title: Isokinetic analysis of ankle and ground reaction forces in runners and triathletes.
abstract: OBJECTIVE
  To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes.
  
  
  METHODS
  Seventy-five males with a mean age of 30.26 (±6.5) years were divided into three groups: a triathlete group (n=26), a long-distance runner group (n = 23), and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer.
  
  
  RESULTS
  The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180º/s) was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60º/s) was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups.
  
  
  CONCLUSIONS
  The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners.
authors.affiliation: Department of Orthopedics and Traumatology, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil. natmsluna@hotmail.com
authors.forename: Natália Mariana Silva
authors.initials: NM
authors.lastname: Luna
authors.forename: Angelica Castilho
authors.initials: AC
authors.lastname: Alonso
authors.forename: Guilherme Carlos
authors.initials: GC
authors.lastname: Brech
authors.forename: Luis
authors.initials: L
authors.lastname: Mochizuki
authors.forename: Eduardo Yoshio
authors.initials: EY
authors.lastname: Nakano
authors.forename: Júlia Maria D'Andrea
authors.initials: JM
authors.lastname: Greve
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000842:Ankle / Q000502:physiology*; D000843:Ankle Joint / Q000502:physiology; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D012420:Running / Q000502:physiology*; D018709:Statistics, Nonparametric; D013977:Tibia / Q000293:injuries; D019415:Torque; D055815:Young Adult