Discussion
sVT, spastic CP
SECONDARY
This study is the first clinical trial comparing the effectiveness of different sVT protocols varying in duration and frequency in children with mild to moderate CP. The results demonstrated that 20 weeks of sVT are more effective in impacting walking mobility, gross motor function, and muscle function, but there were no observed differences in study outcomes between the two sVT frequencies (20 Hz vs 25 Hz). The specific underlying mechanism of the effects of VT remains unclear. However, proposed mechanisms include activation of the a-motoneurons [Long-term sVT (i.e., 20 weeks) had a positive effect on mobility in young children with CP and was more efficacious than short-term sVT. These mobility improvements were supported by 10MWT results, demonstrating an increase in gait speed after 12 weeks of sVT, with further improvements after 20 weeks (2.27 m/s → 2.36 m/s → 2.46 m/s). Our results are consistent with the findings of Gusso et al.’s study that reported improvements in 6MWT after 20 weeks of sVT in adolescents and young adults 11–21 years of age with CP GMFCS level II-IV [There were also beneficial effects of both short-term (12 weeks) and long-term (20 weeks) sVT on gross motor function, although the longer intervention led to additional improvements beyond the 12-week gains. Our findings are important because they show the effectiveness of sVT as a single intervention, whereas previous studies have reported improvements in gross motor function after short- [Given children affected by CP who have better mobility and physical function experience less restrictions in activities of daily living and social participation [The Leonardo mechanography data showed an increase in maximum force measured by STLJT after 12 and 20 weeks, and maximum velocity rise measured by the CRT after 20 weeks of sVT. Conversely, we found no changes in muscle strength, in contrast to previous studies on young children with CP aged 8–12 years that reported increases in knee extension muscle strength after 12 weeks of sVT at 12–18 Hz [As for body composition, there were improvements in spine BMD Z-score after 20 weeks of sVT and in BMC after 12 weeks, with no changes observed in TBLH and leg parameters. To date, previous studies have reported conflicting findings on the effectiveness of VT on BMD and BMC as measured by DXA. El-Bagalaty & Ismaeel reported an increase in the lumbar spine and femoral neck BMD after 12 weeks of sVT in combination with physiotherapy among 46 children aged 5–7 years with spastic CP [The main limitation of our study was the smaller number of participants recruited compared to our original target due to the government-imposed lockdowns associated with the COVID-19 pandemic, which also prevented some participants from completing all clinical assessments; in turn, these most likely affected our ability to detect statistically significant treatment effects on secondary outcomes.