A Surgeon's Upper Extremity Muscle Activation Patterns During a Bowel Inspection under Three Different Surgical Conditions
Abstracts
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Little information is available concerning the effectiveness of training models in obtaining the necessary motor skills to perform minimally invasive surgery (MIS) or how these movement patterns might differ from open surgery (OS). The goal of this case study was to examine if similar muscle activation patterns exist when performing the same task during three conditions (training box, MIS, and OS). To measure muscle activity, bipolar surface electromyography (EMG) electrodes were placed over the subject's right deltoid, trapezius, bicep, pronator teres, flexor carpi ulnaris, and extensor digitorum superficialis muscles. The surgeon performed three trials of a simulated bowel exam using a standard training box. On a separate visit, the surgeon performed an additional three trials each of a bowel inspection using both MIS and OS techniques on two separate cadaveric pigs. Resting and maximum voluntary isometric contraction EMG values for each muscle group were used to normalize the average percentage of time the muscle was 'on' (PTO) relative to their voluntary maximum isometric contraction. A muscle was considered 'on' if its percentage of activation exceeded the resting EMG value by at least 10%. A multivariate ANOVA (p < .05) was used to compare the relationship of EMG patterns between conditions. The PTO was greater for all muscles during the use of the training box compared to the other two conditions with the exception of the deltoid, which demonstrated a lower PTO than either MIS or OS. In addition, MIS demonstrated greater PTO values than OS with the exception of the trapezius. The results indicate that the training box was the most ergonomically difficult task since it required the greatest PTO for the majority of the muscles. This suggests that the training box does provide adequate motor challenges for MIS training, but may put the surgeon at the greatest risk for a cumulative trauma injury as compared to either surgical event on the porcine model. In conclusion, this case study suggests that further work is warranted in this area to determine if these results are reproducible with additional surgeons. |
