Influence of lower limb spasticity on vertical jump capacity in para-athletes with cerebral palsy.

Abstract

Spasticity is a common feature in individuals with cerebral palsy (CP) that may impair muscle function and affect explosive movements such as jumping. Although vertical jump performance is a key indicator of neuromuscular capacity in para-athletes, the specific effects of lower-limb spasticity remain unclear, particularly when comparing unilateral and bilateral profiles. To compare spasticity scores between less and more affected legs as well as across CP profiles, examine differences in vertical jump performance variables between CP participants with unilateral spasticity (US) and bilateral spasticity (BS) profiles and footballers without disabilities, and determine the association between spasticity and jump force-time variables during a countermovement jump (CMJ). In total, 53 parafootballers with CP and 33 footballers without disabilities as a control group (CG) were recruited. Spasticity was assessed in lower limb muscle groups using the Australian Spasticity Assessment Scale, focusing on knee and ankle plantar flexion. Performance variables were evaluated using the CMJ test on a force platform. Significant differences in spasticity of the more affected leg were found between the subgroups with BS and US (p < .01). In addition, significant differences in jump height were observed between footballers with CP and the CG (p < .01). A negative correlation was found between spasticity scores and vertical jump performance (ρ = -0.27 to -0.28, small), and a positive correlation was found between spasticity scores and the maximal rate of force development (ρ = 0.28 to 0.33, small to moderate). Lower-limb spasticity differs across CP profiles and negatively affects CMJ height performance. This study offers new insights into how spasticity influences sport-specific actions in para-athletes with CP, particularly those requiring muscle power for high-speed movements such as jumping.