Raw data associated with the paper: Kalkman, B.M., Holmes, G., Bar-On, L., Barton, G.J., Maganaris, C.N., Bass, A., Wright, D.M., Walton, R. and O'Brien, T.D., 2019. Resistance training combined with stretching increases tendon stiffness and is more effective than stretching alone in children with cerebral palsy: A randomised controlled trial. Frontiers in Pediatrics, 7, p.333. fascicle_data File contains raw data for 2 analysis of 2 data aquisitions for the fascicle length (mm) at rest, maximal plantar flexion (PF), 10 degrees PF and maximal dorsiflexion (DF). Stiffness_data File contains raw data for tendon stiffness (N/mm) at 3 timepoints, Baseline (pre), after 4 weeks of strength training (mid) and at the end of the intervention (post) for the control and the intervention group.