A shovel with a perforated blade reduces energy expenditure required for digging wet clay. Hum Factors 2010 Aug;52(4):492-502
Date
12/15/2010Pubmed ID
21141242DOI
10.1177/0018720810379850Scopus ID
2-s2.0-79952198981 (requires institutional sign-in at Scopus site)Abstract
OBJECTIVE: A shovel with a blade perforated with small holes was tested to see whether a worker would use less whole-body energy to dig wet clay than with a shovel with an opaque blade.
BACKGROUND: A perforated shovel is hypothesized to require less whole-body energy on the basis of adhesion theory; a smaller surface area would require less physical effort to dig and release soil from the blade.
METHOD: The study involved 13 workers from an electric utility who dug wet clay with two 1.5-m long-handled point shovels, which differed only in blade design (perforated and opaque). Oxygen consumption was measured with a portable system while each worker dug wet clay at a self-regulated pace for 10 min.
RESULTS: There was no significant difference in number of scoops dug during the 10-min sessions, but workers dug 9.5% more weight of clay with the perforated shovel than with the conventional shovel (404 kg vs. 369 kg, respectively). Furthermore, stable oxygen uptake normalized to weight of participant and to the weight of clay dug revealed that participants expended 11.7% less relative energy per kilogram of clay dug with the perforated shovel.
CONCLUSION: A point shovel with a perforated blade is recommended for digging and shoveling wet clay. However, the extra weight that workers chose to dig with the perforated shovel may increase the loading on the spine and may offset the metabolic advantages.
APPLICATION: Manual shoveling is a common task, and workers may experience less whole-body and muscle fatigue when using a perforated shovel.
Author List
Harivanam S, Marklin RW, Papanek PE, Cariapa VAuthor
Paula Papanek PhD, MPT, LAT, FACSM Associate Professor & Director of Exercise Science in the Exercise Science & Physical Therapy department at Marquette UniversityMESH terms used to index this publication - Major topics in bold
AdultAluminum Silicates
Biomechanical Phenomena
Body Weight
Energy Metabolism
Humans
Male
Microcomputers
Middle Aged
Oxygen Consumption
Time Factors
Work
