Trunk involvement in performing upper extremity activities while seated in neurological patients with a flaccid trunk – A review

Abstract Background Trunk control is essential during seated activities. The trunk interacts with the upper extremities (UE) and head by being part of a kinematic chain and by providing a stable basis. When trunk control becomes impaired, it may have consequences for the execution of UE tasks. Aim To review trunk involvement in body movement and stability when performing seated activities and its relation with UE and head movements in neurological patients with a flaccid trunk, with a focus on childhood and development with age. Methods and procedures A search using PubMed was conducted and 32 out of 188 potentially eligible articles were included. Outcomes and results Patients with a flaccid trunk (e.g. with spinal cord injury or cerebral palsy) tend to involve the trunk earlier while reaching than healthy persons. Different balance strategies are observed in different types of patients, like using the contralateral arm as counterweight, eliminating degrees of freedom, or reducing movement speed. Conclusions and implications The key role of the trunk in performing activities should be kept in mind when developing interventions to improve seated task performance in neurological patients with a flaccid trunk.