Evaluation of Three Neuromuscular Electrical Stimulation Foot Pad Programmes on Lower Limb Haemodynamics in Healthy Adults

Brief Summary

The goal of this clinical investigation is to evaluate the performance of three neuromuscular electrical stimulation (NMES) foot pad programmes in healthy adults. It will also learn about how well the NMES programmes are tolerated. The main questions it aims to answer are: * Do two newly-developed NMES programmes ('P1' and 'PM7') increase lower limb blood flow more than the existing 'Medic' NMES programme during use? * How do the programmes compare in terms of user discomfort and muscle oxygenation during use? Researchers will compare the P1 and PM7 programmes with the existing Medic programme to determine whether the new programmes produce greater improvements in lower limb haemodynamics during device use. Participants will: * Attend four study visits at a single research site. * Complete 1 familiarisation visit and 3 testing visits, with 12 hours to 7 days between visits. * Use all three NMES programmes once in a randomised order. * Receive 30 minutes of NMES during each testing visit. * Undergo blood flow and muscle oxygenation measurements during each test. * Complete questionnaires about discomfort and their experience using the device.