Construct validity of the walk ratio as a measure of gait control in people with multiple sclerosis without mobility aids

Ambulatory limitations are a key component of disability in people with multiple sclerosis (PwMS). Various tools are employed to assess walking performance in PwMS; however, no ideal measure has as yet been attained. In this situation, a walk ratio might be more advantageous compared with other gait measures. The walk ratio, a simple index for describing temporal and spatial co-ordination, denotes the relationship between step length and cadence during walking. Hence, the primary objective of this study was to determine the relationship between the walk ratio and measures of other theoretically related constructs. The walk ratio was studied using the GAITRite™ system (CIR Systems, Inc. Havertown, USA). The study group included 229 PwMS (143 women) and a mean disease duration of 5.8 (SD = 7.1) years. The walk ratio score of the total sample was 5.3 (SD = 0.8). Significant differences based on the expanded disability status scale (EDSS) scores (F = 11.616, P < 0.001) were observed between the neurological disability subgroups. Scores of the very mild (EDSS 0–2.0), mild (EDSS 2.5–4.0) and moderate (EDSS 4.5–5.5) groups were 5.5 (SD = 0.7), 5.2 (SD = 0.7), 4.9 (SD = 0.9), respectively. In terms of fall status, the MS fallers demonstrated a significant lower walk ratio compared to the MS non-fallers; 5.1 (SD = 0.8) vs. 5.5 (SD = 0.7); P < 0.001. Modest significant correlation scores were found between walk ratio and ambulation tests. Scores were slightly higher in the short walking tests, timed 25-foot walk and timed up and go tests (Pearson's rho = 0.369, 0.364) compared to the 6 and 2-min walk time tests (Pearson's rho = 0.344, 0.308). Collectively, the current study supports the construct validity of the walk ratio index in PwMS without mobility aids.     

The correlation between symptomatic fatigue to definite measures of gait in people with multiple sclerosis

There is a general consensus relating to the multidimensional aspects of fatigue in people with multiple sclerosis (PwMS), however, the exact impact of this symptom on gait is not fully understood. Our primary aim was to examine the relationship between definite parameters of gait with self-reported symptomatic fatigue in PwMS according to their level of neurological impairment. Spatio-temporal parameters of gait were studied using an electronic walkway. The Multiple Sclerosis Walking Scale (MSWS-12) questionnaire, a patient-rated measure of walking ability was collected. The Modified Fatigue Impact Scale (MFIS) questionnaire was used to determine the level of symptomatic fatigue. One hundred and one PwMS (61 women) were included in the study analysis. Subjects were divided into mild and moderate neurological impaired groups. Fatigue was correlated with 5 (out of 14) spatiotemporal parameters. However, correlation scores were all <0.35, thus considered as weak correlations. In the mild group, the double support period was the only variable positively correlated to fatigue (Spearman's rho = 0.28, P = 0.05). In the moderate group, step and stride length were solely negatively correlated to fatigue (Spearman's rho = 0.32, P = 0.03). In contrast to the definite gait parameters, the MSWS-12 self-questionnaire was moderately positively correlated to the level of fatigue. Scores for the total, mild and moderate groups were 0.54, 0.57 and 0.51; P < 0.01, respectively. The present results indicate that modifications in spatio-temporal parameters of gait are not closely related to symptomatic fatigue in PwMS. On the contrary, the self-reported MSWS-12 questionnaire is predisposed to level of fatigue in PwMS.     

Influence of the environment on cognitive-motor interaction during walking in people living with and without multiple sclerosis

