Kinetic relationships between ankle plantar flexor and hip flexor power during gait in mildly affected adults with spastic hemiplegic and diplegic cerebral palsy A case series study based on a ballistic strength training rehabilitation program Silje Marie Rydningen Torberntsson Master Program in Health Science – Physiotherapy by Research Department of Global Public Health and Primary Care Autumn 2019 – Spring 2020 1 Preface and acknowledgements First of all, I want to thank my supervisor Silje Mæland and my wonderful college in this project Beate Eltarvåg Gjesdal, who has been great support and made this project possible. I am so thankful for all your advices regarding the master thesis, but also all the good times we have spent together these two year. You spread lots of joy while working which has made it a pleasure to take part in the project. You are absolutely outstanding! Secondly, I am grateful for the kindness and help from Lars Peder Vatshelle Bovim and Bård Erik Bogen in the rehabilitation laboratory Sim Arena, Western Norway University of Applied Science. I truly respect and appreciate everything I have learned from you. Greetings to all the subjects participating in this project. Your effort and encouragement have been important to initiate future research in this field to improve rehabilitation options for individuals in the same position. Thank you so much! And finally, thanks to my fantastic family and friends for always being supportive. Bergen, May 2020 Silje Marie Rydningen Torberntsson 2 Content Preface and acknowledgements ..................................................................................................................... 2 Content .......................................................................................................................................................... 3 Abstract ......................................................................................................................................................... 6 List of Tables ................................................................................................................................................. 7 List of Figures ................................................................................................................................................ 8 Abbreviations ................................................................................................................................................ 9 Definition of concepts .................................................................................................................................. 10 Theoretical background .............................................................................................................................. 11 Chapter 1: Normal gait ............................................................................................................................... 12 1.1 Normal gait cycle ........................................................................................................................................ 12 1.1.1 Spatiotemporal gait parameters ........................................................................................................... 14 1.1.2 Joint gait kinematics ........................................................................................................................... 14 1.1.3 Joint gait kinetics ................................................................................................................................ 17 1.2 Kinetic analysis during in gait .................................................................................................................... 18 1.2.1 Ankle joint structure and power generation ........................................................................................ 18 1.2.2 Hip joint structure and power generation ............................................................................................ 19 1.2.3 Ankle-hip ratio (A2/H3) ..................................................................................................................... 21 1.3 Management of gait deviations to improve ankle power generation in late stance .................................... 21 1.3.1 Ankle foot orthosis .............................................................................................................................. 22 1.3.2 Botulinum toxin type A ...................................................................................................................... 22 1.3.3 Surgical treatment ............................................................................................................................... 22 1.3.4 Traditional resistance training ............................................................................................................. 23 1.3.5 Ballistic strength training .................................................................................................................... 23 Chapter 2: Spastic cerebral palsy and gait characteristics .......................................................................... 25 2.1 Pathology of spastic cerebral palsy ............................................................................................................ 25 2.2.1 Gross motor function classification system ........................................................................................ 26 2.2.2 Spastic hemiplegic cerebral palsy ....................................................................................................... 27 2.2.3 Spastic diplegic cerebral palsy ............................................................................................................ 27 2.2 Gait cycle in spastic cerebral palsy ............................................................................................................ 28 2.2.1 Spatiotemporal gait parameters ........................................................................................................... 28 2.2.2 Joint gait kinematics ........................................................................................................................... 28 2.2.3 Joint gait kinetics ................................................................................................................................ 29 2.3 Kinetic analysis in spastic cerebral palsy during gait ................................................................................ 29 2.3.1 Ankle power generation ...................................................................................................................... 29 2.3.2 Hip power generation .......................................................................................................................... 30 2.3.3 Ankle-hip ratio (A2/H3) ..................................................................................................................... 31 3 Chapter 3: Rationale and aims .................................................................................................................... 32 3.1 General aim ................................................................................................................................................ 32 3.2 Hypotheses .................................................................................................................................................. 32 Chapter 4: Material and methodology ........................................................................................................ 33 4.1 Case series study ........................................................................................................................................ 33 4.2 Ethical considerations ................................................................................................................................ 33 4.3 Inclusion and exclusion criteria ................................................................................................................. 34 4.4 Study setting and sample ............................................................................................................................ 34 4.5 Ballistic “Leg sled hop” intervention ......................................................................................................... 35 4.5.1. Exercise 1: Jump Squats on the leg sled ............................................................................................ 36 4.5.2 Exercise 2: Single leg hopping on the paretic leg ............................................................................... 36 4.5.3 Exercise 3: Bounding on altering legs (jogging) ................................................................................. 36 4.6 Experimental protocol ................................................................................................................................ 36 4.6.1 Kinematic measures ............................................................................................................................ 38 4.6.2 Kinetic measures ................................................................................................................................. 40 4.6.3 Calibration .......................................................................................................................................... 40 4.6.4 Performing gait trials .........................................................................................................................