Environmental conditions and performance outcomes: a preliminary report of implications for patient outcomes.

Background: Whereas a host of studies have established various forms of experimental bias, few clinical investigations have examined the relationship of the behavior of the observer or examiner to a subject's physical performance.

Objective: To measure the grip strength of volunteers in 2 distinct clinical "environments."

Methodology: Twenty subjects were randomized in a crossover design to undergo grip strength testing in positive and negative environments as created by the distinctly different behavioral/communication approaches of the research staff.