title: Kinematic Mechanisms of How Power Training Improves Healthy Old Adults' Gait Velocity.
abstract: Slow gait predicts many adverse clinical outcomes in old adults, but the mechanisms of how power training can minimize the age-related loss of gait velocity is unclear. We examined the effects of 10 wk of lower extremity power training and detraining on healthy old adults' lower extremity muscle power and gait kinematics.
  
  
  
  As part of the Potsdam Gait Study, participants started with 10 wk of power training followed by 10 wk of detraining (n = 16), and participants started with a 10-wk control period followed by 10 wk of power training (n = 16). We measured gait kinematics (stride characteristic and joint kinematics) and isokinetic power of the ankle plantarflexor (20°·s, 40°·s, and 60°·s) and knee extensor and flexor (60°·s, 120°·s, and 180°·s) muscles at weeks 0, 10, and 20.
  
  
  
  Power training improved isokinetic muscle power by ~30% (P ≤ 0.001) and fast (5.9%, P < 0.05) but not habitual gait velocity. Ankle plantarflexor velocity measured during gait at fast pace decreased by 7.9% (P < 0.05). The changes isokinetic muscle power and joint kinematics did not correlate with increases in fast gait velocity. The mechanisms that increased fast gait velocity involved higher cadence (r = 0.86, P ≤ 0.001) rather than longer strides (r = 0.49, P = 0.066). Detraining did not reverse the training-induced increases in muscle power and fast gait velocity.
  
  
  
  Because increases in muscle power and modifications in joint kinematics did not correlate with increases in fast gait velocity, kinematic mechanisms seem to play a minor role in improving healthy old adults' fast gait velocity after power training.
authors: 1Center for Human Movement Sciences, University Medical Center Groningen, Groningen, THE NETHERLANDS; 2Division of Training and Movement Sciences, University of Potsdam, Potsdam, GERMANY; and 3Department of Kinesiology, East Carolina University, Greenville, NC.
authors: Chantal M I
authors: CM
authors: Beijersbergen
authors: Urs
authors: U
authors: Granacher
authors: Martijn
authors: M
authors: Gäbler
authors: Paul
authors: P
authors: Devita
authors: Tibor
authors: T
authors: Hortobágyi
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D055070:Resistance Training / Q000379:methods*