Abstract：
Muscle structural studies on non-specific low back pain in young female nurses are rare. This study aimed to investigate the changes of lumbar extensor and flexor muscle cross-sectional area and fatty infiltration in young female nurses with chronic bilateral non-specific low back pain by lumbar spine magnetic resonance imaging to speculate on the possible pathogenesis.
The magnetic resonance imaging (MRI) data of 58 female nurses with chronic bilateral non-specific low back pain and 60 healthy female controls were analyzed retrospectively. The lumbar extensor and flexor muscle cross-sectional area/intervertebral disc cross-sectional area ratio, as well as magnetic resonance imaging signal intensity of lumbar extensor (erector spinae; multifidus) and flexor muscles (psoas muscle) were measured, calculated and compared between nurses and healthy controls by independent samples t-test. In addition, each mean MRI signal intensity of lumbar extensor or flexor muscles in nurses at different anatomical segments from lumbar vertebrae 2 (L2)-L3 to L5-sacral vertebrae 1 (S1) was also compared, and one-way Analysis of Variance (ANOVA) analyzed the mean MRI signal intensity between muscles in nurses with multiple comparisons.
There was no significant difference in lumbar extensor and flexor muscle cross-sectional area/intervertebral disc cross-sectional area ratio between nurses with chronic bilateral non-specific low back pain and healthy controls, p > 0.01. The magnetic resonance imaging signal intensity in lumbar extensor and flexor muscle was significantly higher in nurses with chronic bilateral non-specific low back pain than in healthy controls, p < 0.01. The MRI signal intensity of lumbar extensor muscle at the lower lumbar segments was higher than at the upper ones. The magnetic resonance imaging signal intensity of the extensor muscle (erector spinae; multifidus) was significantly higher than that of the flexor muscle (psoas muscle), p < 0.01.
This study showed that young nurses with chronic bilateral non-specific low back pain have lumbar extensor and flexor muscle fatty infiltration without muscle atrophy. We hypothesized that muscle fatty infiltration may occur prior to muscle atrophy. Therefore, the high fatty infiltration of the lumbar extensor and flexor muscle may be a cause or a result of chronic bilateral non-specific low back pain in young nurses.
The magnetic resonance imaging (MRI) data of 58 female nurses with chronic bilateral non-specific low back pain and 60 healthy female controls were analyzed retrospectively. The lumbar extensor and flexor muscle cross-sectional area/intervertebral disc cross-sectional area ratio, as well as magnetic resonance imaging signal intensity of lumbar extensor (erector spinae; multifidus) and flexor muscles (psoas muscle) were measured, calculated and compared between nurses and healthy controls by independent samples t-test. In addition, each mean MRI signal intensity of lumbar extensor or flexor muscles in nurses at different anatomical segments from lumbar vertebrae 2 (L2)-L3 to L5-sacral vertebrae 1 (S1) was also compared, and one-way Analysis of Variance (ANOVA) analyzed the mean MRI signal intensity between muscles in nurses with multiple comparisons.
There was no significant difference in lumbar extensor and flexor muscle cross-sectional area/intervertebral disc cross-sectional area ratio between nurses with chronic bilateral non-specific low back pain and healthy controls, p > 0.01. The magnetic resonance imaging signal intensity in lumbar extensor and flexor muscle was significantly higher in nurses with chronic bilateral non-specific low back pain than in healthy controls, p < 0.01. The MRI signal intensity of lumbar extensor muscle at the lower lumbar segments was higher than at the upper ones. The magnetic resonance imaging signal intensity of the extensor muscle (erector spinae; multifidus) was significantly higher than that of the flexor muscle (psoas muscle), p < 0.01.
This study showed that young nurses with chronic bilateral non-specific low back pain have lumbar extensor and flexor muscle fatty infiltration without muscle atrophy. We hypothesized that muscle fatty infiltration may occur prior to muscle atrophy. Therefore, the high fatty infiltration of the lumbar extensor and flexor muscle may be a cause or a result of chronic bilateral non-specific low back pain in young nurses.
摘要：
背景：关于年轻女护士非特异性下腰痛的肌肉结构研究很少。本研究旨在通过腰椎磁共振成像研究年轻女护士慢性双侧非特异性下腰痛的腰椎伸屈肌横截面积和脂肪浸润的变化，以推测可能的发病机制。
方法：回顾性分析58名慢性双侧非特异性下腰痛女护士和60名健康女性对照者的磁共振成像（MRI）数据。腰椎伸肌和屈肌横截面积/椎间盘横截面积之比,以及测量腰椎伸肌（竖脊肌；多裂肌）和屈肌（腰大肌）的磁共振成像信号强度，通过独立样本t检验计算和比较护士和健康对照。此外,还比较了从腰椎2（L2）-L3到L5-骶椎1（S1）的不同解剖节段的护士腰椎伸肌或屈肌的每个平均MRI信号强度，单因素方差分析(ANOVA)分析了护士肌肉间的平均MRI信号强度。
结果：患有慢性双侧非特异性下腰痛的护士与健康对照组的腰椎伸屈肌横截面积/椎间盘横截面积比值无显著差异，p>0.01。慢性双侧非特异性下腰痛护士腰椎伸肌和屈肌磁共振成像信号强度明显高于健康对照组,p<0.01。下腰椎伸肌的MRI信号强度高于上腰椎。伸肌（竖脊肌；多裂肌）的磁共振成像信号强度显着高于屈肌（腰大肌），p<0.01。
结论：这项研究表明，患有慢性双侧非特异性下腰痛的年轻护士有腰椎伸肌和屈肌脂肪浸润，而没有肌肉萎缩。我们假设肌肉脂肪浸润可能在肌肉萎缩之前发生。因此,腰椎伸肌和屈肌的高脂肪浸润可能是年轻护士慢性双侧非特异性下腰痛的原因或结果.
方法：回顾性分析58名慢性双侧非特异性下腰痛女护士和60名健康女性对照者的磁共振成像（MRI）数据。腰椎伸肌和屈肌横截面积/椎间盘横截面积之比,以及测量腰椎伸肌（竖脊肌；多裂肌）和屈肌（腰大肌）的磁共振成像信号强度，通过独立样本t检验计算和比较护士和健康对照。此外,还比较了从腰椎2（L2）-L3到L5-骶椎1（S1）的不同解剖节段的护士腰椎伸肌或屈肌的每个平均MRI信号强度，单因素方差分析(ANOVA)分析了护士肌肉间的平均MRI信号强度。
结果：患有慢性双侧非特异性下腰痛的护士与健康对照组的腰椎伸屈肌横截面积/椎间盘横截面积比值无显著差异，p>0.01。慢性双侧非特异性下腰痛护士腰椎伸肌和屈肌磁共振成像信号强度明显高于健康对照组,p<0.01。下腰椎伸肌的MRI信号强度高于上腰椎。伸肌（竖脊肌；多裂肌）的磁共振成像信号强度显着高于屈肌（腰大肌），p<0.01。
结论：这项研究表明，患有慢性双侧非特异性下腰痛的年轻护士有腰椎伸肌和屈肌脂肪浸润，而没有肌肉萎缩。我们假设肌肉脂肪浸润可能在肌肉萎缩之前发生。因此,腰椎伸肌和屈肌的高脂肪浸润可能是年轻护士慢性双侧非特异性下腰痛的原因或结果.
