GMPMGross Impaired gross motor development and function are defining features of cerebral palsy (CP). 1 Interventions aim to optimize what the child can do (functional skills) and how they do it (movement quality).2 Both are important prerequisites for advanced motor skills related to activity and participation. Enhancement of quality of movement may be an important precursor to attainment of new gross motor skills.2 While function is the ultimate goal, identifying challenges in quality of movement helps to guide therapists to develop individualized therapy approaches to enhance function. Without measuring movement, quality changes can only be inferred from improvements in other aspects of function, such as timed walk tests, acquisition of new motor skills, or indications of greater functional skill independence. Clinicians and researchers, therefore, remain uncertain about what aspects of quality are changing and when, how, and why. 'No difference' findings in trials that failed to assess quality of movement may have missed important changes in this underlying component of motor skill.Instrumented systems quantify selected attributes of movement quality (e.g. force, amplitude, speed), but their use is limited to specialized centres. Paediatric physiotherapists typically rate quality of performance through clinical observation and Gestalt perceptions of movement.3,4 The absence of appropriate clinical instruments to evaluate movement quality was the impetus to the development of the Gross Motor Performance Measure (GMPM), 3 created through an expert consensus approach as a companion to the original Gross Motor Function Measure (GMFM-88).
5The GMPM was designed to quantify key aspects of movement quality and evaluate change in children with CP and acquired brain injury. 6 Five attributes (Alignment, and it detected change with interventions (orthopaedic surgery, rhizotomy, and ankle orthoses).
11,12The GMPM remains the only published measure that addresses multiple components of quality of gross motor skills for children with CP. Other published upper or lower extremity/total body quality of movement scales are outlined in Table SI (online supporting information). Three concerns about the GMPM are its lack of item-specific response option descriptions, the need for highly experienced raters, 8 and the small representation of motor skills (20 GMFM-88 items). While the GMPM may be suitable for a therapist who is working with a child on basic motor skills that have quality components to them (e.g. Co-ordination and Dissociated movement are relevant attributes to assess for lying/rolling and crawling skills), its evaluation of movement quality across all aspects of motor function does not align well with goals of children who are working specifically on ambulation-based skills. For these children in Gross Motor Function Classification System (GMFCS) levels I to III, evaluation of movement quality should be intensely focused on standing and walking skills with a sufficient number of items to give a complete picture of...