Pain severity, distribution, and duration are associated with spatiotemporal gait performance in community-dwelling older adults with chronic musculoskeletal pain.

BACKGROUND: Our current understanding of the impact of chronic pain on spatiotemporal gait performance has mainly been achieved through comparison studies between individuals with and without chronic pain. Further investigation into the relationship between specific outcome measures of chronic pain and gait may improve our understanding of the impact of pain on gait and may benefit future interventions that aim to improve mobility in this population. RESEARCH QUESTION: Which pain outcome measures are associated with spatiotemporal gait performance in older adults with chronic musculoskeletal pain? METHODS: This study was secondary analysis of older adult participants enrolled in the Neuromodulatory Examination of Pain and Mobility Across the Lifespan (NEPAL) study (n = 43). Pain outcome measures were obtained using self-reported questionnaires, and spatiotemporal gait analysis was conducted using an instrumented gait mat. Separate multiple linear regressions were run to determine which pain outcome measurements were associated with gait performance. RESULTS: Higher pain severities were associated with shorter stride lengths (ß = -0.336, p = 0.041), shorter swing times (ß = -0.345, p = 0.037), and longer double support times (ß = 0.342, p = 0.034). A greater number of pain sites was associated with a wider step width (ß = 0.391, p = 0.024). Longer pain durations were associated with shorter double support times (ß = -0.373, p = 0.022). SIGNIFICANCE: The results of our study illustrate that specific pain outcomes measures are associated with specific gait impairments in community-dwelling older adults with chronic musculoskeletal pain. As such, pain severity, number of pain sites, and pain duration should be considered when developing mobility interventions in this population to reduce disability.

Gait subgroups among older adults with chronic pain differ in cerebellum and basal ganglia gray matter volumes.

BACKGROUND: Current literature regarding morphological gray matter atrophy in chronic pain is mixed, inhibiting our ability to understand neurological mechanisms of chronic pain. The inconsistent findings may be due to the presence of subgroups within the older adult chronic pain population that differ in gait performance, as gait and gray matter have been previously associated. These gait subgroups, however, have been inadequately characterized in prior work and have not been compared across gray matter measures. Therefore, the purpose of this study was to identify and characterize gait subgroups within the older adult chronic pain population, and to evaluate differences in gray matter measures between subgroups. METHODS: The present study was a secondary analysis of the Neuromodulatory Examination of Pain and Mobility Across the Lifespan (NEPAL) study. A subset of older participants (n = 40) completed assessments to evaluate psychological status, cognitive abilities, pain characteristics, and spatiotemporal gait performance using an instrumented gait mat. Gray matter measures were obtained from a T1-weighted anatomical scan using Freesurfer's recon-all function. RESULTS: After data reduction, a hierarchical cluster analysis identified three gait clusters: A Normal Gait cluster (n = 12), a Shuffle Gait cluster (n = 15), and an Unsteady Gait cluster (n = 13). Clusters differed in gait velocity, stride length, step width, double support percentages, and stride length variability. The Shuffle Gait cluster exhibited reduced gray matter volumes in the cerebellum, caudate, putamen, and pallidum, as well as a worse pain severity when compared to the Normal Gait cluster (p < 0.05). The Shuffle Gait cluster also had less gray matter in the cerebellum and caudate when compared to the Unsteady Gait cluster (p < 0.05). CONCLUSIONS: Our results confirm the existence of gait subgroups among the older adult chronic pain population and gray matter differences observed between groups support the need for the consideration of subgroups within this population for future pain, mobility, and aging studies.

Decreased cognitive function is associated with impaired spatiotemporal gait performance in community dwelling older adults with chronic musculoskeletal pain.

OBJECTIVE: Older adults with chronic musculoskeletal pain often suffer from cognitive impairments and diminished lower extremity physical function. Prior work suggests that these impairments may be interrelated, however, the relationship between cognition and spatiotemporal gait performance in this population is understudied. Therefore, the purpose of this study was to examine the association between cognition and spatiotemporal gait performance and determine if cognition mediates the relationship between pain severity and spatiotemporal gait performance in older adults with chronic musculoskeletal pain without cognitive impairment. METHODS: Older adults with chronic musculoskeletal pain (n = 36) completed the Montreal Cognitive Assessment (MoCA) to assess global cognitive function. Spatiotemporal gait analysis was completed using an automated gait mat. Hierarchical regressions and mediation analyses were used to assess the relationship between chronic musculoskeletal pain, cognition, and spatiotemporal gait performance. RESULTS: MoCA scores were significantly associated with double support time, with lower MoCA scores relating with longer double support times (ß = -0.686, p = 0.039). After accounting for cognition, pain severity was also associated with slower gait speed (ß = -0.422, p = 0.019), and double support time (ß = 0.454, p = 0.008). Cognition, however, did not mediate the relationship between pain severity and double support time. CONCLUSIONS: Global cognition and pain severity were associated with spatiotemporal gait performance in older adults with chronic pain. Pain severity, but not cognition, however, primarily explained spatiotemporal gait performance in our sample. Future work is needed to elucidate the role of cognition in spatiotemporal gait performance in older adults with chronic musculoskeletal pain.

Walking indoors, outdoors, and on a treadmill: Gait differences in healthy young and older adults.

BACKGROUND: Although human gait is typically studied in a laboratory environment, the findings of laboratory-based gait assessments are often applied to daily life scenarios. Assessing gait in varied conditions may offer a better understanding of the influence of environment on gait performance. RESEARCH QUESTIONS: How do spatiotemporal gait measures differ between indoor overground walking, outdoor walking, and treadmill walking in healthy adults? Do different walking environments exaggerate age-related alterations in gait performance in older compared to young adults? METHODS: 30 young (18-30yrs) and 28 older adults (60-80yrs) completed four randomized conditions at their typical, comfortable walking pace: 1) 8 m of indoor walking, 2) continuous indoor walking, 3) treadmill walking, and 4) outdoor walking on a sidewalk. Wearable inertial sensors recorded gait data and the magnitudes and variability (in standard deviations) of the following gait measures were computed: cadence, percent double support, stride length (with sample entropy), and gait velocity. RESULTS: Despite the lack of significant univariate interactions between group and walking condition, significant main effects for condition and group were observed in both the magnitude and variability analyses. Treadmill walking resulted in a slower gait with shorter, less variable strides (p < .001), while walking outdoors resulted in faster gait with longer strides (p < .001) compared to other walking conditions. Stride length regularity was reduced when walking outdoors compared to treadmill walking (p = .019). SIGNIFICANCE: The results showed that the effects of walking condition on gait measures were more dramatic than participant age, and gait performance differs between walking environments in both older and younger adults. Since daily life gait encompasses both tightly controlled and unconstrained, free-living walking, researchers and clinicians should use caution when generalizing gait performance across walking conditions. Measures of gait performance typically used in laboratory gait analyses may not adequately characterize daily life gait in indoor and outdoor environments.