After injury or surgery of a knee, leg, ankle, etc. crutches are used in rehabilitation treatment. With the help of two crutches, an injured part does not have to support the patient's full body weight. To ensure proper healing, doctors preset a specific load for the injured leg of e.g. 20 kg. The injured leg must not support excessively more than that. The rest of the patient's body weight must be simultaniously supported by a pair of crutches. The current method to ensure a correct load distribution is to simply teach the patient walking by "feel". At the beginning of his treatment, the patient puts the affected leg on a body scale while standing with both crutches next to the scale. When the scale shows the specified weight, the patient is told to remember the load while walking. At this moment, there there is no way for the patient or doctor to tell if the specified load is kept within limits during any further walking activities in everyday life. Neither a direct feedback for the patient nor a long term evaluation for the doctor is possible.