BackgroundMotor and cognitive impairments are highly prevalent in people with multiple sclerosis (pwMS). The current theoretical frameworks of cognitive-motor interaction (CMI) suggest that the environment can influence both motor and cognitive performance during walking. However, the relationship between increasing environmental demands and CMI in pwMS remains to be elucidated.Research questionWhat is the impact of increased environmental demands on CMI during walking in people living with and without MS?MethodsTwenty pwMS and 20 age-matched healthy adults (HA) participated in this cross-sectional study. Participants (age = 57.6 ± 7.8 years) performed four walks (baseline walking (BW), obstacle walking (OW), narrow walking (NW), and narrow with obstacles (NO)) in single-task and dual-task (serial-7 subtraction test) conditions. The dual-task costs (DTC) of gait (% change in walking time) and cognition (% change in correctly verbalized utterances) were calculated to quantify CMI. Secondary outcomes included physiological profile assessment (PPA), measures of cognition and falls efficacy scale international (FES-I).ResultsMixed-factor ANOVAs revealed no main effect of task (F = 1.71, p = 0.196) and group (F = 0.71, p = 0.406) on DTC of gait, while there were significant main effects of both task (F = 23.75, p < 0.001) and group (F = 6.53, p = 0.015) on DTC of cognition. Simple main effects revealed that pwMS had a significantly higher DTC of cognition during BW (+37.6 %, p=0.013), NW (+34.2 %, p=0.014) and NO (+49 %, p=0.016) compared to HA. Additionally, DTC of cognition increased during the more environmentally demanding conditions compared to BW (range: +28.4 % to +54.2 %, all p-values<0.01) in both pwMS and HA. Only DTCs of cognition were significantly correlated with PPA and FES-I.SignificanceThe study findings suggest that CMI may be influenced by the individual/environment at levels above those described by the more mechanistic theories of attention.     

Exploring the feasibility and acceptability of sensor monitoring of gait and falls in the homes of persons with multiple sclerosis

Gait parameters variability and falls are problems for persons with MS and have not been adequately captured in the home. Our goal was to explore the feasibility and acceptability of monitoring of gait and falls in the homes of persons with MS over a period of 30 days. To test the feasibility of measuring gait and falls for 30 days in the home of persons with MS, spatiotemporal gait parameters stride length, stride time, and gait speed were compared. A 3D infrared depth imaging system has been developed to objectively measure gait and falls in the home environment. Participants also completed a 16-foot GaitRite electronic pathway walk to validate spatiotemporal parameters of gait (gait speed (cm/s), stride length (cm), and gait cycle time(s)) during the timed 25 foot walking test (T25FWT). We also documented barriers to feasibility of installing the in-home sensors for these participants. The results of the study suggest that the Kinect sensor may be used as an alternative device to measure gait for persons with MS, depending on the desired accuracy level. Ultimately, using in-home sensors to analyze gait parameters in real time is feasible and could lead to better analysis of gait in persons with MS.     

Unplanned gait termination in individuals with multiple sclerosis

Despite the pervasive nature of gait impairment in multiple sclerosis (MS), there is limited information concerning the control of gait termination in individuals with MS. The purpose of this investigation was to examine unplanned gait termination with and without cognitive distractors in individuals with MS compared to healthy controls. Thirty-one individuals with MS and 14 healthy controls completed a series of unplanned gait termination tasks over a pressure sensitive walkway under distracting and non-distracting conditions. Individuals with MS were further broken down into groups based on assistive device use: (no assistive device (MS_noAD) n = 18; and assistive device (MS_AD) n = 13). Individuals with MS who walked with an assistive device (MS_AD: 67.8 ± 15.1 cm/s) walked slower than individuals without an assistive device (MS_noAD: 110.4 ± 32.3 cm/s, p < 0.01) and controls (120.0 ± 30.0 cm/s; p < 0.01). There was a significant reduction in velocity in the cognitively distracting condition (93.4 ± 32.1 cm/s) compared to the normal condition [108.8 ± 36.2 cm/s; F(1,43) = 3.4, p = 0.04]. All participants took longer to stop during the distracting condition (1.7±0.6 s) than the non-distracting condition (1.4 ± 0.4 s; U = 673.0 p < 0.01). After controlling for gait velocity, post-hoc analysis revealed the MS_AD group took significantly longer to stop compared to the control group (p = 0.05). Further research investigating the control of unplanned gait termination in MS is warranted.     

