Following brain injury, neuromotor disorders of the upper limb are a major cause of functional disability and poor quality of life. In association with paresis and muscle changes, spasticity leads to motor imbalances responsible for joint deformities in general and in the shoulder in particular. In this expert narrative review, we address the assessment and management of spastic shoulder in patients with brain injury, including analysis of the discomfort and the clinical examination. Motor blocks and electromyography are essential, complementary tools. The definition of personalized SMART objectives (specific, measurable, achievable, realistic, and timely) is a crucial step in treatment planning. Depending on the type of impairment, the severity and the objectives, the treatment will combine conservative approaches (rehabilitation, splints, botulinum toxin injections, and stretching) and targeted surgical procedures (tenotomies, muscle and tendon lengthening, and neurectomies).