Background: Children with spastic hemiplegia had disabilities of the upper extremities such as reaching, grasping, and object manipulation resulting in dependency in daily activities and a lack of successful social integration.Muscle morphology and structures are different in children with cerebral palsy as a result of secondary impairments such as disuse,spasticity, and immobilization. Purpose: To investigate the correlations between spasticity, functional ability and muscle thickness of biceps brachii in children with spastic hemiplegic cerebral palsy and to compare muscle thickness in normal children and spastic hemiplegic cerebral palsy children. Methods: 40 children from both sexes with age ranged from 2 to 5 years included in this study and divided into two equal groups. Group (A) included 20 aged matched normal developmental children and Group (B) included 20 children with hemiplegic cerebral palsy. Muscle thickness of biceps brachiiwas measured with ultrasound imaging. The functional ability was evaluated using the Gross Motor Function Measurement-88 (GMFM-88). The spasticity was evaluated with the Modified Ashworth Scale (MAS). Results: The results of the study revealed that there was a significant difference of biceps brachii thickness between normal group and spastic hemiplegic cerebral palsy group(P≤0.05). For correlation, there was positive significant correlation(r=-0.765; p<0.0001) between spasticity and functional ability. But there was no significant correlation between age and muscle thickness, spasticity and functional ability. Also, there was no significant statistical correlation between muscle thickness and function ability. Conclusion: In children with spastic cerebral palsy, muscle thickness of biceps brachii was less than in age-matched normal children. Furthermore, Children with hemiplegic cerebral palsy may need muscle strengthening exercises in the upper extremities, including the biceps muscle. Therefore prevent muscle atrophy and increase functional daily living activities. 27. Stackhouse SK, Binder-Macleod SA and Lee SC. Voluntary muscle activation, contractile properties, and fatigability in children with and without cerebral palsy. Muscle Nerve. 2005; 31:594-601. 28. Narici M. Human skeletal muscle architecture studied in vivo by noninvasive imaging techniques: functional significance and applications. J Electromyogr Kinesiol. 1999; 9:97-103. | Article | PubMed 29. Yasar E, Adiguzel E, Kesikburun S, Yenihayat I, Yilmaz B, Alaca R and Tan AK. Assessment of forearm muscle spasticity with sonoelastography in patients with stroke. Br J Radiol. 2016; 89:20160603. | Article | PubMed Abstract | PubMed FullText Citation: Ali MS, Abdel-Azim FH and Ali AAA. Correlation between age, muscle thickness, spasticity and functional ability in children with spastic hemiplegic cerebral palsy. Phys Ther Rehabil. 2019; 6:8. http://dx.