The results of the reviews are controversial, and the effects of exercise remain unclear. Short-term interventions and
methodological shortcomings, such as small sample sizes and inadequate study designs, have prevented researchers from
reaching explicit conclusions (Darrah et al., 1997). Because of this insufficient evidence, caution must be used in interpreting
the results. Reviews have limitations in explaining the comprehensive effect of strengthening for individuals with CP,
including the small number and low quality ofthe studies and their heterogeneous design. The data of five studies showed no
effect of muscle strengthening (Scianni et al., 2009), while the effectiveness of strength training was observed in 11 studies
that employed a heterogeneous study design (Dodd et al., 2002).