Trial Outcomes & Findings for Short Term Follow-up of a Botulinum Toxin Intervention in Children With Spastic Cerebral Palsy (NCT NCT05126693)

NCT ID: NCT05126693

Last Updated: 2025-07-31

Results Overview

Estimation of the muscle belly volume by three-dimensional freehand ultrasonography normalized to the product of body weight and height

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 61 participants
• Primary outcome timeframe: Between baseline and 8-10 weeks after the BoNT injections for the intervention group, and between baseline and 8-10 weeks later for the control group.
• Results posted on: 2025-07-31

Participant Flow

Participant milestones

Measure	Intervention Group The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Pre-BoNT/ Pre-3DfUS STARTED	31	30
Pre-BoNT/ Pre-3DfUS COMPLETED	25	20
Pre-BoNT/ Pre-3DfUS NOT COMPLETED	6	10
8-10w Post-BoNT/ 8-10w Post-3DfUS STARTED	25	20
8-10w Post-BoNT/ 8-10w Post-3DfUS COMPLETED	25	20
8-10w Post-BoNT/ 8-10w Post-3DfUS NOT COMPLETED	0	0

Reasons for withdrawal

Measure	Intervention Group The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Pre-BoNT/ Pre-3DfUS Bad 3DGA data	2	0
Pre-BoNT/ Pre-3DfUS No 3DGA	4	0
Pre-BoNT/ Pre-3DfUS Insufficient matching	0	10

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group n=20 Participants This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.	Total n=45 Participants Total of all reporting groups
Age, Categorical <=18 years	25 Participants n=25 Participants	20 Participants n=20 Participants	45 Participants n=45 Participants
Age, Categorical Between 18 and 65 years	0 Participants n=25 Participants	0 Participants n=20 Participants	0 Participants n=45 Participants
Age, Categorical >=65 years	0 Participants n=25 Participants	0 Participants n=20 Participants	0 Participants n=45 Participants
Age, Continuous	6.4 Years n=25 Participants	7.6 Years n=20 Participants	7.1 Years n=45 Participants
Sex: Female, Male Female	12 Participants n=25 Participants	4 Participants n=20 Participants	16 Participants n=45 Participants
Sex: Female, Male Male	13 Participants n=25 Participants	16 Participants n=20 Participants	29 Participants n=45 Participants
Race and Ethnicity Not Collected	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Region of Enrollment Belgium	25 participants n=25 Participants	20 participants n=20 Participants	45 participants n=45 Participants

PRIMARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections for the intervention group, and between baseline and 8-10 weeks later for the control group.

Population: Semitendinosus: Intervention group: n = 24 \< 25 due to bad quality data Control group: n = 19 \< 20 due to bad quality data

Estimation of the muscle belly volume by three-dimensional freehand ultrasonography normalized to the product of body weight and height

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group n=20 Participants This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in Normalized Muscle Volume of the Medial Gastrocnemius and the Distal Compartment of the Semitendinosus Medial Gastrocnemius	-0.08 ml/kg*m Interval -0.16 to 0.04	0.00 ml/kg*m Interval -0.09 to 0.06
Change in Normalized Muscle Volume of the Medial Gastrocnemius and the Distal Compartment of the Semitendinosus Semitendinosus	-0.09 ml/kg*m Interval -0.16 to 0.01	-0.01 ml/kg*m Interval -0.07 to 0.04

PRIMARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections for the intervention group, and between baseline and 8-10 weeks later for the control group.

Population: Semitendinosus: Intervention group: n = 24 \< 25 due to bad quality data Control group: n = 19 \< 20 due to bad quality data

Estimation of the echogenicity intensity of the whole muscle volume by three-dimensional freehand ultrasonography. Echogenicity is expressed in arbitrary units ranging from 0 to 255. Higher values indicate lighter images, which indirectly suggests the presence of more non-contractile muscle tissue.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group n=20 Participants This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in Echogenicity Intensity of the Medial Gastrocnemius and the Distal Compartment of the Semitendinosus Medial Gastrocnemius	2.74 Arbitrary units ranging from 0 to 255 Interval -5.63 to 11.11	-0.08 Arbitrary units ranging from 0 to 255 Interval -3.77 to 9.33
Change in Echogenicity Intensity of the Medial Gastrocnemius and the Distal Compartment of the Semitendinosus Semitendinosus	6.58 Arbitrary units ranging from 0 to 255 Interval -8.27 to 16.61	5.20 Arbitrary units ranging from 0 to 255 Interval -6.9 to 11.9

PRIMARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections for the intervention group, and between baseline and 8-10 weeks later for the control group.

