Associations between gait performance and pain intensity, psychosocial factors, executive functions as well as prefrontal cortex activity in chronic low back pain patients: A cross-sectional fNIRS study

Introduction

Activities of daily living, such as walking, are impaired in chronic low back pain (CLBP) patients compared to healthy individuals. Thereby, pain intensity, psychosocial factors, cognitive functioning and prefrontal cortex (PFC) activity during walking might be related to gait performance during single and dual task walking (STW, DTW). However, to the best of our knowledge, these associations have not yet been explored in a large sample of CLBP patients.

Method

Gait kinematics (inertial measurement units) and PFC activity (functional near-infrared spectroscopy) during STW and DTW were measured in 108 CLBP patients (79 females, 29 males). Additionally, pain intensity, kinesiophobia, pain coping strategies, depression and executive functioning were quantified and correlation coefficients were calculated to determine the associations between parameters.

Results

The gait parameters showed small correlations with acute pain intensity, pain coping strategies and depression. Stride length and velocity during STW and DTW were (slightly to moderately) positively correlated with executive function test performance. Specific small to moderate correlations were found between the gait parameters and dorsolateral PFC activity during STW and DTW.

Conclusion

Patients with higher acute pain intensity and better coping skills demonstrated slower and less variable gait, which might reflect a pain minimization strategy. Psychosocial factors seem to play no or only a minor role, while good executive functions might be a prerequisite for a better gait performance in CLBP patients. The specific associations between gait parameters and PFC activity during walking indicate that the availability and utilization of brain resources are crucial for a good gait performance.

POF Smart Carpet: A Multiplexed Polymer Optical Fiber-Embedded Smart Carpet for Gait Analysis

This paper presents the development of a smart carpet based on polymer optical fiber (POF) for ground reaction force (GRF) and spatio-temporal gait parameter assessment. The proposed carpet has 20 intensity variation-based sensors on one fiber with two photodetectors for acquisition, each one for the response of 10 closer sensors. The used multiplexing technique is based on side-coupling between the light sources and POF lateral sections in which one light-emitting diode (LED) is activated at a time, sequentially. Three tests were performed, two for sensor characterization and one for validation of the smart carpet, where the first test consisted of the application of calibrated weights on the top of each sensor for force characterization. In the second test, the foot was positioned on predefined points distributed on the carpet, where a mean relative error of 2.9% was obtained. Results of the walking tests on the proposed POF-embedded smart carpet showed the possibility of estimating the GRF and spatio-temporal gait parameters (step and stride lengths, cadence, and stance duration). The obtained results make possible the identification of gait events (stance and swing phases) as well as the stance duration and double support periods. The proposed carpet is a low-cost and reliable tool for gait analysis in different applications.

Validity of a Wireless Gait Analysis Tool (Wi-GAT) in assessing spatio-temporal gait parameters at slow, preferred and fast walking speeds

BACKGROUND

The wireless gait assessment tool (Wi-GAT) measures have been shown to have good to excellent concurrent validity with preferred walking speeds, however, the validity of the Wi-GAT measures at slow and fast walking speeds is unknown.

OBJECTIVE

To establish validity of the Wi-GAT spatio-temporal gait measures at slow, fast, and preferred walking speeds.

METHODS

Twenty two healthy adult volunteers, with a mean age of 25.7 (± 5.3) participated in this study. The spatio-temporal gait variables of each participant were concurrently recorded using the GAITrite and the Wi-GAT system, while the participants performed 3 trials for each walking speed in a randomized order. Intraclass correlation analyses were performed to establish the agreement between the measures recorded by the GAITrite and Wi-GAT systems.

RESULTS

Walking speed measured both by the Wi-GAT and the GAITrite systems showed excellent agreement for preferred (ICC = 0.979 p< 0.001), slow (ICC = 0.989 p< 0.001) and fast (ICC = 0.967 p< 0.001) walking speeds. Most gait parameters recorded at slow walking speed showed good (ICC > 0.70) to excellent (ICC > 0.85) agreement.

CONCLUSIONS

Gait parameters recorded by the Wi-GAT system showed fair to excellent validity for preferred and slow walking speeds.