Feedback-Based Balance Training for Adolescents With Idiopathic Scoliosis

Effect of Adding HUBER® 360 Feedback-Based Versus Home-Based Balance Training to Individualized Conservative Scoliosis Exercises on Postural Balance in Adolescent Idiopathic Scoliosis: A Prospective Non-Randomized Controlled Trial With 12-Week Follow-Up

Adolescent idiopathic scoliosis (AIS) is the most common form of scoliosis occurring during the growth period and is associated with significant alterations in postural balance compared with healthy peers. Prior research has shown that adding sensorimotor or balance-focused training to scoliosis-specific exercises may produce greater improvements in postural control and overall balance function than scoliosis-specific exercises alone. However, no study has previously investigated the effects of feedback-based balance training using a multi-axial platform with real-time biofeedback (the HUBER® 360 Evolution system) in this population.

The aim of this study is to evaluate the effect of adding HUBER® 360-based feedback balance training to individualized conservative scoliosis exercises on postural balance, postural symmetry, and health-related quality of life in adolescents with AIS.

The intervention protocol consists of 12 sessions delivered over 4 weeks, three sessions per week. Each session comprises 40 minutes of individualized conservative scoliosis exercises (identical between arms) followed by 30 minutes of balance training that differs between arms: HUBER® 360-based feedback balance training delivered in the clinic in the intervention arm, and a structured home-based balance exercise program performed independently after physiotherapist instruction in the active comparator arm.

Outcomes are assessed at three time points: T0 (baseline, week 0), T1 (immediately post-intervention, week 4), and T2 (12-week follow-up, week 16 from baseline). The primary outcome is the Stability Index measured by the TecnoBody ProKin stabilometric platform. Pre-specified key secondary outcomes include mediolateral standard deviation of the center of pressure, Romberg area ratio, Limits of Stability, the Scoliosis Research Society-22 Patient Questionnaire (SRS-22) total score, and single-leg stance time. Additional exploratory outcomes include further static, dynamic, and proprioceptive balance parameters from the TecnoBody ProKin platform; postural asymmetry parameters from the DIERS Formetric 4D rasterstereography system; and SRS-22 subdomain scores.

Study Overview

• Status: Active, not recruiting
• Conditions: Adolescent Idiopathic Scoliosis; Postural Balance
• Intervention / Treatment: Behavioral: HUBER® 360 Balance Training; Behavioral: Home-Based Balance Exercise Program; Behavioral: Individualized Conservative Scoliosis Exercises

Detailed Description

Background

Adolescent idiopathic scoliosis (AIS) is the most common pediatric spinal deformity, with a global prevalence of approximately 1-3% in adolescents aged 10-18 years. AIS is associated with paraspinal proprioceptive impairment, altered sensory reweighting, and biomechanical asymmetry of the trunk, all of which can disturb static and dynamic postural control. Conservative scoliosis-specific exercises are recommended by the 2016 SOSORT (International Society on Scoliosis Orthopaedic and Rehabilitation Treatment) guidelines as the first-line conservative treatment for mild-to-moderate AIS curves.

Recent randomized trials have suggested that adding sensorimotor or balance-focused training to scoliosis-specific exercises produces greater improvements in postural control and trunk symmetry than scoliosis-specific exercises alone. However, conventional balance training relies on therapist-mediated external feedback and does not provide quantitative real-time information on postural sway or weight distribution. Motor learning research indicates that augmented (device-based) visual feedback accelerates motor control acquisition, particularly when intrinsic proprioceptive feedback is impaired. The HUBER® 360 Evolution (LPG Systems, Valence, France) is a multi-axial neuromuscular training platform with force sensors in its handles and an integrated screen that delivers real-time visual biofeedback on applied force and weight distribution. Although its clinical efficacy has been demonstrated in chronic non-specific low back pain and other musculoskeletal populations, its effect in AIS has not previously been investigated in a controlled study.

Study Design

This is a prospective, two-arm, parallel-group, non-randomized controlled trial (quasi-experimental design) conducted at a single tertiary rehabilitation center. Allocation to study arms is performed using a pre-specified sequential allocation by clinic time slot rather than computer-generated randomization. The a priori sample size required to detect a Group × Time interaction in the primary outcome at α = 0.05 and 80% power was calculated using G*Power as 50 participants (25 per arm); 72 participants are enrolled to allow for attrition during follow-up.

