Translation of Video:

It is generally known that movement against gravity benefits the building of new bone cells.                                            
Dr. Joachim Schulz, leader of the study, says: "The bouncing on a high elastic rebounder (they used the Bellicon Bungee band rebounders for their study) concerns the whole body. Each and every cell is trained: the muscles, the tendons and, the bones. At the end of the down movement when the body reaches the the lowest point, the cells are pressed together and during the movement upwards, all cells are loosened up and relaxed. The result is a training of each and every cell of the body."
All participants of the study had their bone density measured in the beginning and in the end. They had lower bone density than they should have according to their age.
Then on the video clip you see how the group of participants is trained. They start the exercises slowly giving the body time to adapt and gain balance. Notice how their feet stay in contact with the mat. The participants trained three times a day for ten minutes over a period of three months. That program was the basis for the study.
The participants who were interviewed in this video say that they were astonished how much they enjoyed the workout on the rebounder and what a great result in toning their body they achieved.
They also said they became more joyful, that their blood circulation increased, that they felt more fit and that they could easier handle stress. Also their coordination and reflexes improved - which is a great preventive against breaking bones.
At the end of the three month study, Dr. Joachim Schulz said that they know now for certain that the loss of bone density for all participants had stopped. And in an upcoming study which will be done over a longer period of time they want to proof that only by bouncing on the rebounder, the bone density will increase again.

A good book to read is  "The MYTH of OSTEOPOROSIS" by Gillian Sanson ISBN 0-9721233-4-2