Systematic review of biochemical biomarkers for neck and upper-extremity musculoskeletal disorders.

OBJECTIVE: This study systematically summarizes biochemical biomarker research in non-traumatic musculoskeletal disorders (MSD). Two research questions guided the review: (i) Are there biochemical markers associated with neck and upper-extremity MSD? and (ii) Are there biochemical markers associated with the severity of neck and upper-extremity MSD? METHODS: A literature search was conducted in PubMed and SCOPUS, and 87 studies met primary inclusion criteria. Following a quality screen, data were extracted from 44 articles of sufficient quality. RESULTS: Most of the 87 studies were cross-sectional and utilized convenience samples of patients as both cases and controls. A response rate was explicitly stated in only 11 (13%) studies. Less than half of the studies controlled for potential confounding through restriction or in the analysis. Most sufficient-quality studies were conducted in older populations (mean age in one or more analysis group >50 years). In sufficient-quality articles, 82% demonstrated at least one statistically significant association between the MSD and biomarker(s) studied. Evidence suggested that: (i) the collagen-repair marker TIMP-1 is decreased in fibro proliferative disorders, (ii) 5-HT (serotonin) is increased in trapezius myalgia, and (iii) triglycerides are increased in a variety of MSD. Only 5 studies showed an association between a biochemical marker and MSD severity. CONCLUSION: While some MSD biomarkers were identified, limitations in the articles examined included possible selection bias, confounding, spectrum effect (potentially heterogeneous biomarker associations in populations according to symptom severity or duration), and insufficient attention to comorbid conditions. A list of recommendations for future studies is provided.

Ulnar neuropathy at the elbow in computer keyboard operators.

OBJECTIVE: This case series sought to determine the prevalence of ulnar neuropathy at the elbow (UNE) by using electrophysiologic criteria among all computer keyboard operators (CKOs) referred over a four-year period (1995-1999) for electrodiagnosis (EDX) due to clinical suspicion of focal upper limb neuropathies. PARTICIPANTS: All CKOs referred to an EDX laboratory for suspicion of focal upper limb neuropathies primarily from private practice physicians, mostly hand surgeons, and an occupational medicine clinic. METHODS: All 148 CKOs underwent NCV studies of the upper limbs, which included segmental studies of the ulnar nerve and were questioned for the presence and distribution pattern of paresthesias in the symptomatic upper limb(s). The CKOs provided the electromyographer with subjective descriptions of their workstation configuration, layout, and basic office equipment. RESULTS: Focal ulnar neuropathy at the elbow (UNE) was identified in 105 out of 148 CKOs referred to an EDX laboratory for clinical suspicion of upper limb focal neuropathies. CONCLUSIONS: Compared with the more prevalent diagnosis of carpal tunnel syndrome (CTS), ulnar neuropathy at the elbow should also be considered among CKOs referred for EDX testing because of suspicion of focal upper limb neuropathies. Clinicians evaluating CKOs for suspicion of focal upper limb neuropathies should routinely ask about symptoms of ulnar neuropathy.

Cluster analysis of symptoms among patients with upper extremity musculoskeletal disorders.

INTRODUCTION: Some musculoskeletal disorders of the upper extremity are not readily classified. The study objective was to determine if there were symptom patterns in self-identified repetitive strain injury (RSI) patients. METHODS: Members (n = 700) of the Dutch RSI Patients Association filled out a detailed symptom questionnaire. Factor analysis followed by cluster analysis grouped correlated symptoms. RESULTS: Eight clusters, based largely on symptom severity and quality were formulated. All but one cluster showed diffuse symptoms; the exception was characterized by bilateral symptoms of stiffness and aching pain in the shoulder/neck. CONCLUSIONS: Case definitions which localize upper extremity musculoskeletal disorders to a specific anatomical area may be incomplete. Future clustering studies should rely on both signs and symptoms. Data could be collected from health care providers prospectively to determine the possible prognostic value of the identified clusters with respect to natural history, chronicity, and return to work.