Population: Semitendinosus: Intervention group: n = 24 \< 25 due to bad quality data Control group: n = 19 \< 20 due to bad quality data

Estimation of the absolute muscle volume growth rate, calculated by: (muscle volume (mL)post-muscle volume pre)/(age (months)post-age (months)pre)

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group n=20 Participants This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Absolute Muscle Volume Growth Rate of the Medial Gastrocnemius and the Distal Compartment of the Semitendinosus Medial Gastrocnemius	0.00 ml/month Interval -1.34 to 0.97	0.17 ml/month Interval -0.23 to 0.87
Absolute Muscle Volume Growth Rate of the Medial Gastrocnemius and the Distal Compartment of the Semitendinosus Semitendinosus	-0.49 ml/month Interval -1.45 to 0.58	0.02 ml/month Interval -0.39 to 0.48

PRIMARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections

Population: Control group: 3DGA was not performed

Estimation of the kinematic parameters throughout the whole gait cycle by three-dimensional gait analysis.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in Kinematic Parameters Ankle Angle in Sagittal Plane at Initial Contact	3.56 Degrees Interval 0.47 to 6.36	—
Change in Kinematic Parameters Maximal Ankle Angle in Sagittal Plane During Stance Phase	3.99 Degrees Interval -0.32 to 9.99	—
Change in Kinematic Parameters Maximal Ankle Angle in Sagittal Plane During Swing Phase	5.34 Degrees Interval 1.16 to 9.7	—
Change in Kinematic Parameters Knee Range of Motion in Sagittal Plane	1.94 Degrees Interval -3.79 to 8.84	—
Change in Kinematic Parameters Knee Angle in Sagittal Plane at Initial Contact	-1.69 Degrees Interval -9.19 to 1.84	—
Change in Kinematic Parameters Minimal Knee Angle in Sagittal Plane During Stance	-2.44 Degrees Interval -7.61 to 2.23	—
Change in Kinematic Parameters Ankle Range of Motion in Sagittal Plane	-1.74 Degrees Interval -9.04 to 3.07	—

PRIMARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections

Population: Control group: 3DGA was not performed

The Gait Profile Score (GPS) is a summary measure derived from three-dimensional gait analysis that quantifies the overall deviation of a patient's gait kinematics from a normative (typically developing) reference dataset. It is calculated as the root mean square difference between the patient's joint angle trajectories of the lower limb and the corresponding mean trajectories of typically developing individuals across a gait cycle. The GPS is expressed in degrees and is based on nine key kinematic variables: pelvic tilt, obliquity, rotation; hip flexion, abduction, rotation; knee flexion; ankle dorsiflexion; and foot progression angle, typically for both left and right sides. It provides a global index of gait abnormality, where lower scores indicate gait patterns closer to normal, and higher scores reflect greater kinematic deviation.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in Gait Profile Score (Degrees)	-1.76 Degrees Interval -2.51 to -0.15	—

PRIMARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections

Population: Control group: 3DGA was not performed

Estimation of the cadence by three-dimensional gait analysis.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in the Spatial-temporal Parameter "Cadence".	-0.05 Number of steps/second Interval -0.28 to 0.1	—

PRIMARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections

Population: Control group: 3DGA was not performed

Estimation of the walking velocity by three-dimensional gait analysis.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in the Spatial-temporal Parameter "Walking Velocity".	0.01 Meter/second Interval -0.1 to 0.1	—

PRIMARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections

Population: Control group: 3DGA was not performed

Estimation of the stride length by three-dimensional gait analysis.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in the Spatial-temporal Parameter "Stride Length".	0.02 Meters Interval -0.03 to 0.08	—

PRIMARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections

Population: Control group: ISA was not performed n (medial hamstrings) = 13 \< 14 due to insufficient cooperation

Muscle activity of the medial gastrocnemius and the medial hamstrings as recorded by surface electromyography (millivolts) during a passive stretch at high velocity of the plantar flexors and the hamstrings.

Outcome measures

Measure	Intervention Group n=14 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in Spasticity of the Medial Gastrocnemius and the Medial Hamstrings Medial Gastrocnemius	-4.73 µV Interval -15.74 to 1.31	—
Change in Spasticity of the Medial Gastrocnemius and the Medial Hamstrings Medial Hamstrings	-2.82 µV Interval -7.64 to 0.21	—

SECONDARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections for the intervention group, and between baseline and 8-10 weeks later for the control group.

Estimation of the muscle tendon unit length by three-dimensional freehand ultrasonography, expressed as a percentage of total leg length.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group n=20 Participants This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in Normalized Muscle Tendon Unit Length of the Medial Gastrocnemius	0.88 a percentage of total leg length Interval -0.22 to 1.59	-0.35 a percentage of total leg length Interval -0.86 to 0.52

SECONDARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections for the intervention group, and between baseline and 8-10 weeks later for the control group.

Population: Semitendinosus: Intervention group: n = 24 \< 25 due to bad quality data Control group: n = 19 \< 20 due to bad quality data

Estimation of the muscle belly length by three-dimensional freehand ultrasonography, expressed as a percentage of total leg length.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group n=20 Participants This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in Normalized Muscle Belly Length of the Medial Gastrocnemius and the Distal Compartment of the Semitendinosus Medial Gastrocnemius	0.44 a percentage of total leg length Interval 0.03 to 1.25	-0.13 a percentage of total leg length Interval -0.92 to 0.71
Change in Normalized Muscle Belly Length of the Medial Gastrocnemius and the Distal Compartment of the Semitendinosus Semitendinosus	-0.32 a percentage of total leg length Interval -0.9 to 1.47	-0.22 a percentage of total leg length Interval -0.74 to 0.83

SECONDARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections for the intervention group, and between baseline and 8-10 weeks later for the control group.

