Table 1 Inclusion and exclusion criteria

Age 8–24 years

Diagnosis of spastic diplegic or hemiplegic CP

GMFCS classification level I or II (ability to walk independently with using any assistive device)

Visual, perceptual, and cognitive/ communication skills to follow multiple step commands

Seizure-free or well controlled seizures

Ability to communicate pain or discomfort during testing procedures

Parental/guardian consent and child assent/consent

Diagnosis of athetoid, ataxic or quadriplegic CP

Significant scoliosis (scoliometer angle > 9°)

History of selective dorsal root rhizotomy

Botox injections in the lower limb within the past 6 months

Severe spasticity of the lower extremity muscles (e.g. a score of 4 on the Modified Ashworth Scale)

Severely limited range of motion/irreversible muscle contractures

Lower extremity surgery or fractures in the year prior testing^*

Joint instability or dislocation in the lower extremities^*

Marked visual or hearing deficits^*