Falls and Physical Activity in Persons with Multiple Sclerosis

Objectives. To examine the association between fall history and physical activity using an objective measure of physical activity (i.e., accelerometry) in persons with multiple sclerosis. Design. A community-based sample of 75 ambulatory persons with multiple sclerosis volunteered for the investigation. Participants self-reported fall history in the last year, underwent a neurological exam to determine Expanded Disability Status Scale (EDSS) score, and wore an accelerometer around the waist for 7 consecutive days to determine physical activity. Results. Overall, 37 persons (49.3% of the sample) reported falling in the last year with 28 of the 37 falling more than once. Persons who fell in the last year had a significantly lower number of steps/day than nonfallers (3510 versus 4940 steps/day; P \u3c .05). However, when controlling for disability status there was no statistically significant difference between fallers and nonfallers (4092 versus 4373 steps/day; P \u3e.05). Conclusions. Collectively, the findings suggest that fall history may have little impact on current physical activity levels in persons with multiple sclerosis

Cognitive-Motor Interference in Multiple Sclerosis: A Systematic Review of Evidence, Correlates, and Consequences

Individuals with multiple sclerosis (MS) regularly exhibit deficits in motor and cognitive function. Recent evidence suggests that these impairments are compounded when motor and cognitive task are performed simultaneously such as walking while talking. The changes incurred during simultaneous performance of motor and cognitive tasks are a result of cognitive-motor interference (CMI) and operationalized as dual task costs (DTC). Recently in MS, research has been conducted to understand and analyze the impact of CMI. The purpose of this paper was to review the current literature related to the evidence, correlates, and consequences of CMI in MS. Relevant literature was collected from the results of a PubMed search for terms including "Cognitive-motor interference" or "Cognitive-motor interaction" or "Dual task" and "multiple sclerosis. " Overall, 20 papers were included for review which focused on CMI during balance and walking tasks. The finding that there is a lack of evidence pertaining to changes in the cognitive domain as well as to the specific consequences of CMI in MS was noted. Future work should aim to fill these gaps and ultimately investigate the usefulness of targeted interventions in reducing the deleterious effects of CMI in individuals with MS

Gait Variability and Multiple Sclerosis

Gait variability, that is, fluctuations in movement during walking, is an indicator of walking function and has been associated with various adverse outcomes such as falls. In this paper, current research concerning gait variability in persons with multiple sclerosis (MS) is discussed. It is well established that persons with MS have greater gait variability compared to age and gender matched controls without MS. The reasons for the increase in gait variability are not completely understood. Evidence indicates that disability level, assistive device use, attentional requirement, and fatigue are related to gait variability in persons with MS. Future research should address the time-evolving structure (i.e., temporal characteristics) of gait variability, the clinical importance of gait variability, and underlying mechanisms that drive gait variability in individuals with MS

The Role of Neck Musculature in Traumatic Brain Injuries in Older Adults: Implications From Sports Medicine

Traumatic brain injuries (TBIs) are common and serious injuries to older adults. The majority of TBIs in older adults are sustained when the head impacts the ground or other surface during a fall. While several non-modifiable risk factors have been identified for fall-related TBIs in older adults, there still remains a dearth of knowledge surrounding modifiable risk factors. Thus, this significant knowledge gap warrants an investigation into research across disciplines. The sports medicine literature has examined several modifiable risk factors to prevent a mild form of TBI known as concussion. While this research has identified several risk factors, one particular risk factor may have potential implications to fall-related TBIs in older adults. The sports medicine literature has shown that decreased neck strength and slower neck muscle activation are significant predictors for sports-related concussion. Similarly, older adults experience age-related declines to neck muscle strength and muscle activation. Consequently, these age-related declines to the neck musculature may result in the inability of older adults to control their head during a fall, which results in greater impact forces being transmitted to the brain and increases the risk of TBI. This perspective article assesses the sports medicine literature related to the implications of neck strength and muscle activation in sports-related concussion, discusses age-related declines to neck strength and muscle activation, and highlights the potential impact of the neck musculature on fall-related TBIs in older adults