Metrics extracted from a single wearable sensor during sit-stand transitions relate to mobility impairment and fall risk in people with multiple sclerosis

BackgroundApproximately half of the 2.3 million people with multiple sclerosis (PwMS) will fall in any three-month period. Currently clinicians rely on self-report measures or simple functional assessments, administered at discrete time points, to assess fall risk. Wearable inertial sensors are a promising technology for increasing the sensitivity of clinical assessments to accurately predict fall risk, but current accelerometer-based approaches are limited.Research questionWill metrics derived from wearable accelerometers during a 30-second chair stand test (30CST) correlate with clinical measures of disease severity, balance confidence and fatigue in PwMS, and can these metrics be used to accurately discriminate fallers from non-fallers?MethodsThirty-eight PwMS (21 fallers) completed self-report outcome measures then performed the 30CST while triaxial acceleration data were collected from inertial sensors adhered to the thigh and chest. Accelerometer metrics were derived for the sit-to-stand and stand-to-sit transitions and relationships with clinical metrics were assessed. Finally, the metrics were used to develop a logistic regression model to classify fall status.ResultsAccelerometer-derived metrics were significantly associated with multiple clinical metrics that capture disease severity, balance confidence and fatigue. Performance of a logistic regression for classifying fall status was enhanced by including accelerometer features (accuracy 74%, AUC 0.78) compared to the standard of care (accuracy 68%, AUC 0.74) or patient reported outcomes (accuracy 71%, AUC 0.75).SignificanceAccelerometer derived metrics were associated with clinically relevant measures of disease severity, fatigue and balance confidence during a balance challenging task. Inertial sensors could feasibly be utilized to enhance the accuracy of functional assessments to identify fall risk in PwMS. Simplicity of these accelerometer-based metrics could facilitate deployment for community-based monitoring.     

Cortical activity and gait parameter characteristics in people with multiple sclerosis during unobstructed gait and obstacle avoidance

BackgroundPeople with Multiple Sclerosis (PwMS) present higher cortical activity during walking. However, the cortical activity during gait while avoiding an obstacle is still not clear.ObjectiveTo investigate cortical activity and gait spatial-temporal parameters in PwMS during two different gait tasks (i.e., unobstructed and obstacle avoidance).MethodFifteen PwMS and 15 healthy controls (CG) were recruited. Participants performed ten trials in each gait condition, wearing a 64-electrode cap electroencephalogram (EEG) at 1024 Hz. Kinematic data were obtained through 10 Vicon® cameras at 200 Hz. EEG was analyzed through four cortical areas (frontal, motor, parietal, and occipital cortex areas) and five frequency bands (delta, theta, alpha, beta, and gamma) obtained through the power spectral density. In addition, spatial-temporal gait parameters (e.g., step length and velocity) were measured. Two-way ANOVA (group x gait condition) and MANOVA (group x gait condition) were used to compare gait and EEG parameters, respectively. One-way ANOVA was used to compare groups in the crossing phase of the obstacle avoidance condition.ResultsPwMS presented lower step length and velocity, and higher cortical activity in frontal (beta and gamma) and parietal (gamma) cortical areas in both gait conditions compared to CG. Moreover, PwMS presented increased cortical activation (frontal and parietal) and decreased step length and velocity in obstacle avoidance compared with unobstructed gait. In addition, PwMS required more cortical resources (frontal and parietal) than CG to accomplish both gait conditions. During the obstacle avoidance task, it was further observed that PwMS positioned their feet closer to the obstacle, before and after the task, compared to CG.ConclusionPwMS demand higher cortical resources to accomplish gait tasks, mainly when it is necessary to negotiate an obstacle in the pathway. This higher cortical activity may be a compensatory mechanism to deal with damage in subcortical structures caused by multiple sclerosis.     

Reliability of gait and dual-task measures in multiple sclerosis

BackgroundSingle-task (ST) and dual-task (DT) assessments are commonly used to evaluate motor and cognitive impairment in people with multiple sclerosis (MS). Although variability can influence repeated DT testing measures, the reliability of several DT variables over time has not been adequately explored. For instance, a third testing session has never been included to observe whether DT has a learning effect. DT cognition rate reliability has not yet been examined and dual-task cost (DTC), a widely used calculation for DT interpretation, has not been proven reliable.Research questionTo evaluate the reliability of ST and DT measures of gait and cognition over three test sessions.MethodsThis was a cross-sectional study involving 18 people with MS and 12 controls. Participants attended three test sessions, each one week apart. ST and DT (serial seven subtraction) gait variables, DTC, coefficient of variability (CV), and cognition rate were extracted and calculated using an instrumented walkway. Reliability was assessed using intraclass correlation coefficients (ICC) or Kendall’s coefficient of concordance (KCC; nonparametric test) and minimum detectable change (MDC); between-session learning effect was assessed using repeated measures ANOVA.ResultsICC/KCC values for ST and DT gait variables ranged from moderate to excellent (0.50-0.99). However, reliability for DT stride width and cognition rate was lower in controls. In general, DTC and CV variables had poor ICCs and high MDC values (49.19–1478.67 %), although some DTC variables had moderate or higher reliability in controls. Cognition rate was reliable in both MS (ICC 0.91) and controls (ICC 0.84). A learning effect between sessions was observed for DT velocity in both groups and for DTC cadence in people with MS.SignificanceST and DT gait measures as well as DT cognition rate are reliable outcomes for repeated testing, while DTC and CV variables may not be suitable for long-term monitoring.     

