title: Preliminary investigation of residual limb plantarflexion and dorsiflexion muscle activity during treadmill walking for trans-tibial amputees.
abstract: BACKGROUND
  Novel powered prosthetic ankles currently incorporate finite state control, using kinematic and kinetic sensors to differentiate stance and swing phases/sub-phases and control joint impedance and position or torque. For more intuitive control, myoelectric control of the ankle using the remnant residual limb dorsiflexors and plantarflexors, perhaps in concert with kinetic and kinematic sensors, may be possible.
  
  
  OBJECTIVE
  The specific research objective was to assess the feasibility of using myoelectric control of future active or powered prosthetic ankle joints for trans-tibial amputees.
  
  
  METHODS
  The project involved human subject trials to determine whether current techniques of myoelectric control of upper extremity prostheses might be readily adapted for lower extremity prosthetic control.
  
  
  METHODS
  Gait analysis was conducted for three unilateral trans-tibial amputee subjects during ambulation on an instrumented split belt treadmill. Data included ankle plantarflexor and dorsiflexor activity for the residual limb, as well as lower limb kinematics and ground reaction forces and moments of both the sound and prosthetic limbs.
  
  
  RESULTS
  These data indicate that: 1) trans-tibial amputees retain some independent ankle plantarflexor and dorsiflexor muscle activity of their residual limb; 2) it is possible to position surface electromyographic electrodes within a trans-tibial socket that maintain contact during ambulation; 3) both the plantarflexors and dorsiflexors of the residual limb are active during gait; 4) plantarflexor and dorsiflexor activity is consistent during multiple gait cycles; and 5) with minimal training, trans-tibial amputees may be able to activate their plantarflexors during push-off.
  
  
  CONCLUSIONS
  These observations demonstrate the potential for future myoelectric control of active prosthetic ankles. Clinical relevance This study demonstrated the feasibility of applying upper extremity prosthetic myoelectric signal acquisition, processing and control techniques to future myoelectric control of active prosthetic ankles for trans-tibial amputees.
authors.affiliation: Marquette University, 1515 W Wisconsin Ave, Milwaukee, WI 53233, USA. barbara.silver-thorn@marquette.edu
authors.forename: Barbara
authors.initials: B
authors.lastname: Silver-Thorn
authors.forename: Thomas
authors.initials: T
authors.lastname: Current
authors.forename: Benjamin
authors.initials: B
authors.lastname: Kuhse
mesh_terms: D000328:Adult; D000674:Amputees / Q000534:rehabilitation; D000843:Ankle Joint / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D004576:Electromyography; D005240:Feasibility Studies; D005684:Gait / Q000502:physiology; D006801:Humans; D007866:Leg / Q000503:physiopathology*; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted; D016138:Walking / Q000502:physiology*