BACKGROUND Words uttered by other people can have an enormous influence on how we perceive our surroundings, what we expect, what we experience, and how we behave. This study aimed to evaluate the effect of verbal reinforcement on the placebo effect in the context of finger flexor muscle activation measured with surface electromyography (sEMG) and hand grip strength measured with a hand dynamometer in healthy subjects. MATERIAL AND METHODS Eighty-eight individuals aged 22.64±5.2 years took part in the study. For each person, paper tape was applied (placebo). The participants were randomly assigned to 1 of the 3 groups: positive information group (P) - "the tape increases hand muscle strength", negative information group (N) - "the tape decreases hand muscle strength", and control group (C) - "the effect of the tape on hand muscle strength is unknown." The activation of muscles was assessed using surface electromyography (sEMG) while measuring the strength of wrist and finger flexors with a hand dynamometer. Each participant was examined twice - prior to and immediately after taping and providing verbal reinforcement. RESULTS Only group N manifested a decrease in muscle strength, from 39.7N to 37.6N (P=0.003). Group C displayed an increase in muscle strength from 34.3N to 36.4N (P=0.035). None of the groups demonstrated statistically significant changes in bioelectrical activity of the muscles. At no stage of examination were the differences between the groups significant. CONCLUSIONS Negative verbal information combined with the placebo intervention resulted in a significant decrease in the strength of finger flexors.
BACKGROUND This study aimed to compare the ankle-brachial index (ABI), maximal claudication distance (MCD), pain-free walking distance (PFWD), claudication pain, and quality of life (intermittent claudication questionnaire [ICQ]) before and 3 months after revascularization surgery in 98 patients diagnosed with peripheral arterial disease (PAD) at a single center in Poland. MATERIAL AND METHODS Ninety-eight patients were examined (77% men, 23% women, 65.65±7.27 years old), diagnosed with PAD, and qualified for revascularization. The diagnosis of PAD was made on the basis of ABI ≤0.9 and medical records. The patients underwent a noninvasive examination, including measurement of ABI (by Doppler with the EZ8 probe), assessment of the quality of life by ICQ, distance of intermittent claudication on a treadmill using the Gardner-Skinner protocol (including PFWD and MCD), and pain intensity during walking (numeric rating scale [NRS11]). The assessment was carried out twice: 1 to 5 days before surgery and 3 months after surgery. RESULTS There was an increase of ABI (0.4 vs 0.62, P<0.001), PFWD (26.64 vs 80.21, P<0.001), MCD (60.08 vs 181.85, P<0.001), and ICQ (79.92 vs 60.23, P<0.001) and reduction of PFWD pain (7.26 vs 6.05, P<0.001) and MCD pain (9.24 vs 8.11, P<0.001). CONCLUSIONS Revascularization surgery improved the ABI and patients functional efficiency expressed in the improvement of subjective indicators PFWD, MCD, NRS11, and ICQ. Patients who had a longer duration of disease had worse outcomes after revascularization. More attention should be paid to increasing access to preventive examinations aimed at early detection of PAD and the possibility of implementing conservative treatment.