Interaction Between Spasticity and the Initial Response After Balance Perturbations in Children With Spastic Cerebral Palsy

NCT07616193 | Completed

• 1 other identifier: S63321
• Study Type: observational
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of this study was to investigate the link between spasticity and the initial response after standing balance perturbations in children with spastic cerebral palsy. Reactive balance performance was tested using a moving platform. The investigators provided two types of perturbations, (1) backward translations and (2) rotations towards dorsiflexion, of different magnitudes. Spasticity was assessed using instrumented clinical tests of spasticity as the pendulum test and isolated passive joint rotations. Kinematics and EMG were measured simultaneously.

Conditions

Cerebral Palsy (CP); Typically Developing Children

Keywords

spastic cerebral palsy; Reactive balance; muscle co-activation; neurological impairment; Sensorimotor processing; Center of mass feedback; Balance control

Outcome Measures

Primary Outcomes (10)

• Balance performance

  The number (#) of completed perturbation levels (backward translational and toe-up rotational) without stepping.

  Cross-sectional data collection at a single time point (baseline measurement).

• Maximal horizontal center of mass displacement

  The maximal horizontal Center of Mass (CoM) displacement (cm) is computed in a period of 1.5s following perturbation onset. CoM position is computed by consequently applying OpenSim's Inverse Kinematics and Body Kinematics tools with reflective marker trajectories as input. CoM displacement was calculated relative to the ankle.

  Cross-sectional data collection at a single time point (baseline measurement).

• Goodness of fit between predicted and reconstructed muscles activity - R²

  Computational model; Sensorimotor transformations were evaluated by reconstructing measured EMG trajectories (V) by delayed feedback from CoM kinematics. EMGrecon=e0+⌊kd∗dCoM(t -τ)+kv∗vCoM(t -τ)+ka∗aCoM(t -τ)+ks ∗aCoM Init(t -τ)⌋ with EMG recon = reconstructed muscle activity E0 = baseline muscle activity (during quiet standing) dCoM, vCoM, aCoM = CoM displacement, velocity and acceleration kd, kv, ka = feedbakc gains or weights τ = common time delay of 100 ms To test whether CoM feedback can explain reactive muscle activity, the goodness of fit was assessed between predicted and reconstructed muscle activity using the coefficient of determination (r²). R² was calculated as the squared correlation coefficient.

  Cross-sectional data collection at a single time point (baseline measurement)

• Goodness of fit between predicted and reconstructed muscles activity - VAF

  Computational model; Sensorimotor transformations were evaluated by reconstructing measured EMG trajectories (V) by delayed feedback from CoM kinematics. EMGrecon=e0+⌊kd∗dCoM(t -τ)+kv∗vCoM(t -τ)+ka∗aCoM(t -τ)+ks ∗aCoM Init(t -τ)⌋ with EMG recon = reconstructed muscle activity E0 = baseline muscle activity (during quiet standing) dCoM, vCoM, aCoM = CoM displacement, velocity and acceleration kd, kv, ka = feedbakc gains or weights τ = common time delay of 100 ms To test whether CoM feedback can explain reactive muscle activity, the goodness of fit was assessed between predicted and reconstructed muscle activity using the Variance Accounted For (VAF). VAF was calculated as the uncentered r²

  Cross-sectional data collection at a single time point (baseline measurement)

• Goodness of fit between predicted and reconstructed muscles activity - RMSE

  Computational model; Sensorimotor transformations were evaluated by reconstructing measured EMG trajectories (V) by delayed feedback from CoM kinematics. EMGrecon=e0+⌊kd∗dCoM(t -τ)+kv∗vCoM(t -τ)+ka∗aCoM(t -τ)+ks ∗aCoM Init(t -τ)⌋ with EMG recon = reconstructed muscle activity E0 = baseline muscle activity (during quiet standing) dCoM, vCoM, aCoM = CoM displacement, velocity and acceleration kd, kv, ka = feedbakc gains or weights τ = common time delay of 100 ms To test whether CoM feedback can explain reactive muscle activity, the goodness of fit was assessed between predicted and reconstructed muscle activity using the Root Mean Square Error (RMSE).

