Scientists probe tiny muscle changes to help kids with cerebral palsy

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

CHILDREN WITH CP Inclusion criteria * Children (boys/girls) diagnosed with predominantly spastic type of CP * Uni- or bilateral involvement * Gross Motor Function Classification Scale (GMFCS) Level I-III50 * 2 to 9 years of age * Planned for an orthopedic intervention that requires general anesthesia (botulinum toxin injections, orthopedic surgery, or diagnostic imaging such as Magnetic Resonance Imaging \[MRI\], etc.) Exclusion criteria * Presence of dystonia or ataxia * Previous surgery less than 6 months at the investigated muscles * Severe co-morbidities (that are likely to prevent proper assessment, such as severe cognitive problems) TYPICALY DEVELOPING CHILDREN Inclusion criteria * Children (boys/girls) * 2 to 9 years of age * Planned for a surgical intervention that requires general anesthesia (pure pediatric upper limb orthopedic surgery or trauma surgery, or ophthalmic or ear-nose-throat surgery) Exclusion criteria * History of neurological problems * History of orthopedic problems at the gastrocnemius or semitendinosus * Trauma at the level of the lower limbs * Involvement in an elite or high-performance sporting program (Children performing sports for \> 3 5 hours/week will be excluded) ADOSESCENTS WITH HSP of 12-18 years old and ADULTS WITH HPS Inclusion criteria * Adolescents (boys/girls) or adults (male/female) diagnosed with HSP, SPG3a or SPG4 * Gross Motor Function Classification Scale (GMFCS) Level I-III50 * Adolescents 12 to 18 years or adults 18-40 years of age Exclusion criteria * Presence of dystonia or ataxia * Previous surgery less than 6 months at the investigated muscles * Severe co-morbidities (that are likely to prevent proper assessment, such as severe cognitive problems) TYPICALLY DEVELOPING ADOLESCENTS of 12-18 years old and HEALTHY ADULTS (age- and gender-matched with the recruited HSP patients) Inclusion criteria * Typically developing adolescents (boys/girls) and healthy adults (male/female), who are age and gender matched with the recruited HSP participants * Adolescents 12-18 years of age or adults 18-40 years of age Exclusion criteria * History of neurological problems * History of orthopedic or muscular problems at the gastrocnemius * Trauma at the level of the lower limbs * Involvement in an elite or high-performance sporting program (participants performing sports for \> 5 hours/week will be excluded) * Sport session less than 72 hours prior to the biopsy collection