Every year in Switzerland about 70,000 people over the age of 65 suffer falls. Around 10,000 of them will suffer broken hips as a result, and of these patients every fifth will consequently become unable to look after themselves and will thus need care in an old persons home. Some 500 pensioners will die within a year of the accident as a result of the fracture. Martin Hugi of the bfu, the Swiss Council for Accident Prevention, used these statistics to illustrate the effects of a fall on an elderly person.

Since life expectancies are continuously increasing, the number of falls is also expected to increase significantly with time. This is not only a social problem but also an economic one, as the costs resulting from a single hip breakage total about CHF 65,000. In view of this trend, the bfu has created a program aimed at preventing fractures of the upper thigh bone in which hip guards play an important role. The device consists of two hard shells, soft plastic pads or combinations of the two which are sewn into the underwear or held in place in special pockets. The guards cushion a sideways falls, thereby preventing hip fractures.

Prepared for a fall

For several years now a number of different hip guards have been available on the market. The level of protection they offer varies, and therefore it has become increasingly important to investigate their effectiveness under realistic test conditions. Working together with the bfu, the Empa has therefore developed an anatomically shaped mechanical model of a hip joint. “The model allows us to scientifically test the level of protection offered by a hip guard” said Adriaan Spierings of the Empa’s Protection and Physiology Laboratory.

In an initial series of measurements the Empa researchers investigated the cushioning effect of ten different hip guards. The results show significant differences. Only three devices met the requirements of the Empa tests – a protective effect of about 80% for the age group most affected – as well as the bfu’s conditions on wearing comfort, and these types have been recently awarded the bfu’s safety mark. “While these hip guards can’t prevent a fall, they can save a life,” said Hugi, putting his finger on the crux of the matter, adding “They are a blessing to humanity.” The names of the products concerned are available from the bfu.

Bones – living organs

But why do older bones fracture more readily? ”Bones are not rigid, hard structures but living organs that continuously both grow and degrade with time* explained Professor Gerold Holzer of the Medical University of Vienna. While in youthful years the growth processes predominate, after the age of about 30 more degradation occurs than growth. Bone density slowly declines and the microstructure of the bone changes. If the density falls below a threshold value the condition is known as osteoporosis, and as a result of this skeletal disease bones cannot withstand normal loads. Even a minor overstressing can result in a fracture.

Author

Dr. Bärbel Zierl, Communication dept., Tel. 044 823 49 09, baerbel.zierl@empa.ch

Contact

Adriaan B. Spierings, Protection and Physiology Laboratory, Tel. 071 274 77 76, adriaan.spierings@empa.ch

What is a Science Apéro?

The EMPA Academy provides a forum for debating current scientific and socially relevant issues through its Science Apéros. Held at regular intervals, these usually involve three or four speakers with backgrounds in research, politics and commerce, who present results and trends relevant to the selected topic seen from their particular point of view. After the round of presentations, a lively discussion usually ensues involving the audience who may or may not be well versed in the theme under consideration. This continues during the aperitif after the formal proceedings come to a close.

The next Science Apéro will take place on 29. August 2005 on the topic
«The Road – an Intelligent Partner in Combating Traffic-Induced Stress».
Location: EMPA Academy, Duebendorf. Time: 16:30. No prior registration required