Linda L.M. Bossi

Helmet accommodation analysis using 3D laser scanning

A method used to determine the probable population accommodation of a helmet sizing system is described. The method involves the use of 3D laser scanning, as a means of measuring helmet standoff distance (distance between the inside of the helmet and the skull), and the selection of a representative sample of test subjects. The laser scanner and the software developed to calculate standoff distance proved to be an excellent tool for the assessment of helmet fit. The main advantages include ease of use and visualization of problem areas. This 3D-analysis method gives designers objective evidence of the need for design changes as well as an idea of what these changes should be. A comparison was made between standoff distance results obtained from the scanner and those obtained using a physical measurement method (a probe). Although discrepancies were found between the two, sources of errors intrinsic to both methods make it difficult to determine which of the two methods yielded the truest standoff distance. Analysis of the comparison data shows laser scanning to be slightly more conservative than the probe method for standoff distance purposes, i.e. erring on the side of safety.

A suite of objective biomechanical measurement tools for personal load carriage system assessment

For application to military and civilian needs, Defence Research and Development Canada—Toronto contracted Queens University, Kingston to develop a suite of biomechanical assessment and analytical tools to supplement human-based load carriage system assessment methods. This suite of tools permitted efficient objective evaluation of biomechanical aspects of load-bearing webbing, vests, packs and their components, and therefore contributed to early system assessment and a rapid iterative design process. This paper is a summary of five assessment and analytical tools. A dynamic load carriage simulator was developed to simulate cadence of walking, jogging and running. The simulator comprised a computer-controlled pneumatic platform that oscillated anthropometrically weighted mannequins of varying dimensions from which measures of skin contact pressure, hip reaction forces and moments and relative pack-person displacements were taken. A stiffness tester for range of motion provided force-displacement data on pack suspension systems. A biomechanical model was used to determine forces and moments on the shoulders and hips, and validated using a static load distribution mannequin. Subjective perceptual rating systems were used gather soldier feedback during a standardized mobility circuit. Objective outcome measures were validated by means of other objective measures (e.g., Optotrak®, video, Instron®, etc.) and then compared to subjective ratings. This approach led to development of objective performance criteria for load carriage systems and to improvements in load carriage designs that could be used both in the military and in general.

Determination of Orientation and Practice Requirements When Using an Obstacle Course for Mobility Performance Assessment

Objective: Determine effect of orientation (introduction and familiarization) and practice (repeated performance) on human performance under various load conditions as assessed by an obstacle course. Background: Obstacle courses are commonly used as screening tools by military, police, and firefighters or to assess human capabilities and the effect of wearing personal protective equipment (PPE) and other occupationally necessary equipment on mobility task performance. Unfortunately, little is formally documented about the effect of orientation and practice on performance outcomes of obstacle or mobility courses being used. Method: Forty-eight participants were recruited from the Canadian Army Infantry and Combat Engineer population. Participants either received regular or extensive orientation of the course before completing it. Following orientation, participants completed the course five consecutive times while wearing their PPE with full fighting order (FFO) and five consecutive times while wearing no PPE and non-FFO across a five-day period (maximum two runs per day), with ensemble presentation order counterbalanced. Total course completion time and individual obstacle completion times were measured for each run of the course. Results: While wearing FFO, participants continued to decrease the time required for completing the course; however, while wearing non-FFO, time to course completion did not significantly change over the five runs. There were no differences in course completion times for the regular and extensive course orientation groups. Conclusions: Considerations required to mitigate orientation and practicing effects can differ depending on type or complexity of load condition. While wearing FFO, practicing effects can introduce undesired confounding factors into data collection. Application: Any practice runs on an obstacle course prior to its use as an assessment tool should focus on the loaded (e.g., FFO) condition because improvement on loaded runs is likely transferred to unloaded, but this does not apply in the reverse.

A Preliminary Investigation of the Effect of Protective Clothing Weight, Bulk and Stiffness on Combat Mobility Course Performance

Soldier loads continue to rise in response to new technological capabilities and emerging threats. However, literature addressing the extent to which load mass properties affects operational task performance and mission outcome is sparse. The objective of this preliminary study was to quantify the effect of PPE mass properties (weight, bulk and stiffness) on combat mobility, as measured using the standardized Load Effects Assessment Program (LEAP) course. Twenty-four soldiers completed the LEAP course in three clothing and individual equipment (CIE) configurations (UE: unencumbered; FFO: full fighting order (FFO) without body armour; and FFO+: FFO with body armour). Significant differences between clothing conditions were revealed for LEAP performance metrics (overall course time). Regression analysis revealed significant relationships between overall mobility performance and condition mass properties of weight, bulk, and stiffness. Outcomes will influence the design of future CIE and future research in this area.

