Table 1 Participant, diagnosis, intervention, duration, outcome measures, and results

Study

Participant

Diagnosis

Intervention

Duration

Outcome measure

Results

Rayn et al. [37]

N = 64

(Exp.gp = 33, Con.gp = 31)

Age (yrs:m) mean (±SD):

Exp.gp= 13:6 (2:7), Con.gp= 13:11 (2:6)

Spastic CP, ([GMFCS] levels I–III)

Resistance group: ankle plantar flexors (primarily gastrocnemius) exercises

Over a 10-week period, the intensity of exercise increased progressively according to a standardized programme, with sets increasing from 4 to 8. Each session’s resistance was increased until the fatigue level was reached, indicating that the exercise was being performed at the recommended intensity.

Completed 10 supervised sessions and 20 home sessions of resistance training over 10 weeks

Plantar flexors strength [Nm]

NS

GMFM-66 dimension E, %

NS

GMFM-66 dimension D, %

NS

Gait speed [m s⁻¹]

NS

Kalkman et al. [38]

N = 22

(Exp.gp=12, Con.gp=10)

Age (years) 7–14

Spastic CP, ([GMFCS] levels I–III)

Exercises were performed 4 times a week, of which the principal investigator supervised one session and 3 were performed at home.

Intervention group: 4 weeks of calf muscle strengthening exercises, followed by 6 weeks of calf muscle stretching and strengthening exercises. 3 sets of 12 repetitions, reaching volitional fatigue at the end of each set

10 weeks

Plantar flexors strength

P = 0.009*

Dorsiflexion angle

NS

Ankle angle at resting length

NS

Ankle angle at lengthening position shifted towards plantar flexion

P=0.03*

Resting gastrocnemius muscle length

NS

Resting gastrocnemius fascicle length

P = 0.02*

Gastrocnemius muscle and tendon length after intervention

NS

Achilles Tendon stiffness

P = 0.04*

Hosl et al. [39]

N = 10

(BDTT.gp=5, Stretch.gp=5)

Age (yrs) mean (±SD): 12 (±4)

Spastic CP, ([GMFCS] levels I–II)

Two treatments and two crossover designs were used. Each one required a 9-week treatment period (3 sessions per week), which was preceded by a 5-week passive run-in and wash-out period.

Static calf stretching: 7 exercises referring to Morrel and Lau. Exercises were alternately ended with 5 repetitions per leg and end-range positions were held for 20 s.

Backward Downhill Treadmill Training (BDTT): Eccentric exercise backward-downhill treadmill training (BDTT). From the second week, the load was gradually increased by using a belt speed, a decline slope, and a weight belt. Participants were instructed to take large steps, maintain an erect posture, and limit their use of the handrail.

9 weeks

Peak plantar flexion moment [Nm/kg]

NS

Peak plantar flexion power [W/kg]

NS

Peak dorsiflexion stance [°]

NS

Peak dorsiflexion swing [°]

NS

Comfortable walking speed

• Knee flexion angle in swing phase [°]

• Mean dorsiflexion single stance [°]

• P=0.037*

• P=0.041*

Fastest possible walking speed

• Knee flexion angle in swing phase [°]

• Velocity [m/s]

• Cadence [steps/min]

• Peak gastrocnemius muscle-tendon unit velocity (GAS vel.) swing [cm/s]

• P=0.003*

• P=0.017*

• P=0.004*

• P=0.023*

Mean knee flexion single stance [°], step length [cm], mean toe clearance [cm]

NS

Functional ambulatory mobility tests

• GMFM D, E [Score 0–100]

• Timed-Up-and-Go [sec]

• Clinical spasticity assessment

NS

Active ankle-joint assessments

Peak moment [Nm]

NS

Passive ankle-joint assessments

• . Peak dorsiflexion [°]

• Dorsiflexion at fixed moment [°]

• Peak moment [Nm]

• Joint stiffness [Nm/°]

NS

Muscle-tendon properties medial gastrocnemius morphometrics [at rest]

• Fascicle angle [°]

• Thickness [cm]

• Fascicle length [cm]

• Muscle length [cm]

• Tendon length [cm]

NS

Total strain in medial gastrocnemius [resting length to max. length]

• Fascicle [%]

• Muscle belly [%]

• Tendon [%]

NS

Passive resistive ankle stiffness [between 20 and 80% common passive joint moment]

• Tendon [Nm/cm]

• Muscle belly [Nm/cm]

NS

Kruse et al. [40]

N = 27

(PRT.gp = 12, HICT.gp = 15)

Age (yrs:m) mean (±SD): 12:8 (±2:6)

Spastic CP, ([GMFCS] levels I–II)

Progressive resistance training (PRT): For 8 weeks, perform 3 times a week. Warm up for 10 min and cool down for 5 min. In between, 5 functional lower extremity exercises (sit-to-stand, heel raises, forward lunges, lateral step-up, and bridging) are performed in 3 circuits with 10–12 repetitions. The exercises were performed in a controlled manner at a slow to moderate speed for 2 min. Take a break between sets. The training load was gradually increased using a weight vest and a 10 repetitions maximum test.

