Development of muscle contractures and spasticity during subacute rehabilitation after severe acquired brain injury: a prospective cohort study.

: This study investigated the development of contractures, passive stiffness, and spasticity in the ankle joint in patients with severe acquired brain injury (ABI) from admission to rehabilitation unit until 1-year post-injury compared to healthy controls. : An observational longitudinal cohort study : Nineteen patients (26 affected ankle joints) with severe ABI >17 years old and with paresis of a lower limb admitted to sub-acute neurorehabilitation were compared to 14 healthy controls (28 ankle joints). Passive and reflex-mediated ankle joint stiffness was obtained measuring torque, range of motion, velocity and acceleration of the ankle movements. Data was collected at inclusion, after 4-5 weeks, after 8-9 weeks and at 1-year follow-up. : At admittance to rehabilitation range of motion and stiffness was significantly lower compared to controls. Range of motion decreased by one degree in three weeks and passive ankle joint stiffness increased significantly by 1% per week. More patients than controls had no stretch reflex. : Patients with severe ABI show reduced mobility and increased passive stiffness despite less spasticity in the ankle joint compared to healthy controls. Research and clinical practice should therefore focus intensively on the prevention of contractures in the ankle joint. ISRCTN17910097.