Effect of ankle-foot orthosis alignment and foot-plate length on the gait of adults with poststroke hemiplegia

Arch Phys Med Rehabil. 2009 May;90(5):810-8. doi: 10.1016/j.apmr.2008.11.012.


Objective: To investigate the effect of ankle-foot orthosis (AFO) alignment and foot-plate length on sagittal plane knee kinematics and kinetics during gait in adults with poststroke hemiplegia.

Design: Repeated measures, quasi-experimental study.

Setting: Motion analysis laboratory.

Participants: Volunteer sample of adults with poststroke hemiplegia (n=16) and able-bodied adults (n=12) of similar age.

Interventions: Subjects with hemiplegia were measured walking with standardized footwear in 4 conditions: (1) no AFO (shoes only); (2) articulated AFO with 90 degrees plantar flexion stop and full-length foot-plate-conventionally aligned AFO (CAFO); (3) the same AFO realigned with the tibia vertical in the shoe-heel-height compensated AFO (HHCAFO); and (4) the same AFO (tibia vertical) with 3/4 length foot-plate-3/4 AFO. Gait of able-bodied control subjects was measured on a single occasion to provide a normal reference.

Main outcome measures: Sagittal plane ankle and knee kinematics and kinetics.

Results: In adults with hemiplegia, walking speed was unaffected by the different conditions (P=.095). Compared with the no AFO condition, all AFOs decreased plantar flexion at initial contact and mid-swing (P<.001) and changed the peak knee moment in early stance from flexor to extensor (P<.000). Both AFOs with full-length foot-plates significantly increased the peak stance phase plantar flexor moment compared with no AFO and resulted in a peak knee extensor moment in early stance that was significantly greater than control subjects, whereas the AFO with three-quarter length foot-plate resulted in ankle dorsiflexion during stance and swing that was significantly less than control subjects.

Conclusions: These findings suggest that when an articulated AFO is to be used, a full-length foot-plate in conjunction with a plantar flexion stop may be considered to improve early stance knee moments for people with poststroke hemiplegia.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Aged
  • Ankle Joint / physiology*
  • Biomechanical Phenomena
  • Cohort Studies
  • Female
  • Gait Disorders, Neurologic / etiology*
  • Gait Disorders, Neurologic / physiopathology
  • Gait Disorders, Neurologic / rehabilitation*
  • Hemiplegia / complications
  • Hemiplegia / physiopathology
  • Hemiplegia / rehabilitation
  • Humans
  • Male
  • Middle Aged
  • Orthotic Devices*
  • Probability
  • Range of Motion, Articular / physiology
  • Recovery of Function
  • Risk Factors
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Stroke / complications
  • Stroke / diagnosis
  • Stroke Rehabilitation*
  • Treatment Outcome