Mobility, Balance and Falls in Persons with Multiple Sclerosis

BACKGROUND: There is a lack of information concerning the relation between objective measures of gait and balance and fall history in persons with MS (PwMS). This investigation assessed the relation between demographic, clinical, mobility and balance metrics and falls history in persons with multiple sclerosis (MS). METHODS: 52 ambulatory persons with MS (PwMS) participated in the investigation. All persons provided demographic information including fall history over the last 12 months. Disease status was assessed with Expanded Disability Status Scale (EDSS). Walking speed, coordination, endurance and postural control were quantified with a multidimensional mobility battery. RESULTS: Over 51% of the participants fell in the previous year with 79% of these people being suffering recurrent falls. Overall, fallers were older, had a greater prevalence of assistive devices use, worse disability, decreased walking endurance, and greater postural sway velocity with eyes closed compared to non-fallers. Additionally, fallers had greater impairment in cerebellar, sensory, pyramidal, and bladder/bowel subscales of the EDSS. CONCLUSIONS: The current observations suggest that PwMS who are older, more disabled, utilize an assistive device, have decreased walking coordination and endurance and have diminished balance have fallen in the previous year. This suggests that individuals who meet these criteria need to be carefully monitored for future falls. Future research is needed to determine a prospective model of falls specific to PwMS. Additionally, the utility of interventions aimed at reducing falls and fall risk in PwMS needs to be established

Increased Postural Demand Is Associated With Greater Cognitive Workload in Healthy Young Adults: A Pupillometry Study

Introduction: Balance tasks require cognitive resources to ensure postural stability. Pupillometry has been used to quantify cognitive workload of various cognitive tasks, but has not been studied in postural control. The current investigation utilized pupillometry to quantify the cognitive workload of postural control in healthy young adults. We hypothesized that cognitive workload, indexed by pupil size, will increase with challenging postural control conditions including visual occlusion and cognitive dual tasking.Methods: Twenty-one young healthy adults (mean ± standard error of the mean), (age = 23.2 ± 0.49 years; 12 females) were recruited for this study. Participants completed four tasks: (1) standing with eyes open; (2) standing with eyes occluded (3) standing with eyes open while performing an auditory Stroop task; and (4) standing with eyes occluded while performing an auditory Stroop task. Participants wore eye tracking glasses while standing on a force platform. The eye tracking glasses recorded changes in pupil size that in turn were converted into the Index of Cognitive Activity (ICA). ICA values were averaged for each eye and condition. A two-way Analysis of Variance with post-hoc Sidak correction for pairwise comparisons was run to examine the effect of visual occlusion and dual tasking on ICA values as well on Center of Pressure (CoP) sway velocity in anterior–posterior (AP) and medio-lateral (ML) directions. A Pearson’s correlation coefficient was utilized to determine the relationship between ICA values and CoP sway velocity.Results: Significant within-condition effect was observed with visual occlusion for the right eye ICA values (p = 0.008). Right eye ICA increased from eyes open to eyes occluded conditions (p = 0.008). In addition, a significant inverse correlation was observed between right eye ICA values and CoP sway velocity in the ML direction across all the conditions (r = -0.25, p = 0.02).Conclusion: This study demonstrated support for increased cognitive workload, measured by pupillometry, as a result of changes in postural control in healthy young adults. Further research is warranted to investigate the clinical application of pupillometry in balance assessment

Cumulative Head Impact Burden in High School Football

Impacts to the head are common in collision sports such as football. Emerging research has begun to elucidate concussion tolerance levels, but sub-concussive impacts that do not result in clinical signs or symptoms of concussion are much more common, and are speculated to lead to alterations in cerebral structure and function later in life. We investigated the cumulative number of head impacts and their associated acceleration burden in 95 high school football players across four seasons of play using the Head Impact Telemetry System (HITS). The 4-year investigation resulted in 101,994 impacts collected across 190 practice sessions and 50 games. The number of impacts per 14-week season varied by playing position and starting status, with the average player sustaining 652 impacts. Linemen sustained the highest number of impacts per season (868); followed by tight ends, running backs, and linebackers (619); then quarterbacks (467); and receivers, cornerbacks, and safeties (372). Post-impact accelerations of the head also varied by playing position and starting status, with a seasonal linear acceleration burden of 16,746.1g, while the rotational acceleration and HIT severity profile burdens were 1,090,697.7-rad/sec2 and 10,021, respectively. The adolescent athletes in this study clearly sustained a large number of impacts to the head, with an impressive associated acceleration burden as a direct result of football participation. These findings raise concern about the relationship between sub-concussive head impacts incurred during football participation and late-life cerebral pathogenesis, and justify consideration of ways to best minimize impacts and mitigate cognitive declines.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90454/1/neu-2E2011-2E1825.pd

