title: Within-session acquisition of anticipatory postural adjustments during forward reaching task.
abstract: OBJECTIVE
  To describe the acquisition of anticipatory postural adjustment (APA) in healthy adults during standing forward reaching.
  
  
  METHODS
  Repeated-measures design Subjects/Patients: Ten healthy subjects.
  
  
  METHODS
  Within one day, all subjects practiced forward reaching to a moving target for sixty trials (10 trials, 6 blocks). APAs were recorded by electromyography (EMG), center of pressure (COP), and kinematic measurements. Repeated measure ANOVA was used to compare the changes of APA among the six blocks.
  
  
  RESULTS
  All subjects showed basic APA patterns in the beginning, such as posterior shift of COP and tibialis anterior firing first. The adults demonstrated significantly quicker onset of posterior shift of COP between block 2 and 6 (p<0.05) and decreased muscle activation of ispilateral tibialis anterior between block 1 and 3 (p=0.01).
  
  
  CONCLUSIONS
  The results suggested the acquisition process of APA could be observed after 50 trials of practice. Further study will need to verify the optimal practice trials in different populations with movement disorders.
authors: Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taiwan.
authors: Wen-Yu
authors: WY
authors: Liu
authors: Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taiwan.
authors: Yang-Hua
authors: YH
authors: Lin
authors: Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taiwan.
authors: Hen-Yu
authors: HY
authors: Lien
authors: Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taiwan; Healthy Aging Research Center, Chang Gung University, Taiwan.
authors: Lin-Ya
authors: LY
authors: Hsu
authors: Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taiwan; Healthy Aging Research Center, Chang Gung University, Taiwan.
authors: Yi-Ju
authors: YJ
authors: Tsai
authors: Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taiwan; Healthy Aging Research Center, Chang Gung University, Taiwan.
authors: Chia-Fang
authors: CF
authors: Liao
authors: Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Linkou, Taiwan; School of Medicine, Chang Gung University, Taiwan. Electronic address: fttang@adm.cgmh.org.tw.
authors: Simon Fuk-Tan
authors: SF
authors: Tang
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D001132:Arm; D001696:Biomechanical Phenomena; D004576:Electromyography; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D011187:Posture; D055815:Young Adult
keywords: Anticipatory postural adjustments; Forward reaching; Healthy adult; Within-session acquisition