Andersen RE, Franckowiak SC, Snyder J, et al. Can inexpensive signs encourage the use of stairs? Results from a community intervention. Ann Intern Med 1998; 129:363-369.

The addition of simple signs encouraging stair use can significantly increase physical activity in the workplace, according to this study from The Johns Hopkins University School of Medicine and The Johns Hopkins Weight Management Center, both in Baltimore.

Health professionals have long advocated walking and taking the stairs as modest but effective ways to increase physical activity and overall health. To determine how easy or difficult it is to change people’s habits with regard to stairs, the researchers studied 17,901 people in a shopping mall in which escalators and stairs were adjacent. The stairway consisted of 10 stairs, a 6-foot landing, and 10 more stairs.

The authors first studied stair use as a baseline. They found that, overall, 4.8% of shoppers used the stairs instead of the escalator. Those under 40 years old were slightly more likely to use the stairs, and men and women used the stairs at about the same rate. With shoppers who did not appear overweight, 5.4% used the stairs. But only 3.8% of overweight shoppers used the stairs. Race had some effect, with 5.1% of white shoppers and 4.1% of black shoppers using the stairs.

Then the researchers placed a 22-inch by 28-inch sign on an easel beside the escalator and stairs. It featured a caricature of a heart and the caption, "Your heart needs exercise. Use the stairs." After a month of watching shoppers again, the authors found that stair use increased significantly to 6.9% overall.

To study the effects of a weight loss message rather than a general health message, the researchers replaced the first sign with one featuring a caricature of a woman at the top of set of stairs. She wore pants that were too large for her thin waistline, and the caption read, "Improve your waistline. Use the stairs." With that sign, stair use increased significantly to 7.2%.

There were some interesting differences in the way people reacted to the signs. Shoppers over age 40 responded by taking the stairs more often than younger shoppers, and women responded more than men to the health benefits sign. They responded almost equally well to the weight loss sign. Overweight people were more likely to take the stairs after seeing the weight loss sign than the general health sign.

One result was particularly troubling to the researchers, and they have no explanation. Stair use among blacks actually decreased from 4.1% to 3.4% with the health benefits sign, as stair use among whites increased from 5.1% to 7.5%. With the weight loss sign, blacks increased use of the stairs modestly from 4.1% to 5%, but whites went from 5.1% to 7.8%.

The researchers conclude that simple, low-cost signs can significantly increase stair use, but they say educating blacks is an additional challenge.

Chang MH, Chiang HT, Lee SS, et al. Oral drug of choice in carpal tunnel syndrome. Neurology 1998; 51:390-393.

Steroids are more effective than other drug choices in treating carpal tunnel syndrome (CTS), according to these researchers in Taiwan.

They studied the most commonly used oral medications for CTS, using diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs), and steroids. A prospective, randomized, double-blind, placebo-controlled study included patients with clinical symptoms of CTS confirmed by standard electrodiagnosis.

The baseline assessments included a standardized symptom questionnaire in which the patient rated five categories of symptoms on a scale of 0 to 10. The total score in each of the five categories was used as the global symptom score.

The 73 patients were randomized to one of four treatment protocols: four weeks of placebo, four weeks of diuretic, four weeks of slow-release NSAID, or two weeks of 20 mg prednisolone daily and then two weeks of 10 mg daily. During and after the treatment, the patients’ global symptom scores were compared to their baselines.

The researchers found that after two weeks of treatment, the steroid group had a significantly greater reduction in the average global symptom score than the placebo, NSAID, and diuretic groups. After four weeks of treatment, significant reduction in symptoms continued only in the steroid treatment group. Four weeks of steroid treatment caused the patients’ global symptom scores to decrease from an average 27.9 to 10. The placebo, diuretic, and NSAID groups had no significant reduction from their baseline scores after four weeks.

"For patients with mild to moderate CTS who opt for conservative treatment, corticosteroids are of greater benefit," the researchers conclude.

Smith JM, Conwit RA, Blumenthal PD. Ulnar nerve injury associated with removal of Norplant implants. Contraception 1998; 57:99-101.

The removal of Norplant contraceptive implants can cause an ulnar nerve injury that might be misinterpreted as a cumulative trauma disorder, according to this study from The Johns Hopkins University School of Medicine in Baltimore.

The authors report the case of a 23-year-old woman who underwent what should have been a routine procedure to remove her Norplant implants. They had been inserted 3.5 years earlier with no complications, and she had experienced no pain, paresthesias, or weakness in the arms, hands, or fingers. The implants were directly over the most anterior aspect of the triceps muscle, with the lower end of the implants lying approximately 5 cm from the medial condyle of the elbow.

The woman’s gynecologist prepared to remove the implants in the standard fashion by first injecting the site with 3 ml of 1% lidocaine. The patient immediately complained of a sharp pain shooting down the medial aspect of the lower arm to the fourth and fifth digits. After incising and exploring for obvious nerve injury and finding none, the doctor removed the implants.

At the end of the procedure, the patient reported a slightly painful tingling sensation. She returned four days later with persistent pain, definite weakness of the ulnar-innervated muscles of the right hand, and numbness over the hypothenar eminence and especially the fourth and fifth digits. A clinical neurologic evaluation was consistent with an ulnar nerve injury. Nerve conduction studies revealed normal ulnar motor conduction velocity but reduced compound muscle action potential amplitude.

Her condition improved over a two-month follow-up. The traumatic injury was traced to improper placement of the implants, leading to damage to the neurovascular structures at the time of removal. The authors note that significant symptoms may not appear for up to eight days after removal and can mimic other injuries involving the ulnar nerve. "If nerve injury is suspected, immediate nerve conduction studies appear to be warranted because they establish a baseline for comparison," they say. "We conclude that if pain, paresthesia, or anesthesia persists four to six weeks after the injury, repeat nerve conduction studies may be of prognostic significance and may help outline a plan for rehabilitation."

Sokejima S, Kagamimori S. The effect of working hours on the incidence of myocardial infarctions. British Medical J 1998; 317:775-780.

Both unusually short working hours and unusually long working hours appear to increase male workers’ likelihood of having acute myocardial infarctions, according to this research from Toyama (Japan) Medical and Pharmaceutical University.

The researchers studied the work schedules of 200 men ages 30 to 69 who had been hospitalized for acute myocardial infarction, along with 300 male controls with similar ages and occupations. The analysis revealed that men working less than seven hours a day were 3.07 times as likely to have suffered a heart attack than those working seven to nine hours per day. Those spending more than 11 hours a day on the job were 2.44 times more likely to have had heart attacks than those working seven to nine hours a day.

The risk associated with longer working hours was easier to explain than with shorter hours. "A possible biological explanation for long working hours eliciting an acute myocardial infarction might be changes in the activity of the autonomic nervous system," the researchers say. They also suggest that changes in average working hours could affect the circadian rhythm of autonomic nerve activity and failure of the autonomic nervous system to adapt adequately to the change could increase the risk of myocardial infarction.

To account for the risk associated with shorter hours, the researchers theorize that the men may have had premorbid conditions and may have experienced unemployment during the study period. They note that other studies have shown that the risk of myocardial infarction increases during unemployment.