Interventions

The intervention protocol consists of 12 clinic-based sessions delivered over 4 weeks, three sessions per week. Each session comprises 40 minutes of individualized conservative scoliosis exercises (identical between arms) followed by a 30-minute balance training component that differs between arms.

The individualized conservative scoliosis exercise program is informed by the general principles outlined in the 2016 SOSORT guidelines (three-dimensional auto-correction, adaptation to activities of daily living, stabilization of the corrected posture, and patient education) and is tailored to each patient based on curve pattern, apex location, and clinical examination findings. The program is delivered by physiotherapists experienced in scoliosis rehabilitation but who are not formally certified in any specific Physiotherapeutic Scoliosis-Specific Exercise (PSSE) school.

Intervention arm: 40 minutes of individualized conservative scoliosis exercises followed by 30 minutes of HUBER® 360-based feedback balance training, both delivered under physiotherapist supervision in the clinic.

Active comparator arm: 40 minutes of individualized conservative scoliosis exercises delivered in the clinic under physiotherapist supervision, plus a 30-minute structured home-based balance exercise program performed by the participant independently after detailed instruction by a physiotherapist. The home-based balance program is performed three times per week for 4 weeks (matching the frequency and total exposure of the intervention arm) and includes bilateral and unilateral stance exercises, balance tasks with eyes open and closed, exercises on different surfaces, and controlled weight-shifting tasks, organized according to a progressive difficulty principle. No device-based or real-time biofeedback is used.

Outcome Assessment

Outcomes are assessed at three pre-specified time points: T0 (baseline, week 0), T1 (immediately after the 4-week intervention, week 4), and T2 (12-week follow-up, week 16 from baseline). All assessments use validated, device-based, automated measurement systems where applicable, minimizing observer bias.

The primary outcome is the change in the Stability Index, a measure of overall postural control performance during a multi-axial dynamic balance task on the TecnoBody ProKin PK252 stabilometric platform (TecnoBody S.r.l., Dalmine, Italy), where lower values indicate better postural stability. This parameter is conceptually comparable to the Overall Stability Index (OSI) reported by the Biodex Balance System, which was used as the reference source for the a priori sample size calculation.

Pre-specified key secondary outcomes are: change in mediolateral standard deviation of the center of pressure; change in Romberg area ratio (eyes-closed to eyes-open sway area); change in Limits of Stability (LOS); change in the Scoliosis Research Society-22 Patient Questionnaire (SRS-22) total score; and change in single-leg stance time.

Pre-specified exploratory outcomes include the remaining TecnoBody ProKin static, dynamic, and proprioceptive parameters; postural and spinal alignment parameters measured by the DIERS Formetric 4D rasterstereographic surface topography system (DIERS International GmbH, Wiesbaden, Germany); and SRS-22 subdomain scores (function/activity, pain, self-image, mental health).

• Study Type: Interventional
• Enrollment (Actual): 72
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Yenimahalle
    • Ankara, Yenimahalle, Turkey (Türkiye), 06170
      • Ankara Etlik City Hospital, Department of Physical Medicine and Rehabilitation

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age between 10 and 17 years
• Diagnosis of adolescent idiopathic scoliosis confirmed by a specialist physiatrist
• No history of brace treatment
• Radiological evaluation showing a Cobb angle between 10° and 25°

Exclusion Criteria:

• Congenital scoliosis
• Neuromuscular scoliosis
• History of spinal surgery (including procedures involving paravertebral muscles or other spinal operations)
• Presence of metabolic bone disease affecting skeletal structure
• Severe autoimmune or endocrinological disease
• Connective tissue disorder or skeletal dysplasia
• Mental retardation preventing comprehension of simple instructions
• Advanced peripheral joint disease
• Coexisting polyneuropathy
• Coexisting myopathy
• Central nervous system disease that may affect balance
• History of abdominal surgery or abdominal trauma
• Presence of additional chronic comorbidities
• Lack of parental consent for participation in the study
• Functional scoliosis
• Current or prior brace use

