The Walter Reed Army Medical Center (WRAMC) in Washington, DC, provides comprehensive health care for more than 150,000 service members, military retirees, and their families. A large number of service members wounded in Iraq and Afghanistan are medically evacuated to WRAMC as their first point of medical care in the United States. Approximately 30% of all soldiers within the Warrior Transition Brigade at WRAMC have some degree of traumatic brain injury (TBI).
The following case is a typical example of the assessment and rehabilitation of a wounded soldier who sustained a TBI and other injuries as a result of multiple blast exposure:The day of the attack began with an ordinary convoy mission. Sergeant Kellogg was driving the armored military vehicle when an improvised explosive device detonated to the right of the vehicle. He immediately lost consciousness from the force of the blast. Kellogg was awakened by a rocket-propelled grenade (RPG) striking to the left of the vehicle. He was thrown forward, backward, bounced about, and again lost consciousness. The incident continued with a total of five RPGs hitting the vehicle. Once the incident subsided, Kellogg was air evacuated for medical treatment. Following a short stay at Landstuhl Regional Medical Center, Germany, he arrived at WRAMC for multidisciplinary medical treatment, including physical therapy services.
Comprehensive warrior care at WRAMC included diagnostic screening for a TBI. Based on Department of Defense guidelines, Kellogg was diagnosed with a mild TBI on the basis of periods of loss of consciousness and altered levels of consciousness, as well as a period of post-traumatic amnesia. He exhibited postinjury symptom sequelae of memory difficulties, headache, dizziness, attention deficits, and word-finding difficulties. Appropriate imaging was obtained from the medical team with no visible pathology of his head, neck, or lumbar spine. He was referred for a physical therapy evaluation with WRAMC’s TBI Team.
The physical therapists within the TBI Team at WRAMC use repeatable and progressive objective measures for gait and balance in order to quantify function and track progress. These are used across continuums of care: inpatient, outpatient, and progression to independent treatment programs.
Initial evaluation of Kellogg revealed subjective complaints of extreme headache, cervical pain, dizziness with all movement, severe disequilibrium, and difficulty ambulating. Evaluation included gross motor and sensation testing, functional mobility and ambulation, occulomotor and vestibular screening, and balance assessment. Evaluation findings included decreased cervical range of motion, occulomotor abnormalities, ataxic gait requiring assistance to prevent falls, and difficulty with all functional transfers. Kellogg’s acute care physical therapist included the Functional Gait Assessment (FGA), gait speed, and computerized dynamic posturography (CDP) as initial outcome measures in her evaluation.
The FGA was developed by Wrisley et al1 in an effort to apply the Dynamic Gait Index (DGI) to individuals with vestibular dysfunction. It is also designed to assess ambulation in higher functioning individuals, possibly preventing the ceiling effect seen with DGI. It assesses stability and speed during multiple gait conditions including gait with head turns, gait with eyes closed, backward ambulation, tandem walking, and stepping over an obstacle. The FGA has been shown to be both reliable and valid when testing those with vestibular dysfunction.1 The maximum achievable score is 30/30 points.
Included in the FGA is a 20-foot timed condition in which gait speed can be easily calculated. Termed the “sixth vital sign” by authors Fritz and Lusardi,2 gait speed is easily obtained in any clinical setting, and can be performed with many different patient populations, and correlated with multiple functional outcomes.2 Gait speed findings can be compared with age-matched norms as published by Bohannon.3 At the WRAMC gait assessment laboratory, a gait speed of 1.5 m/s (or 4.92 ft/s) has been established as the gait speed of male active duty control subjects,4 compared to ranges of 3.57 ft/s to 4.17 ft/s in males in the general population, ages 20-49.2
Computerized dynamic posturography assesses both sensory and motor function and is regularly used in research for patients status post neurological insult. Described by Dr Lewis Nashner, CDP “determines the cause(s) underlying functional limitations by quantifying impairments to the sensory input, central integrative, and automatic motor response systems necessary for normal balance and mobility.”5 The Sensory Organization Test (SOT), a component of CDP, isolates visual, somatosensory, or vestibular sensory input and aids in objective identification of an individual’s ability to use and integrate these inputs in order to maintain postural stability. The test assesses the individual’s postural sway and relative equilibrium in six conditions: eyes open, eyes closed, and visual interference on both stable and unstable support surfaces.5
Kellogg performed significantly below normal in all of the above assessments. Initial gait speed was .95 ft/s. FGA score was 3/30. He was unable to complete most tasks without assistance. His SOT score was 12/100 with falls on all conditions except eyes open on a stable surface. A treatment plan was designed for Kellogg based on these functional deficits as well as his subjective symptoms and additional examination findings.
