title: The effect of swinging the arms on muscle activation and production of leg force during ski skating at different skiing speeds.
abstract: The study investigated the effects of arm swing during leg push-off in V2-alternate/G4 skating on neuromuscular activation and force production by the leg muscles. Nine skilled cross-country skiers performed V2-alternate skating without poles at moderate, high, and maximal speeds, both with free (SWING) and restricted arm swing (NOSWING). Maximal speed was 5% greater in SWING (P<0.01), while neuromuscular activation and produced forces did not differ between techniques. At both moderate and high speed the maximal (2% and 5%, respectively) and average (both 5%) vertical force and associated impulse (10% and 14%) were greater with SWING (all P<0.05). At high speed range of motion and angular velocity of knee flexion were 24% greater with SWING (both P<0.05), while average EMG of m. biceps femoris was 31% lower (all P<0.05) in SWING. In a similar manner, the average EMG of m. vastus medialis and m. biceps femoris were lower (17% and 32%, P<0.05) during the following knee extension. Thus, swinging the arms while performing V2-alternate can enhance both maximal speed and skiing economy at moderate and, in particularly, high speeds.
authors.affiliation: Department of Sport Science and Kinesiology, University of Salzburg, Schlossallee 49, 5400 Hallein/Rif, Salzburg, Austria; Sports Technology Unit, Department of Biology of Physical Activity, Neuromuscular Research Centre, University of Jyväskylä, Kidekuja 2, Snowpolis, 88610 Vuokatti, Finland. Electronic address: caro.goepfert@gmx.de.
authors.forename: Caroline
authors.initials: C
authors.lastname: Göpfert
authors.affiliation: Department of Sport Science and Kinesiology, University of Salzburg, Schlossallee 49, 5400 Hallein/Rif, Salzburg, Austria. Electronic address: stefan.lindinger@sbg.ac.at.
authors.forename: Stefan J
authors.initials: SJ
authors.lastname: Lindinger
authors.affiliation: Sports Technology Unit, Department of Biology of Physical Activity, Neuromuscular Research Centre, University of Jyväskylä, Kidekuja 2, Snowpolis, 88610 Vuokatti, Finland. Electronic address: olli.ohtonen@jyu.fi.
authors.forename: Olli
authors.initials: O
authors.lastname: Ohtonen
authors.affiliation: Department of Sport and Sport Science, University of Freiburg, Schwarzwaldstraße 175, 79117 Freiburg, Germany. Electronic address: walter.rapp@sport.uni-freiburg.de.
authors.forename: Walter
authors.initials: W
authors.lastname: Rapp
authors.affiliation: Department of Sport Science and Kinesiology, University of Salzburg, Schlossallee 49, 5400 Hallein/Rif, Salzburg, Austria. Electronic address: erich.mueller@sbg.ac.at.
authors.forename: Erich
authors.initials: E
authors.lastname: Müller
authors.affiliation: Sports Technology Unit, Department of Biology of Physical Activity, Neuromuscular Research Centre, University of Jyväskylä, Kidekuja 2, Snowpolis, 88610 Vuokatti, Finland. Electronic address: vesa.linnamo@jyu.fi.
authors.forename: Vesa
authors.initials: V
authors.lastname: Linnamo
mesh_terms: D000328:Adult; D001132:Arm / Q000502:physiology*; D056352:Athletes; D001696:Biomechanical Phenomena; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D016059:Range of Motion, Articular; D012865:Skiing / Q000502:physiology*; D055815:Young Adult
keywords: Arm swing; Cross-country skiing; EMG; Ski forces