To evaluate short‐term (1y postoperatively; E1) and long‐term (at least 4y postoperatively; E2) changes in hamstring muscle‐tendon length (MTL) and lengthening velocity after hamstring lengthening in children with bilateral cerebral palsy (CP).. To read the full article, log in using your NHS Athens details. To access full-text: click “Log in/Register” (top right hand side). Click ‘Institutional Login’ then select 'OpenAthens Federation', then ‘NHS England’. Enter your Athens details to view the article.