Larger strength losses and muscle activation deficits in plantar flexors induced by backward downhill in reference to distance-matched forward uphill treadmill walk
| Autor: | Hakim Chalabi, Mounir Chennaoui, Olivier Girard, C. Drogou, Nathalie Koulmann, Sébastien Banzet, Sebastien Racinais |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Adult
Male medicine.medical_specialty Motor nerve Physical Therapy Sports Therapy and Rehabilitation Walking Isometric exercise Body weight Plantar flexion 03 medical and health sciences 0302 clinical medicine Physical medicine and rehabilitation Isometric Contraction medicine Humans Eccentric Orthopedics and Sports Medicine Treadmill Muscle Skeletal Gait business.industry Muscle activation Myalgia 030229 sport sciences General Medicine Electric Stimulation Biomechanical Phenomena Torque Exercise Test business 030217 neurology & neurosurgery |
| Zdroj: | European Journal of Sport Science. 18:1346-1356 |
| ISSN: | 1536-7290 1746-1391 |
| DOI: | 10.1080/17461391.2018.1497091 |
| Popis: | We tested the hypothesis that backward downhill walking (eccentric component) impairs both voluntary activation and muscle contractile properties in the plantar flexors and delays recovery as compared to a gradient and distance-matched uphill walk. Fourteen males performed two 30-min walking exercises (velocity: 1 m/ s; grade: 25%; load: 12% of body weight), one downhill (DW) and one uphill (UP), in a counterbalanced order, separated by 6 weeks. Neuromuscular test sessions were performed before, after, 24-, 48- and 72-h post-exercise, including motor nerve stimulations during brief (5 s) and sustained (1 min) maximal isometric voluntary contractions of the plantar flexors. DW (-18.1 ± 11.1%, P .001), but not UP (-6.0 ± 7.7%, P =.15), decreased torque production during brief contractions for at least three days post-exercise (P .05). Voluntary activation during brief contractions decreased after DW (P .05), but not UP, and recovered by 24 h. Both UP (-9.3 ± 9.0%, P = .024) and DW (-25.6 ± 10.3%, P .001) decreased torque production during sustained contractions but voluntary activation (P = .001) was lower in DW than UP. Peak twitch torque and maximum rates of torque development and relaxation were equally reduced after UP and DW (P .05), and recovered by 24 h. DW induced an increase in muscle soreness with peak values observed 48 h post-walking (P .001), whereas post-UP exercise changes were non-significant (all P .05). Using a direct comparison, the capacity to drive the plantar flexors during sustained contractions remains sub-optimal during the three-day recovery period in response to non-exhaustive, downhill backward walking in reference to an uphill exercise matched for distance covered. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|