to participate in rehabilitation regimens. Additional work is being
conducted by Dr. Tsao
’s team to determine if genetic factors influ-
ence PLP since some individuals do not develop this debilitating
condition following limb amputation, whereas others are severely
affected. Lastly, studies are being conducted to determine how many
sessions of mirror therapy are needed for pain relief and whether
existing neuropathic pain models are applicable for treating PLP.
Heterotopic Ossification
Heterotopic ossi
fication (HO) is a pathologic process characterized
by ectopic osseous growth in muscle and/or periarticular regions.
28
Although HO may develop from rare genetic disorders, abnormal
bone growth has been most frequently reported following trauma,
arthroplasty, burns, spinal cord injury, and traumatic brain injury.
28
While, most cases of HO in the general population are clinically
asymptomatic, and do not require surgical intervention, military ser-
vice members injured by blasts in Afghanistan and Iraq, have much
different prognosis.
29,30
Armaments such as improvised explosive
devices (IEDs) and rocket propelled grenades (RPGs) generate exten-
sive polytrauma, and approximately 63% of war
fighters with limb
loss have developed post-traumatic HO (with 20% to 40% requiring
surgical excision).
31,32
Symptomatic HO is problematic for service
members since it delays rehabilitation regimens, causes pain, limits
range of motion, and requires modi
fications of prosthetic limbs.
32,33
The CRSR is committed to understanding the etiology of
these ectopic osseous masses and improving surgical planning
for servicemen and women. Dr. Brad Isaacson is the lead
investigator and received two Congressionally Directed Medical
Research Programs (CDMRP) grants (W81XWH-12-2-0017 and
W81XWH-16-2-0037) and private donations from the Wounded
Warrior Amputee Softball Team to advance this
field of orthopedics/
rehabilitation. Data from his laboratory has demonstrated a link
between bench top research and bedside care, with the mineral
apposition rate (MAR), a hallmark for bone growth, computed
to be 1.7 times faster in trauma-induced HO compared to non-
pathological human bone.
29
Further, when data from this cohort
of wounded warriors was limited to patients with no more than a
two-year period from injury to excision, and known correlates
(traumatic brain injury and nonsteroidal anti-in
flammatory drugs),
the MAR and recurrence severity were signi
ficantly related.
29
Research by Dr. Isaacson and his team will now focus on devel-
oping a translatable animal model to investigate combat-related
factors which have been associated with ectopic bone growth
(tourniquets,
34
wound vacuum usage, bioburden, and trauma).
RESEARCH FOCUS AREA 3: APPLICATION
OF NEW TECHNOLOGIES TO ADVANCE
REHABILITATION AND PERFORMANCE
CRSR supports and enhances existing clinical programs at the
MTFs by facilitating the use of new technologies for rehabilita-
tion and performance optimization. A strong partnership has been
forged with the MHS, VA, and EACE to help provide infrastruc-
ture and personnel support for research projects. Efforts within this
research area are led by a team of principal investigators, including
Drs. Erik Wolf, Brad Hendershot, Alison Pruziner, Jason Wilken,
Christopher Rábago, Elizabeth Russell Esposito, and Ms.
Marilynn Wyatt. Advanced evaluation and treatment techniques
are applied to help service members regain functionality after
physical and cognitive injuries and to understand the longer-term
implications of such injuries and rehabilitation processes.
Novel rehabilitation techniques applied in multisensory virtual
reality environments (VRE) promote resilience and recovery to
improve physical and cognitive skills in wounded service members.
4
There are four high-end VRE (Computer Assisted Rehabilitation
Environment, Motekforce Link, The Netherlands) used in the MHS
to provide a safe, interactive setting for clinicians to simulate com-
munity, recreational, or occupational tasks.
Dr. Wolf led a CRSR effort to determine the most bene
ficial bio-
mechanical and physiological feedback modalities within a VRE for
delivering physical therapy to injured service members. Preliminary
results indicate that a game-style application that provides feedback
to the patient in an indirect manner produces the most positive out-
comes. In collaboration with Dr. Wolf
’s efforts, Drs. Pruziner and
Hendershot are utilizing a VRE to identify how dual tasking with
increased cognitive demand affects walking ability for people with
unilateral lower limb amputation. Previous research has shown that
performing tasks requiring divided attentional resources result in
abnormal gait mechanics. Preliminary analyses suggest individuals
with amputations may differentially prioritize cognitive and motor
processes when walking. This study has potentially important impli-
cations regarding the ability to fully participate in a person
’s natural
environment after limb loss, and also may relate to an increased risk
of falling. Additional ongoing efforts are aimed at evaluating bio-
mechanical and cognitive responses to walking in more ecologi-
cally valid VRE, as opposed to game-style environments, which
will include additional challenges to working memory, decision-
making, and navigational skills.
Optimizing performance and maximizing functional outcomes
are critical components of a rehabilitation program and are synony-
mous with returning to active duty for many wounded service mem-
bers. Drs. Wilken and Rábago implemented an assessment battery
within a militarized VRE to identify functional and cognitive de
ficits
that emerge when performing military-speci
fic tasks. This study
incorporates load carriage, variable terrain negotiation, and quick
decision-making. Physiological and biomechanical data collected
during these tasks can guide future therapies and the prescription
of prosthetic or orthotic devices for service members with lower
extremity injuries. This study is the
first step in developing a
military-relevant assessment battery with objective performance
metrics that correlate to return to duty rehabilitation goal. Follow-
up studies supported by CRSR will incorporate the knowledge
gained from the assessment study into a VRE-based, military-
speci
fic treatment intervention aimed at returning injured service
members to duty and increasing military readiness.
In addition to VRE-based rehabilitation, other studies within this
focus area seek to understand secondary musculoskeletal complica-
tions of limb loss and the in
fluences of various technologies and reha-
bilitation paradigms. As noted, LBP is especially prevalent among
persons with amputation(s), perhaps related to altered gait and move-
ment patterns. To better understand these speci
fic risk factors,
Dr. Hendershot has performed several retrospective studies using the
large biomechanical database at WRNMMC to directly quantify how
gait deviations in
fluence trunk and spine motion among service mem-
bers with lower limb loss. Notably, larger and asymmetric trunk
MILITARY MEDICINE, Vol. 181, November/December Supplement 2016
23
Advancing the Rehabilitative Care for Service Members With Complex Trauma