title: Reduced lower leg muscle activity while balancing on cobblestone shaped surfaces.
abstract: The purpose of this study was to test the hypothesis that muscle intensity and ankle joint motion will be greater when balancing on a surface shaped like a cobblestone pathway than on a smooth surface. Nineteen healthy male and female subjects participated in this study. Electromyographic (EMG) activity of the soleus, gastrocnemii medialis and lateralis, peroneus longus and tibialis anterior and ankle dorsiflexion/plantarflexion and eversion/inversion were recorded for unilateral balancing tasks on a hard smooth (control), soft smooth and two cobblestone shaped balance surfaces. Mean ankle kinematics did not differ between conditions. EMG intensity of the lower leg muscles were significant lower for the cobblestone shaped surface than for the control surface (-40 to -80%; P<.01). EMG intensity of the lower leg muscles were significantly higher for the soft smooth surface than for the control surface (+12 to +30%; P<.01). Different balance strategies or tendon stretching may be responsible for these differences. Not only material properties but also surface shape of balance surfaces should be considered to optimize training output and tailored to the specific goal of a training regimen.
authors.affiliation: Medical Park Bad Wiessee St. Hubertus, Bad Wiessee, Germany. Electronic address: t.horstmann@medicalpark.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Horstmann
authors.affiliation: Department of Orthopaedics, University Hospital Basel, Basel, Switzerland; Division of Sport Science, University of Konstanz, Germany.
authors.forename: Annegret
authors.initials: A
authors.lastname: Mündermann
authors.affiliation: Department of Sports Medicine, Medical Clinic, University of Tübingen, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Rapp
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena; D004576:Electromyography; D005260:Female; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009142:Musculoskeletal Physiological Phenomena; D004856:Postural Balance / Q000502:physiology*; D055815:Young Adult
keywords: Ankle kinematics; Balance control; Lower leg muscle activity; Material hardness; Surface shape