Pilot Study on the Validity, Tolerability, and Impact of a Walking Rehabilitation Intervention Using Cruro-Malleolar Cast in Children With Cerebral Palsy (RCMs)

This pilot study investigates whether walking training using cruro-malleolar casts (CMCs) - rigid leg splints extending from the thigh to the ankle - can safely improve gait quality in children with bilateral cerebral palsy (CP). CMCs are already used in routine clinical care at our center, but their biomechanical effects and therapeutic value have never been formally studied.Children aged 7 to 14 with bilateral spastic CP (diplegia or quadriplegia, GMFCS levels I-III) will participate in a 4-week treadmill walking program wearing CMCs, preceded by a 1-month observation baseline and followed by a 6-month follow-up. The investigators will use motion capture technology and surface electromyography to measure how the CMCs immediately change the way children walk - particularly at the hip and pelvis - and whether the training program leads to lasting improvements in walking speed, quality, and endurance.The study also carefully monitors pain and effort perceived by children during each training session, so that tolerance of the intervention can be rigorously assessed. Six participants will be enrolled. The study uses a Single-Case Experimental Design (SCED), which allows rigorous conclusions to be drawn from a small number of patients through repeated measurements over time.

Study Overview

• Status: Not yet recruiting
• Conditions: Cerebral Palsy
• Intervention / Treatment: Device: Cruro-Malleolar Cast Walking Training

Detailed Description

Background and rationale Cerebral palsy is the most common cause of motor disability in children. Among its clinical forms, spastic diplegia is characterized by predominant lower limb involvement and progressive gait deterioration during growth, driven by musculotendinous contractures and secondary orthopedic complications. From Rodda and Graham's gait classification Group II ("jump gait") onward, hamstring overactivity plays a central role - contributing to excessive knee flexion and limited hip extension in late stance. Interventions targeting active hamstring stretching in a controlled gait pattern may therefore have significant clinical value.

Cruro-malleolar casts (CMCs) are knee-extension orthoses molded over the child's walking ankle-foot orthosis. In current clinical practice at our center, they are used both for passive stretching postures and as a gait rehabilitation tool. The hypothesized mechanisms during CMC-assisted walking include: active hamstring stretch at initial contact; increased hip extensor (gluteus maximus) activation during loading response and mid-stance; improved pelvic belt mobility and trunk extension in the frontal plane; increased eccentric hip flexor activity and posterior step in late stance - effects that are expected to be amplified when training is performed on a treadmill. Despite their use in clinical practice, no published study has evaluated the biomechanical, muscular, or functional effects of CMCs during walking training.

Study design This study uses a nested Single-Case Experimental Design (SCED), combining an A-B-Follow-up series with an Alternating Treatments Design (ATD) embedded within Phase B.

Phase A (Baseline, 1 month): Three repeated measurement sessions (every 15 days), with no intervention. Establishes each participant's individual baseline trajectory.

Phase B (Intervention, 1 month): Four weekly measurement sessions. Participants perform 4 sessions per week of treadmill walking training with CMCs (20 minutes per session, with verbal and/or manual guidance from a physiotherapist, and music chosen by the child to support motivation). At each of the 4 measurement time points within Phase B, participants are assessed in 4 randomized conditions: walking on ground with ankle-foot orthoses (AFO) alone; walking on ground with AFO + CMCs; walking on the instrumented treadmill (DIG) with AFO alone; walking on DIG with AFO + CMCs. Randomization of condition order is restricted by practical and safety constraints (ground assessments must precede treadmill assessments; treadmill speed is capped at ground walking speed).

Phase FU (Follow-up, 6 months): Three measurement sessions at 1, 3, and 6 months post-intervention.

The per-patient protocol lasts 8 months. Inclusion will span 30 months, for a total study duration of 3 years, starting from CPP approval.