High-Intensity Circuit Training (HICT): The warm-up, cool-down, and functional exercises were the same as in PRT, but the exercise load was defined by the number of repetitions that could be completed within a 30-s interval. A break period of 30 s was provided.

8 weeks

Plantar flexor strength

P=0.01*

Ankle joint ROM [°]

NS

Maximum dorsiflexion [°]

NS

Maximum plantar flexion [°]

S*

Resting angle [°]

NS

Absolute plantar flexor muscle-tendon unit length

NS

Gastrocnemius muscle belly length

NS

Gastrocnemius fascicle length

NS

Pennation angle

NS

Gastrocnemius thickness

NS

Vastus lateralis thickness

P = 0.01*

Rectus femoris thickness

P = 0.004*

Achilles tendon length

NS

Achilles tendon cross-sectional area, mm²

NS

Peak passive ankle torque, N·m

NS

Peak active ankle torque

NS

Achilles tendon elongation, mm

NS

Achilles tendon stiffness, N/mm

NS

Achilles tendon strain, %

NS

Achilles tendon stress, N/mm²

NS

Achilles tendon moment arm

NS

Young modulus N/mm²

NS

Bohm et al. [40]

N=8

(Exp.gp=4, Con.gp=4)

Age (yrs:m) mean (±SD): 13:0 (±4:3)

Spastic CP, ([GMFCS] levels I–III), manual ability classification MACS (ǀ - ‖).

The training protocol designed for the beginners over the 6-week training.

1st week: wand and safety gear

2nd week: bring the centre of gravity towards the wall

3rd week: stabilize at the wall

4th week: strength training

5th week: climb down the wall

6th week: all techniques practised

A wash-out period of 4 weeks without therapy before the start of the study and between the two interventions

6 weeks

Ankle dorsiflexion angle [°]

NS

Knee flexion angle [°]

P=0.039*

Hip internal rotation angle [°]

NS

Speed

NS

Step length

NS

Step time

NS

Gait profile score (GPS) [°]

NS

Scholtes et al. [41]

N = 51

(Exp.gp=26, Con.gp=25)

Age (yrs:m) mean (±SD):

Exp.gp: 10:4 (1:10)

Con.gp: 10:3 (2:3)

Spastic CP, ([GMFCS] levels I–III)

Functional Progressive Resistance Exercise training (PRE-training) exercises for 12 weeks. Every session consists of:

• One exercise on a child-adapted leg press

• Three functional exercises (sit-to-stand, lateral step-up, half knee-rise), loaded with a weighted vest

The intensity was gradually increased. 3 times a week, the children do 3 sets of 8 repetitions. Each session lasted 60 min and is held in small groups of 4–5 children at school.

12 weeks

Ankle plantar flexors strength (N/kg)

NS

Knee extensors strength (N/kg)

NS

IN (T2) P = 0.01*

Knee flexors strength (N/kg)

NS

Total strength (hip extensors, flexors, and abductors, knee extensors and flexors, and ankle plantar flexors) (N/kg)

NS

In (T2) = 0.04*

Anaerobic muscle power (W/kg)

NS

ROM of gastrocnemuis (°)

NS

ROM of soleus (°)

NS

Step length (m)

NS

Cadence (steps/min)

NS

Comfortable walking speed (m/s)

NS

Fast walking speed (m/s)

NS

Timed stair test (m)

NS

Dodd et al. [42]

N=21

(Exp.gp=11, Con.gp=10)

Age (yrs:m) mean (±SD): 13 :1 (±3:1)

Spastic diplegic CP

Strength training exercise: 3 exercises that target ankle plantar flexors, knee extensors, hip extensors.

1) Bilateral heel rises

2) Bilateral half squats

3) Step-ups

After adjusting the initial load, the participants were instructed to perform 3 sets of 8 to 10 repetitions of each exercise 3 times a week for 6 weeks. Each session lasted between 20 and 30 min. The training load was adjusted by adding free weights to the child’s backpack.

6 weeks

Ankle plantar flexors

NS

Knee extensors strength

NS

Combined ankle plantar flexors, knee extensors strength

Total extensors strength (ankle plantar flexors, knee extensors, hip extensors)

NS

GMFM D, %

NS

GMFM E, %

NS

GMFM total, %

NS

Walking speed, m/min

NS

Timed stair, s

NS