title: Strength training in old age: adaptation of antagonist muscles at the ankle joint.
abstract: The purpose of this study was to determine whether strength training could reduce the deficit in plantarflexion (PF) maximal voluntary contraction (MVC) torque observed in previous studies in older subjects relative to young adults. Accordingly, the effects of a 6-month strength training program on the muscle and neural properties of the major muscle groups around the ankle were examined. PF and dorsiflexion (DF) isometric MVC torques were measured and surface electromyographic activity of the triceps surae and tibialis anterior muscles was recorded. The strength training program was very effective in improving strength in PF (+24.5%), and it thus reduced the DF-to-PF MVC torque ratio; in addition, it also induced gains in DF (+7.6%). Thus, there must be an improvement in ankle joint stability. In PF, gains were due particularly to a modification of the agonist neural drive; in DF, the gains appeared to be the consequence of a reduction in antagonist coactivation. Our findings indicate that the investigation of one muscle group should always be accompanied by examination of its antagonist muscle group.
authors.affiliation: Equipe INSERM-ERM 207 Motricité-Plasticité, Faculté des Sciences du Sport, Université de Bourgogne, BP 27877, 21078 Dijon, France. emilie.simoneau@u-bourgogne.fr
authors.forename: Emilie
authors.initials: E
authors.lastname: Simoneau
authors.forename: Alain
authors.initials: A
authors.lastname: Martin
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Porter
authors.forename: Jacques
authors.initials: J
authors.lastname: Van Hoecke
mesh_terms: D000222:Adaptation, Physiological; D000368:Aged / Q000502:physiology*; D000465:Algorithms; D000843:Ankle Joint / Q000502:physiology*; D003627:Data Interpretation, Statistical; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D014891:Weight Lifting / Q000502:physiology*