title: The effects of prosthetic foot type and visual alteration on postural steadiness in below-knee amputees.
abstract: BACKGROUND
  Achieving independent upright posture has known to be one of the main goals in rehabilitation following lower limb amputation. The purpose of this study was to compare postural steadiness of below knee amputees with visual alterations while wearing three different prosthetic feet.
  
  
  METHODS
  Ten male below-knee amputees were instructed to stand quietly on the Biodex® balance platform while wearing solid ankle cushion heel (SACH), single axis (SA) and energy storage and release (ESAR) prosthetic foot under different visual input conditions (eyes-opened and eyes-closed). The overall stability index (OSI), anterior- posterior stability index (APSI), and medial-lateral stability index (MLSI) were computed. Perceived balance assessment of each foot was evaluated using Activities-specific Balance Confidence (ABC) score.
  
  
  RESULTS
  The findings highlights that SACH showed lowest overall stability index (indicating less body sway) during eyes-opened (OSI: SACH = 1.09, SA = 1.58, ESAR = 1.59) and SA showed lowest overall stability index during eyes-closed (OSI: SACH = 2.52, SA = 2.30, ESAR = 2.76) condition. However, overall stability indexes between foot types did not differ significantly during eyes-opened or eyes-closed (p = 0.651). There was a trend of instability which occurred more in medial-lateral compared to anterior-posterior direction for all foot types, with significant result in ESAR foot(eyes-opened: MLSI = 1.59, APSI = 0.65, p = 0.034; eyes-closed: MLSI = 2.76, APSI = 1.80, p = 0.017, respectively). When comparing between visual conditions, stability score was significantly higher during eyes-closed compared to eyes-opened situations for SACH and ESAR foot (eyes-closed vs opened; SACH OSI: 3.43 vs 1.71, p = 0.018 and MLSI: 3.43 vs 1.71, p = 0.018; ESAR OSI: 3.58 vs 1.86, p = 0.043 and APSI: 1.80 vs 0.65, p = 0.027).
  
  
  CONCLUSIONS
  The results of this study suggested postural steadiness in below-knee amputees was not affected by the types of prosthetic foot during quiet upright standing, but was significantly affected when visual cues was absent.
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia. anidaum@yahoo.com.
authors.forename: Nooranida
authors.initials: N
authors.lastname: Arifin
authors.forename: Noor Azuan
authors.initials: NA
authors.lastname: Abu Osman
authors.forename: Sadeeq
authors.initials: S
authors.lastname: Ali
authors.forename: Wan Abu Bakar
authors.initials: WA
authors.lastname: Wan Abas
mesh_terms: D000328:Adult; D000674:Amputees; D000842:Ankle / Q000502:physiology; D001186:Artificial Limbs; D005260:Female; D005528:Foot / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance; D011474:Prosthesis Design; D055815:Young Adult