Amit Bhattacharya - US grants

DESCRIPTION: (Adapted from the investigator's abstract) This proposed two year study provides an experimental design which has the potential for investigating the interaction between age and other fall risk factors such as surface condition and firmness, lighting, peripheral vision, and workload. In the proposed study, postural instability and fall potential of above-mentioned fall risk factors of 100 industrial workers will be evaluated in 32 tests simulating various combinations of these risk factors while performing simulated tasks which might occur in an industrial environment. Subjects ranging in age from 21 years to 55 years will be tested immediately after exposure to light and moderate-to-heavy workloads to quantitate their postural stability while standing on surfaces with different contamination conditions and firmness, peripheral vision (blocked and unblocked), and environmental lighting conditions. Each subject will undergo 32 tests consisting of each of 32 possible treatment combinations among four risk factor conditions and two workloads. Condition 1 will be standing on dry or oily surface. Condition 2 will be "acceptable, good" or "unacceptable, poor" environmental lighting. Condition 3 will be blocked or unblocked peripheral vision, and Condition 4 will be standing on firm or compliant surface. All subjects will also be tested for the measurement of Estimated Maximum Displacement of Center of Pressure (EMAXDCP). The results of this test will provide an estimation of subject's "Functional Stability Boundary" and the calculation of Index of Proximity to Stability Boundary (IPSB). The value of IPSB obtained during the postural stability tests will be used to determine which of the test conditions (out of 32 tests) pushed the body's center of pressure (CP) to or beyond its stability boundary and, therefore, had the potential to create an accident due to a fall. Before and immediately after completion of a workload, the subject will be tested for upright postural sway and postural corrective responses to a number of simulated tasks which might occur in an industrial environment. Postural sway parameters will be measured to investigate the age-associated differences in maintenance of upright postural balance under all combinations of workloads and four risk factor conditions. The results obtained from 32 tests will be rank ordered for fall potential using various criteria. Based on results of the present study, future studies with a larger worker population are planned to develop intervention strategies for fall prevention.

DESCRIPTION: (Adapted from the Investigator's Abstract) Workers (construction workers, roofers, etc.) who work on elevated and/or inclined surfaces have relatively higher incidences of deaths/injuries due to falls than other work related causes. This five year study provides an experimental design which has the potential for investigating the interaction between work experience of working on elevated and/or inclined surface, age, sex, and other fall risk factors such as physical workload, standing surface inclination and environmental lighting. A series of experiments will be carried out with 240 industrial workers (such as roofers, glazers, painters, ironworkers, etc) with and without experience in working on inclined and/or elevated surfaces to test the following hypotheses: a). There will be a difference in workload induced changes in visual spatial perception abilities between the "experienced" workers and the "inexperienced" workers. b). The experienced workers will have smaller numbers of errors in detecting vertical/horizontal cues after exposure to a workload or while standing on an inclined surface, compared to those from inexperienced workers. c). The workload and poor environmental lighting will have detrimental effects (increase in postural sway variables and/or increase in susceptibility to loss of balance as described by appropriate variables in this application later) on inexperienced workers ability to maintain upright postural balance while performing simulated industrial tasks, as compared to experienced workers. d). The highest level of (100 watts) workload and poor environmental lighting either individually and/or collectively will increase the muscular contraction levels needed to maintain upright balance while performing simulated industrial tasks on inclined surfaces. The experienced workers will show lower levels of postural muscular contractions compared to those with no experience. e. The strategically placed visual cues will significantly improve workers ability to maintain upright balance after exposure to the highest workload (100 watts) and poor environmental lighting and lower the levels of muscular contractions of the postural muscles. As no quantitative data regarding the characteristics of postural balance of experienced workers exists the proposed study is designed to collect such data. Availability of such data will allow to 1) develop planned training programs for new workers who have to perform physically demanding tasks on inclined/elevated surfaces 2) to determine the need of visual cues to minimize excessive postural muscle fatigue and provide a safe upright balance maintenance while working on an inclined and/or elevated surfaces.

