title: Limits of stability in persons with transtibial amputation with respect to prosthetic alignment alterations.
abstract: OBJECTIVE
  To evaluate the limits of stability (LOS) in persons with transtibial amputation (TTA), and to determine the effects of prosthetic alignment alterations on motor control strategies.
  
  
  METHODS
  Before-and-after trial.
  
  
  METHODS
  A kinesiology laboratory at a university hospital.
  
  
  METHODS
  Male patients with TTA (n=10) and controls (n=17).
  
  
  METHODS
  Prosthetic alignment.
  
  
  METHODS
  For the LOS test, the maximum excursion, endpoint excursion, direction control, movement velocity, and reaction time with inclination in the forward direction, toward the amputated leg/right leg, and in the backward direction, and toward the nonamputated leg/left leg. Measurements were performed using the following 5 prosthetic alignments: the optimal alignment, with the prosthesis shorter by 1cm, with the prosthesis longer by 1cm, and with the prosthetic foot in 5° of extra plantar flexion and 5° of extra dorsiflexion.
  
  
  RESULTS
  Compared with the control group, maximum excursion and direction control were lower (P<.05) in patients with TTA with backward body inclination for all tested prosthetic alignments. Direction control in backward inclination was reduced (P<.05) compared with other tested directions for all assessed prosthetic alignments. Differences between the tested alignments were not significant in any of the tested directions.
  
  
  CONCLUSIONS
  Patients with TTA have decreased voluntary body inclination backward within the LOS for all tested prosthetic alignments. Compared with controls, changes in prosthetic foot settings by means of rotation in the sagittal plane had a larger impact on movement strategy in patients with TTA than did changes to the length of the prosthesis.
authors.affiliation: Department of Natural Sciences in Kinanthropology, Faculty of Physical Culture, Palacky University, Olomouc, Czech Republic; Department of Physiotherapy, Faculty of Health Sciences, Palacky University, Olomouc, Czech Republic. Electronic address: barbora.kolarova@upol.cz.
authors.forename: Barbora
authors.initials: B
authors.lastname: Kolarova
authors.forename: Miroslav
authors.initials: M
authors.lastname: Janura
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Svoboda
authors.forename: Milan
authors.initials: M
authors.lastname: Elfmark
mesh_terms: D000328:Adult; D000368:Aged; D000671:Amputation, Surgical; D000674:Amputees / Q000534:rehabilitation*; D001186:Artificial Limbs; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D011474:Prosthesis Design; D013977:Tibia / Q000601:surgery
keywords: ADL; ANOVA; Amputation; COG; DCL; EPE; LOS; MVL; MXE; Postural balance; Prosthesis; Rehabilitation; TTA; activities of daily living; analysis of variance; center of gravity; direction control; endpoint excursion; limits of stability; maximum excursion; movement velocity; transtibial amputation