscle activity (mV)	from the main flexors and extensors of the thigh, using EMGs	through study completion, an average of 1 year

Collaborators and Investigators

• Sponsor: Centre de recherche Inria de l'Université de Rennes
• Collaborators: Lyon 1 University

Study record dates

Study Major Dates

• Study Start (Actual): March 19, 2026
• Primary Completion (Actual): April 24, 2026
• Study Completion (Actual): April 24, 2026

Study Registration Dates

• First Submitted: June 2, 2026
• First Submitted That Met QC Criteria: June 8, 2026
• First Posted (Actual): June 10, 2026

Study Record Updates

• Last Update Posted (Actual): June 10, 2026
• Last Update Submitted That Met QC Criteria: June 8, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: InriaRennes; Étude N°26.00181.001002 (Other Identifier: Comité de protection des personnes Ile de France III)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No