Kellogg’s cervical pain and range of motion deficits were treated with traditional stretching, active range of motion exercises, and manual therapy. Due to observed occulomotor abnormalities, gaze stabilization exercises were incorporated into treatment sessions and assigned for home exercise to be completed daily. Functional transfers were practiced using repetition, and his wife was educated in proper assistance techniques to ensure patient and caregiver safety. Balance training, such as static standing with eyes open, eyes closed, and reaching with unilateral upper extremity support, was performed. He was able to progress his balance training tasks to marching and turning in place with eyes closed, and do basic foam stance activities with and without dual tasking (ball toss, memory games, basic math). Gait training began with simple progression of speed and safety with turns. During his inpatient stay, he was able to progress to gait training with slow head movements and treadmill ambulation without upper extremity support at speeds of 2.3 mph (3.23 ft/s). Once Kellogg was able to ambulate independently indoors on level surfaces and perform basic mobility and activities of daily living independently, he was transitioned to WRAMC’s outpatient TBI physical therapy team.
Outpatient evaluation of Kellogg revealed subjective complaints of headache, cervical pain, blurry vision, and dizziness. He primarily described disequilibrium with quick movements, head turns, or distractions and difficulty ambulating on uneven terrain and in busy environments. Because his symptoms were now less severe, the physical therapist was able to evaluate his condition in more depth. Evaluation findings included musculoskeletal findings consistent with severe whiplash disorder and functional vision deficits such as difficulty tracking objects or switching his visual focus between targets. Because of his continued occulomotor abnormalities and dizziness, he was referred to Audiology to complete a battery of vestibular function tests. The results of caloric, rotary chair, and vestibular evoked myogenic potential testing were indicative of incomplete peripheral vestibular weakness. Kellogg’s outpatient physical therapist included gait speed, FGA, CDP, the High Level Mobility Assessment Tool (HiMAT), and Head-Shake Sensory Organization Test (HS-SOT) as outcome measurements in her assessments.
The HiMAT was designed and developed by Williams et al6-8 in an effort to quantify high level mobility performance in individuals who wish to progress their rehabilitation goals toward unlimited community mobility, and return to recreational activities or sport. It assesses the speed and capability of individuals during multiple mobility conditions including, but not limited to, skipping, hopping, bounding, and running. The individual must be able to ambulate independently without an assistive device for 20 meters in order to complete the test, therefore it has a floor effect in acute patients. However, with little ceiling effect, it is very appropriate for the latter stages of rehabilitation and recovery. The HiMAT has been shown to have excellent validity, inter-rater, and retest reliability.6-8 The maximum achievable score is 54/54 points.
The HS-SOT is an enhancement of the standard SOT that allows for increased sensitivity, specificity, and quantification of functional balance deficits related to head movement. It is most useful for individuals who perform well or within the normal range on the standard SOT or other gait and balance assessments. Information is gathered related to the use of vestibular cues to maintain postural stability in higher demand situations in which younger individuals or military service members are required to function.9 Individuals are required to maintain postural stability with eyes closed on both stable and unstable surfaces while turning the head side to side at a speed of approximately 85º per second. Normal performance on the HS-SOT is equivalent to performance with the head stationary on a firm surface (condition 2). Although there are no clear documented normal performance values for the HS-SOT with an unstable surface (condition 5), individuals with known uncompensated peripheral vestibular weakness decline in performance by greater than 30% in this condition, indicating likely abnormal performance.9
Kellogg’s performance on objective measurements demonstrated improvement; however, his scores were still well below normal. His gait speed was 3.12 ft/s. FGA score was 16/30 with most difficulty on gait with head turns, eyes closed, and narrow base of support (NBOS). HiMAT score was 18/54. His SOT score was 42/100 with falls on conditions 5 and 6. He demonstrated an excessive reliance on visual cues to maintain postural stability regardless of whether those cues were accurate. Because of falls on conditions 5 and 6, Kellogg was not tested on the HS-SOT during his initial outpatient evaluation. His outpatient treatment plan was established based on these functional deficits as well as his subjective symptoms and additional diagnostic findings. He continued to be treated for cervical musculoskeletal pain and dysfunction, including the addition of cervical kinesthetic and postural awareness. He was assigned visual tracking and gaze stabilization exercises in both the clinic and home. Balance and gait progression was focused on progressively increasing speed with the addition of head turns, unstable surfaces, quick body turns, agility moves, and various combinations of two or more of these challenges. He participated in various balance training tasks with visual interference such as ball tossing from hand to hand while negotiating obstacles.
