Clinical walk tests, such as the 6-Minute Walk Test (6MWT) and 2-Minute Walk Test (2MWT), are widely used to evaluate functional capacity and endurance in patients. Their simplicity, cost-effectiveness, and ease of administration make them valuable tools in both clinical practice and research. Originally developed for cardiopulmonary assessment, the 6MWT has since been adopted for a range of medical applications, including neurological conditions such as Parkinson’s disease and stroke (1-3).
Gait is increasingly recognized as a key biomarker for neurological conditions. Traditional walk tests, however, primarily focus on distance covered, missing critical insights into gait mechanics, stability and symmetry. By integrating wearable sensors into these tests, clinicians and researchers can obtain detailed, objective gait parameters, enhancing both diagnostic accuracy and the evaluation of treatment efficacy (4).
Information
Wearable sensors can enable clinicians to assess gait related disease progression and evaluate treatment efficacy by capturing objective gait measures.
The 2-Minute Walk Test with Sensor Insoles
By embedding sensor technology into the 2MWT, researchers and clinicians can capture objective outcome parameters related to gait mechanics and timing, beyond the standard distance measure.
Vid-1 illustrates the workflow for integrating sensor insoles into a 2MWT, enabling detailed ad-hoc reports on the objective gait characteristics.
The data presented in this blog post were collected from a 45 year old female patient with multiple sclerosis and left-sided peroneal nerve palsy during two 2MWT trials:
- With an Ottobock L300 Go orthosis
- Without the orthosis
Vid-2 illustrates segments of these trials from multiple perspectives.
Distance: the primary outcome measure
Traditionally, walking distance is the primary outcome of tests such as the 6MWT and 2MWT. However, relying solely on distance covered can overlook critical aspects of gait such as stride length and width (4).
Fig-1 presents the distance and gait-related metrics recorded for this patient:
- With the orthosis: 148 meters
- Without the orthosis: 141 meters
- Walking speed: 1.26 m/s vs. 1.19 m/s
- Higher step count and cadence with the orthosis
Temporal outcome parameters: Stance Time, Double Support Time, Swing Time
Beyond distance, sensor insoles provide detailed temporal gait cycle characteristics, which are essential for understanding asymmetry.
In Fig-2, the gait cycle phases are displayed relative to mean gait cycle time:
- With the orthosis: Nearly symmetrical stance and swing phases between both legs.
- Without the orthosis: The affected left leg exhibits a shorter stance phase, resulting in an unbalanced gait pattern.
Spatial outcome parameters: Stride Length & Swing Width
In addition to temporal aspects, sensor insoles allow for detailed spatial gait analysis, which is often challenging to assess through visual observation alone.
Fig-3 presents Stride Length and Swing Width from both trials:
- With the orthosis: Stride Length decreases due to higher cadence and step count.
- Swing Width on the left is significantly greater without the orthosis, indicating increased lateral foot movement during the swing phase.
Pressure related outcome parameters: Initial & Final Contact Points
Insufficient gait stability can be seen, for example, in a high variance of the points of initial contact and push-off during the ground contact phases of a gait cycle. These points can be accurately identified at any given time using pressure distribution measurements, referred to as pressure centers. A high variance during the contact and push-off phases may indicate an increased risk of falling or, more generally, an unsteady gait.
In the example dataset shown in this article, the variance of the points of initial contact and push-off is relatively low, which indicates that the patient is able to perform a steady, stable walk. Fig-4 shows the results with and without orthosis, along with one random example of a significantly more unstable walking style.
Summary
In summary, the orthosis enhances the gait pattern, promoting balanced joint loading on both sides of the body for smoother, more efficient movement in everyday situations. These results highlight how instrumenting walk tests with sensor insoles provides richer context—offering detailed gait data beyond total distance.
Advancing gait assessments in clinical research
Traditional walk tests provide essential insights into functional mobility, but their reliance on distance as the sole outcome measure limits their clinical utility. By instrumenting walk tests with sensor insoles, clinicians and researchers can access a wealth of objective gait parameters, improving diagnostic accuracy and treatment evaluation.
Moticon’s wireless, fully integrated Sensor Insoles offer an accessible, valid, and reliable (5) method for advanced gait analysis—enhancing the standard 6MWT and 2MWT with comprehensive biomechanical data. Their ability to measure pressure distribution, temporal gait phases, and spatial parameters make them a valuable tool for both clinical research and practical patient assessments.
Literature
- Agarwala P, Salzman SH. Six-Minute Walk Test: Clinical Role, Technique, Coding, and Reimbursement. Chest. 2020 Mar;157(3):603-611. doi: 10.1016/j.chest.2019.10.014. Epub 2019 Nov 2. PMID: 31689414; PMCID: PMC7609960.
- ATS Committee on Proficiency Standards for Clinical Pulmonary Function Laboratories. ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med. 2002 Jul 1;166(1):111-7. doi: 10.1164/ajrccm.166.1.at1102. Erratum in: Am J Respir Crit Care Med. 2016 May 15;193(10):1185. doi: 10.1164/rccm.19310erratum. PMID: 12091180.
- Moore JL, Potter K, Blankshain K, Kaplan SL, OʼDwyer LC, Sullivan JE. A Core Set of Outcome Measures for Adults With Neurologic Conditions Undergoing Rehabilitation: A CLINICAL PRACTICE GUIDELINE. J Neurol Phys Ther. 2018 Jul;42(3):174-220. doi: 10.1097/NPT.0000000000000229. PMID: 29901487; PMCID: PMC6023606.
- Storm FA, Cesareo A, Reni G, Biffi E. Wearable Inertial Sensors to Assess Gait during the 6-Minute Walk Test: A Systematic Review. Sensors (Basel). 2020 May 6;20(9):2660. doi: 10.3390/s20092660. PMID: 32384806; PMCID: PMC7249076.
- Cramer LA, Wimmer MA, Malloy P, O’Keefe JA, Knowlton CB, Ferrigno C. Validity and Reliability of the Insole3 Instrumented Shoe Insole for Ground Reaction Force Measurement during Walking and Running. Sensors (Basel). 2022 Mar 11;22(6):2203. doi: 10.3390/s22062203. PMID: 35336374; PMCID: PMC8951440.
