Ray McGorry

Ray-Portrait

rmcgorry@yahoo.com

 

 

 

Raymond McGorry was a Senior Research Scientist at the Liberty Mutual Research Institute for Safety from 1993-2014. Ray began his research career with the Center for Safety Research, and then following the institute expansion and reorganization, was a researcher the Center for Physical Ergonomics. During his 22 year tenure he authored/co-authored 75 peer-reviewed journal articles. His research focused on work-related injury and illness in both clinical and laboratory investigations. His research interests spanned the areas or biomechanics, postural stability measures, slips and falls prevention, force and exposure measurement during hand tool use, and evaluation and treatment of back pain. During his working career at LMRIS he was awarded two patents related to human performance measurement and movement.

Research conducted at LMRIS was, almost by definition, extremely collaborative and multi-disciplinary. Since all research was internally funded, once scientific and business relevance was demonstrated, researchers were free to create research teams by collaborating with researchers within and across institute centers, as well as with external (typically academic) scientists. The goal of any and all research conducted at LMRIS was to produce publishable quality research that could aid in quantifying, preventing, or mitigating of workplace injury and disease, or related disability. To this end Mr. McGorry conducted or collaborated in research in several areas. Examples of his research follow:

Upper Extremity / Hand Tool Use –

Direct measurement – Significant research effort was invested in methodologies and instrumentation to measure force exposure in tasks as diverse as shoveling snow, operating pneumatic nut runners, and scooping ice cream.1-3 Expanding on this direct measurement approach, a research program emerged focusing on studying forces related to hand tool use. Quantifying gripping forces exerted on tool handles presented unique challenges, as grip forces were difficult to measure accurately with existing measurement systems. To satisfy this need, a unique measurement technique was developed using force transducers embedded in an instrumented core, that could be configured to simulate a variety of hand tools.4,5

Evaluation of the quality of self-estimated grip forces – It was found that individuals varied greatly in their ability to accurately estimate gripping forces, but the mean estimate of a population of 16 or more individuals gave a reasonable approximation of mean grip force on a handle.6 Estimate quality was also found to be affected by the nature of the external force application and handle configuration.7

Exposure assessment in meat cutting tasks – A high incidence of work-related upper extremity injury and disease has long been associated with working in the meat packing industry. We investigated gripping and cutting forces associated with poultry, pork and beef processing tasks, and observed high gripping and cutting forces coupled with very high frequency cutting.8 The effect of knife sharpness on exposure was also assessed in a field study using a unique sharpness testing system.9

Carpal tunnel pressure – fluid pressures developing within the carpal tunnel have been implicated as a potential risk factor for the development of carpal tunnel syndrome. Using a pressure transducer implanted within the carpal tunnel in 16 healthy individuals we measured the pressures associated with several gripping tasks. In addition to previous reports of pressure elevation with wrist flexion, we observed significantly elevated pressures at end range wrist extension.10

 

Slips and Falls-

In addition to a well-developed tribology-based research program (see Wen Chang), additional research was conducted with a focus on measurement of micro-slips, the very small heel movements occurring at, or immediately following heel strikes. A first priority was to document the presence of micro-slips during realistic walking conditions, and to determine if their observation could be useful to the identification of potentially slippery conditions. This was accomplished in a laboratory study with participants walking under various heel-floor interface conditions. Several articles followed, characterizing unique features of the kinematics of the heel-floor interface.11,12 A system using heel-mounted accelerometers was developed and validated, providing the basis for a potential field-based measurement of heel slippage.13

 

Low Back Pain (LBP)

Exposure assessment – several projects were undertaken to quantify potential risk factors for low back “injury” One effort involved measurement of intra-abdominal pressure, which, according to several models was theorized to modulate (reduce) moments about the lumbar spine during lifting. This study involved passing a pressure sensor through the nose and into the stomach, to measure change in abdominal pressures during lifting tasks while using breath-holding techniques with, and without back belts.14 This study required developing instrumentation to measure lumbar curvature to evaluate the effect of the back belt on lumbar lordosis. 15 Another study examined the effect back pain had on the flexion relaxation response, a feature observed in lumbar EMG. 16

*This list is not meant to be an exhaustive presentation of the work of Mr. McGorry, but rather as example of the type of the research conducted by he and his colleagues at the Liberty Mutual Research Institute for Safety.

References

 

  • McGorry RW, Dempsey PG, Leamon TB. The effect of technique and shaft configuration in snow shoveling on physiologic, kinematic, kinetic and productivity variables.  Applied Ergonomics, 2003; 34:225-231.

 

  • Lin J-H, McGorry RW, Dempsey P G, & Chang C-C. Effects of user experience, working posture, and joint hardness on powered nutrunner torque reactions. Ergonomics, 2007;50:859-876.

 

  • Dempsey PG, McGorry RW, Cotnam J, Braun TW. Ergonomic investigation of retail ice cream scooping operations. Applied Ergonomics, 2000;31:121-130

 

  • McGorry RW. A system for the measurement of grip forces and applied moments during hand tool use.  Applied Ergonomics, 2001;32:271-279.

 

  • McGorry RW, Lin JH. Power grip strength as a function of tool handle shape, orientation and location. Ergonomics, 2007;50:1392-1403.

 

  • McGorry RW, Lin JH, Dempsey PG, Casey JS. Accuracy of the Borg CR10 scale for estimating grip forces associated with hand tool tasks.  Journal of Occupational and Environmental Hygiene, 2010;7:298-306.

 

  • McGorry RW, Dempsey PG, Casey JS. The effect of force distribution and magnitude at the hand-tool interface on the accuracy of grip force estimates.  Journal of Occupational Rehabilitation, 2004; 14:255-266.

 

  • McGorry RW, Dowd PC, Dempsey PG. A technique for field measurement of knife sharpness.  Applied Ergonomics, 2005, 36:635-640.

 

  • McGorry RW, Dowd PC, Dempsey PG. Cutting moments and grip forces in meat cutting operations and the effect of knife sharpness.  Applied Ergonomics, 2003;34:375-382.

 

  • McGorry RW, Fallentin N, Andersen JH, Keir PJ, Hansen TB, Pransky GS, Lin JH. Effect of grip type, wrist motion and resistance level on pressures within the carpal tunnel of normal wrists. J Orthop Res. 2014;32(4):524-30.

 

  • McGorry RW, Chang CC, DiDomenico A. Rearward movement of the heel at heel strike. Applied Ergonomics, 2008;39:678-684.

 

  • McGorry RW, DiDomenico A, Chang CC. The anatomy of a slip: Kinetic and kinematic characteristics of slip and non-slip matched trials. Applied Ergonomics, 2010;41:41-46.

 

  • McGorry RW, DiDomenico A, Chang CC. The use of a heel-accelerometer as an adjunct measure of slip distance. Applied Ergonomics, 2007;38:369-376.

 

  • McGorry RW, Hsiang SM. The effect of industrial back belts and breathing technique on trunk and pelvic coordination during a lifting task. Spine, 1999;24:1124-1130.

 

  • McGorry RW, Hsiang SM. A method for dynamic measurement of lumbar lordosis. Journal of Spinal Disorders, 2000,13(2)118-123.

 

  • McGorry RW, Lin J-H. Flexion relaxation and its relation to pain and function over the duration of a back pain episode. PLoS ONE 7(6): e39207. doi:10.1371/journal.pone.0039207, 2012.