Symmetry in vertical ground reaction force is not related to walking and balance difficulties in people with multiple sclerosis

Analysis of vertical ground reaction force (GRF) symmetry may benefit people with multiple sclerosis (PwMS) since it can detect important differences in gait mechanics which have not previously been discussed in the related literature. Therefore, the primary objective of the current study was to determine whether symmetry of the vertical GRF during gait is associated with validated gait and balance tests in PwMS. Additionally, we examined whether the symmetry of the vertical GRF differs between MS fallers, non-fallers and between neurological disability levels. Gait and balance data were collected from 402 PwMS (249 women) with a mean age of 42.1 (S.D = 14.1) years. Vertical GRF parameters were obtained using the Zebris FDM-T Treadmill (Zebris Medical GmbH, Germany). Clinical gait and balance tests included the 2 and 6-min Walk Test, Timed Up and Go Test, Timed 25 Foot Walk, Four Square Step Test, Multiple Sclerosis Walking Scale questionnaire, Modified Fatigue Impact Scale and the Falls Efficacy Scale International questionnaire. The vertical GRF symmetry index score of the total sample was 3.7 (SD = 3.1). In terms of fall status, non-significant differences were observed between the fallers and non-faller groups and between the neurological disability subgroups. Non-significant correlation scores were found between the vertical GRF symmetry index, all clinical walking and balance tests and self-reported questionnaires. We suggest clinicians, especially those involved in physical rehabilitation, accord low priority to this gait phenomenon in the MS population.     

Acute effects of axial loading on postural control during walking and turning in people with multiple sclerosis: A pilot study

BackgroundImpaired sensory integration is heavily involved in gait control and accentuates fall risk in individuals with multiple sclerosis (MS). While axial loading has been found beneficial, little is known about the effect of non-specific axial loads on gait parameters and mobility tasks in those with MS. Research Question: What are the effects of non-specific axial loading via weighted vests on walking and turning in those with MS.MethodsTwelve participants with MS and eleven age- and gender-matched healthy controls participated in a cross-sectional study. All participants completed five trials of continuous walking with turns wearing weighted vests at 0%, 2%, 4%, 5%, and then 0% of their body weight. Gait parameters were measured using wireless inertial sensors. A 2 (group) x 5 (vest weight) multivariate analysis of variance (MANOVA) was performed to determine any significant differences between groups and across weighted vests for each gait variable. Post-hoc analysis and paired t-tests with corresponding effect sizes were also conducted.ResultsA significant between groups main effect was found for group (F (6100) = 14.74, p = .000) in multiple gait parameters (p < 0.05), although no significant main effect was found for weighted vest. Within group analyses indicated significantly increased cadence and gait speed across varying weighted vests for both MS and control groups (p < 0 >05). Increased vest weight from 0%PRE to 2% also had large effect on shortening double support time and increasing stride length in the MS group.SignificanceThis study provided preliminary evidence that non-specific axial loads of varying weights appear to improve certain gait parameters. As such, this modality may offer mobility benefit and serve as an accessible home-based intervention alternative aimed at improving walking in individuals with MS.     