Upon successive retesting of his SOT, Kellogg scored a total of 79/100 (within normal range) and was able to maintain postural stability during conditions 5 and 6. He then completed the HS-SOT with 98% equilibrium ratio on condition 2 compared without head movement, but consistently fell with eyes closed, unstable surface, and head turns (condition 5). Training was focused to higher speed and agility levels with specific emphasis on multiple tasks with eyes closed and uneven, unstable surfaces.
Kellogg completed his rehabilitation with 1x/week appointments to assess and upgrade a daily home exercise program. At the time of discharge, he achieved scores on all outcome measures within the normal range for his age: Gait speed was 4.73 ft/s. Ceiling effect was reached in the FGA with a score of 30/30. HS-SOT equilibrium ratios of 99% and 78% were achieved for conditions 2 and 5, respectively. HiMAT score was 50/54.
Kellogg was able to return to unlimited community mobility and to his recreational activities without symptoms. He discharged from the WRAMC campus to his home, family, and unit in New York to pursue a return to full active duty status.
Janette Scardillo, PT, MPT, DPT, serves as staff physical therapist on the inpatient Traumatic Brain Injury Team at Walter Reed Army Medical Center in Washington, DC. CAPT Jennifer Hundt, PT, DPT, NCS, ATP, serves as chief of Traumatic Brain Injury Physical Therapy at Walter Reed Army Medical Center.
- Wrisley DM, Marchetti GF, Kuharsky DK, Whitney SL. Reliability, internal consistency, and validity of data obtained with the Functional Gait Assessment. Phys Ther. 2004;84:906-918.
- Fritz S, Lusardi M. White Paper: Walking Speed: The Sixth Vital Sign. J Geriatr Phys Ther. 2009;32:2-5.
- Bohannon RW. Comfortable and maximum walking speed of adults aged 20-79 years: referenced values and determinants. Age Ageing. 1997;26:15-19.
- Schnall BL, Montgomery JD, Wolf EJ. Initial gait characteristics of service members with transtibial amputations. Poster session presented at: 2nd Joint National Capital Regional Military Research Competition (NCRMRC). April 2010; Bethesda, Md.
- Nashner LM. Computerized dynamic posturography. In: Goebel JS, ed. Practical Management of the Dizzy Patient. 2nd ed. Philadelphia: Lippincott Williams and Wilkins; 1998:153-182.
- Williams G, Robertson V, Greenwood K, Goldie P, Morris ME. The high-level mobility assessment tool (HiMAT) for traumatic brain injury. Part 2: Content validity and discriminability. Brain Inj. 2005;19:833-843.
- Williams G, Greenwood K, Robertson V, Goldie P, Morris ME. The High-Level Mobility Assessment Tool (HiMAT): inter-rater reliability, retest reliability, and internal consistency. Phys Ther. 2006;86:395-400.
- Williams G, Greenwood K, Robertson V, Goldie P, Morris ME. The concurrent validity and responsiveness of the high-level mobility assessment tool (HiMAT) for measuring the mobility limitations of people with traumatic brain injury. Arch Phys Med Rehab. 2006; 87:437-442.
- Balance Manager Systems Clinical Operations Guide. Clackamas, Ore: Neurocom International; June 2008:97-99. Rev 8. CIS 100-03A D102376-00C.