AIM To analyze neuromuscular activity patterns of the trunk in healthy controls(H) and back pain patients(BPP) during one-handed lifting of light to heavy loads. METHODS After assessment of back pain(graded chronic pa...AIM To analyze neuromuscular activity patterns of the trunk in healthy controls(H) and back pain patients(BPP) during one-handed lifting of light to heavy loads. METHODS After assessment of back pain(graded chronic pain scale according to von Korff) all subjects(n = 43) performed a warm-up(treadmill walking). Next, subjects were instructed to lift 3 × a 20 kg weight placed in front of them(with both hand) onto a table(height: 0.75 m). Subsequently, all subjects lifted with one hand(left-side, 3 repetitions) a weight of 1 kg(light), 10 kg(middle) and 20 kg(heavy) in random order from the ground up onto the table left of them. Trunk muscle activity was assessed with a 12-lead EMG(6 ventral/6 dorsal muscles; 4000 Hz). EMG-RMS(%) was averaged over the 3 repetitions and analyzed for the whole one-handed lifting cycle, then normalized to RMS of the two-handed lifting. Additionally, the mean(normalized) EMG-RMS of four trunk areas [right/left ventral area(VR/VL); right/left dorsal area(DR/DL)] was calculated. Data were analyzed descriptively(mean ± SD) followed by student's t-test comparing H and BPP(α = 0.05). With respect to the unequal distribution of subjects in H and BPP, a matched-group analysis was conducted. Seven healthy controls were gender- and age-matched(group H_(matched)) to the 7 BPP. In addition, task failure was calculated and compared between H/H_(matched) vs BPP using χ~2. RESULTS Seven subjects(3m/4f; 32 ± 7 years; 171 ± 7 cm; 65 ± 11 kg) were assigned to BPP(pain grade ≥ 2) and 36(13m/23f; 28 ± 8 years; 174 ± 10 cm; 71 ± 12 kg) to H(pain grade ≤ 1). H and BPP did not differ significantly in anthropometrics(P > 0.05). All subjects were able to lift the light and middle loads, but 57% of BPP and 22% of H were not able to lift the heavy load(all women). χ~2 analysis revealed statistically significant differences in task failure between H vs BPP(P = 0.03). EMG-RMS ranged from 33% ± 10%/30% ± 9%(DL, 1 kg) to 356% ± 148%/283% ± 80%(VR, 20 kg) in H/BPP with no statistical difference betw展开更多
基金Supported by German Federal Institute of Sport Science and realized under the auspices of MiSpEx-the National Research Network for Medicine in Spine Exercise,No.BISp IIA1-080102A/11-14funded by the European Union(European Regional Development Fund),No.80132471
文摘AIM To analyze neuromuscular activity patterns of the trunk in healthy controls(H) and back pain patients(BPP) during one-handed lifting of light to heavy loads. METHODS After assessment of back pain(graded chronic pain scale according to von Korff) all subjects(n = 43) performed a warm-up(treadmill walking). Next, subjects were instructed to lift 3 × a 20 kg weight placed in front of them(with both hand) onto a table(height: 0.75 m). Subsequently, all subjects lifted with one hand(left-side, 3 repetitions) a weight of 1 kg(light), 10 kg(middle) and 20 kg(heavy) in random order from the ground up onto the table left of them. Trunk muscle activity was assessed with a 12-lead EMG(6 ventral/6 dorsal muscles; 4000 Hz). EMG-RMS(%) was averaged over the 3 repetitions and analyzed for the whole one-handed lifting cycle, then normalized to RMS of the two-handed lifting. Additionally, the mean(normalized) EMG-RMS of four trunk areas [right/left ventral area(VR/VL); right/left dorsal area(DR/DL)] was calculated. Data were analyzed descriptively(mean ± SD) followed by student's t-test comparing H and BPP(α = 0.05). With respect to the unequal distribution of subjects in H and BPP, a matched-group analysis was conducted. Seven healthy controls were gender- and age-matched(group H_(matched)) to the 7 BPP. In addition, task failure was calculated and compared between H/H_(matched) vs BPP using χ~2. RESULTS Seven subjects(3m/4f; 32 ± 7 years; 171 ± 7 cm; 65 ± 11 kg) were assigned to BPP(pain grade ≥ 2) and 36(13m/23f; 28 ± 8 years; 174 ± 10 cm; 71 ± 12 kg) to H(pain grade ≤ 1). H and BPP did not differ significantly in anthropometrics(P > 0.05). All subjects were able to lift the light and middle loads, but 57% of BPP and 22% of H were not able to lift the heavy load(all women). χ~2 analysis revealed statistically significant differences in task failure between H vs BPP(P = 0.03). EMG-RMS ranged from 33% ± 10%/30% ± 9%(DL, 1 kg) to 356% ± 148%/283% ± 80%(VR, 20 kg) in H/BPP with no statistical difference betw
