Matthew R. Scherer

Returning Service Members to Duty Following Mild Traumatic Brain Injury: Exploring the Use of Dual-Task and Multitask Assessment Methods

Within the last decade, more than 220,000 service members have sustained traumatic brain injury (TBI) in support of military operations in Iraq and Afghanistan. Mild TBI may result in subtle cognitive and sensorimotor deficits that adversely affect warfighter performance, creating significant challenges for service members, commanders, and clinicians. In recent conflicts, physical therapists and occupational therapists have played an important role in evaluating service member readiness to return to duty (RTD), incorporating research and best practices from the sports concussion literature. Because premorbid (baseline) performance metrics are not typically available for deployed service members as for athletes, clinicians commonly determine duty readiness based upon the absence of postconcussive symptoms and return to “normal” performance on clinical assessments not yet validated in the military population. Although practices described in the sports concussion literature guide “return-to-play” determinations, resolution of symptoms or improvement of isolated impairments may be inadequate to predict readiness in a military operational environment. Existing clinical metrics informing RTD decision making are limited because they fail to emphasize functional, warrior task demands and they lack versatility to assess the effects of comorbid deficits. Recently, a number of complex task-oriented RTD approaches have emerged from Department of Defense laboratory and clinical settings to address this gap. Immersive virtual reality environments, field-based scenario-driven assessment programs, and militarized dual-task and multitask-based approaches have all been proposed for the evaluation of sensorimotor and cognitive function following TBI. There remains a need for clinically feasible assessment methods that can be used to verify functional performance and operational competence in a variety of practice settings. Complex and ecologically valid assessment techniques incorporating dual-task and multitask methods may prove useful in validating return-to-activity requirements in civilian and military populations.

Clinician Perception of the Impact of Deployed Physical Therapists as Physician Extenders in a Combat Environment

UNLABELLED Physical therapists (PTs) serve as physician extenders performing direct access evaluations for musculoskeletal conditions. The previous war-time mission of PTs was limited to level III medical care. Recently PTs began providing care at levels I/II with brigade combat teams (BCTs). PURPOSE Determine the sentiment of battlefield providers at levels I/II regarding the operational impact of PTs. METHODS Surveys were provided to BCT medical providers. RESULTS There were 107 responses (response rate of 51%). According to the responses, PTs made a significant impact on overall mission accomplishment (97%) and patient prognosis (83%) and were considered local experts in musculoskeletal pathology (92%), including the ordering of radiographs (79%). Their presence was thought to significantly decrease medical evacuations within theater (68%) and out of theater (73%). CONCLUSION There was a positive sentiment toward PTs in the BCT, suggesting they are highly valued. Future studies need to clarify further operational, medical, and fiscal implications.

Further Development of the Assessment of Military Multitasking Performance: Iterative Reliability Testing.

The Assessment of Military Multitasking Performance (AMMP) is a battery of functional dual-tasks and multitasks based on military activities that target known sensorimotor, cognitive, and exertional vulnerabilities after concussion/mild traumatic brain injury (mTBI). The AMMP was developed to help address known limitations in post concussive return to duty assessment and decision making. Once validated, the AMMP is intended for use in combination with other metrics to inform duty-readiness decisions in Active Duty Service Members following concussion. This study used an iterative process of repeated interrater reliability testing and feasibility feedback to drive modifications to the 9 tasks of the original AMMP which resulted in a final version of 6 tasks with metrics that demonstrated clinically acceptable ICCs of > 0.92 (range of 0.92–1.0) for the 3 dual tasks and > 0.87 (range 0.87–1.0) for the metrics of the 3 multitasks. Three metrics involved in recording subject errors across 2 tasks did not achieve ICCs above 0.85 set apriori for multitasks (0.64) and above 0.90 set for dual-tasks (0.77 and 0.86) and were not used for further analysis. This iterative process involved 3 phases of testing with between 13 and 26 subjects, ages 18–42 years, tested in each phase from a combined cohort of healthy controls and Service Members with mTBI. Study findings support continued validation of this assessment tool to provide rehabilitation clinicians further return to duty assessment methods robust to ceiling effects with strong face validity to injured Warriors and their leaders.

Military-civilian collaborations for mTBI rehabilitation research in an active duty population: lessons learned from the assessment of Military Multitasking Performance Project

This article describes lessons learned in the planning, development, and administration of a collaborative military-civilian research project, the Assessment of Military Multitasking Performance, which was designed to address a gap in clinical assessment for active duty service members with mild traumatic brain injury who wish to return to active duty. Our team worked over the course of multiple years to develop an assessment for military therapists to address this need. Insights gained through trial and error are shared to provide guidance for civilian researchers who may wish to collaborate with active duty researchers.

Measuring Soldier Performance During the Patrol-Exertion Multitask: Preliminary Validation of a Postconcussive Functional Return-to-Duty Metric

OBJECTIVE To assess the discriminant validity of the Patrol-Exertion Multitask (PEMT), a novel, multidomain, functional return-to-duty clinical assessment for active duty military personnel. DESIGN Measurement development study. SETTING Nonclinical indoor testing facility. PARTICIPANTS Participants (N=84) were healthy control (HC) service members (SMs; n=51) and military personnel (n=33) with persistent postconcussive symptoms receiving rehabilitation (mild traumatic brain injury [mTBI]). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Known-groups discriminant validity was evaluated by comparing performance on the PEMT in 2 groups of active duty SMs: HCs and personnel with mTBI residual symptoms. Participant PEMT performance was based on responses in 4 subtasks during a 12-minute patrolling scenario: (1) accuracy in identifying virtual improvised explosive device (IED) markers and responses to scenario-derived questions from a computer-simulated foot patrol; (2) auditory reaction time responses; (3) rating of perceived exertion during stepping; and (4) self-reported visual clarity (ie, gaze stability) during vertical head-in-space translation while stepping. RESULTS Significant between-group differences for the PEMT were observed in 2 of 4 performance domains. Postpatrol IED identification task/question responses (P=.179) and rating of perceived exertion (P=.133) did not discriminate between groups. Participant self-report of visual clarity during stepping revealed significant (P<.001) between-group differences. SM reaction time responses to scenario-based auditory cues were significantly delayed in the mTBI group in both the early (P=.013) and late (P=.002) stages of the PEMT. CONCLUSIONS Findings from this study support the use of a naturalistic, multidomain, complex clinical assessment to discriminate between healthy SMs and personnel with mTBI residual symptoms. Based on this preliminary study, additional research to further refine the PEMT and extend its application to return-to-work outcomes in military and civilian environments is warranted.