Exploring how different protocols of noxious electrical stimulation differentially modulate performance in two isometric strength-endurance tasks
Authors
Fredborg, Nynne Povlsen ; Mølgaard, Mette Vejen ; Jensen, Michelle Dahl
Term
4. semester
Education
Publication year
2020
Submitted on
2020-05-30
Pages
39
Abstract
This project examines whether intermittent, noxious electrical stimulation (ES) can enhance performance in two isometric strength-endurance tasks, measured as time to exhaustion (TTE): a wall squat and a handgrip task. Using a randomized crossover design, three sessions were planned for 34 physically active adults: no ES (No-Pain), ES delivered throughout the task (Throughout-Pain), and ES initiated at the onset of acute muscle soreness (AMS-Pain). Participants were to report the timing of AMS and TTE, heart rate was monitored at rest and during tasks, and stimulation intensity was set at 110% of individual pain threshold with pain rated on a numerical scale. Due to COVID-19 laboratory closures, the primary dataset consisted of supervisor-generated mock data; an e-familiarization for the wall squat was completed by 17 participants. Based on the available (mock) results, AMS-Pain significantly improved wall squat performance compared with No-Pain and Throughout-Pain, with no difference between No-Pain and Throughout-Pain. For handgrip, both Throughout-Pain and AMS-Pain increased TTE relative to No-Pain, with the largest effect in AMS-Pain. These findings suggest that noxious ES may counteract the physiological effects of AMS and enhance isometric endurance, with effects depending on protocol and task. Given the use of mock data, the results should be considered preliminary; the thesis emphasizes experimental design, statistical interpretation, and future applications, including development of a performance-enhancing device.
Dette projekt undersøger, om intermitterende, smertefuld elektrisk stimulering (ES) kan forbedre præstationen i to isometriske styrke-udholdenhedsopgaver målt som tid til udmattelse (TTE): vægsquat og håndgreb. I et randomiseret crossover-design var tre sessioner planlagt for 34 fysisk aktive voksne: uden ES (No-Pain), ES gennem hele opgaven (Throughout-Pain) og ES påbegyndt ved debut af akut muskelsmerte (AMS-Pain). Deltagerne skulle rapportere tidspunkt for AMS og TTE, og puls blev målt ved hvile og under opgaverne; smerteintensitet blev sat til 110% af den individuelle smertetærskel og vurderet på en numerisk skala. På grund af COVID-19-relaterede laboratorielukninger bestod hoveddatasættet af mock-data leveret af vejledere; der blev dog gennemført e-familiarisering med vægsquat hos 17 deltagere. Ifølge de tilgængelige (mock-)resultater forbedrede AMS-Pain vægsquat-præstationen signifikant sammenlignet med No-Pain og Throughout-Pain, mens der ikke sås forskel mellem No-Pain og Throughout-Pain. For håndgreb var både Throughout-Pain og AMS-Pain forbundet med længere TTE end No-Pain, med størst effekt i AMS-Pain. Fundene tyder på, at noxious ES kan modvirke de fysiologiske konsekvenser af AMS og forbedre isometrisk udholdenhed, men at effekten er både protokol- og opgavespecifik. På grund af brugen af mock-data bør resultaterne betragtes som foreløbige; studiet lægger vægt på forsøgsdesign, statistisk tilgang og perspektiver for fremtidig anvendelse, herunder udvikling af en enhed til præstationsfremme.
[This apstract has been generated with the help of AI directly from the project full text]