Barton P M, Hayes K C
Department of Clinical Neurosciences, University of Calgary, Alberta, Canada.
Arch Phys Med Rehabil. 1996 Jul;77(7):680-7. doi: 10.1016/s0003-9993(96)90008-8.
To determine the test-retest reliability of a new method for measuring muscular strength, efficiency, and relaxation times of the neck flexor musculature of healthy adults, and to compare these neck flexor muscle properties in subjects who have unilateral neck pain and headache with those in controls.
Subjects lay supine and isometrically flexed their necks against a force transducer attached to the back of a webbing and velcro helmet. Electromyograms (EMGs) were recorded from surface electrodes on the sternocleidomastoid (SCM) muscles. Two consecutive sessions of five contractions of varying levels of effort from minimal through moderate and maximal effort were analyzed.
Ambulatory referral center.
Volunteer control subjects (n = 10, 3 men and 7 women) were recruited from hospital and university personnel. Volunteer neck pain subjects (n = 10, 3 men and 7 women) were recruited from a physiatric chronic pain practice and a hospital outpatient physical therapy practice.
In the controls, the intraclass correlation coefficients (ICCs) for the first two maximum neck flexion contractions were; peak force ICC = .81; peak force/body weight ICC = .75; average force ICC = .75; force relaxation time ICC = .73; SCM EMG relaxation times: right ICC = .60 and left ICC = .67. Comparing sessions 1 and 2 the intraclass correlations for SCM efficiencies were right ICC = .58 and left ICC = .97. The peak force in controls (mean = 45.3 +/- 17.6N) was reduced by 50% in the neck pain subjects (mean = 22.4 +/- 13.1N) (p = .004). Similarly, peak force/body weight in the neck pain subjects (X = 0.3 +/- 0.2N/kg) was 46% of control (mean = 0.7 +/- 0.2N/kg) (p = .001), and average force in the neck pain subjects (X = 12.1 +/- 7.5N) was 43% of controls (mean = 28.5 +/- 11.0N) (p = .001). In two neck pain subjects. SCM, EMG and force relaxation times were abnormally long in both the affected and the unaffected SCM muscles, exceeding the control values by greater than 3 standard deviations. The difference between the right SCM efficiency of the control subjects (mean = 0.3 +/- 0.2N/ microV) and the affected SCM efficiency of the neck pain subjects (mean = 0.1 +/- 0.1 N/microV) approached the p < .05 criterion for significance (p = .055).
The technique was found to be highly reliable for the measurement of neck flexor peak force, peak force/body weight, average force, and force relaxation time, and moderately reliable for the quantitation of SCM EMG relaxation times and SCM efficiency. All force values were significantly lower in the neck pain population compared with the controls. In the neck pain population, force and SCM EMG relaxation times, as well as efficiencies, suggested abnormalities. Neck pain subjects showed no significant differences in SCM EMG relaxation time or SCM efficiency between affected and unaffected SCM muscles.
确定一种测量健康成年人颈部屈肌肌肉力量、效率和放松时间的新方法的重测信度，并比较单侧颈部疼痛和头痛患者与对照组患者颈部屈肌的这些肌肉特性。
受试者仰卧，通过附着在安全带和尼龙搭扣头盔后部的力传感器等长收缩颈部。从胸锁乳突肌（SCM）表面电极记录肌电图（EMG）。分析连续两次进行的五组不同用力程度（从最小到中等再到最大用力）收缩的情况。
门诊转诊中心。
从医院和大学工作人员中招募了10名志愿者作为对照组（3名男性和7名女性）。从物理医学慢性疼痛诊所和医院门诊物理治疗诊所招募了10名颈部疼痛志愿者（3名男性和7名女性）。
在对照组中，前两次最大颈部屈曲收缩的组内相关系数（ICC）分别为：峰值力ICC = 0.81；峰值力/体重ICC = 0.75；平均力ICC = 0.75；力放松时间ICC = 0.73；SCM肌电图放松时间：右侧ICC = 0.60，左侧ICC = 0.67。比较第1次和第2次测量，SCM效率的组内相关系数为右侧ICC = 0.58，左侧ICC = 0.97。对照组的峰值力（平均 = 45.3±17.6N）在颈部疼痛患者中降低了50%（平均 = 22.4±13.1N）（p = 0.004）。同样，颈部疼痛患者的峰值力/体重（X = 0.3±0.2N/kg）是对照组的46%（平均 = 0.7±0.2N/kg）（p = 0.001），颈部疼痛患者的平均力（X = 12.1±7.5N）是对照组的43%（平均 = 28.5±11.0N）（p = 0.001）。在两名颈部疼痛患者中，患侧和未患侧SCM肌肉的EMG和力放松时间均异常延长，超过对照组值3个标准差以上。对照组右侧SCM效率（平均 = 0.3±0.2N/μV）与颈部疼痛患者患侧SCM效率（平均 = 0.1±0.1N/μV）之间的差异接近p < 0.05的显著性标准（p = 0.055）。
该技术在测量颈部屈肌峰值力、峰值力/体重、平均力和力放松时间方面具有高度可靠性，在定量SCM肌电图放松时间和SCM效率方面具有中等可靠性。与对照组相比，颈部疼痛人群的所有力值均显著较低。在颈部疼痛人群中，力、SCM肌电图放松时间以及效率均显示异常。颈部疼痛患者患侧和未患侧SCM肌肉的SCM肌电图放松时间或SCM效率无显著差异。
