title: Motor strategies responsible for maintaining standing posture after deafferentation of the unilateral leg.
abstract: OBJECTIVE
  To identify the motor strategies responsible for maintaining standing posture after deafferentation of the unilateral leg.
  
  
  METHODS
  Pretest-posttest, repeated-measures design.
  
  
  METHODS
  A Japanese university hospital rehabilitation facility.
  
  
  METHODS
  Nine healthy subjects aged 25 to 32 years.
  
  
  METHODS
  Two separate sessions that consisted of prolonged standing (control task) and standing until the H-reflex disappeared through the application of an inflated pneumatic cuff above the right knee.
  
  
  METHODS
  Center of pressure (COP), hip and ankle joint positions, and electromyographic activities.
  
  
  RESULTS
  In the control task, no time-related change during prolonged standing was found in any of the measured parameters. After deafferentation, the right soleus activity decreased significantly (P<.01), so the mean velocities of the COP in the anteroposterior and mediolateral directions were greater and the average COP position under the right foot shifted backward compared with those in the previous periods (P<.01). Also, the left tibialis anterior and soleus were activated, as was the bilateral gluteus medius.
  
  
  CONCLUSIONS
  The unilateral loss of leg and foot sensory information necessitated additional regulatory activities to stabilize the standing posture. The newly organized posture appeared to partly simulate the standing posture in patients with sensory disturbance of a unilateral leg.
authors.affiliation: Department of Rehabilitation, Keio University Hospital, Tokyo, Japan. imai@sc.itc.keio.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Imai
authors.forename: Kimitaka
authors.initials: K
authors.lastname: Hase
authors.forename: Kuniyasu
authors.initials: K
authors.lastname: Imanaka
authors.forename: Etsuko
authors.initials: E
authors.lastname: Suzuki
authors.forename: Naofumi
authors.initials: N
authors.lastname: Tanaka
authors.forename: Meigen
authors.initials: M
authors.lastname: Liu
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004576:Electromyography; D006181:H-Reflex / Q000502:physiology; D006801:Humans; D007866:Leg / Q000294:innervation* / Q000502:physiology; D008297:Male; D009121:Muscle Denervation; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology; D011187:Posture / Q000502:physiology*; D011434:Proprioception / Q000502:physiology*; D013997:Time Factors