[Biomechanical Evaluation of Rehabilitation after Surgical Repair of Achilles Tendon Ruptures].

 Muscles and tendons are subjected to a high level of stress in everyday life and sports. This often leads to injuries and is associated with training failure and reduced performance as well as with high costs for treatment and rehabilitation. Fast and successful treatment is therefore very important, both from an athletic and economic point of view. This study aims to demonstrate the relevance of biomechanical procedures for the objective monitoring of rehabilitation. At the same time, the results are to be used to establish progress and evaluation criteria for an efficient and controlled rehabilitation.  In a retrospective study, a total of 42 patients were evaluated biomechanically after surgical repair of a complete Achilles tendon rupture 18 (18 W) and 26 weeks (26 W) postoperatively. Ground reaction forces in barefoot walking on a treadmill as well as isokinetic maximum strength for the plantar flexors and dorsal extensors were assessed.  The push-off force on the injured side increased from 0.88 (18 W) to 0.95 (26 W). The percentage of heel contact time on the injured side was 59 % at 18 W and 55 % at 26 W. Plantar flexion torque increased from 70 Nm (18 W) to 90 Nm (26 W) on average on the injured side. The percentage of the plantar flexion deficit (injured/non-injured side) decreased from 34 % to 21 % on the two postoperative measuring dates.  The described biomechanical methods allow for a quantitative assessment and an objective control of the rehabilitation process. The results can also be used for the definition of evaluation and progression criteria in order to assess the progress of a patient's therapy and to guide the rehabilitation process in a controlled manner.