The aim of this study is to compare the effects of synchronous and asynchronous action observation therapy (AOT) on balance, gait, and functional capacity in children with cerebral palsy (CP). CP is a neurodevelopmental disorder characterized by impairments in motor skills, particularly motor control and postural balance. By examining the contributions of synchronous (real-time) and asynchronous (delayed) AOT methods to motor performance, this study seeks to identify the most effective therapeutic approach for this population.

Cerebral palsy (CP) is defined as a non-progressive neurological disorder that arises during fetal development, the neonatal period, or early childhood and results in permanent motor impairments. Lesions in the central nervous system of children with CP lead to a range of musculoskeletal, neuromuscular, and sensory system problems, causing postural abnormalities, balance and coordination deficits, and limitations in mobility. These impairments significantly reduce independence in activities of daily living.

Various therapeutic approaches are utilized in the rehabilitation process to improve the functional independence of children with CP. According to the International Classification of Functioning, Disability and Health (ICF), rehabilitation interventions should be grounded in neuroplasticity-based principles to maximize functional outcomes. One such neuroplasticity-based approach that has gained increasing attention in recent years is Action Observation Therapy (AOT).

AOT is based on the mirror neuron theory, which posits that observing an action activates similar neural regions in the cerebral cortex as performing the action itself. This simultaneous activation facilitates action understanding, imitation, and motor learning, suggesting that AOT may be an effective intervention to enhance motor function in individuals with CP. Improving motor functions in children with CP is crucial to enhancing their participation in daily life activities and overall quality of life. In addition to conventional physiotherapy interventions, AOT has emerged in recent years as an effective rehabilitation strategy that supports neuroplasticity. AOT facilitates motor learning and skill acquisition by targeting the brain's mirror neuron system.

Although there is substantial evidence in the literature demonstrating that AOT improves upper extremity functions, studies systematically comparing its effects on balance, gait, and general functional capacity remain limited. In particular, the differential effects of synchronous and asynchronous AOT applications on various motor outcomes have not yet been thoroughly investigated. Understanding the mechanisms of action of these two approaches may contribute to the development of more individualized and tailored treatment programs for children with CP.

Moreover, the low cost and easy applicability of AOT increase its potential for clinical use. Therefore, the findings of this study could enhance the effectiveness of rehabilitation programs, offering more accessible treatment alternatives for both healthcare professionals and families. To address this gap in the literature, the present study aims to comprehensively investigate the effects of synchronous and asynchronous AOT on motor functions in children with CP.

In this study, both groups will receive neurodevelopmental treatment (NDT) for 20 minutes as part of their intervention program. In addition, participants in the synchronous AOT group will observe exercise videos divided into four components (1. Sitting posture and sit-to-stand exercises; 2. Weight-shifting exercises; 3. Balance exercises; 4. Gait exercises) and perform the observed movements simultaneously in real time. Conversely, the asynchronous AOT group will first observe each of these video segments for 3 minutes and then perform the corresponding exercises sequentially after observation. Each session will last 45 minutes, conducted twice a week for 8 weeks.

The exercise videos were developed to include 12 task-oriented exercises tailored to the GMFCS level and extremity involvement of the children. The exercises are designed with varying levels of difficulty to enhance functional skills and lower extremity performance.

Inclusion Criteria:

• Voluntary participation of both the child and their family in the study
• Diagnosis of cerebral palsy with spastic clinical type, including hemiparetic and diparetic distribution
• Age between 6 and 18 years
• Classified as Level I or II according to the Gross Motor Function Classification System (GMFCS)
• Ability to comply with exercise interventions (based on medical report indicating normal mental level or "mild mental retardation")
• Ability to understand and speak Turkish

Exclusion Criteria:

• Presence of spasticity ≥3 in lower extremity muscle groups as measured by the Modified Ashworth Scale
• Inability to cooperate with verbal commands
• Presence of visual or hearing impairments
• Diagnosis of epilepsy or current use of antiepileptic medications
• Presence of joint contractures
• Botulinum toxin injection to the lower extremities within the past 6 months
• Undergoing orthopedic surgery within the past 6 months
• Presence of any additional systemic or neurological diseases
• Missing three consecutive rehabilitation sessions