Injuries associated with slip and fall accidents pose a significant problem to industry, both in terms of human suffering and economic losses. Existing evidence has identified several aging effects related to slip and fall accidents, yet has not explained determining causes of older individual's higher likelihood of slip and fall accidents. In this proposal, intrinsic changes associated with aging such as gait adaptation, musculoskeletal and sensory degradation and its effect on the initiation, detection, and recovery processes of slips and falls will be evaluated to answer the question of why older adults are exposed to a higher likelihood of slip-induced falls.
The aim of the proposed research is to investigate changes in walking and the ability to recover from slips associated with increasing age. An experiment is proposed to measure how deterioration of lower extremity muscular strength activation rate, and sensory functions among older individuals affect several biomechanical parameters under normal and abnormal conditions. Independent variables for the experiment will include; age groups (3 levels - l8 to about 35 years, 40-60 years, and 65 years or over), and floor surfaces (2 levels - oily vinyl tiles and outdoor carpet). Biomechanical parameters measured will include: hamstrings muscle activation rate, horizontal heel contact velocity, friction demands, slip distances, and the joint reactive moments (ankle, knee, and hip). Prior to the experiment, a sensory organization test (SOT) and muscle control test (MCT) will be performed on all subjects to obtain information concerning the proprioceptive, visual, and vesicular functions as well as muscle control reaction) times. Isometric and isokinetic tests will be performed to evaluate leg strength. It is hypothesized that older adults' musculoskeletal and sensory degradation will constrain the counterbalancing joint reactive moments to reduce segmental motion during recovery from slips and falls, and expose older individuals to a higher likelihood of slip and fall accidents. This information will allow engineers to design better work environments and jobs to reduce the incidence of slips and falls for an aging workforce. Additionally, it will provide information on possible intervention strategies (muscle strengthening and balance exercises) for improving dynamic equilibrium in older workers.

National Institute of Health (NIH)
National Institute for Occupational Safety and Health (NIOSH)
Research Scientist Development Award - Research & Training (K01)
Project #
Application #
Study Section
Safety and Occupational Health Study Section (SOH)
Program Officer
Newhall, Jim
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Virginia Polytechnic Institute and State University
Engineering (All Types)
Schools of Engineering
United States
Zip Code
Liu, Jian; Lockhart, Thurmon E (2009) Age-related joint moment characteristics during normal gait and successful reactive-recovery from unexpected slip perturbations. Gait Posture 30:276-81
Lockhart, Thurmon E (2008) An integrated approach towards identifying age-related mechanisms of slip initiated falls. J Electromyogr Kinesiol 18:205-17
Lockhart, Thurmon E; Spaulding, Jeremy M; Park, Sung Ha (2007) Age-related slip avoidance strategy while walking over a known slippery floor surface. Gait Posture 26:142-9