Estimation of the tendon length by three-dimensional freehand ultrasonography, expressed as a percentage of total leg length.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group n=20 Participants This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in Normalized Tendon Length of the Medial Gastrocnemius	-0.03 a percentage of total leg length Interval -0.88 to 1.17	-0.26 a percentage of total leg length Interval -0.55 to 0.24

SECONDARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections for the intervention group, and between baseline and 8-10 weeks later for the control group.

Population: Semitendinosus: Intervention group: n = 24 \< 25 due to bad quality data Control group: n = 19 \< 20 due to bad quality data

Estimation of the normalized muscle volume growth rates, calculated by (Normalized muscle volume (mL/kg*m)post-Normalized muscle volume pre (mL/kg*m))/(age (months)post-age (months)pre)

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group n=20 Participants This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Normalized Muscle Volume Growth Rates of the Medial Gastrocnemius and the Distal Compartment of the Semitendinosus Medial Gastrocnemius	-0.02 ml/kg*m/month Interval -0.07 to 0.03	0.01 ml/kg*m/month Interval -0.04 to 0.02
Normalized Muscle Volume Growth Rates of the Medial Gastrocnemius and the Distal Compartment of the Semitendinosus Semitendinosus	-0.02 ml/kg*m/month Interval -0.08 to 0.01	-0.00 ml/kg*m/month Interval -0.03 to 0.02

SECONDARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections

Population: Control group: 3DGA was not performed

Estimation of ankle range of motion in sagittal plane during stance phase by three-dimensional gait analysis.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in the Kinematic Parameter "Ankle Range of Motion in Sagittal Plane During Stance Phase"	0.31 Degrees Interval -4.38 to 3.74	—

SECONDARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections

Population: Control group: 3DGA was not performed

Estimation of knee range of motion in sagittal plane during stance phase by three-dimensional gait analysis.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in the Kinematic Parameter "Knee Range of Motion in Sagittal Plane During Stance Phase"	3.68 Degrees Interval -0.43 to 6.91	—

SECONDARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections

Population: Control group: ISA was not performed n (medial hamstrings) = 13 \< 14 due to insufficient cooperation

Calculated by subtracting the muscle activation during a low-velocity stretch. Muscle activity of the medial gastrocnemius and Medial Hamstrings is recorded by surface electromyography (millivolts) during a passive stretch of the plantar flexors and of the hamstrings.

Outcome measures

Measure	Intervention Group n=14 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change in Muscle Activation of the Medial Gastrocnemius and the Medial Hamstrings (i.e. the Change During the High-velocity Stretch). Medial Gastrocnemius	-2.64 µV Interval -8.06 to 2.48	—
Change in Muscle Activation of the Medial Gastrocnemius and the Medial Hamstrings (i.e. the Change During the High-velocity Stretch). Medial Hamstrings	-3.13 µV Interval -5.78 to 0.87	—

SECONDARY outcome

Timeframe: Between baseline and 8-10 weeks after the BoNT injections

Population: A standardized clinical examination was performed during the pre- and post-BoNT-A assessments of the intervention group and during the pre-assessment of the control group. These data were used to describe and compare both groups at baseline.

Evaluation by goniometry expressed in degrees. For the ankle plantar flexion range of motion with the knee extended, for the hamstrings unilateral popliteal angle.

Outcome measures

Measure	Intervention Group n=25 Participants The children in the intervention group will receive BoNT injections in the medial gastrocnemius and/or the semitendinosus muscle(s). As part of the standard treatment approach of the CP Reference Centre of the University Hospitals Leuven, the injections are followed by a period of bilateral stretching casts if indicated (below the knee walking casts and removable knee extension casts when necessary). All children will then undergo an intensive physical therapy program lasting 8-10 weeks. This post-BoNT therapy phase is guided by individualized treatment goals, which are established based on baseline assessments. These goals are determined during a multidisciplinary meeting with the treating physician, held prior to the BoNT injections. Thus, the intervention consists of BoNT treatment combined with an 8-10 week period of intensive physical therapy tailored to each child's specific therapeutic needs.	Control Group This group will continue their usual care or normal routine treatment, i.e. physiotherapy and orthotic management during a period of 8-10 weeks.
Change of Range of Motion in the Ankle and Knee Joint Plantar flexors	0.0 Degrees Interval 0.0 to 5.0	—
Change of Range of Motion in the Ankle and Knee Joint Hamstrings	0.0 Degrees Interval -0.5 to 1.3	—

Adverse Events

Intervention Group

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Control Group

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Prof. dr. Kaat Desloovere

KU Leuven

Phone: +32 486 40 13 73

Email: kaat.desloovere@kuleuven.be

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place