The effect of intraarticular anesthesia and elastic bandage on elbow proprioception

Twenty uninjured male volunteers were studied to characterize normal elbow proprioception and to investigate the effect of applying an elastic bandage to the extremity and injection of an intraarticular anesthetic. A modified Biodex dynamometer was used to study position sense and detection of motio n. In part 1 of the study position sense was tested by flexing the elbow to a predetermined angle, returning to the starting position, and then asking the subject to identify that angle. In part 2 detection of motion was test ed by asking the subject to disengage the apparatus by pressing a stop butt on when movement was detected. The testing conditions in part I and part 2 were repeated after the elbow was wrapped with an elastic bandage and again after an intraarticular injection of 3 cc 1% lidocaine with the bandage re moved. Ten additional subjects underwent testing of both elbows to examine the effect of arm dominance. Mean position sense was within 3.3 degrees +/- 1.3 degrees of the actual angle in trials without an elastic bandage or an anesthetic. A significant improvement in position sense was observed (2.2 degrees +/- 1.2 degrees) after an elastic bandage was applied (P < .004). N o significant difference was seen in position sense after lidocaine was inj ected The mean threshold for detection of motion in trials without an elast ic bandage or an anesthetic was 4.21 degrees +/- 1.56 degrees. No significa nt differences were seen in detection of motion observed with the elastic b andage or intraarticular anesthetic. No significant differences were seen b etween dominant and nondominant extremities for both position sense and det ection of motion. The application of an elastic bandage improved position sense, suggesting t hat tactile cues From cutaneous or other extraarticular receptors may play a role in elbow proprioception. Intraarticular anesthesia, however, had lit tle effect, suggesting that intracapsular receptors play a lesser role in e lbow proprioception. The determination of proprioceptive qualities for the normal elbow can aid in the understanding of elbow function and provide a b asis for defining its role in elbow dysfunction.