Targeted Muscle Activation During Strength Training for Children With CP

NCT07800221 | Not Yet Recruiting

• 1 other identifier: S72414
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Cerebral palsy (CP) is the most common cause of physical disability in children and is associated with muscle weakness, spasticity, and impaired motor control. These impairments often lead to compensatory movement strategies, in which other muscles are recruited or movements are adapted to offload weaker target muscles. Although lower limb strengthening is widely used to improve motor function in children with CP, outcomes remain inconsistent. One potentially important but rarely examined factor is whether the intended muscles are actually activated during training. This study aims to develop and apply an activation-driven assessment protocol that combines individualized exercise selection, real-time electromyography (EMG) biofeedback, and compensation monitoring to identify conditions that promote target-muscle activation while limiting compensatory mechanisms. The focus is on three key muscle groups: hip extensors (HE), knee extensors (KE), and plantar flexors (PF). In this prospective\[JV2.1\], within-subject repeated-measures study, 30 ambulant children aged 5-12 years with spastic CP and Gross Motor Function Classification System levels I-III will complete three assessment visits in which exercise conditions and feedback strategies are compared using surface EMG and three-dimensional movement analysis.

Conditions

Cerebral Palsy (CP)

Keywords

Spastic Cerebral Palsy; Electromyography; Biofeedback; Motion analysis; Targeted muscle activation; Lower limb strengthening

Outcome Measures

Primary Outcomes (7)

• Peak EMG amplitude of the target muscles

  Peak normalized EMG amplitude during the exercise, used as a measure of maximal targeted activation of the hip extensors (HE), knee extensors (KE), and plantar flexors (PF).

  Assessed across three study visits over approximately 4 weeks.

• Integrated EMG of the target muscles

  Integrated normalized EMG over the duration of the complete task or phase of interest, used as a measure of total targeted muscle activation.

  Assessed across three study visits over approximately 4 weeks.

• Co-activation index

  Quantification of simultaneous activation of the target muscle and relevant antagonist or compensatory muscle, used to assess co-activation during strengthening exercises. It is calculated as: Co-activation index (%) = 2 × (Common Area of A and B / (Area of A + Area of B)) × 100 where A and B represent the two muscles being compared. Values range from 0% to 100%, with higher values indicating greater simultaneous muscle activation (co-activation).

  Assessed across three study visits over approximately 4 weeks.

• Selectivity ratio

  Integrated EMG of the point-by-point ratio between the time-normalized activation waveform of the target muscle and the corresponding activation waveform of a relevant synergistic or compensatory muscle, used as a measure of target muscle selectivity during the exercise.

  Assessed across three study visits over approximately 4 weeks.

• Joint angle compensation parameter

  A predefined joint angle (expressed in °) selected according to the exercise task, used to quantify compensatory movement strategies.

  Assessed across three study visits over approximately 4 weeks.

• Joint moment compensation parameter

  A predefined joint moment (expressed in Nm/kg) selected according to the exercise task, used to quantify compensatory movement strategies.

  Assessed across three study visits over approximately 4 weeks.

• Joint power compensation parameter

  A predefined joint power (expressed in W/kg) selected according to the exercise task, used to quantify compensatory movement strategies.

  Assessed across three study visits over approximately 4 weeks.

Secondary Outcomes (25)

• Continuous EMG waveforms

  Assessed across three study visits over approximately 4 weeks.

• Continuous joint angle waveforms

  Assessed across three study visits over approximately 4 weeks.

• Continuous joint moment waveforms

  Assessed across three study visits over approximately 4 weeks.

• Continuous joint power waveforms

  Assessed across three study visits over approximately 4 weeks.

• Mean EMG amplitude

  Assessed across three study visits over approximately 4 weeks.

Study Arms (1)

Children with cerebral palsy

Children with spastic cerebral palsy, aged 5-12 years, GMFCS levels I-III

Eligibility Criteria

• Age: 5 Years - 12 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)
• Sampling Method: Non-Probability Sample

Study Population

Children with spastic cerebral palsy, who have routine follow-up care at the CP reference center of the university hospitals Leuven

You may qualify if:

• Confirmed diagnosis of spastic cerebral palsy
• GMFCS level I - III
• At least 3 months post-injection with Botulinum neurotoxin in muscles relevant to the target or compensatory activation patterns (rationale: there is no expected residual neuromuscular effect of Botulinum neurotoxin injections on muscle activation patterns ≥3 months post Botulinum neurotoxin injection)
• ≥12 months post lower-limb orthopaedic surgery

You may not qualify if:

• Dyskinetic or ataxic cerebral palsy
• Severe spasticity (Modified Ashworth ≥3)
• Severe bony deformities or comorbidities precluding valid assessments
• Insufficient ability to understand instructions or cooperate with the assessment procedures.

Sponsors & Collaborators

• Universitaire Ziekenhuizen KU Leuven: lead

Study Sites (1)

UZ Leuven

Leuven, Vlaams-Brabant, 3000, Belgium

Location

MeSH Terms

Conditions

Cerebral Palsy

Condition Hierarchy (Ancestors)

Brain Damage, Chronic; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases

Study Officials

• Kaat Desloovere, Prof. dr.

  Department of Rehabilitation Sciences, KU Leuven, Belgium

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Jolien Vanloocke

CONTACT

+32 16 34 10 16; jolien.vanloocke@kuleuven.be

Julie Stegen

CONTACT

julie.stegen@kuleuven.be

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Prof. dr.

Study Record Dates

• First Submitted: August 24, 2026
• First Posted: September 2, 2026
• Study Start: September 1, 2026
• Primary Completion (Estimated): February 28, 2029
• Study Completion (Estimated): February 28, 2029
• Last Updated: September 2, 2026

Record last verified: 2026-08

Locations

BE (1)