The Effect of Short Time Computer Work on Muscle Oxygenation in Presence of Delayed Onset Muscle Soreness

We aimed at investigating the effect of a short time low load repetitive task on the local muscle oxygenation kinetics in presence of delayed onset muscle soreness. Computer work was investigated as a model of low load repetitive task. Nine healthy male subjects participated in an experimental protocol consisting of a rest period and two blocks, each including two maximum voluntary contractions (MVC) of isometric bilateral shoulder elevation and a computer work session with 2 or 5 min duration between the MVCs in each block. Then a set of unaccustomed eccentric exercise (ECC) of shoulder elevation was implemented to induce delayed onset muscle soreness (DOMS) in the trapezius muscle. Identical experimental blocks were performed immediately and 24 h after ECC. Local tissue saturation index (TSI) was continuously recorded over upper trapezius throughout the experiment. TSI parameters such as mean TSI at rest, during computer work as well as TSI drop, recovery and their descending and ascending slopes were computed following the MVCs. TSI drop and recovery and their corresponding descending and ascending slopes were reduced immediately after ECC (p < 0.05). The computer work caused an increase in TSI at rest prior to the MVCs (p < 0.05) and elevated oxygen consumption (p < 0.05). The observed changes in oxygenation kinetics seemed to appear after a strenuous exercise and they do not seem to be affected by the presence of DOMS. However, computer work as a model of low load repetitive task caused increased oxygen consumption in a following bout of muscle contraction.