Carpal Tunnel Syndrome As an Occupational Disease

Article Figures & Data

Table 1.

Cross-Sectional Studies That Found No Association between Occupational Exposure and CTS

Study	No. of Patients	Setting of Study	Measurement of Occupational Exposure	CTS Diagnostic Criteria	Controlling of Confounding Factors	Findings	Comment
Chiang et al22	207	Fish processing workers	Observation and EMG force recording	S, PE	Age, gender	No association with repetition on the exposure group	Excluded the subjects with medical condition that can cause CTS
English et al., 199524	1167	Orthopedic clinic	Self-report	Not specified	Gender, height, weight	No association with wrist ergonomics
Moore et al23	230	Pork processing plant	Observation	S, PE, NCV	No	No association	Based on the medical records review
Nathan et al17	471	Employees from 27 occupations in 4 industries	Observation by investigators	NCV	Age, gender	No association between occupational hand activity and NCV finding	Case definition does not include symptom, physical examination
Schottland et al19	178	Poultry-processing plant	Employment status, not observation	NCV	Age, gender	No association between employment experience and the NCV finding	Case definition does not include symptom, physical examination
Steven et al27	257	Orthopedic clinic	Not specified	S, PE, NCV	No	No association

CTS, carpal tunnel syndrome; EMG, electromyelogram; S, self-report; PE, physical examination; NCV, nerve conduction velocity.

Table 2.

Cross-Sectional Studies That Found an Association between Occupational Exposure and CTS

Author	No. of Patients.	Setting	Measurement of Occupational Exposure	CTS Diagnostic Criteria	Controlling of confounding factors	Result	Comment
Chiang et al 21	207	Two frozen food plants	Observation	S, PE, NCV	Age, gender, length of employment	Strongly positive association between repetition and CTS (OR = 7.40)	Excluded the subjects with medical condition that can cause CTS
Latko et al26	352	Three companies	Observation	S, PE, NCV	Age, gender	Positive association with repetition (OR = 3.1)
Osorio et al20	56	Grocery store	Observation	S, PE, NCV	Age, gender, alcohol assumption and high-risk medical history	Strongly positive association (OR = 6.7)
Silverstein et al14	652	Active workers in 39 jobs from 7 different industrial sites	Observation, (EMG) recordings	S, PE	Demographic information including age, gender, years on the job, etc	Strongly positive association between high force-high repetitive job and CTS prevalence (OR = 15)	CTS diagnosis was not confirmed by NCV
Stetson et al16	345	Industrial workers	Observation and workers interview	S, NCV	Age, height, skin temperature and finger circumference	Positive association between ergonomic factors and NCV finding
Werner et al25	184	Six work sites	Observation	S, NCV	Demographic, anthropometric, history of diabetes and psychosocial factors	Positive association

CTS, carpal tunnel syndrome; EMG, electromyelogram; S, self-report; PE, physical examination; NCV, nerve conduction velocity.

Table 3.

Quick Guide to Estimating Risk of Work-Related CTS

Ask the patient, “In your current occupation . . . ”

Is this the hand you primarily use to perform your current job?
Do you bend the wrist up and down or from side to side repeatedly more than twice a minute (wrist flexion/extension, ulnar/radial deviation) or twist/rotate the wrist with palm facing up and then down more than twice a minute (wrist rotation)?
Do you have repeated finger-tapping movement more than twice a minute?
Do you spend more than 4 hours per day moving your hand/wrist in the same fashion?
Do you grip or hold any object in the palm with a force greater than 12 lb while performing the activities listed in questions 2, 3, or 4?
Do you hold tools that vibrate during most of your workday?

Scoring: the number of “Yes” answers is directly proportional to the degree of risk: 0 to 2, low risk for occupational CTS; 3 to 4, moderate risk; 5 to 6, high risk.