Background: The impact of physical reactions on human operators generated byhandheld powered tightening tools has been researched by evaluating variousparameters, here referred to as ‘reaction parameters’. The objective of this literaturereview is to investigate which reaction parameters commonly are assessed duringphysical load evaluations of tightening tools, as well as reported correlations betweenreaction parameters and risk of developing cumulative trauma disorders (CTDs). Anadditional aim is to map exposure limits established for reaction parameters and identifyknowledge gaps regarding tightening tool impact on operators, if any.Methods: A systematic approach was adopted to review relevant literature, followingthe PRISMA flow-diagram. Synonyms of defined keywords were combined for search in3 databases. 76 articles were read and evaluated against inclusion criteria, of which 47articles where included in a qualitative synthesis. An overview of the assessed reactionparameters was obtained, as well as suggested linkages between these parameters andrisk of injury development.Results: Main parameters studied in literature are reaction force/torque (79%) andhandle displacement (74%). Impulse and handle velocity are studied in 26% and 15% ofthe articles, respectively. 51% of the studies also report a correlation between assessedreaction parameters and risk of developing CTDs. Three studies present exposure limitsfor reaction parameters. 1/3 of the studies were conducted on electric tools, whereasapproximately 2/3 were performed on pneumatic tools.Conclusions: There is a knowledge gap concerning several reaction parametersand their implications for developing CTDs, especially regarding impulse, tool handlevelocity/acceleration and grip force. Their influence is suggested to be explored infurther studies. Establishing exposure limits related to the reaction parameters wouldtranslate the scientific knowledge into industrially applicable recommendations. Further,the need for studies on electric tools is evident, due to a shift in the industry frompneumatic to electric tools.