• Study Type: Interventional
• Enrollment (Estimated): 6
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Julie Rozaire, PhD; Phone Number: +334 72 38 11 43; Email: lab.massues@croix-rouge.fr

Participation Criteria

Eligibility Criteria

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

Description

INCLUSION CRITERIA

• Children aged 7 to 14 years
• Pubertal development at Tanner stage 1 or 2
• Bilateral cerebral palsy (diplegia or quadriplegia)
• Ambulatory with or without assistive device (GMFCS levels I, II, or III)
• Clinical indication for walking training
• Ability to use an adapted visual analogue scale to rate perceived pain
• No botulinum toxin injection in the 4 months preceding study entry
• Affiliated to or beneficiary of a French social security scheme
• Not currently enrolled in another biomedical research study (not in an exclusion period from the national registry)

EXCLUSION CRITERIA

• Pubertal development at Tanner stage greater than 2
• Refusal to wear cruro-malleolar casts (CMCs)
• Inability to walk on a treadmill
• Refusal to participate in the repeated assessment sessions required by the study protocol
• Refusal to delay the next scheduled botulinum toxin injection series until after completion of study participation

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: Assisted Treadmill Walking Training; Children with bilateral spastic cerebral palsy undergo a 4-week treadmill walking program wearing cruro-malleolar casts (CMCs) - rigid bivalved knee-extension orthoses molded over their existing ankle-foot orthoses. Training consists of 16 sessions (4/week) of 20-minute treadmill walking with physiotherapist guidance and self-selected music. At 4 weekly assessment time points, participants are evaluated in 4 randomized conditions: ground walking with AFO alone, ground walking with AFO + CMCs, instrumented treadmill with AFO alone, and treadmill with AFO + CMCs, using 3D motion capture, surface EMG, and force platforms. Pain (Faces VAS) and perceived exertion (modified Borg scale) are recorded after each session. This phase is preceded by a 1-month baseline (3 sessions) and followed by a 6-month follow-up (at 1, 3, and 6 months).

