Mechanical Energy and Propulsion in Ergometer Double Poling by Cross-country Skiers
2015 (English)In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 12, p. 2586-2594Article in journal (Refereed) Published
Abstract [en]
Purpose This study aims to investigate fluctuations in total mechanical energy of the body (E-body) in relation to external ergometer work (W-erg) during the poling and recovery phases of simulated double-poling cross-country skiing. Methods Nine male cross-country skiers (mean SD age, 24 5 yr; mean +/- SD body mass, 81.7 +/- 6.5 kg) performed 4-min submaximal tests at low-intensity, moderate-intensity, and high-intensity levels and a 3-min all-out test on a ski ergometer. Motion capture analysis and load cell recordings were used to measure body kinematics and dynamics. From these, W-erg, E-body (sum of the translational, rotational, and gravitational potential energies of all segments), and their time differentials (power P) were calculated. P(tot)the rate of energy absorption or generation by muscles-tendonswas defined as the sum of P-body and P-erg. ResultsE(body) showed large fluctuations over the movement cycle, decreasing during poling and increasing during the recovery phase. The fluctuation in P-body was almost perfectly out of phase with P-erg. Some muscle-tendon energy absorption was observed at the onset of poling. For the rest of poling and throughout the recovery phase, muscles-tendons generated energy to do W-erg and to increase E-body. Approximately 50% of cycle P-tot occurred during recovery for all intensity levels. Conclusions In double poling, the extensive contribution of the lower extremities and trunk to whole-body muscle-tendon work during recovery facilitates a direct transfer of E-body to W-erg during the poling phase. This observation reveals that double poling involves a unique movement pattern different from most other forms of legged terrestrial locomotion, which are characterized primarily by inverted pendulum or spring-mass types of movement.
Place, publisher, year, edition, pages
2015. Vol. 47, no 12, p. 2586-2594
Keywords [en]
CROSS-COUNTRY SKIING, DYNAMICS, MECHANICAL WORK, BIOMECHANICS, LOCOMOTION
National Category
Sport and Fitness Sciences
Identifiers
URN: urn:nbn:se:ltu:diva-84504DOI: 10.1249/MSS.0000000000000723ISI: 000364561800013PubMedID: 26110695Scopus ID: 2-s2.0-84947283516OAI: oai:DiVA.org:ltu-84504DiVA, id: diva2:1555705
2021-05-192021-05-192025-02-11Bibliographically approved