Relationship between surface electromyography of the spinae erector musclesand subjectively adjusted step length in the supporting standing-up motion

摘要

[Purpose] Caregivers experience low back pain owing to frequent patient handling motionssuch as supporting the body while standing up. To prevent low back pain in caregivers, lowload posture while engaging in patient handling motions is required. We determined therelationship between surface electromyography of the erector spinae muscles and subjectivestep length as “long” and “short” during the supporting standing-up motions of caregivers.[Participants and Methods] Ten young male participants were asked to perform supportingstanding-up motion 10 times using two-step lengths comprised of subjective long and shortsteps. During supporting standing-up motion, we measured surface electromyograms of theerector spinae muscles and calculated the integral electromyographic values. [Results] Thesubjective long/short-step length normalized by body height did not differ across theparticipants. In addition, the subjective long-step length was longer than the subjectiveshort-step length in all the participants. Integral electromyographic values for both theleft and right erector spinae muscles in the short-step length were significantly lowerthan those in the long-step length when the data obtained from all the participants wereused. [Conclusion] We considered that the load of the erector spinae muscle will bereduced if the short-step instead of the long-step instruction is given. In the future,instructions based on the subjective step-length variation in caregivers must beconsidered.