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ObjectiveCommercial devices for pneumatic compressive treatment of the limbs generally provide predefined stereotyped compressive profiles. The possibility to deliver compressive stimuli with a customizable pressure profile would be useful to differently probe the vascular reactivity to muscle compression (MC) and improve the understanding of MC-induced hyperemia. Aim of this study was the realization of a novel pneumatic system capable of generating adjustable and stable compressive conditions, preceding and following a "standard" MC stimulus Approach A custom-made pneumatic system specifically built to this purpose is tested and characterized in 10 subjects.Three different compressive patterns were delivered to the leg: 1) a constant level: 50 mmHg for 50 s; 2) MC: 200 mmHg for 1 s; 3) a complex profile: 20 mmHg for 50 s, 200 mmHg for 1 s, 50 mmHg for 50 s. Main resultsThe implemented system allowed to deliver graded compressions to the limb characterized by fast transitions (0 to 200 mmHg in 0.5 ± 0.07 s) and stable plateau levels (50.4 ± 0.5 mmHg). SignificanceA new, low-cost, pneumatic prototype has been presented and tested in the present study allowing to deliver compressive stimuli with pre-and post-compressions of adjustable level. This device has been conceived for research purposes and may find application in therapeutic compressive treatments.

Background Access to prevention options, including HIV pre-exposure prophylaxis (PrEP), remains a public health priority for gay, bisexual, and other men who have sex with men (MSM), especially in London. We describe PrEP use in a London community sample of MSM before the introduction of a national PrEP programme in October 2020. Methods From June–August 2019, MSM aged ≥ 18 recruited from London commercial venues were asked to self-complete a sexual health questionnaire and provide an oral fluid sample for anonymous HIV antibody testing. Descriptive analyses of demographic characteristics, service engagement and outcomes, as well as sexual risk and prevention behaviours were examined in the survey population and in those reporting current PrEP use. We performed sequential, multivariate analyses examining current PrEP use in MSM of self-perceived HIV-negative/unknown status with identified PrEP-need defined as the report of condomless anal sex (CAS) in the last three months, or the report of CAS (in the last year) with an HIV-positive/unknown status partner not known to be on HIV treatment, in reflection of UK PrEP guidelines. Results One thousand five hundred and thirty-fifth questionnaires were completed across 34 venues, where 1408 were analysed. One in five MSM of self-perceived HIV-negative/unknown status reported current PrEP use (19.7%, 242/1230). In men with PrEP-need, 68.2% (431/632) did not report current use. Current PrEP use was associated with age (aOR: 3.52, 95% CI: 1.76–7.02 in men aged 40–44 vs men aged 18–25) and education (aOR: 1.72, 95% CI: 1.01–2.92 in men with ≥ 2 years/still full-time vs no/ < 2 years of education since age 16). Conclusion Among MSM in London, PrEP use is high but there is indication of unmet PrEP-need in men of younger age and lower levels of post-16 education. National programme monitoring and evaluation will require continued community monitoring to guide interventions ensuring equitable PrEP access and uptake in those who could most benefit from PrEP.

The movements required for piano playing usually involve low impact loads that do not exceed physiologic limits of human body, but their repetition may provoke microtrauma leading to overuse injuries. Experience may allow a pianist to modify the motor patterns used for a performance, allowing the highest accuracy with minimum effort. In the present study, hand and finger movement patterns were analyzed in 19 pianists (8 concert players, 11 students and teachers) while they played 16 measures of a minuet. The threedimensional coordinates of their right hand and fingers were obtained by a motion analyzer. Three-dimensional finger velocity was determined, unitary kinetic energy was computed, and movements were divided into useful (for sound production) and erratic (extraneous movements not used for sound production). The number of key presses for each pianist was counted, and singlefinger unitary kinetic energy computed. On average, the concert players used more total unitary kinetic energy than the students and teachers (p < 0.05, Wilcoxon test), while the useful unitary kinetic energy was similar. The number of key presses for each finger did not differ (p > 0.05, chi-squared test). The useful unitary kinetic energy per single key press differed between groups (p = 0.035, with concert players greater than students and teachers, analysis of variance) and among the five fingers (p = 0.008, with second and first fingers larger). In conclusion, the same piano exercise was performed with different movement patterns depending on the pianist’s experience. The patterns of extraneous hand and finger movements during playing could be investigated to assess their relationship to overuse injuries.

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