  Cross-sectional data collection at a single time point (baseline measurement)

• Sensitiviy of reactive muscle activity to CoM perturbations - gains

  Computational model; Sensorimotor transformations were evaluated by reconstructing measured EMG trajectories (V) by delayed feedback from CoM kinematics. EMGrecon=e0+⌊kd∗dCoM(t -τ)+kv∗vCoM(t -τ)+ka∗aCoM(t -τ)+ks ∗aCoM Init(t -τ)⌋ with EMG recon = reconstructed muscle activity E0 = baseline muscle activity (during quiet standing) dCoM, vCoM, aCoM = CoM displacement, velocity and acceleration kd, kv, ka = feedbakc gains or weights τ = common time delay of 100 ms To test the sensitivity of the reactive muscle activity to the CoM perurbations, the gains (kd,kv,ka) were assessed. Gains indicate the sensitivity of the muscle response to CoM perturbations.

  Cross-sectional data collection at a single time point (baseline measurement)

• Mean reactive muscle activity

  Average reactive muscle activity for * lateral gastrocnemius * medial gastrocnemius * soleus * tibialis anterior was computed in three time bins. Reactive muscle activity was calculated by subtracting baseline activity, i.e. average muscle activity in the 100 ms preceding perturbation onset, from the filtered and scaled EMG. The first time bin lasted from platform onset to 150 ms after perturbation onset. The second time bin lasted from 150 ms to 250 ms after perturbation onset. The third time bin lasted from 250 ms to 400 ms after perturbation onset.

  Cross-sectional data collection at a single time point (baseline measurement).

• Mean center of mass movement

  Average horizontal center of mass movement (cm) was computed in three time bins. The first time bin lasted from platform onset to 50 ms after perturbation onset. The second time bin lasted from 50 ms to 150 ms after perturbation onset. The third time bin lasted from 150 ms to 300 ms after perturbation onset.

  Cross-sectional data collection at a single time point (baseline measurement).

• Mean ankle kinematics

  Average ankle kinematics (°) was computed in three time bins. The first time bin lasted from platform onset to 50 ms after perturbation onset. The second time bin lasted from 50 ms to 150 ms after perturbation onset. The third time bin lasted from 150 ms to 300 ms after perturbation onset.

  Cross-sectional data collection at a single time point (baseline measurement).

• Co-Contraction Index (CCI) during translational and rotational perturbations and during isolated joint rotations

  The co-contraction index was calculated as the minimum tibialis anterior and respectively lateral gastrocnemius, medial gastrocnemius and soleus filtered and scaled EMG averaged over the time interval of interest. CCI was calculated during backward translational, toe-up rotational perturbations and during isolated joint rotations.

  Cross-sectional data collection at a single time point (baseline measurement).

Study Arms (2)

Children with cerebral palsy

Children with CP aged between 5 and 17

Typically developing children

Typically developing children aged between 5 and 17

Eligibility Criteria

• Age: 5 Years - 17 Years
• Sex: all
• Healthy Volunteers: Yes
• 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. Typically developing children are recruited through the social and professional network of involved researchers and thesis studies, who approach participants through flyers and social media.

You may qualify if:

• Diagnosis of cerebral palsy
• Spasticity as defined by clinical assessment
• Aged between 5-17 years old
• Gross motor classification scale I-III
• Able to stand independently for at least 10 minutes

You may not qualify if:

• Orthopedic/neurological surgery in the previous year
• Botulinum neurotoxin injections in the past 6 months
• Presence of ataxia or dystonia
• Cognitive problems that impede measurements
• Severe co-morbidities
• Typically developing children:
• Aged between 5 and 17 years old
• Good health
• Presence of neuro-musculoskeletal or vestibular diseases
• Lower limb injuries during the past 6 months
• Irritated skin or open wounds where sensors will be placed (CP en TD)

Sponsors & Collaborators

• KU Leuven: collaborator
• Universitaire Ziekenhuizen KU Leuven: lead

Study Sites (1)

UZ Leuven

Leuven, Vlaams-Brabant, 3000, Belgium

Location

MeSH Terms

Conditions

Cerebral Palsy; Neurologic Manifestations

Condition Hierarchy (Ancestors)

Brain Damage, Chronic; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Kaat Desloovere, Prof. dr.

  Department of Rehabilitation Sciences, KU Leuven, Belgium

  PRINCIPAL INVESTIGATOR

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: May 8, 2026
• First Posted: June 1, 2026
• Study Start: March 13, 2020
• Primary Completion: August 30, 2021
• Study Completion: August 30, 2021
• Last Updated: June 1, 2026

Record last verified: 2026-04

Locations

BE (1)