Differences in morphological parameters of calf muscles among children and adolescents with spastic cerebral palsy at different mobility levels and their relationships with walking ability.

BACKGROUND

Previous studies have demonstrated alterations in skeletal muscle morphology and architecture in individuals with spastic cerebral palsy (CP). However, it remains unclear whether these morphological parameters vary across different mobility levels or how they relate to walking ability.

PURPOSE: This study aimed to examine morphological parameters of calf muscle across functional mobility levels in children and adolescents with spastic CP and their relationships with walking ability.

METHODS

Children and adolescents with spastic CP, aged 5-17 years (mean age: 11.72 ± 4.6 years), were recruited in the study. Morphological parameters of the gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and soleus muscle in the more severely affected lower limb were assessed using a B-mode ultrasound. Walking ability (i.e. mobility and locomotion activities) was evaluated using both the Gillette Functional Assessment Questionnaire-22 item skill set (FAQ-22) and ABILOCO-Kids.

RESULTS

Analysis revealed a significant decrease in muscle thickness (p1 = .013; p2 = .032; p3 < .001) and fascicle length (p1 < .001; p2 < .001) with declining mobility levels, except for GL fascicle length (p = .061). Conversely, pennation angle was significantly greater in children with severe motor involvement (p < .001 for all). Moderate to very strong correlations were found between calf muscle morphological parameters and walking ability (r = -0.41 to 0.89). Notably, muscle thickness demonstrated the strongest correlation coefficients with walking ability (r = 0.83-0.89).

CONCLUSION

The significant associations between GM and soleus muscle thickness and walking ability indicated that these muscles are important contributors to functional mobility in children and adolescents with CP. These findings also emphasized that musculoskeletal integrity remains a critical factor of mobility and locomotion activities, even within contemporary participation‑focused rehabilitation models.