[Reconstructive hand surgery improves hand function in tetraplegia. Basic research and clinical studies paved the way for this development].

Structural and mechanical changes in muscles and muscle cells were studied after spinal cord injury with tetraplegia as well as secondary to upper motor neural lesion with spasticity. A multi-level approach was applied. It included measuring human sarcomere length intraoperatively, designing and validating biomechanical models for muscle-tendon-joint systems, mechanically testing muscle and using molecular methods to identify muscle cytoskeletal fragments. Using this combination of muscle modeling and physiological testing, the actual effect of surgical intervention can be predicted. Our improved understanding of muscle mechanics has been critical for development of several therapeutic treatments including both muscle tendon transfer surgery and rehabilitation. Successful tendon transfer procedures improve patient function, which facilitates employability and allows patient to regain independence and reduce the need for a constant care.