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Individualized Conservative Scoliosis Exercises + HUBER® 360 Feedback Balance Training; Participants in this arm receive 40 minutes of clinic-based, physiotherapist-supervised individualized conservative scoliosis exercises followed by 30 minutes of HUBER® 360-based feedback balance training in the clinic. Sessions are delivered three times per week for 4 weeks (12 sessions in total) by a physiotherapist on a one-to-one basis.	Behavioral: HUBER® 360 Balance Training; Participants complete 30-minute balance training sessions on the HUBER® 360 Evolution multi-axial neuromuscular training platform (LPG Systems, Valence, France). The platform delivers real-time visual biofeedback on weight distribution and applied force through force sensors in the handles and an integrated screen. The protocol focuses on stretching the posterior chain, opening and increasing the concavity, and reinforcing the convexity. Sessions are supervised by a physiotherapist on a one-to-one basis.; Behavioral: Individualized Conservative Scoliosis Exercises; Participants perform 40-minute supervised exercise sessions tailored to each patient's curve pattern, apex location, and clinical findings. The program includes posture exercises, pelvic tilt, symmetric extension, scapular adduction with pectoral stretching, asymmetric lateral stretching, Cotrel exercise, flexibility and strengthening exercises, and active three-dimensional postural correction. All sessions are delivered one-to-one by a physiotherapist experienced in scoliosis rehabilitation.
Active Comparator: Individualized Conservative Scoliosis Exercises + Home-Based Balance Exercise Program; Participants in this arm receive 40 minutes of clinic-based, physiotherapist-supervised individualized conservative scoliosis exercises three times per week for 4 weeks (12 clinic sessions in total). In addition, participants perform a 30-minute structured home-based balance exercise program three times per week for the same 4-week period. The home-based balance program is taught in detail by a physiotherapist prior to the intervention period and performed independently by the participant at home.	Behavioral: Home-Based Balance Exercise Program; Participants complete a 30-minute structured home-based balance exercise program three times per week for 4 weeks. The program is taught in detail by a physiotherapist prior to the intervention period and performed independently by the participant at home. It includes bilateral and unilateral stance exercises, balance tasks with eyes open and closed, exercises on different surfaces, and controlled weight-shifting tasks, organized according to a progressive difficulty principle. No device-based or real-time biofeedback is used.; Behavioral: Individualized Conservative Scoliosis Exercises; Participants perform 40-minute supervised exercise sessions tailored to each patient's curve pattern, apex location, and clinical findings. The program includes posture exercises, pelvic tilt, symmetric extension, scapular adduction with pectoral stretching, asymmetric lateral stretching, Cotrel exercise, flexibility and strengthening exercises, and active three-dimensional postural correction. All sessions are delivered one-to-one by a physiotherapist experienced in scoliosis rehabilitation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Stability Index measured by the TecnoBody balance system	The primary outcome is the change in the Stability Index measured by the TecnoBody ProKin PK252 stabilometric platform (TecnoBody S.r.l., Dalmine, Italy). The Stability Index reflects overall postural control during a multi-axial dynamic balance task on the TecnoBody platform, where lower values indicate better postural stability. This parameter is conceptually comparable to the Overall Stability Index (OSI) reported by the Biodex Balance System, which was used as the reference source for the a priori sample size calculation.	Baseline (T0), immediately post-intervention (T1, week 4), and at 12-week follow-up (T2, week 16)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Mediolateral Standard Deviation of the Center of Pressure (CoP)	Mediolateral postural sway variability is assessed during quiet standing on the TecnoBody ProKin PK252 stabilometric platform. The standard deviation of the medio-lateral component of the CoP trajectory is computed in millimeters, with lower values indicating reduced lateral postural sway.	Baseline (T0), immediately post-intervention (T1, week 4), and at 12-week follow-up (T2, week 16)
Change in Romberg Area Ratio	Visual contribution to postural balance is quantified using the Romberg area ratio, calculated as the ratio of the eyes-closed CoP sway area to the eyes-open CoP sway area, both measured by the TecnoBody ProKin PK252 stabilometric platform. Higher ratios indicate greater visual dependence for postural control.	Baseline (T0), immediately post-intervention (T1, week 4), and at 12-week follow-up (T2, week 16)
Change in Limits of Stability (LOS)	Functional dynamic balance is assessed using the Limits of Stability (LOS) test on the TecnoBody ProKin PK252 stabilometric platform. Participants perform controlled weight shifts toward eight directional targets, and the test result is expressed as the percentage of successfully reached targets within a fixed time. Higher LOS values indicate greater dynamic balance capacity.	Baseline (T0), immediately post-intervention (T1, week 4), and at 12-week follow-up (T2, week 16)
Change in Postural Asymmetry Measured by the DIERS Formetric 4D Rasterstereographic Surface Topography System	Postural asymmetry and three-dimensional spinal alignment are assessed using the DIERS Formetric 4D system (DIERS International GmbH, Wiesbaden, Germany), a validated, radiation-free rasterstereographic surface topography method that reconstructs the three-dimensional shape of the back from projected light patterns. Pre-specified parameters include scoliosis angle, coronal and sagittal trunk imbalance, pelvic obliquity, pelvic torsion, kyphotic and lordotic angles, vertebral surface rotation, and lateral deviation. For all parameters, values closer to zero indicate greater postural symmetry	Baseline (T0), immediately post-intervention (T1, week 4), and at 12-week follow-up (T2, week 16)
Change in Unipodal Balance Test Performance	Static balance will be assessed using the Unipodal Balance Test. The duration (in seconds) that the participant is able to maintain balance on the right and left leg separately will be recorded.	Baseline (T0), immediately post-intervention (T1, week 4), and at 12-week follow-up (T2, week 16)
Change in Health-Related Quality of Life Measured by the Scoliosis Research Society-22 Patient Questionnaire (SRS-22)	Health-related quality of life is assessed using the Scoliosis Research Society-22 Patient Questionnaire (SRS-22), a validated patient-reported outcome measure for adolescent idiopathic scoliosis. Four domains (function/activity, pain, self-image/appearance, mental health) and a total score derived from these four domains are analyzed. The original instrument's fifth domain (satisfaction with management) is excluded because it cannot be administered at baseline. Each item is rated on a 5-point Likert scale, and a mean score is calculated for each domain and as a total. Possible scores range from a minimum of 1 to a maximum of 5, with higher scores indicating better health-related quality of life.	Baseline (T0), immediately post-intervention (T1, week 4), and at 12-week follow-up (T2, week 16)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Demographic Characteristics of Participants	Demographic data including age, sex, height, weight, and body mass index (BMI) will be collected to describe the study population and to explore potential correlations with balance outcomes.	Baseline

