eLife Assessment
This valuable study introduces a novel experimental and modeling framework to quantify passive joint torques in Drosophila, revealing that passive forces are insufficient to support body weight, contrary to prior assumptions based on larger insects. The approach is technically impressive, combining genetic silencing, kinematic tracking, and biomechanical modeling. However, the strength of evidence is incomplete, limited by concerns about the specificity of the genetic tools, simplifications in the mechanical model, and limited functional interpretation.