The relationship between energy cost of walking,ankle push-off and walking speed in persons with multiple sclerosis

BackgroundThe energy cost of walking (ECw) is an important indicator of walking dysfunction in persons with multiple sclerosis (PwMS). However, its underlying causes and its relation with ankle push-off and walking speed are not well understood.Research questionWhat is the contribution of ankle push-off and walking speed to increased ECw in PwMS?MethodsTen PwMS with walking limitations and 10 individually gender- and age-matched healthy controls (HC) were included. All participants performed two 6-min walking trials on a treadmill at comfortable walking speed (CWS of PwMS) and fast walking speed (FWS, 130 % of CWS of PwMS). Kinetics and metabolic cost were evaluated. Generalized estimating equations were performed to investigate effects of group and walking speed, and their interaction. Spearman correlations were conducted to examine whether ECw was related to ankle push-off in PwMS, controlling for differences in walking speed in PwMS.ResultsECw at matched walking speed was significantly higher in PwMS compared to HC. Kinetic parameters were not different between the most impaired leg in PwMS and HC at matched walking speed, but asymmetry between both legs of PwMS was observed. At FWS, ECw reduced and ankle push-off increased similarly in both groups. ECw was inversely related to peak ankle power of the most impaired leg in PwMS at CWS.SignificanceSlow walking speed is one factor that contributes to increased ECw in PwMS. Furthermore, PwMS who had a higher ECw showed a lower peak ankle power, independent of walking speed. This indicates that ankle push-off could be a contributor to increased ECw.     

Torque responses to in-place-perturbations in people with multiple sclerosis

BackgroundAutomatic postural responses are critical to prevent falls after a loss of balance. Although responses have been shown to be delayed in people with multiple sclerosis (PwMS), the degree to which other aspects of these movements are impacted by MS remains unknown.Research QuestionDo responses to in-place support-surface perturbations differ in PwMS compared to neurotypical adults? Are these responses related to a functional measure of postural response performance- center of mass (COM) displacement?.Method52 PwMS and 20 neurotypical, age-matched adults (NA) experienced backward support surface perturbations resulting in forward loss of balance and requiring an in-place response. Center of pressure (COP) and torque were calculated from force plates while center of mass (COM) approximations were collected via motion capture. Primary outcomes were maximal torque production at the foot and its timing, rate, and onset.ResultsPwMS and NA demonstrated no differences in maximal torque production (p = 0.79), timing of maximal torque (p = 0.29), rate of torque development (p = 0.76), or the onset of AP COP movement (p = 0.44). There was a significant negative association between the rate of torque development and forward COM displacement in both groups (Control: r=-0.64, p = 0.002; MS: r=-0.35, p = 0.01). Larger maximal torque production was also associated with smaller COM displacement in PwMS (r=-0.33, p = 0.02).ConclusionTorque profiles in response to backward support surface translations resulting in feet in-place responses were similar in people with mild MS and neurotypical adults. The rate of development and maximal torque were however correlated to functional postural response outcomes. These findings suggest that while not worse in PwMS during in-place perturbations, force-responses seem to be important predictors of the effectiveness of reactive postural control responses.     

Reliability of spatial–temporal gait parameters during dual-task interference in people with multiple sclerosis. A cross-sectional study

PurposeTo evaluate the reliability and minimum detectable change (MDC) of spatial–temporal gait parameters in subjects with multiple sclerosis (MS) during dual tasking.MethodThis cross-sectional study involved 25 healthy subjects (mean age 49.9 ± 15.8 years) and 25 people with MS (mean age 49.2 ± 11.5 years). Gait under motor-cognitive and motor–motor dual tasking conditions was evaluated in two sessions separated by a one-day interval using the GAITRite^® Walkway System. Test–retest reliability was assessed using intraclass correlation coefficients (ICCs), standard errors of measurement (SEM), and coefficients of variation (CV). MDC scores were computed for the velocity, cadence, step and stride length, step and stride time, double support time, the % of gait cycle for single support and stance phase, and base of support.ResultsAll of the gait parameters reported good to excellent ICCs under both conditions, with healthy subject values of >0.69 and MS subject values of >0.84. SEM values were always below 18% for both groups of subjects. The gait patterns of the people with MS were slightly more variable than those of the normal controls (CVs: 5.88–41.53% vs 2.84–30.48%).ConclusionsThe assessment of quantitative gait parameters in healthy subjects and people with MS is highly reliable under both of the investigated dual tasking conditions.     

The energy cost of level walking in patients with hemiplegia

The energy cost of level walking (C_w) was measured from the ratio of O₂ consumption to speed (from 0.1 to 1.2 m-s⁻¹) in hemiplegic patients ( n =20) and in a control group of healthy subjects ( n =17). Average age and body mass were 58, 54 years and 73, 78 kg, respectively. In hemiplegic patients C_w was higher than in control subjects (average value at 1.0 m-s⁻¹=3.6 and 3.3 J-m⁻¹. kg⁻¹, respectively) and this difference increased at lower speeds (from 5.1% at 1.2 m-s⁻¹ to 28.7% at 0.1 m-s⁻¹).     

