Does having a computerized prosthetic knee influence cognitive performance during amputee walking?
OBJECTIVE
To compare objective cognitive performance and perception of cognitive burden during walking tasks using 2 different prosthetic knees: a computerized hydraulic knee (Otto Bock C-leg) and a noncomputerized hydraulic knee (Ossur Mauch SNS).


METHODS
Two-group crossover trial, with participants randomly assigned to order of prosthesis. Participants completed assessments under 2 conditions, a self-selected speed walk and a controlled speed walk, on 2 separate occasions (precrossover, postcrossover).


METHODS
Veterans Health Administration hospital.


METHODS
Eight transfemoral amputees.


METHODS
Computerized versus noncomputerized prosthetic knee.


METHODS
Objective cognitive performance measures included verbal fluency (Controlled Oral Word Association Test, Category Test), attention and working memory (serial subtraction), and walking speed during cognitive tasks. Measures of perceived cognitive burden included subjective attentional requirements of walking and cognitive tasks and subjective general cognitive burden of prosthesis.


RESULTS
There were no significant differences in objective cognitive performance on any task between prostheses, nor did walking speed vary by prosthesis during the free-speed walk. Participants reported that walking required less attention while wearing the C-leg and that the C-leg was less of a cognitive burden than the noncomputerized prosthesis.


CONCLUSIONS
In nondemanding walking conditions with experienced amputees, participants reported that the more costly C-leg required less cognitive attention than the noncomputerized knee. However, this subjective experience did not translate to improved performance on neuropsychologic screening instruments or on walking speed. Noncomputerized prostheses may be adequate for a majority of amputees, and further research is needed to identify particular groups of amputees (ie, new amputees, amputees with complex physical or cognitive demands) who may benefit from computerized prostheses.
Williams
Rhonda M
RM
VA Puget Sound Health Care System, Seattle, WA 98108, USA. Rhonda.Williams1@med.va.gov
Turner
Aaron P
AP
Orendurff
Michael
M
Segal
Ava D
AD
Klute
Glenn K
GK
Pecoraro
Jan
J
Czerniecki
Joseph
J
D000328:Adult; D000674:Amputees; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D003071:Cognition / Q000502:physiology*; D003199:Computer Systems; D018592:Cross-Over Studies; D006801:Humans; D007720:Knee Prosthesis; D016014:Linear Models; D008875:Middle Aged; D011474:Prosthesis Design; D016138:Walking / Q000502:physiology*