Jin Qin


Repetitive motion injuries (RMIs) are disorders of the soft tissues due to repeated exertion and excessive movement of the body. Sign language interpreters who have to move their fingers, hands, wrists and arms repeatedly are susceptible to RMIs. One of the major research voids in the studies of RMIs in sign language interpreters is the lack of quantification of biomechanical exposures. The objective of this study was to analyze the impact of pace and psychosocial stress of sign language interpreting on the biomechanical responses in a quantitative manner and compare the results with the industrial high risk benchmarks.

Twelve professional sign language interpreters participated in this study with a one-half hour interpreting task. Biomechanical variables in flexion/extension and radial/ulnar planes of wrist motion in different pace and stress conditions were measured. It was found that pace has a significant positive effect on bilateral biomechanical responses while a positive stress effect was found only for the left hand. The dominant hand was significantly more physically stressed than the non-dominant hand, as indicated by wrist kinetic variables and other wrist motion variables measured in this study. In addition, wrist kinetic variables of sign language interpreting were found similar to or higher than the high risk industrial benchmarks. The results of this study proved with quantitative data that sign language interpreting is a high risk job of RMIs, requiring highly deviated wrist positions, ballistic wrist movements, and highly repetitive wrist motions. The results also shed light on how different factors may influence the biomechanical responses of sign language interpreters.

Library of Congress Subject Headings

Wrist--Wounds and injuries; Wrist--Mechanical properties; Overuse injuries; Interpreters for the deaf--Effect of stress on

Publication Date


Document Type


Student Type


Degree Name

Industrial and Systems Engineering (MS)

Department, Program, or Center

Industrial and Systems Engineering (KGCOE)


Matthew Marshall

Advisor/Committee Member

Jacqueline Mozrall


Physical copy available from RIT's Wallace Library at RD559 .Q56 2005


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