Field Walking Test

Summary / Explanation

Field walking tests are invaluable for evaluating physical fitness and functional capacity, especially in individuals with cardiopulmonary or musculoskeletal conditions. They provide a quick, cost-effective, and standardized way to measure a person's ability to perform daily activities and gauge their overall health and fitness.[1] Within the spectrum of field walking tests, the 6-Minute Walk Test (6MWT), Incremental Shuttle Walk Test (ISWT), and Endurance Shuttle Walk Test (ESWT) stand out as 3 frequently used assessments, each presenting unique advantages and limitations. This essay delves into the methodologies, applications, and comparative merits of these tests.

The 6-Minute Walk Test

Equipment: The various equipment needed for conducting the 6MWT are listed below.

• A measured walkway that is usually 30 meters in length
• Cones or markers to indicate the walking path
• A stopwatch or timer to track the 6-minute duration
• Comfortable clothing and appropriate footwear for the participant
• A pulse oximeter to monitor oxygen saturation levels
• A sphygmomanometer for measuring blood pressure
• The Borg scale to assess the level of dyspnea experienced by the individual during the test

Procedure: Participants are instructed to walk along a straight, pre-measured pathway for 6 minutes, aiming to cover as much distance as possible. The test is typically conducted indoors or in a controlled environment to minimize external factors. Before the test, baseline measurements such as heart rate, blood pressure, and oxygen saturation are recorded. The Borg scale is used to assess the dyspnea levels of the patient both before and during the test. Upon completion of the walk, vital signs are reassessed. Participants are allowed to self-pace and take rest breaks during the test, with limited standardized phrases for encouragement. The total distance covered within the 6-minute time frame is recorded, and the test protocol must be performed twice.[2]

Outcome interpretation: The 6MWT is a widely used field walking test designed to assess an individual's endurance and functional capacity. During this test, participants are tasked with walking as far as they can within a span of 6 minutes. Typically conducted indoors, the 6MWT takes place along a flat, straight, and marked corridor, with markers positioned at 30-meter intervals. Participants are instructed to walk back and forth along the corridor for 6 minutes to cover as much ground as possible.

The 6MWT is known for its simplicity and ease of administration, requiring only minimal equipment and space. Implementing this test does not necessitate specialized training for the tester, thereby making it suitable for diverse clinical settings. The primary outcome parameter of the test is the distance covered within the 6-minute duration, commonly referred to as the 6-minute walk distance (6MWD). This outcome measure provides valuable information about an individual's exercise tolerance, aerobic capacity, and overall functional status.

The vital signs of a patient, such as heart rate, blood pressure, and oxygen saturation per pulse oximetry, are measured before and after the walk. A perceived dyspnea scale, such as the Borg scale, is used to determine the patient's level of dyspnea. If the patient requires supplemental oxygen, they should utilize it during the walk, and the method of transporting the oxygen tank or concentrator should be documented for consistency while performing future 6MWTs similarly. Given that the test is conducted twice, the tester should employ standardized phrases of encouragement to support the patient throughout the assessment. 

The Incremental Shuttle Walk Test

Equipment: The various equipment needed for conducting the ISWT are listed below.

• A 10-meter shuttle course with markings
• Audio recording of a pre-recorded incremental test signal
• Cones or markers
• Stopwatch or timer for timing the test
• Pulse oximeter for monitoring oxygen saturation
• Sphygmomanometer for measuring blood pressure
• Borg scale for measuring dyspnea levels

Procedure: The ISWT, another field walking test, evaluates functional capacity, particularly in individuals with respiratory conditions such as chronic obstructive pulmonary disease. This test involves walking back and forth between 2 cones set 10 meters apart at progressively increasing speeds. ISWT is conducted in a hallway or corridor and is facilitated by an audio recording guiding the participant's walking pace. The ISWT starts with a walking speed of 0.5 m/s and increases by 0.17 m/s every minute. Participants are encouraged to continue walking as long as possible, with the test ending when they can no longer maintain the required speed or choose to stop.[3]

Outcome interpretation: The primary outcome measure of the ISWT is the distance walked during the test, along with variables such as the peak walking speed and the incremental shuttle distance. Compared to the 6MWT, the ISWT is considered superior in assessing exercise capacity and endurance, especially in individuals with limited peak oxygen uptake. The test provides valuable information about a patient's exercise tolerance and ability to perform activities that require increasing exertion levels.[4]

Vital signs, oxygen saturation, and perceived dyspnea should be assessed both before and after the test. The test protocol requires it to be conducted twice. Standardized phrases of encouragement are recommended to ensure consistency and support for the participant throughout the assessment.  

