Exoskeleton-assisted Physiotherapy for Children With Mobility Impairments

Inclusion Criteria: * Weight of 50-100 lbs (23- 46 kgs), leg length (hip to floor): 40-56c * GMFCS Level IV equivalent * Knee and hip range of motion sufficient to allow exoskeleton fit (see exclusion criteria) * Able to follow GMFM testing instructions, and able to participate in a minimum of 30 minutes of active PT * Able to reliably signal pain, fear and discomfort * At least 2 months after any lower limb Botulinum Toxin (BTX) injections * Will be safe for BTX to be put on hold during their study participation (i.e., a period of 6 months which is equivalent to one BTX treatment cycle). Exclusion Criteria: * Any weightbearing restrictions * Fixed knee contracture (passive) \> 20 degrees, knee valgus \>40 degrees such that orthosis will not be adaptable to lower limbs. Note: Fixed hip and ankle contractures in themselves are not a contraindication for Trexo * Hip subluxation \> 40% unless with orthopedic clearance for weight bearing with the Trexo * Orthopaedic surgery within the last 9 months (if muscle) or 12 months (if bone) * Severe spasticity may be a contraindication (still OK to consider) * Seizure disorder that is not controlled by medication. For a child on seizure medication, must not have had a seizure in the last 12 months (as verified by the child's treating physician) * Open skin lesions or vascular disorder of lower extremities * Osteogenesis imperfecta * Not able to co-operate for positioning/adjustments within the Trexo * Involved in another intervention study (any type). May be concurrently enrolled though in a single point assessment study (e.g., annual follow-up of status, measurement study)