Collaborators and Investigators

• Sponsor: Ankara Etlik City Hospital
• Investigators: Study Chair: Ece Ünlü Akyüz, MD, Professor, Ankara Etlik City Hospital, Department of Physical Medicine and Rehabilitation; Study Director: Damla Cankurtaran, MD, Associate Professor, Ankara Etlik City Hospital, Department of Physical Medicine and Rehabilitation

Publications and helpful links

General Publications

• Le Berre M, Guyot MA, Agnani O, Bourdeauducq I, Versyp MC, Donze C, Thevenon A, Catanzariti JF. Clinical balance tests, proprioceptive system and adolescent idiopathic scoliosis. Eur Spine J. 2017 Jun;26(6):1638-1644. doi: 10.1007/s00586-016-4802-z. Epub 2016 Nov 14.
• Shen X, Yang Z, Zhang P, Xu Y, Wang J. Effects of balance training combined with Schroth therapy on adolescents with mild idiopathic scoliosis: A six-week randomized controlled trial. J Back Musculoskelet Rehabil. 2023;36(6):1365-1373. doi: 10.3233/BMR-220383.
• Abdel-Aziem AA, Abdelraouf OR, Ghally SA, Dahlawi HA, Radwan RE. A 10-Week Program of Combined Hippotherapy and Scroth's Exercises Improves Balance and Postural Asymmetries in Adolescence Idiopathic Scoliosis: A Randomized Controlled Study. Children (Basel). 2021 Dec 30;9(1):23. doi: 10.3390/children9010023.

Helpful Links

• Ankara Etlik City Hospital website
• DIERS Formetric 4D rasterstereographic surface topography system - manufacturer website
• HUBER® 360 Evolution multi-axial neuromuscular training platform used in the intervention arm of this study - manufacturer website

Study record dates

Study Major Dates

• Study Start (Actual): April 4, 2025
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: February 18, 2026
• First Submitted That Met QC Criteria: February 18, 2026
• First Posted (Actual): February 24, 2026

Study Record Updates

• Last Update Posted (Actual): May 19, 2026
• Last Update Submitted That Met QC Criteria: May 16, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Postural Balance; Adolescent Idiopathic Scoliosis; Balance Training; Postural Control; Physical Therapy Rehabilitation; HUBER® 360; TecnoBody Balance System; Scoliosis Exercises; DIERS Formetric 4D; Rasterstereography; Individualized Conservative Scoliosis Exercises
• Other Study ID Numbers: AEŞH-EK-2025-0136

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared because this is a single-center, thesis-based clinical trial with a limited sample size and no external data repository plan.

Drug and device information, study documents

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