Gait asymmetry, and bilateral coordination of gait during a six-minute walk test in persons with multiple sclerosis

Abstract

Gait impairments in persons with multiple sclerosis (pwMS) leading to decreased ambulation and reduced walking endurance remain poorly understood. our objective was to assess gait asymmetry (GA) and bilateral coordination of gait (BCG), among pwMS during the six-minute walk test (6MWT), and determine their association with disease severity. We recruited 92 pwMS (age: 46.6 ± 7.9; 83% females) with a range of clinical disability, who completed the 6MWT wearing gait analysis system. GA was assessed by comparing left and right swing times, and BcG was assessed by the phase coordination index (pci). Several functional and subjective gait assessments were performed. Results show that gait is more asymmetric and less coordinated as the disease progresses (p < 0.0001). Participants with mild MS showed significantly better BCG as reflected by lower PCI values in comparison to the other two MS severity groups (severe: p = 0.001, moderate: p = 0.02). GA and PCI also deteriorated significantly each minute during the 6MWT (p < 0.0001). GA and PCI (i.e., BCG) show weaker associations with clinical MS status than associations observed between functional and subjective gait assessments and MS status. Similar to other neurological cohorts, GA and pci may be important parameters to assess and target in interventions among pwMS. Multiple sclerosis (MS) is a degenerative, progressive, autoimmune disease of the central nervous system, often resulting in a continuous deterioration of walking 1. Hence, gait parameters, e.g. cadence, step-length, step-time, are impaired as compared to those measured in abled bodied individuals 1-4. This gait deterioration has been demonstrated as a decline in the ability to walk long distances, based on the 6-min or 500-m walk tests 5,6. One critical component of walking impairment is gait variability. Gait variability tends to change throughout the MS disease course, with greater variability in the higher levels of disability 7,8. Furthermore, gait variability is associated with increased fall risk 9. Human gait requires a high degree of symmetry and coordination. Gait asymmetry is associated with reduced walking velocity 10-12 and increased energy expenditure 13. Spinal cord injury is frequent in persons with multiple sclerosis (pwMS), noted in 83% by MRI and up to 99% at autopsy 14,15. Spinal cord injury is associated with lower extremity sensorimotor deficits and impaired ambulation. It was previously reported that walking velocity in pwMS was reduced when in vivo diffusion tensor imaging (DTI) of the cervical spinal cord reveals myelin and tissue injury within posterior columns (PC) and lateral corticospinal tracts (CST) 16. Since CST injury in pwMS is asymmetric 17 , we hypothesize that MS will be associated with increased gait asymmetry, since asymmetric lesions in the spinal white matter lesions have been shown to correspond to asymmetric motor function 18. Gait coordination is the ability to maintain a consistent phase-dependent cyclical relationship between different body segments or joints in...

Spatio-temporal gait parameters obtained from foot-worn inertial sensors are reliable in healthy adults in single- and dual-task conditions

“…Also of note is that chronic gait asymmetry could also lead to increased risk of lower-limb overuse injuries and articular joint degeneration due to the increased weight bearing and propulsion demands placed on one lower limb during walking, in both pathological 69 – 72 and healthy populations 73 . Along these lines, gait asymmetry can be used as (i) a metric to assess pathology status, patients’ functional recovery or disease progression, (ii) a target for interventions aiming to improve gait performance, and (iii) outcome to evaluate and compare different gait rehabilitation programs interventions 43 , 55 , 74 – 77 . Interestingly, various rehabilitation programs have been shown to improve gait to a more symmetric gait pattern in individuals with lower-limb amputations (see for review 78 ), stroke survivors (see for review 79 ) or patients with Parkinson disease 80 , 81 .…”

Evaluation of Prolonged Walking in Persons with Multiple Sclerosis: Reliability of the Spatio-Temporal Walking Variables during the 6-Minute Walk Test

“…For these reasons, the prolonged tests are a better indicator of the ability of PwMS to perform the activities of daily living and have been evaluated for use in clinical practice and research [8,15,16]. Studies in PwMS [15,[17][18][19] and in other populations [20,21] have demonstrated that some walking variables measured during a 6MWT like walking velocity, cadence, or stride time could be altered across the 6MWT. These results suggest that the measurement of variables other than the classic distance to complete the 6MWT could provide a more detailed idea of the patients' performance.…”

The application of principal component analysis to characterize gait and its association with falls in multiple sclerosis

“…In addition to walking slower, fallers also walked with greater stance and swing time asymmetries. Recent investigations suggest that asymmetric gait is a robust measure characterizing the gait in PwMS and related to disease severity and falls 23 , 24 . Notably, asymmetric gait is not necessarily an uncoordinated gait 25 .…”