John D. Lloyd, PhD, CPE
Board Certified Ergonomist
32824 Michigan Avenue
San Antonio, Florida 33576
Tel: 813-624-8986
Email: DrJohnLloyd@Tampabay.RR.com
Biomechanical Evaluation of Injury Severity Associated with Patient Falls from Bed
Background: The incidence of falls in the elderly is a concern in the healthcare industry as associated morbidity is high. According to the literature, approximately one-third of persons aged over 65 years fall annually, accounting for 40% of trauma related injuries in this population. The literature further reports that 20 to 24% of all falls involve falls from bed. These falls are significantly associated with age. Thirty-seven percent of falls from bed result in injuries including: fractures, lacerations, and hematomas.
Objectives: This study investigates the severity of injuries associated with patient falls from bed and the effectiveness of injury prevention strategies.
Method: An instrumented anthropomorphic test dummy was utilized in the current study to measure deceleration profiles of the head, thorax, and pelvis upon impact onto a tile surface and floor mat. Deceleration profiles were measured for six fall heights (33.5 to 97.5 cm) using a height adjustable bed. The trials were conducted for two different fall directions: head first falls and feet first falls.
Results: Injury severity correlated by injury criteria used in the automotive industry indicated up to a 25% chance of experiencing a severe head injury during feet first falls from the highest bed height. This risk of injury increased to 40% with height added by use of bedrails. Utilization of a floor mat significantly decreased risk to less than 1% for the same height. Instantaneous impact forces were calculated for the head and pelvis. Results were compared to skull and hip fracture limits. Calculated head impact forces indicate a clear risk of skull fracture during head first falls without floor mat use. Pelvis impact forces were not indicative of a risk of hip fracture regardless of mat use.
Discussion: The investigators recommend that a floor mat should be placed bedside to decrease the risk of injury associated with falling from bed as this intervention significantly decreased injury criteria compared to a tile surface. Furthermore, a height adjustable bed should be implemented and lowered to the lowest position when the patient is not being attended. The use of bedrails should be discontinued as risk of serious head injury significantly increased with an increase in height added by bedrails.
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