Comparison of helmet-mounted display designs in support of wayfinding

The Canadian Soldier Information Requirements Technology Demonstration (SIREQ TD) soldier modernization research and development program has conducted experiments to help determine the types and amount of information needed to support wayfinding across a range of terrain environments, the most effective display modality for providing the information (visual, auditory or tactile) that will minimize conflict with other infantry tasks, and to optimize interface design. In this study, seven different visual helmet-mounted display (HMD) designs were developed based on soldier feedback from previous studies. The displays and an in-service compass condition were contrasted to investigate how the visual HMD interfaces influenced navigation performance. Displays varied with respect to their information content, frame of reference, point of view, and display features. Twelve male infantry soldiers used all eight experimental conditions to locate bearings to waypoints. From a constant location, participants were required to face waypoints presented at offset bearings of 25, 65, and 120 degrees. Performance measures included time to identify waypoints, accuracy, and head misdirection errors. Subjective measures of performance included ratings of ease of use, acceptance for land navigation, and mental demand. Comments were collected to identify likes, dislikes and possible improvements required for HMDs. Results underlined the potential performance enhancement of GPS-based navigation with HMDs, the requirement for explicit directional information, the desirability of both analog and digital information, the performance benefits of an egocentric frame of reference, the merit of a forward field of view, and the desirability of a guide to help landmark. Implications for the information requirements and human factors design of HMDs for land-based navigational tasks are discussed.

Marksmanship as a critical military occupational task Issues, approaches and methods for optimal performance and equipment design

A variety of methodologies are used to assess marksmanship performance, and while all are relevant, their constraints must be understood so that the portability and applicability of results are realized. Some measures are more appropriate for specific research questions than others. While some consider live fire to be the gold standard, it has several drawbacks. Many alternative methods (i.e., simulated target engagement) allow for controlled data collection and may be more appropriate than live fire, depending on their application and study design. The panelists represent a wide variety of experience conducting research investigating marksmanship performance, and applying a range of marksmanship tools and metrics for different applications. This panel will discuss the relative merits and limitations of their approaches (tools, metrics, methods, engagement scenarios) in an effort to provide the landscape of current approaches and issues in marksmanship performance research.

Investigation of alternative organizational structures for a digitized platoon

To evaluate the effect of digitization on platoon effectiveness and investigate the suitability of different platoon structures, a twelve-day field trial was undertaken with a Company of light infantry at Fort Benning, Georgia. Test missions were conducted in both day and night conditions, in wooded and urban terrain environments, in each of three organizational structures, with and without digitization. The three different organizational structures included our current in-service 8-man Section, a 13-man USMC squad, and a distributed model comprising six four-man teams. Results of this study confirmed that the effectiveness of a dismounted platoon is significantly enhanced by the use of select digital enhancements in the areas of navigation, situation awareness, communications, and command. During night operations, digitally-enabled capabilities were the difference between mission success and failure. None of the organizational structures tested proved to be universally better than the others at optimizing the benefits of digitally-enhanced capabilities, although each had their strengths and weaknesses. However, considerable insights were gained in the organizational structure issues of distributed small unit command and control, swarming formation tactics, and the tactics, techniques, and procedures necessary to employ small units effectively in a NCW environment.

Field investigation of radio network usage at the dismounted infantry section level

The Soldier Information Requirements Technology Demonstration (SIREQ TD) project is an experimentation program to identify technologies that significantly enhance the performance of our future soldiers. One of the study series involved a 2 x 2 factorial comparison of the benefits of digital maps over paper maps, and the use of radios vs. no radios. Thirty-two Canadian regular force infantry soldiers performed force-on-force tactical assault missions in wooded terrain, with each soldier participating in all four test conditions. The radios were configured to operate in 4 subnets: 1 channel for each of the 2 Assault Groups (4 soldiers on a channel); a Section Commander/2IC channel; and an all-users channel. Note that in the no-radio conditions soldiers still operated the press-to-talk switch to allow recording of communications, but the speaker volume was set to zero. All communications were date/time stamped, identified as to the user and channel, and the audio was digitally recorded for later analysis as to the nature and content of the message. The study showed that although the type and function of communication did not change dramatically across the four test conditions, there was an increased amount of overall communication when soldiers carried radios compared to when they did not. Other quantitative results pertaining to communications, situation awareness, perceived workload, and team effectiveness are presented, along with subjective measures collected by questionnaires and focus group discussions.