Tenosynovitis, CTS and RSI – Medical Background, the Meaning for the Laboratory and Possible Prevention

In a study by Björksten et al. 1994 [1], approximately 60 % of female laboratory technicians who pipetted more than 300 hours per year, reported hand ailments. Buckle and David 1997 [2] reported that approximately 90 % of participants complained of problems in the hand area following continuous pipetting for 60 minutes. The possible health consequences of such strain in the laboratory are obvious. Half of all actions in our hand are performed by the thumb. Also during pipetting, it is the main actor among the fingers [3]. In order to move the thumb during pipetting, two antagonistic and two agonistic muscles are required. Static activity of these muscles, where “static” is defined as holding a muscle tone for longer than 4 seconds, can, in combination with an extension of the metacarpophalangeal joint (as is the case when operating the push button of a pipette) increase the risk of suffering tenosynovitis (“tendinitis”) [4]. In their entirety, the carpal joints resemble a convex “roof” which forms a tunnel system for nerves, tendons and tendon sheaths. For this reason, an inflammation of these joints may cause swelling inside the tunnel system, which, in turn, can lead to carpal tunnel syndrome or medianus compression, respectively (ICD-10 Code for CTS: G 56.0) [5]. Tenosynovitis and CTS are only two of the numerous injuries which may be caused long-term by a pathophysiological mechanism for work-induced musculoskeletal disturbances in the lower arm and hand area, the RSIs Eppendorf PhysioCare Concept 6 | March 2012