Falls and physical activity in persons with multiple sclerosis

Objectives. To examine the association between fall history and physical activity using an objective measure of physical activity (i.e., accelerometry) in persons with multiple sclerosis. Design. A community-based sample of 75 ambulatory persons with multiple sclerosis volunteered for the investigation. Participants self-reported fall history in the last year, underwent a neurological exam to determine Expanded Disability Status Scale (EDSS) score, and wore an accelerometer around the waist for 7 consecutive days to determine physical activity. Results. Overall, 37 persons (49.3% of the sample) reported falling in the last year with 28 of the 37 falling more than once. Persons who fell in the last year had a significantly lower number of steps/day than nonfallers (3510 versus 4940 steps/day; P < .05). However, when controlling for disability status there was no statistically significant difference between fallers and nonfallers (4092 versus 4373 steps/day; P > .05). Conclusions. Collectively, the findings suggest that fall history may have little impact on current physical activity levels in persons with multiple sclerosis

Response timing in the lunge and target change in elite versus medium-level fencers.

The aim of the present work is to examine the differences between two groups of fencers with different levels of competition, elite and medium level. The timing parameters of the response reaction have been compared together with the kinetic variables which determine the sequence of segmented participation used during the lunge with a change in target during movement. A total of 30 male sword fencers participated, 13 elite and 17 medium level. Two force platforms recorded the horizontal component of the force and the start of the movement. One system filmed the movement in 3D, recording the spatial positions of 11 markers, while another system projected a mobile target over a screen. For synchronisation, an electronic signal enabled all the systems to be started simultaneously. Among the timing parameters of the reaction response, the choice reaction time (CRT) to the target change during the lunge was measured. The results revealed differences between the groups regarding the flight time, horizontal velocity at the end of the acceleration phase, and the length of the lunge, these being higher for the elite group, as well as other variables related to the temporal sequence of movement. No significant differences have been found in the simple reaction time or in CRT. According to the literature, the CRT appears to improve with sports practice, although this factor did not differentiate the elite from medium-level fencers. The coordination of fencing movements, that is, the right technique, constitutes a factor that differentiates elite fencers from medium-level ones

Evidence for the different physiological significance of the 6- and 2-minute walk tests in multiple sclerosis

<p>Abstract</p> <p>Background</p> <p>Researchers have recently advocated for the 2-minute walk (2MW) as an alternative for the 6-minute walk (6MW) to assess long distance ambulation in persons with multiple sclerosis (MS). This recommendation has not been based on physiological considerations such as the rate of oxygen consumption (V·O₂) over the 6MW range.</p> <p>Objective</p> <p>This study examined the pattern of change in V·O₂over the range of the 6MW in a large sample of persons with MS who varied as a function of disability status.</p> <p>Method</p> <p>Ninety-five persons with clinically-definite MS underwent a neurological examination for generating an Expanded Disability Status Scale (EDSS) score, and then completion of the 6MW protocol while wearing a portable metabolic unit and an accelerometer.</p> <p>Results</p> <p>There was a time main effect on V·O₂during the 6MW (<it>p </it>= .0001) such that V·O₂increased significantly every 30 seconds over the first 3 minutes of the 6MW, and then remained stable over the second 3 minutes of the 6MW. This occurred despite no change in cadence across the 6MW (<it>p </it>= .84).</p> <p>Conclusions</p> <p>The pattern of change in V·O₂indicates that there are different metabolic systems providing energy for ambulation during the 6MW in MS subjects and steady state aerobic metabolism is reached during the last 3 minutes of the 6MW. By extension, the first 3 minutes would represent a test of mixed aerobic and anaerobic work, whereas the second 3 minutes would represent a test of aerobic work during walking.</p