Force reduction by an external hip protector on the human hip after falls

Area of Science:

• Biomechanics
• Gerontology
• Orthopedics

Background:

• Hip fractures are a major cause of morbidity and mortality in the elderly.
• Hip protectors are designed to mitigate impact forces during falls.
• Previous studies have not quantitatively assessed impact force reduction in vivo.

Purpose of the Study:

• To quantitatively measure the impact force transmitted to the hip during lateral falls while wearing hip protectors.
• To evaluate the effectiveness of hip protectors in preventing hip injuries.
• To assess the compliance of elderly individuals with hip protector use.

Main Methods:

• Drop weight tests using piezoelectric sensors to measure impact force.
• Volunteer studies involving lateral falls from standing onto a concrete surface with hip protectors.
• In vitro testing with osteoporotic cadaver hips.
• A 1-month compliance study with 106 elderly participants.

Main Results:

• Hip protector pads transmitted only 9% of impact force in drop weight tests.
• In volunteer falls, 5% or less impact force was transmitted to skin sensors.
• No hip fractures occurred in 85 volunteer falls; only transient skin pain was reported.
• Force transmission was below the fracture threshold for osteoporotic cadaver hips.
• Compliance with protector use ranged from 70% to 95% of waking hours.

Conclusions:

• Hip protectors are effective in significantly reducing impact forces during falls.
• The use of hip protectors demonstrates a high safety profile and potential for preventing hip fractures in the elderly.
• Variability in force reduction among individuals was observed, suggesting potential for personalized fitting or pad design improvements.