Device: Cruro-Malleolar Cast Walking Training; Cruro-malleolar casts (CMCs) are rigid bivalved knee-extension orthoses molded over the child's existing functional ankle-foot orthosis. Fabricated by a nurse-plaster technician and physiotherapist, they include protective padding, corrective felt inserts promoting knee extension, and supra-condylar fixation hooks. Windows are cut in the CMCs to allow surface EMG electrode and reflective marker placement during gait analysis. CMCs are worn during treadmill walking training (16 sessions over 4 weeks, 4 sessions/week, 20 minutes/session) on an instrumented treadmill (DIG system) with physiotherapist guidance. They are also worn during ground and treadmill gait analysis sessions. CMC walking is compared to walking with ankle-foot orthoses alone, both on ground and on the instrumented treadmill, within each participant across repeated assessment sessions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hip and Lumbopelvic 3D Kinematics during CMC-assisted Walking	Three-dimensional kinematic curves of the hip and lumbopelvic complex recorded by motion capture (Qualisys optoelectronic system, IOR Full Body Gait Model) during walking with and without CMCs, on ground and on treadmill (DIG). Mean joint angles are extracted at key gait cycle events (initial contact, loading response ~10%, mid-stance, terminal stance, peak swing ~70%).	Assessed at each of the 4 weekly measurement sessions during Phase B (weeks 5, 6, 7, and 8 from study start).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Surface EMG Muscle Activation Timing	Activation timing (onset and offset, expressed as % of gait cycle) of hamstrings (semitendinosus), rectus femoris, vastus lateralis, and gluteus maximus, recorded by surface EMG (Cometa Pico) during walking with and without CMCs, on ground and on treadmill.	Assessed at each of the 4 weekly measurement sessions during Phase B (weeks 5-8).
Walking Speed	Walking speed is defined as the velocity at which an individual walks, recorded with and without CMCs, on ground and on treadmill.	Assessed at all 10 measurement time points: 3 baseline sessions (Phase A, weeks 1-4), 4 intervention sessions (Phase B, weeks 5-8), and 3 follow-up sessions (1, 3, and 6 months post-intervention).
Pain Perception during CMC Training	Child-reported pain perception related to CMC wearing, measured by the Faces Visual Analogue Scale (0-10, 0 = no pain, 10 = unbearable pain) after each training session.	Recorded after each of the 16 training sessions during Phase B (weeks 5-8).
Hip Extensor and Flexor Muscle Strength	Isometric strength of hip extensor and flexor muscles measured by dynamometry, and active hip extension range of motion, assessed in prone position at the edge of the table.	Assessed at all 10 measurement time points across Phase A (weeks 1-4), Phase B (weeks 5-8), and Phase FU (1, 3, and 6 months post-intervention).
Gait Quality - 3D Kinematic and Kinetic Curves without CMCs	Full lower limb 3D kinematic curves and joint moments/powers (hip, knee, ankle) recorded without CMCs, on ground and on treadmill., used to assess changes in overall gait pattern over time including sagittal plane locomotor profile, anterior knee vector positioning, and trunk/pelvic alignment.	Assessed at all 10 measurement time points across Phase A (weeks 1-4), Phase B (weeks 5-8), and Phase FU (1, 3, and 6 months post-intervention).
Walking Endurance - 6-Minute Walk Test (6MWT)	Distance covered in 6 minutes (meters) on a 30-meter indoor corridor with standardized instructions and encouragements, performed with the participant's habitual walking aids and orthoses. A validated functional walking capacity test widely used in pediatric cerebral palsy populations.	Assessed at all 10 measurement time points across Phase A (weeks 1-4), Phase B (weeks 5-8), and Phase FU (1, 3, and 6 months post-intervention).
Cadence	Cadence is a measure of speed calculated as the total number of full cycles (of both a right and left foot strike) taken within a given period of time, often expressed in steps per minute or cycles per minute recorded with and without CMCs, on ground and on treadmill.	Assessed at all 10 measurement time points: 3 baseline sessions (Phase A, weeks 1-4), 4 intervention sessions (Phase B, weeks 5-8), and 3 follow-up sessions (1, 3, and 6 months post-intervention)
Step Length	Step length is the distance between the point of initial contact of one foot and the point of initial contact of the opposite foot. Recorded with and without CMCs, on ground and on treadmill.	Assessed at all 10 measurement time points: 3 baseline sessions (Phase A, weeks 1-4), 4 intervention sessions (Phase B, weeks 5-8), and 3 follow-up sessions (1, 3, and 6 months post-intervention)
Stride Length	Stride length is defined as the distance between two points where the same foot strikes the ground sequentially, encompassing the sum of left and right step lengths. Recorded with and without CMCs, on ground and on treadmill.	Assessed at all 10 measurement time points: 3 baseline sessions (Phase A, weeks 1-4), 4 intervention sessions (Phase B, weeks 5-8), and 3 follow-up sessions (1, 3, and 6 months post-intervention)
Step Width	The mediolateral space between the two feet (the difference between right and left heels during gait). Recorded with and without CMCs, on ground and on treadmill.	Assessed at all 10 measurement time points: 3 baseline sessions (Phase A, weeks 1-4), 4 intervention sessions (Phase B, weeks 5-8), and 3 follow-up sessions (1, 3, and 6 months post-intervention)
Single Support Duration	The period of time when only one foot is in contact with the ground recoreded with and without CMCs, on ground and on treadmill.	Assessed at all 10 measurement time points: 3 baseline sessions (Phase A, weeks 1-4), 4 intervention sessions (Phase B, weeks 5-8), and 3 follow-up sessions (1, 3, and 6 months post-intervention)
Double Support Time	The period of time when both feet are in contact with the ground recorded with and without CMCs, on ground and on treadmill.	Assessed at all 10 measurement time points: 3 baseline sessions (Phase A, weeks 1-4), 4 intervention sessions (Phase B, weeks 5-8), and 3 follow-up sessions (1, 3, and 6 months post-intervention)
Stance ratio	The ratio between the entire gait cycle and stance phase recoreded with and without CMCs, on ground and on treadmill.	Assessed at all 10 measurement time points: 3 baseline sessions (Phase A, weeks 1-4), 4 intervention sessions (Phase B, weeks 5-8), and 3 follow-up sessions (1, 3, and 6 months post-intervention)

Collaborators and Investigators

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

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): September 1, 2028

Study Registration Dates

• First Submitted: May 21, 2026
• First Submitted That Met QC Criteria: June 10, 2026
• First Posted (Actual): June 16, 2026

Study Record Updates

• Last Update Posted (Actual): June 18, 2026
• Last Update Submitted That Met QC Criteria: June 16, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Cerebral Palsy; Gait rehabilitation; Treadmill training; Single-case experimental design; Knee-extension orthosis
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Brain Damage, Chronic; Cerebral Palsy
• Other Study ID Numbers: 2026_01_RCMs_RIPH

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