Functional Capacity Evaluations (FCE) on Persons with Low Back Pain and Healthy Controls by using Surface Electromyography (EMG)

Chia-Chun Hung*, Tsu-Wang Shen
Institute of Medical Informatics, Tzu Chi University, Hualien, Taiwan
慈濟大學學術研討會(2009)
Abstract:
Background and Purpose
Functional Capacity Evaluations (FCE) is widely applied for workers’ compensation, insurance issues and case management decisions. We want to find the relationship between pain states and EMG by using FCE.

Method:
EMG data from ten volunteer subjects was collected from Tzu Chi university students and hospital staffs. The including criteria is based on the diagnosis of physician. The excluded criteria include unclear conscious, injured upper extremities, acute back pain or post surgery. Eight of ten subjects were identified as chronic and past history. The other two subjects are identified as normal. Subjects were asked to execute FCE with randomly selected the lifting weights. The started weight is defined as 50% of maximum grasp power. Surface electrodes were placed bilaterally over the greatest convexity of the erector spine muscles at the L2/L3 and L4/L5 level with a fix distance at 5 cm. Biopac MP35 is used for EMG data acquisition with sampling rate at 1000 Hz. Both root-mean-square (RMS) voltage and spectra of short-term Fourier transformation (STFT) were investigated for the whole test period by the MATLAB software.
Results
By observing the spectrum of STFT, there are no distinct biomarkers that may classify LBP and normal control. It is promising to find that the slope of RMS can classify two groups with 75% sensitivity, 100% specificity, and 80% accuracy. Moreover, when the times of lifting are increased, the sensitivity is 100%, the specificity is 100%, and the accuracy is 100%.For further analysis and method improvement, more data samples are necessary.
Conclusions:
Previous researches indicated RMS which is associated with subjects’ motivation or cooperation to exert power, so more biomarkers are needed. In the future, fatigue index may apply as another factor for study.