Relationship between spastic catch measurements and ankle joint movement in walking and hopping in children with cerebral palsy

• Published in: Gait & posture 2023-09, Vol.106, p.232-241
• Main Authors: Peltoniemi, Mika, Finni, Taija, Mäenpää, Helena, Piitulainen, Harri, Kulmala, Juha-Pekka
• Format: Article
• Language: English
• ISSN: 0966-6362; 1879-2219
• DOI: 10.1016/j.gaitpost.2023.07.195

Spasticity assessment is part of the management of children with cerebral palsy (CP), and often-recommended methods like the Modified Tardieu Scale (MTS) have been utilized in clinical practice [1]. MTS aligns with the traditional definition of spasticity: a velocity-dependent increase in the tonic stretch reflex [2]. However, the spastic catch angle of relaxed muscle might not be related to joint movement in dynamic tasks [3,4], such as walking or hopping. This study investigates the relevance of passively measured spastic catch angle to ankle movement in walking and hopping. Does the spastic catch stop the ankle movement similarly in hopping compared to the passive condition? Sixteen children (13.1 ± 2.5 years, GMFCS level 1) with unilateral spastic CP underwent 3D gait and hopping analysis in a motion analysis laboratory. 3D movement analysis measures included sagittal ankle angles, ankle angular velocities, and estimated calf muscle lengthening velocities during gait and a two-legged hopping task. Unilateral assessments of the ankle spastic catch angle (MTS) and maximum passive and active dorsiflexion angles (knee at 0° and 90°) were performed as clinical tests. Compared to walking (affected 15.5%/s and unaffected 25.2%/s), estimated gastrocnemius lengthening velocities were significantly higher in hopping (67.9%/s and 71.7%/s respectively, Fig. 1.A), indicating fast muscle stretch. However, this does not constrain the affected side ankle motion since the maximum ankle dorsiflexion was significantly greater in hopping than in clinical tests (p