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Updated: Jun 19, 2026
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Design and Analysis for Fall Detection System Simplification
Published on: April 6, 2020
Age differences in energy absorption in the upper extremity during a descent movement: implications for arresting a
Meena M Sran1, Paula J Stotz, Sarah C Normandin
1Injury Prevention and Mobility Lab, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.
Summary
Older women absorb significantly less energy with their arms during simulated falls compared to younger women. Strengthening arm muscles may help reduce fall-related injuries in seniors.
Area of Science:
- Gerontology
- Biomechanics
- Injury Prevention
Background:
- Falls represent the leading cause of unintentional injuries among older adults.
- The "breaking the fall" reflex using outstretched arms is crucial for preventing hip and head injuries.
- This study investigates age-related differences in upper extremity energy absorption during simulated falls.
Purpose of the Study:
- To compare the impact energy absorption capabilities of the outstretched arms in young versus older women.
- To quantify differences in peak upper extremity energy absorption, arm deflection, and hand contact force between age groups.
Main Methods:
- Twenty young (mean age 21) and 20 older (mean age 78) women participated.
- Participants simulated the descent phase of a fall by lowering their body weight from various lean angles (15-90 degrees).
- Key biomechanical measures including energy absorption, arm deflection, and hand contact force were recorded.
Main Results:
- Older women absorbed 45% less energy in their dominant arm compared to young women (1.7% vs 3.1% of body weight x height).
- The average energy of a simulated forward fall exceeded the absorption capacity of older women by 5-fold and young women by 2.7-fold.
- Significant differences were observed in peak upper extremity energy absorption between the two age groups (p < .001).
Conclusions:
- The energy-absorbing capacity of the upper extremities is nearly halved in older women compared to younger women during simulated fall arrest.
- Even for young women, fully absorbing fall impact energy with the arms is challenging.
- Targeted strengthening of upper extremity muscles may improve fall energy absorption and reduce injury risk in older adults.
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