Development of a new design of hip protectors using finite element analysis and mechanical tests.
The rate of hip fractures due to falls increases with age. External hip protectors placed over the greater trochanter can prevent hip fractures, but the willingness to wear such protective devices is rather low. Most of the commercially available hip protectors consist either of an energy-absorbing foam pad or of a hard shell that distributes the load to the surrounding tissue. In the present study, a fibre-reinforced shell composed of three curved strips bonded with a ring, was designed and lined with shock absorbing foam. The development of the new shell design was based on quasi-static and impact tests of manufactured shells in combination with finite element simulations. The results of the numerical analysis showed the potential protection effect of the shell and indicated how the design can be further improved. First impact tests on an anatomical hip model showed promising results of the new protector shell in combination with a foam pad.
Schmid Daners
Marianne
M
Laboratory for Protection and Physiology, Empa, Swiss Federal Laboratories for Materials Testing and Research, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland. marianne.schmid@imrt.mavt.ethz.ch
Wullschleger
Luc
L
Derler
Siegfried
S
Schmitt
Kai-Uwe
KU
D000054:Acceleration; D017076:Computer-Aided Design; D055119:Elastic Modulus; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D020342:Finite Element Analysis; D006244:Hardness; D025981:Hip Injuries / Q000503:physiopathology* / Q000517:prevention & control*; D006621:Hip Joint / Q000503:physiopathology*; D010812:Physical Stimulation / Q000379:methods; D011482:Protective Devices; D013314:Stress, Mechanical