DESCRIPTION (adapted from the applicant's abstract): Previous studies have shown that succimer is a soft tissue chelator of lead; therefore, potential neurobehavioral health benefits may be expected. However, most of the published studies focused their attention toward succimer's ability to reduce blood lead level without evaluating its impact on neurobehavioral health. The proposed cross-sectional study is designed to evaluate the fine motor and gross motor proficiency as well as postural balance and gait in 200 children [from the Cincinnati Clinical Center for Treatment of Lead in Children (TLC)] who are currently active in a randomized double blind clinical trial designed to assess the effects of lead chelation using the drug succimer. In the proposed study, we will be assessing postural balance and gait and fine and gross motor development after the TLC children have completed their succimer or placebo program and the TLC follow-up period. The postural balance and gait and fine and gross motor assessments will be carried out with established techniques which have been used by us over 13 years on the Cincinnati Lead Program Project (LPP) cohort. The postural balance and gait will be assessed with a microprocessor-based force platform system along with a test protocol which indirectly assesses the roles of various physiological systems relevant for postural balance. The fine motor and gross motor assessments will be carried out using the comprehensive Bruininks-Oserestsky Test of Motor Proficiency (BOTMP) test battery. The TLC clinical trial of succimer is focused mainly on global measures of cognitive development. Assessments of motor development in the gross and fine motor spheres, postural balance and locomotion are not emphasized. Thus, this study will make a unique contribution to our understanding of the developmental benefits of chelation therapy and other measures to reduce lead in the range of exposures that are being considered. Our published findings from Cincinnati LPP cohort with the proposed motor development measurement instrument (BOTMP), postural balance test and locomotion test indicate that these measurement techniques are sensitive and, compared to cognitive measures are relatively uninfluenced by socioeconomic cofactors. Thus, the project has significance for furthering out understanding of the clinical benefits of succimer on developmental aspects of postural balance, locomotional outcomes and fine and gross motor functions in the developing central nervous system in socioeconomically disadvantaged populations.

The proposed study provides an experimental design that addresses two of the priority areas of National Occupational Research Agenda (NORA), i.e. "Work related traumatic injuries" and "Special population at risk-nature and magnitude of the special risk factors experienced by older workers" With the aging of America, it is projected that in the year 2000 there will be at least 59 million between the ages of 45 and 64 yrs. As mandatory retirement age has been abolished, the view of the older worker as a resource is replacing the perspective of the older workers as a liability. Therefore, this new growing workforce of elderly workers needs to be studied carefully to determine their abilities and limitations in the light of some of the work related demands and task associated and environmental risk factors. Therefore, the present study will focus on investigating the role of age associated influence on 113 workers' neuromuscular performance and ability to maintain safe upright postural balance during task performance, such as reaching and bending to pick up objects and walking with weights in hand on various types of surfaces (level and ramp surfaces of known slipperiness) with various kinds of shoe wear. The results from the proposed study will expand our current data base of younger (21 to 55 yrs.) workers' abilities and limitation to include those of older workers up to the age of 75 years. Based on results of the present study, intervention strategies for fall/loss of balance prevention can be developed in a future study: (1) by improving suboptimal environmental conditions; (2) by developing ergonomic solutions to bring the workload to acceptable levels; (3) by identifying certain combinations of risk factors that are more dangerous in producing slips/falls and (4) by determining if there is a need to have hand rails at ramp slope angles less than that currently required by OSHA. Currently, no criteria exists for the need to have handrails during task performance on ramps which are slippery. The results from the proposed study will provide scientific data to determine whether or not older workers are capable of performing tasks on ramp surfaces under various combinations of risk factors.

The manual material handling tasks in underground low seam mines present a myriad of ergonomic risk factors which places inordinate demands on miners' neuromuscular system. Material handling and scaling tasks in restricted posture will cause potential loss of stability/balance to increase therefore, lifting task analysis should include information about postural stability/balance. Currently such information does not exist for material handling in a static stooped posture and dynamic (gait) stooped posture while exposed to individual and/or combined ergonomic risk factors commonly found in an underground mine. The proposed study provides the design to collect such information in a series of experiments (41 hours of testing on each worker) with miner workers. For example, all experimental conditions (encompassing risk factors such as, restricted work postures, task type, surface slipperiness, surface unevenness, and environmental lighting and glare) to be evaluated in the proposed study will be rank-ordered for postural instability and/or loss of balance using established objective criteria described in Section D. Also, number of slips/falls experienced during the performance of simulated industrial tasks (described in Section D) will allow us to determine the relationship between measures of postural instability and/or loss of balance and actual incidence of slips/falls in the simulated environment. The results will provide enhancement (by adding new risk factor effects) to our existing statistical model of prediction of postural instability assoicated with work place risk factors encompassing environmental, job-task factors. These findings will provide the framework within which future mining worker- population-based prospective studies can be designed to address the following issues. A) Provide guidelines for mining workplace design to allow appropriate sufficient floor spacing so that workers can increase their base of support, minimizing the potential of postural instability. B) The results can be used as scientific data input about postural instability under various combinations of mine related risk factors as input into the MSHA's training programs where softwares are being developed to include human factors issues.

