Lumbar spine loads are reduced for activities of daily living when using a braced arm-to-thigh technique

Activities of daily living (ADL) often involve forward bending. Some of these tasks can be performed using a one-handed braced arm-to-thigh technique (BATT) to support the trunk on the thigh. Three common ADL (i.e. weeding, reaching for objects in low cupboards, and car egress) were simulated in the laboratory using custom apparatus. Ten young healthy males performed each task first using a self-selected technique, then using the BATT. Three-dimensional trunk kinematics and L4/L5 spinal loads were estimated using an OpenSim full-body model with a detailed lumbar spine and compared between techniques. The BATT significantly reduced extension moments, compression and antero-posterior (AP) shear forces at L4/L5, compared to self-selected techniques.