This study was designed to examine whether increased associated movements (AMs) reflect motor difficulties or the symptoms associated with attention disorders. Four groups of male children (N = 51) aged 6–8 years participated: Group 1 consisted of 13 children diagnosed with developmental coordination disorder (DCD); Group 2 consisted of 13 children diagnosed with attention deficit hyperactivity disorder (ADHD); Group 3 consisted of 10 children diagnosed with co-occurring DCD and ADHD, and Group 4 was a control sample of 15 children, with no known movement or attention difficulties. Various AM tasks were selected from established assessments and previous research to measure AM severity. The results supported the hypothesis that increased severity of AMs reflect movement difficulties with children in the DCD and DCD/ADHD groups displaying significantly more AMs than children in the ADHD and control groups (p <.001). No differences were found between the ADHD only and control groups (p = .67) or the DCD and DCD/ADHD groups (p = .81) suggesting that AM severity is not influenced by the neurodevelopmental symptoms associated with ADHD.
Licari, M., & Larkin, D. (2008). Increased associated movements: Influence of attention deficits and movement difficulties. Human Movement Science, 27(2), 310-324. https://doi.org/10.1016/j.humov.2008.02.013