Showing papers by "Stephen D. Perry published in 1999"
TL;DR: Evidence is provided that mechanical facilitation of sensation from the boundaries of the plantar surface of the foot can improve the efficacy of certain types of stabilizing reactions evoked by unpredictable postural perturbation.
Abstract: Background. One of the more pervasive effects of aging is loss of cutaneous sensation, which appears to correlate with im paired postural control and increased risk of falling. This study examined the potential for compensating for the destabilizing effects of reduced cutaneous sensitivity by placing a raised edge underneath the perimeter of the plantar foot surface, so as to facilitate sensation from the stability boundaries of the base of support. Methods.The main experiment involved 14 healthy older adults (aged 65-73) selected because they were known, from a previous study, to have moderate plantar cutaneous insensitivity. We also report results of an initial experiment involving 7 healthy young adults (aged 23-31). In both experiments, we studied effects of the plantar facilitation on control of rapid step ping reactions evoked by unpredictable postural perturbation, applied via sudden platform movement in forward, backward, and lateral directions. We also studied effects on "feet-in-place" responses evoked by continuous pseudorandom platform mo tion in mediolateral and anteroposterior directions. Subjects were blindfolded in all tests. Results.Plantar facilitation reduced the incidence of "extra" limb movements, beyond the initial step, during forward-step reactions in the older adults. There also appeared to be an improved ability to control feet-in-place reactions: young subjects were better able to recover balance without stepping when falling backward (given instructions to "try not to step"), and both young and older subjects reduced the extent to which the center of foot pressure approached the posterior foot boundary during continuous anteroposterior platform motion. Conclusions. This study provides evidence that mechanical facilitation of sensation from the boundaries of the plantar surface of the foot can improve the efficacy of certain types of stabilizing reactions evoked by unpredictable postural perturbation. The re sults may bedirectly transferable to the design of special footwear insoles to reduce instability and risk of falling in older adults.
206 citations
TL;DR: The benefits of any fixation method, in terms of cervical spine immobilization, are likely to be limited unless the motion of the trunk is also controlled effectively, and future research and development should address techniques to better control head and trunk motion.
Abstract: Study design Laboratory experiment. Objective To compare the efficacy of different head immobilization techniques during motion simulating ambulance transport. Background A significant number of neurologic injuries associated with cervical spine fractures arise or are aggravated during emergency extrication or patient transport. Previous studies have not addressed the effect of head immobilization on the passive motion that could occur across the neck during transport. Methods Three different head-immobilization methods were compared in six healthy young adults by using a computer-controlled moving platform to simulate the swaying and jarring movements that can occur during ambulance transport. In all tests, the trunk was secured by means of a commonly used "criss-cross" strapping technique. Efficacy of head immobilization was evaluated using measures of head motion and neck rotation. Results None of the three immobilization techniques was successful in eliminating head motion or neck rotation. Movement of the trunk contributed substantially to the lateral bending that occurred across the neck. A new product involving the placement of wedges underneath the head provided some small, but statistically significant improvements in fixation of the head to the fracture board; however, there was no improvement in terms of the relative motion occurring across the neck. Conclusions Somewhat improved fixation of the head to the fracture board can be achieved by placing wedges under the head; however, the benefits of any fixation method, in terms of cervical spine immobilization, are likely to be limited unless the motion of the trunk is also controlled effectively. Future research and development should address techniques to better control head and trunk motion.
47 citations
TL;DR: This article applied the universal value structure theory articulated by Schwarrs and Bilsky (1987) to mass communication and employed value type analysis to investigate how respondents' cultural background and television viewing habits are related to their perceptions of the importance of value types and to individualistic or collectivistic value structures.
Abstract: Applying the postulates and methodology of the universal value structure theory articulated by Schwarrs and Bilsky (1987, 1990) to mass communication, this study employs value type analysis to investigate how respondents' cultural background and television viewing habits are related to their perceptions of the importance of value types and to individualistic or collectivistic value structures. In this study, we found significant relations between television program genres viewed and individualist, collectivist, and mixed value types. The findings indicate that-throughout individualist, collectivist, and mixed value types-television program genre usually serves as a stronger predictor of value type importance than do demographic variables.
7 citations
TL;DR: The Power of Broadcast Radio in Thirties America: The Power of Radio in Twenty-First-Century America (2nd ed. as discussed by the authors ). New York: Rosen Publishing Group, Inc., 1998.
Abstract: John Zondlo. Discovering Dxing! How to hear distant AM, FM & TV stations (2nd ed.). Reynoldsburg, OH: Universal Radio Research, 1998. Chris Weigant. Careers as a Disc Jockey. New York: Rosen Publishing Group, Inc., 1998. Michele Hilmes. Radio Voices: American Broadcasting, 1922–1952. Minneapolis: University of Minnesota Press, 1997. Robert J. Brown. Manipulating the Ether: The Power of Broadcast Radio in Thirties America. Jefferson, NC, 1998. Tony Jones, editor. International Broadcasting Services, Ltd. Passport to Web Radio (2nd ed.). Penn's Park, PA: IBS North America, 1998. Joanna R. Lynch & Greg Gillispie. Process and Practice of Radio Programming. Lanham: University Press of America Inc., 1998. Tim Crook. International Radio Journalism: History, Theory and Practice. London: Routledge, 1998. Michael B. Kassel. America's Favorite Radio Station: WKRP in Cincinnati. Bowling Green, OH: Popular Culture Press, 1993. Robert L. Hilliard and Michael C. Keith. Waves of Rancor: Tuning in the Radical Right. Armon...