Neck Myalgia Research Articles

Work-related chronic neck impairment. Neck motion analysis in female traverse crane operators

Twenty-one female steel industry traverse crane operators with long-term sick-leave (3 (1-8) years) due to chronic neck disability underwent careful analysis of case history, physical status and electrogoniometric three-dimensional recordings of active neck motion. Results were compared with those from working female crane operators having identical work posture and tasks and, further, with a group of working female clerks. The sick-listed crane operators had previous frequent contacts with the primary health care because of complaints from the neck and back. In comparison with the reference groups, the sick-listed crane operators showed tenderness of the trapezius and levator scapulae muscles and a short neck stature in combination with impaired active neck motion range with reduced motion speed. The motion pattern was however unchanged. The findings are consistent with the clinical picture of chronic neck myalgia that persisted despite long-term absence from the previous exposure to high static work load upon the neck-shoulders.

Cerebellar cavernous hemangioma that presented with posterior neck myalgia

Cavernous hemangioma can occur in the entire brain but rarely in cerebellum, especially in the pediatric age group. Headache, seizure, gait disturbance, recurrent bleeding may be seen. This tumor is a relatively benign condition but if the lesion located in the posterior fossa or the brain stem bleeds, irreversible brain damage may occur because of its restrictive space. Moreover, it must be differentiated from malignant tumors. We report 12.6 year-old boy who represented posterior neck myalgia as the presenting symptom. The pain continued for about a month despite analgesic medications. Brain MRI showed intracranial hemorrhage in the left cerebellum (4.5 cm) representing repeated hemorrhages at different times and originated from the cavernous hemangioma accompanied by mild hydrocephalus. The lesion was surgically removed successfully and the cavernous hemangioma was confirmed by pathologic findings. After the follow-up period of 14 months, he is in good condition without any complications.

Linking work factors to neck myalgia: the nitric oxide/oxygen ratio hypothesis

The pathophysiological link between work-related exposures and neck myalgia remains a puzzle. According to the hypothesis presented here, neck myalgia is evoked when low-level contractions in the trapezius muscle are combined with sympathetic vasoconstriction due to psychological stress or prolonged head-down neck flexion at work. These ischemic contractions increase nitric oxide/oxygen concentration ratio in the muscle fibres, enhancing herewith the reversible inhibition of mitochondrial cytochrome oxidase by nitric oxide. The result is depletion of adenosine triphosphate, which elicits production/efflux of lactic acid, in turn activating and sensitising proton-sensitive nociceptive fibres in the connective tissue, causing myalgic pain and tenderness. High estrogen-level, which gives a high expression of nitric oxide synthase in the muscle, accentuates the situation. During episodes of sustained inhibition of cytochrome oxidase by nitric oxide, peroxynitrite may be produced and cause irreversible inactivation of several enzymes in the mitochondrial electron-carrier chain. With repeated episodes, an increasing part of the enzymatic capacity for cellular respiration is inactivated. Even if this process only takes place within a small portion of the muscle fibres, it may contribute to frequent exacerbations of pain. Effects of peroxinitrite may also explain the mitochondrial abnormalities found in the trapezius muscle of many neck myalgia patients. Adrenergic antagonists and nitric oxide synthase inhibitors could reduce symptoms. Ascorbic acid, alpha tocopherol, and flavonoids, which are safe and effective scavengers of peroxynitrite, could prevent chronicity. The most effective non-pharmacological measure may be to reduce exposure to prolonged head-down neck flexions and psychosocial stress at work.

Tracheal intubation of outpatients with and without muscle relaxants.

To compare intubating conditions and postoperative myalgias in outpatients after intubation with propofol/alfentanil compared with propofol/alfentanil/succinylcholine with and without precurarisation with d-tubocurarine. 144 ASA I-II ambulatory patients for dental extraction under anesthesia were studied. Subjects received either 3 mg d-tubocurarine (Group II) or saline (Groups I, III) i.v. prior to induction of anesthesia with 20 microg x kg(-1) alfentanil and 2.5 mg x kg(-1) propofol followed by 1.5 mg x kg(-1) succinylcholine (II and III) or saline 0.9% (I) for muscle relaxation. The ease of airway management and the postoperative incidence, severity and distribution of muscle pains were examined. Intubation was successful in all patients and there were no differences in jaw mobility, ease of bag-mask ventilation, visualization of the vocal cords or cord position. Limb movement was more common during intubation in Group I (37.5%) than in Group III (8.3%) or Group II (2%), P < 0.05. At home, VAS scores for myalgia were higher in Group III than in Group I and II. Neck myalgia was more common in Group II (72%) than in Groups II (44%) and I (41%), P < 0.05. Myalgias were also more common in Group III patients (P < 0.05). Acceptable intubating conditions were achieved with propofol and alfentanil alone. Succinylcholine reduced limb movement during intubation but was associated with postoperative myalgias for up to five days. Precurarisation with tubocurarine reduced the severity of succinylcholine myalgia.