DESCRIPTION (provided by applicant): Osteoporosis has a significant impact on the United States population, with more than 25 million people affected by the disease. Often times, this predisposed degenerative disease leads to about 1.3 million fractures per year with the costs being in excess of 10 billion dollars. This revised grant application will develop and evaluate a novel and yet economical technique, which has the potential to be used as a non-invasive and objective tool for detecting indications of spine fractures in post-menopausal osteoporotic women. The proposed non-invasive technique can provide critical information about the quality of the bone that can supplement traditional DEXA bone mineral density (BMD) measurements. The post-menopausal osteoporosis technique will utilize miniature skin mounted accelerometers to capture the changes in effective damping capacities and other mechanical properties (including brittleness) of natural shock absorbers of the human musculoskeletal systems (soft tissues including muscles and trabecular bone which has significant elastic capacity in healthy bones), associated with heel strike induced force propagation. The literature lacks information regarding how osteoporosis affects natural shock absorbers. The potential of success for the proposed technique's ability to capture shock absorption properties of osteoporotic bones is high since preliminary studies from our group have successfully quantitated natural shock absorbers of the musculoskeletal system in another type of degenerative musculoskeletal diseases i.e. osteoarthritic patients. The proposed technique is totally non-invasive, objective, simple and quick to administer. The proposed study will focus on measuring natural shock absorption properties of postmenopausal osteoporosis with and without fractures and supplement information gathered from BMD measurements. Once the proposed technique shows promise future prospective study will allow determination of the effectiveness of the technique to diagnose individuals at risk for fracture, pre-clinically.

DESCRIPTION (provided by applicant): The proposed study is designed to provide transformative knowledge for the first time, about how childhood history of environmental lead (Pb) exposure impacts combined bone and musculature (CBAM) health later in life among African American women. While blood lead concentrations (PbB) in the general population of the U.S. have declined since the discontinuation of Pb as a gasoline additive, Pb sequestered in bone continues to be a source of internal exposure for millions of women, especially minorities exposed to moderate to high levels of Pb during their formative years. African-American women have lower dietary calcium, more likely to be lactose intolerant, vitamin D deficient and have environmental Pb exposure that is associated with lower birth weight, poor postural balance and falls. Therefore, combined risks of nutritional status and Pb exposure potentially compromise several bone and muscular parameters. These include bone mineral content (BMC), bone mineral density (BMD), lower birth weight affecting postnatal bone growth and structural integrity of CBAM. Lower structural integrity suggests reduced ability of CBAM to absorb externally applied dynamic loads thereby increasing susceptibility to bone fracture. The energy absorption or damping (?) ability of the CBAM system is measured with a non-invasive, bone shock absorption (BSA) tool recently developed by our group. These Pb associated detrimental changes in bone and muscular parameters could collectively predispose to development of early osteoporosis associated susceptibility to fracture than those with no or lower Pb exposure. Furthermore, Pb affects osteoclastic and osteoblastic processes, hormonal signaling pathways, and the rate of growth plate chondrocyte maturation and contributes to functional postural instability (FPS) as an added risk for fall related fractures and injuries. These studies form the basis for our long-term core hypothesis: early life exposure to Pb detrimentally affects bone health as characterized by bone mass, macrostructure of the skeleton, and CBAM's structural integrity ability to sustain dynamic load, as well as postural stability/balance thereby predisposing the subjects to increased fracture risk later in life. The proposed study will be carried out with our existing Cincinnati Lead Study (CLS) cohort; thus allowing us to leverage the extensive data resources of our CLS prospective study which has experienced moderate to high levels of Pb exposure during their early life (late1970s and 1980's) and is now approaching bone maturation age (28-32 years).The first step towards addressing the long term core hypothesis is to evaluate the abilities of the proposed measures of bone's macrostructure, BMD, FPS and ?, collectively and individually for identifying Pb exposed subjects who meet or approach the independent thresholds from the literature for falls, and osteoporosis associated fracture and no fracture as well as from healthy subjects within the CLS age range.