Separating the effects of age and walking speed on gait variability

Gait variability has been correlated with fall risk in the elderly. Older adults typically display greater variability than young adults, but the cause of this increase is unclear. Slower walking leads to greater variability in young adults, but slow speeds are also typical in older adults. Increased variability in older adults may result from slower walking speeds, or possibly from other factors related to aging. We tested whether greater variability in healthy older adults could be attributed directly to slower walking speed. Eighteen healthy older adults (age 72 ± 6) and 17 gender-, height- and weight-matched young adults (age 23 ± 3) walked on a treadmill at speeds of 80–120% of their preferred speed. Variability of spatio-temporal gait measures, lower extremity joint angles, and trunk motions were quantified, along with bilateral isometric leg strengths and passive joint ranges of motion. Preferred walking speeds were not different between our healthy elderly and young subjects. In both groups, variability was speed-dependent for stride time, frontal hip and knee motions, knee internal/external rotations, and all trunk motions (p < 0.002). Older adults exhibited greater variability (p = 0.0003) for trunk roll, independent of changes in speed. Step length (p = 0.005), stride time (p = 0.018), and trunk pitch (p = 0.022) exhibited similar trends. This greater variability was explained by decreased leg strength and passive ranges of motion. Thus, the greater variability observed in the gait of older adults may result more from loss of strength and flexibility than from their slower speeds.     

Evaluation of unsupervised 30-second chair stand test performance assessed by wearable sensors to predict fall status in multiple sclerosis

BackgroundOne in two people with multiple sclerosis (PwMS) will fall in a three-month period. Predicting which patients will fall remains a challenge for clinicians. Standardized functional assessments provide insight into balance deficits and fall risk but their use has been limited to supervised visits.Research questionThe study aim was to characterize unsupervised 30-second chair stand test (30CST) performance using accelerometer-derived metrics and assess its ability to classify fall status in PwMS compared to supervised 30CST.MethodsThirty-seven PwMS (21 fallers) performed instrumented supervised and unsupervised 30CSTs with a single wearable sensor on the thigh. In unsupervised conditions, participants performed bi-hourly 30CSTs and rated their balance confidence and fatigue over 48-hours. ROC analysis was used to classify fall status for 30CST performance.ResultsNon-fallers (p = 0.02) but not fallers (p = 0.23) differed in their average unsupervised 30CST performance (repetitions) compared to their supervised performance. The unsupervised maximum number of 30CST repetitions performed optimized ROC classification AUC (0.79), accuracy (78.4%) and specificity (90.0%) for fall status with an optimal cutoff of 17 repetitions.SignificanceBrief durations of instrumented unsupervised monitoring as an adjunct to routine clinical assessments could improve the ability for predicting fall risk and fluctuations in functional mobility in PwMS.     

Trunk and pelvis movement compensation in people with multiple sclerosis: Relationships to muscle function and gait performance outcomes

BackgroundProblems with gait are common in people with multiple sclerosis (MS), but little is known about pelvis and trunk kinematics, especially in the frontal plane.Research questionAre pelvis and trunk kinematics in people with MS related to muscle function, spatiotemporal parameters, and gait performance?MethodsIn this cross-sectional study, 20 people with MS (Expanded Disability Status Scale 1.5–5.5) and 10 people with comparable age and sex (CTL) underwent threedimensional gait analysis, muscle function assessments (hip and trunk strength and endurance), and gait performance measures (Timed 25-Foot Walk – T25FW, 2-Minute Walk Test – 2MWT). Frontal and sagittal plane pelvis and trunk excursion during the stance period of walking were compared between groups; and in the MS group, associations were determined between kinematic variables, muscle function, spatiotemporal parameters, and gait performance.ResultsCompared to the CTL group, the MS group had significantly greater sagittal plane trunk and pelvis excursion for both the stronger (p = 0.031) and weaker (p = 0.042) sides; less frontal plane trunk and pelvis excursion for both the stronger (p = 0.008) and weaker (p = 0.024) sides; and more sagittal plane trunk excursion for the stronger side (p = 0.047) during stance phase. There were low-to-moderate correlations in the MS group for sagittal plane pelvis excursion with muscle function (p = 0.019 to 0.030), spatiotemporal parameters (p < 0.001 to 0.005), and gait performance (p = < 0.001 to 0.001). Using linear regression, frontal and sagittal plane pelvis excursion were significant predictors of both T25FW and 2MWT, explaining 34 % and 46 % of the variance of each gait performance measure, respectively.SignificanceRehabilitation interventions may consider addressing pelvis movement compensations in order to improve spatiotemporal parameters and gait performance in people with MS.     