Can stress-related shoulder and neck pain develop independently of muscle activity?

A case-control designed was used to investigate associations and interactions between muscle activity measured by surface electromyography (EMG) in the upper trapezius muscle and subjectively reported risk factors in workers with and without shoulder and neck pain. EMG data were collected both in the workplace (indicating vocational muscle activity) and in a laboratory setting (indicating non-specific muscle activity). Women in manual (15 pairs) and office (24 pairs) work were included. The pairs were matched on age, gender and on current and historical work load, such as working hours, type and length of employment. Previous reports of this study have indicated that shoulder and neck myalgia was associated with increased muscle activity for the manual workers, and with psychological and psychosocial factors for the office workers. These risk factors were in the present report used as the basis for studying associations and interactions between muscle activity (1), psychological and psychosocial factors (2), and shoulder and neck pain (3). Subjectively reported or perceived general tension, a stress symptom presumed related to psychosocial and psychological factors, was previously found to be the strongest and only variable separating cases and controls in both work groups. In this paper, no relationship was found between perceived general tension and EMG variables for the office workers. For the manual workers a strong interaction was found; perceived general tension correlated positively with EMG variables for the controls, and negatively with EMG variables for the cases. It is hypothesised that the feeling of geneal tension represents a physiological activation response that may or may not include muscle fibre activation. This implies that pain provoked by psychosocial stress factors may not be mediated through increased muscle activity.

The effect of pain reduction on perceived tension and EMG-recorded trapezius muscle activity in workers with shoulder and neck pain

The study was initiated to evaluate the effect of pain-reducing therapies on factors previously associated with work-related shoulder and neck pain, namely increased muscle activity in the upper trapezius and perceived general tension. Thirty-three women in three groups were assessed before and after an intervention period and by questionnaire 6 months later. The purpose of this study was primarily to investigate associations between upper trapezius muscle activity, perceived general tension and pain, and secondly, to compare effects of individually based physiotherapy and group exercise for workers with shoulder and neck myalgia. All three groups reported a significant alleviation of pain and perceived general tension, while the electromyographically (EMG) recorded upper trapezius muscle activity level remained unchanged or increased. Improvements were similar in all three treatment groups, but individual-based therapies were rated more beneficial on subjective measures. Significant correlation was found between pain and perceived general tension (r = 0.66, p

A case-control study of psychological and psychosocial risk factors for shoulder and neck pain at the workplace.

Risk factors associated with work-related shoulder and neck myalgia were investigated in a case-control study with pairs matched for age, gender, and physical exposure. Guided interviews with standardized and self-constructed questionnaires were performed among manual (n = 15 pairs) and office (n = 24 pairs) workers. Perceived general tension was the variable with the strongest association with shoulder and neck pain in both work groups. Otherwise, the results in the two groups were very different, indicating that different risk factors and mechanisms were associated with shoulder and neck pain in the two work groups. The study provides background information for future attempts to establish causal relationships between physical and psychosocial exposure and shoulder and neck pain, which can be more accurately investigated in a longitudinal rather than a cross-sectional experimental design.

Work-related chronic neck impairment. Neck motion analysis in female traverse crane operators

Twenty-one female steel industry traverse crane operators with long-term sick-leave (3 (1-8) years) due to chronic neck disability underwent careful analysis of case history, physical status and electrogoniometric three-dimensional recordings of active neck motion. Results were compared with those from working female crane operators having identical work posture and tasks and, further, with a group of working female clerks. The sick-listed crane operators had previous frequent contacts with the primary health care because of complaints from the neck and back. In comparison with the reference groups, the sick-listed crane operators showed tenderness of the trapezius and levator scapulae muscles and a short neck stature in combination with impaired active neck motion range with reduced motion speed. The motion pattern was however unchanged. The findings are consistent with the clinical picture of chronic neck myalgia that persisted despite long-term absence from the previous exposure to high static work load upon the neck-shoulders.