Workers whose performance is tracked by computers and other electronic devices suffer more health problems than those simply watched over by human managers, a study shows.

University of Wisconsin-Madison researchers said their nationwide survey of 762 workers in the telephone industry found electronically monitored workers reported substantially more headaches and wrist, arm, shoulder and neck pains than non-monitored workers.In addition, electronically monitored employees were more likely to be troubled by depression, tension, extreme anxiety and severe fatigue than workers whose performance was judged mainly by traditional, human means.

Electronic monitoring is used extensively in a wide array of jobs, including air traffic controllers, grocery store cashiers, package deliverers and bank tellers.

Such monitoring usually involves using a computer system, often in conjunction with a video display terminal or VDT, to see if a person performs a task during an assigned time period. For example, a telephone operator may be expected to handle a directory assistance call in 19 seconds. If the employee takes longer than the ideal time to complete the task, the computer makes a note that a supervisor can see when he or she reviews a daily or weekly computer printout of the employee's work record.

Another form of monitoring used in the telephone industry involves managers using electronic equipment to listen in on operators' conversations with customers to make sure they are helpful and courteous.

In their study, Michael Smith and his colleagues found 51 percent of electronically monitored telephone workers, most of whom used VDTs, reported stiff or sore wrists in the past year, compared with 24 percent of non-monitored workers, who also used VDTs. About 64 percent of electronically monitored workers suffered neck pain, compared with 41 percent of non-monitored.

"This outcome clearly demonstrates there are major differences in health distress," linked to the methods used to gauge work performance, said Smith, who announced his findings at a news conference sponsored by the Communication Workers of America, which helped fund the study.

Psychological complaints were also greater among electronically monitored workers than among the non-monitored.