Page 76 - REV T-I JOURNAL INTERIOR ISSUU 18 2-3

152 HIGHSMITH ET AL.

INTRODUCTION reflective markers and an 8-camera Vicon (Oxford,
The Genium microprocessor knee (MPK) sys- United Kingdom) motion analysis system. Subjects
tem (Ottobock Healthcare, Duderstadt, Germany) walked up and down 5° ramps at slow, normal, and
reportedly implements several engineering advance- fast walking speeds. The task variations (walking
ments over previously manufactured MPK systems speeds, ascent/descent) were intended to evaluate
(1-5). Study of these advancements has resulted in knee component performance under diverse gait
a recent body of literature showing improved per- conditions seen during community ambulation.
formance of the Genium even when compared to
the C-Leg (Ottobock Healthcare, Duderstadt, Ger- Randomization and Interventions
many), the most studied commercially available All subjects entering the study were C-Leg users
MPK system (1-5). Compared to C-Leg, Genium for ≥1 year prior to enrollment. An electronic random
use resulted in improved symmetry in peak knee flex- number generator was used to assign subjects (off site)
ion angles during stance and swing when ascending to either continue with their C-Leg or to be fit with a
and descending ramps in a sample of transfemo- Genium knee system at recruitment. The study pros-
ral amputation (TFA) patients (6). This improved thetist was notified of the subject’s assigned condition
kinematic pattern was more similar to non-amputee via telephone on the day of the subject’s knee fitting.
controls when walking on different hill conditions All fittings and adjustments were performed by the
and at different speeds. Given the improved kine- study prosthetist, who was state-licensed and certified
matics associated with hill walking while using the by the American Board for Certification in Orthotics,
Genium, a similar improvement in the symmetry of Prosthetics, and Pedorthics as well as by Ottobock
knee kinetics is also feasible. Healthcare for fitting both C-Leg and Genium MPK
Due to the increased kinematic symmetry of the systems. The subjects’ prosthetic sockets and suspen-
knee previously reported following Genium accom- sion systems were not changed for the duration of the
modation and use, the hypothesis of this study was experiment to reduce the confounding effects from
that the Genium MPK system would increase sym- fit and acclimation issues. All subjects were fit with
metry in peak knee flexion moment during ramp an Ottobock Trias (standard height) or Axtion (low
gait. Thus, the study’s purpose was to determine if profile) prosthetic foot, based on limb length, for use
use of the Genium MPK would reduce the degree over the study duration. Manufacturer specifications
of asymmetry (DoA) of peak stance knee flexion were used to set componentry alignment and were
moment compared to the C-Leg MPK in persons verified using the LASAR (Ottobock, Duderstadt,
with transfemoral amputation. Germany) alignment system.

METHODS Fitting and Accommodation Periods
The study was approved by the University of South After enrollment, anthropometric data, random-
Florida’s Institutional Review Board and listed on ization order, and the study foot were recorded. Knee
clinicaltrials.gov (#NCT01473992). Subjects gave fittings and alignment were conducted and recorded.
informed consent prior to participation in the study. All subjects were invited to return to the study pros-
thetist or physical therapist for adjustment, alignment,
Study Design Overview and training as many times as they wished to optimize
This study was a randomized experimental their fit, comfort, and function and to mirror real clin-
crossover of TFA patients using Genium and C-Leg ical practice and component prescription. Visits were
MPKs. Each subject tested on both knee conditions counted, and reasons for each visit were recorded. All
in a random order separated by an accommodation subjects, regardless of which knee system they began
period of >2 weeks to <3 months, depending upon the study with, received an initial training session
when subjects determined their readiness to test. from the study physical therapist for each knee sys-
Subjects’ gait patterns were recorded using passive tem for training in transitional movements, obstacle