motions with amputation were associated with increased loading at
the lower back during walking
35
and sit-to-stand movements.
36
Although these increases were of small-moderate magnitude, repeated
exposures over time may predispose these individuals to LBP onset
and recurrence.
37
Ongoing and future research will investigate the
origins of altered trunk motion and subsequently assess methods
or devices to minimize these loads in an effort to mitigate the preva-
lence of LBP among service members with lower limb amputation.
Another secondary musculoskeletal complication of unilateral
limb loss is osteoarthritis (OA) within joints of the intact limb. Per-
sons with unilateral lower limb amputation tend to preferentially use
their intact limb during gait and movement, which leads to larger and
more prolonged forces applied to the intact knee and/or hip joints.
CRSR has funded two retrospective studies to assess gait mechanics
in individuals with transtibial and transfemoral limb loss to deter-
mine how the intact limb is loaded at various time points during the
rehabilitative process. Excessive intact limb loads (relative to con-
trols) were only present at early time points among people with trans-
tibial amputation, but persisted through late rehabilitation for
persons with transfemoral amputation.
38
Such evidence suggests an
increased risk for early onset of OA and supports the development
and assessment of interventions to correct modi
fiable gait mechanics
in this population. A prospective evaluation of knee loading has
been initiated to begin to address this gap.
In order to assist with multisite efforts aimed at sharing and com-
bining commonly used biomechanical data across the MTFs, CRSR
supported a project to evaluate the intra- and interlab reliability
of gait data obtained at WRNMMC, CFI, and NMCSD.
39
Ten par-
ticipants traveled to each site to complete three biomechanical gait
evaluations according to each laboratory
’s standard operating proce-
dures. Data were analyzed by a third party to eliminate bias. Results
indicated that these measurements were highly reliable both within
and between laboratories, with mean kinematic errors less than
5 degrees across all joints and planes of motion, and mean kinetic
errors less than 10% for all joint moments. The ability to collect
reliable biomechanical data at these three major facilities will
support future multisite studies and data sharing.
RESEARCH FOCUS AREA 4: TRANSFER OF NEW TECH-
NOLOGY TO IMPROVE INDIVIDUAL PERFORMANCE
AND FUNCTIONALITY AFTER INJURYNovel devices, includ-
ing prosthetics and orthotics, help return service members with cog-
nitive and physical trauma to independent function. Previous
research supported by CRSR and USAMRMC compared passive
energy-storing and return (ESR) prosthetic feet with a powered ankle
foot prosthesis to determine, which novel technology could provide
the highest quality of life and expedite rehabilitation regimens.
40
Results indicated that the powered device had a larger range of
motion and generated more power during the preswing phase of
gait as compared to the energy storing and return,
40
demonstrating
how powered devices may assist those with limb loss improve
their gait. Ongoing studies continue to examine the effects of
advanced prosthetic components, including microprocessor and
power knee prosthetics.
In addition to examining prosthetic components, orthotic
devices are being evaluated to determine their ef
ficacy for improv-
ing gait in injured service members with extremity trauma and
limb salvage. Recent initiatives by Drs. Wilken and Russell
Esposito systematically modi
fied several mechanical parameters of
an ankle-foot orthosis to identify optimal design and prescription
criteria for various terrains.
41,42
Because of the high incidence of upper limb loss occurring in
combat casualties, focused research has been needed to improve
prosthetics and control strategies for individuals with upper limb
amputation. CRSR partnered with the Alfred Mann Foundation
(http://aemf.org) to conduct a clinical trial through the Food and
Drug Administration (FDA) entitled,
“First-in-man demonstration of
a fully implanted myoelectric sensors system to control an advanced
electromechanical prosthetic hand.
”
43
A signi
ficant limitation to cur-
rent myoelectric devices is their dependence on surface skin sensor
electrodes to control their actuation. Unfortunately, these sensors are
often unreliable, especially when individuals perspire or when their
prosthetic socket moves in different positions. In addition, surface
electrodes are limited in that they can only detect super
ficial muscle
activity and do not provide the user with enough intuitive control.
This collaborative study demonstrated the feasibility of implanting
wireless electrodes in the forearm of service members with trans-
radial amputation to control a 3-degrees-of-freedom prosthetic hand.
Future work will include expanding the use of this technology for
individuals with transhumeral level amputations.
Expanding on the
field of upper extremity prosthetics, CRSR is
also proud of its partnership with the Defense Advanced Projects
Agency (DARPA) to evaluate the performance of the DEKA arm
(http://www.dekaresearch.com/deka_arm.shtml). This revolutionary
multiple degrees-of-freedom prosthetic arm has received FDA
approval and is the
first of its kind to help pioneer the intersection
between robotics and improving human performance for individuals
with disabilities. CRSR also works with DARPA and other aca-
demic and industry groups to utilize novel neuroprosthetics to help
restore sensory/haptic feedback for prosthetic users. Our research
portfolio is bolstered by strong partnerships with teams, such as the
Human Engineering Research Laboratories (www.herlpitt.edu),
which have helped collectively develop a specialized patient-
controlled analgesia device adapter to improve postsurgical
pain, autonomy, and independence for patients who have lost the
use of their limbs, enabling them to participate in rehabilitation.
CONCLUSIONSThe clinical research community has an obliga-
tion to address the needs of these service members and veterans
with complex orthopedic and neurological injuries stemming
from recent con
flicts. Injuries to young military service mem-
bers, particularly those caused by blasts, pose unique challenges
to rehabilitation that require research programs and consortia to
help advance science and care. CRSR is dedicated to not only
identifying gaps in the research but also to aligning resources in
a synergized fashion to de
fine and validate the most effective
rehabilitation strategies for this patient population. CRSR
engages a broad group of interdisciplinary investigators from
medicine, biology, engineering, anthropology, and physiology
and connects them directly with clinicians, patients, and families
to help solve clinically relevant problems for our service mem-
bers, veterans, and their families.
ACKNOWLEDGMENTS
This work is supported by the Department of Physical Medicine and Reha-
bilitation, Center for Rehabilitation Science Research, USU, Bethesda,
Maryland, awards HU0001-11-1-0004 and HU0001-15-2-0003.
MILITARY MEDICINE, Vol. 181, November/December Supplement 2016
24
Advancing the Rehabilitative Care for Service Members With Complex Trauma