Introduction: Selective mutism (SM) is characterized by a consistent difficulty to speak in specific social situations despite speaking in others. It is commonly conceptualized as an anxiety-related disorder. Clinical interventions for children with SM generally seek to reduce patients’ anxiety and tension before directly targeting speech. Physical play is often incorporated to promote relaxation and engagement, particularly among preschool-aged children. However, few studies have quantitatively examined how physical activity influences observable emotional and behavioral indicators in children with SM. The present case study investigated the clinical utility of physical activity by focusing on two indices: (1) facial expression as an indicator of emotional expression and tension, and (2) spontaneous behavior as an indicator of self-initiated social action. By comparing more and less physically active play contexts, this study explored how activity type relates to changes in these indicators.
Methods: The participant was a five-year-six-month-old girl who spoke at home but rarely spoke at preschool and was suspected of having SM. She participated in 12 weekly individual sessions of 40–50 minutes each over three months. Each session included both standing physical play (targeting gross motor activities) and seated, less active play. All sessions were video-recorded. Facial tension was rated using a one-minute interval system adapted from previous SM research. “Spontaneous behaviors” were defined as child-initiated actions occurring without an immediate prompt from the adult. They were categorized into four types. Two raters independently coded the data, and inter-rater reliability was acceptable.
Results: Facial tension levels were generally lower at the onset of standing play than seated play. However, tension did not decrease progressively during standing play; instead, the child tended to begin and remain in a relatively relaxed state. Seated play more often began with higher facial tension, although fluctuations were observed. No consistent difference in the frequency of spontaneous behavior was found between standing and seated activities. However, qualitative changes emerged across sessions. Self-directed or rule-deviating behaviors characterized early sessions. Later sessions showed increased reactions to events and, eventually, spontaneous behaviors directed toward the adult. Overall, they increased gradually over the repeated sessions.
Discussion: The findings suggest that physical play may create conditions in which lower facial tension is more likely to emerge at the outset. Physically demanding tasks may have required attentional resources for object tracking and bodily coordination, thereby reducing excessive self-consciousness about speech or social evaluation. In seated activities, direct face-to-face interaction may have heightened social awareness and tension. Spontaneous social engagement appeared to depend more on the continuity of intervention and relationship development than activity type. While physical play may have facilitated emotional expression and a relaxed state, it may be insufficient to promote self-initiated social communication on its own. Integrating continuous support with cognitive–behavioral strategies may therefore be necessary to facilitate broader communicative change. The study’s limitations included reliance on facial expression as the primary indicator of tension and the single-case design.

論文