Characterization of Visual Perception Impairments in Patients With Idiopathic Scoliosis (EYAIS)

Characterization of Visual Perception Alterations in Patients With Idiopathic Scoliosis: Towards a Theory of Perceptual Imbalance

Scoliosis is more than just a curve in the spine; it is a complex, 3D twisting of the backbone. While it can be caused by birth defects or tumors, the most common type-idiopathic scoliosis-appears in healthy teenagers for no clearly known reason.

The Theory of Balance Researchers believe that scoliosis might actually be caused by a "glitch" in how the body stays upright. Instead of the spine curving on its own, the curve might be the body's way of compensating for a poor sense of balance.

To stay balanced, the human brain relies on three main "inputs":

1. The Vestibular System: Located in the inner ear (detects movement).
2. Proprioception: The body's "inner map" (sensing where your limbs are).
3. Vision: Seeing the world around you to stay oriented.

The Goal of the Study Even though humans rely heavily on their eyes to stay balanced, the role of vision in scoliosis has not been studied very much.

This experiment aims to test the hypothesis that teenagers with scoliosis have trouble processing visual information to maintain their posture. By using advanced motion analysis, researchers want to see if a "misunderstanding" of visual cues is contributing to the spinal deformity.

Study Overview

• Status: Recruiting
• Conditions: Idiopathic Scoliosis
• Intervention / Treatment: Other: Motion Analysis

• Study Type: Interventional
• Enrollment (Estimated): 70
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Lyon, France, 69005
    • Recruiting
    • Centre Médico chirurgical de Réadaptation des Massues
    • Contact: Julie Rozaire, PhD; Phone Number: +33 4 72 38 11 43; Email: lab.massues@croix-rouge.fr

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

Group Scoliosis:

• Girls or boys aged 11 to 18 inclusive.
• Patients with progressive idiopathic scoliosis
• Candidates for either orthopedic (brace) or surgical (arthrodesis correction) treatment for which a pre-therapeutic multimodal assessment is planned.

Control group:

- Girls or boys aged 11 to 18 inclusive.

Exclusion Criteria:

The following individuals will not be included:

• Individuals with another musculoskeletal disorder.
• Individuals with a neurosensory disorder that may affect the balance of the trunk or lower limbs.
• Individuals with uncorrected visual perception disorders (visual check within 12 months prior to the examination).
• Lack of consent from the subject.
• Lack of consent from legal representatives.
• Failure to understand the instructions for performing the tests.

In addition, for the control group:

- Suffering from scoliosis

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• 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: Vertical Perception Assessment	Other: Motion Analysis; Researchers use motion capture to track exactly how a patient's body moves and shifts in response to different environments.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Margin of Dynamic Stability	This measures how close a person is to losing their balance while moving. It calculates the distance between where the body's weight is moving and the edge of the person's "footprint" (base of support).	At enrollment
Center of Pressure	The point on the ground where the most weight is being concentrated. Tracking how much this point "wobbles" or shifts shows how hard the body is working to stay upright.	At enrollment
Extrapolated Center of Mass	A calculation that looks at both the position of the body and its velocity. It helps researchers predict if the person's momentum is about to carry them off-balance.	At enrollment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Base of Support	The total area on the ground occupied by the feet. A wider BoS often suggests the subject is trying to create a "wider stance" to feel more stable.	At enrollment
Visual Field Perception	The "Distance Error." Using a joystick, the patient tries to place a 3D avatar exactly halfway between two other figures. The difference between the true middle and where the patient thinks the middle is reveals if their depth perception is distorted.	At enrollment
Subjective Visual Vertical	Angular Error. A glowing line is tilted on a screen, and the patient must tell the operator how to rotate it until it is perfectly vertical.	At enrollment

Collaborators and Investigators

• Sponsor: Centre Médico-Chirurgical de Réadaptation des Massues Croix Rouge Française

Study record dates

Study Major Dates

• Study Start (Actual): April 21, 2026
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): September 1, 2027

Study Registration Dates

• First Submitted: January 13, 2026
• First Submitted That Met QC Criteria: January 13, 2026
• First Posted (Actual): January 21, 2026

Study Record Updates

• Last Update Posted (Actual): May 26, 2026
• Last Update Submitted That Met QC Criteria: May 22, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 2025_10_EYAIS_RIPH2; 2025-A01301-48 (Other Identifier: ANSM)

Drug and device information, study documents

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