The Endurance Shuttle Walk Test

Equipment: The various equipment needed for conducting the ESWT are listed below. 

• A 10-meter shuttle course with markings
• Audio recording of a constant-speed shuttle walk signal
• Cones or markers
• Stopwatch or timer
• Pulse oximeter for monitoring oxygen saturation
• Sphygmomanometer for measuring blood pressure
• Borg scale for measuring dyspnea levels

Procedure: Similar to the ISWT, participants walk back and forth along a 10-meter shuttle course, but with the ESWT, the audio signal requires maintaining a steady pace. This pace is determined by completing the ISWT to determine the patient's maximal walking speed. The set pace for the ESWT is between 70% and 85% of the top speed of the ISWT. The test continues until the participant reaches maximal effort or decides to stop. Baseline measurements are taken before and after the test.[5]

Outcome interpretation: The ESWT is a field walking test designed to assess an individual's endurance and exercise capacity, particularly in patients with cardiac or respiratory conditions. The ESWT involves walking back and forth between 2 cones placed 10 meters apart, similar to the ISWT. However, unlike the ISWT, the ESWT is conducted at a constant walking speed set at 70% to 85% of the patient's peak speed achieved during the ISWT.[3] A metronome guides the participant, and the test continues until the patient reaches their target heart rate or decides to stop.

The primary outcome measure of the ESWT is the total distance walked during the test, which reflects the patient's exercise capacity at a submaximal intensity level. This provides a unique advantage in evaluating the patient's ability to sustain effort over an extended period while maintaining a specific heart rate. The ESWT is particularly relevant for patients with cardiovascular conditions, as it offers insights into their capability to perform activities requiring prolonged exertion, such as walking or cycling.

Vital signs, oxygen saturation, and perceived dyspnea should be assessed both before and after the test. A 1.5-minute warm-up session should be conducted before starting the test, which is performed only once. Standardized phrases of encouragement should be utilized throughout the test. 

Comparative Analysis

Each of the 3 field walking tests—the 6MWT, ISWT, and ESWT—serves specific purposes and has distinct advantages and limitations in assessing an individual's functional capacity and endurance. Their respective strengths and weaknesses can be considered to facilitate a comparative analysis.

The 6-Minute Walk Test

Advantages: The advantages of 6MWT are listed below.

• Simplicity and ease of administration
• Minimal equipment and space requirements
• Applicability in diverse clinical settings
• Effective in assessing overall functional status

Limitations: The limitations of 6MWT are listed below.

• Lack of standardized walking speeds
• Inability to assess peak exercise capacity
• Insensitivity to small changes in functional capacity

Incremental Shuttle Walk Test

Advantages: The advantages of ISWT are listed below.

• Assessment of peak exercise capacity
• Progressive intensity with standardized walking speeds
• Applicability for patients with respiratory conditions
• Objective measurement of exercise tolerance

Limitations: The limitations of ISWT are listed below.

• Requires an audio recording and specific equipment
• Potential for participant fatigue during the test

The Endurance Shuttle Walk Test

Advantages: The advantages of ESWT are listed below.

• Assessment of endurance and ability to sustain effort
• Specific heart rate target for submaximal exertion
• Relevance for patients with cardiovascular conditions

Limitations: The limitations of ESWT are listed below.

• Requires monitoring of heart rate and metronome
• Limited applicability in assessing peak exercise capacity

Conclusion

Field walking tests are valuable tools for assessing an individual's endurance, functional capacity, and exercise tolerance. The 6MWT, ISWT, and ESWT have unique applications and advantages. The 6MWT is simple to administer and provides a broad overview of functional status. The ISWT is particularly relevant for individuals with respiratory conditions and provides a standardized and progressive assessment of peak exercise capacity. In contrast, the ESWT is valuable for patients with cardiovascular conditions, evaluating their ability to sustain effort over time.

The selection of a field walking test should be guided by the specific objectives of the assessment and the characteristics of the target population. Each test offers unique perspectives on an individual's physical fitness and functional capacity.[1] Clinicians and researchers must consider the advantages and limitations of these tests carefully when selecting the most appropriate assessment tool for their needs, thereby contributing to more accurate diagnoses and tailored treatment plans.