Traditional outcome measurement scales, such as the Medical Research Council (MRC) score, the Active Movement Scale (AMS), and Mallet score, are used by surgeons to assess outcomes in patients with obstetric brachial plexus palsy (OBPP). The measurement scales used to evaluate patients fall under the International Classification of Functioning (ICF) domains of Body Function, Body Structure, Activity, Participation, and Environment and are used to assess function and disability of patients. Currently used outcome measures scales for OBPP are also contrasted with those used for another perinatal condition affecting the upper limb, cerebral palsy (CP).