The association between bladder dysfunction,balance and falls in women with multiple sclerosis: The specific contribution of fear of falling

BackgroundBladder dysfunction is the most common autonomic disturbance in people with MS (PwMS). Only a few studies have examined the relationship between bladder dysfunction and falls in PwMS. Bladder dysfunction has been deemed only a secondary outcome measure, and classified by a gross measure providing a limited perspective of this disturbing symptom. Furthermore, no study to date has focused on the relationship between bladder dysfunction and balance performance in PwMS.Research questionDetermine the relationship between bladder dysfunction with balance, falls and fear of falling in women with MS.MethodsThe study was observational, including 44 women with MS, mean age 46.3 (SD = 5.7), all with at least a mild bladder dysfunction. Outcome measures included the Urinary Incontinence Quality of Life Scale (I-QoL), Bladder Control Scale (BLCS), Timed Up and Go Test (TUG), Four Square Step Test (FSST), Falls Efficacy Scale International (FES-I), Falls status, and posturography.ResultsParticipants performed the TUG in 14.1 s (S.D. = 11.1), and the FSST in 20.5 s (S.D. = 22.4). A relatively large proportion (68.2 %) of women was classified as fallers. However, no differences were found between those classified as fallers (n = 30) or non-fallers (n = 14) in terms of the I-QoL and the BLCS, controlling for age, EDSS and number of vaginal deliveries. Significant correlations scores were found between the I-QoL, BLCS and FES-I (rho ∼0.47), while controlling for age, EDSS and number of vaginal deliveries. No associations were demonstrated between the bladder dysfunction outcome scores and either the TUG and/or FSST.SignificanceWomen afflicted with MS and suffering from bladder dysfunction tend to fall and present with more balance difficulties compared with disability-matched PwMS. Nevertheless, once bladder dysfunction is detected, the perceived severity of the condition is not associated with balance and prevalence of falling, but rather on fear of falling.     

Correlates of dual task cost of standing balance in individuals with multiple sclerosis

Cognitive and balance dysfunction are common symptoms in individuals with multiple sclerosis (MS). Although traditionally seen as separate impairments, performing a concurrent cognitive task while maintaining an upright posture results in individuals with MS increasing their postural sway (i.e. dual task cost (DTC) of balance). However, the factors relating to this phenomenon are not clear. This investigation examined the demographic, clinical and cognitive correlates of DTC of balance in individuals with MS. Sixty-two persons with MS completed both quiet standing and dual task balance trials on a force platform. Additionally, they provided demographic information and performed clinical tests of balance, spasticity, fall risk and cognitive processing speed. Dual task cost was calculated as the percentage change in sway area from the baseline to dual task force platform conditions. Overall, there were no significant correlations between DTC of balance and any of the outcome measures in the entire sample. In contrast, postural sway in the baseline and dual task condition were found to correlate with disability, fall risk, balance performance, fatigue, cognitive processing speed and age. Secondary analysis revealed different correlates of DTC of balance in those with low versus high baseline sway. The results suggest that the change in standing balance with the simultaneous performance of cognitive task may only be informative in individuals with minimal balance dysfunction.     

Somatosensory impairment and its association with balance limitation in people with multiple sclerosis

BackgroundSomatosensory impairments are common in multiple sclerosis. However, little data are available to characterize the nature and frequency of these problems in people with multiple sclerosis.ObjectiveTo investigate the frequency of somatosensory impairments and identify any association with balance limitations in people with multiple sclerosis.MethodsThe design was a prospective cross-sectional study, involving 82 people with multiple sclerosis and 30 healthy controls. Tactile and proprioceptive sensory acuity were measured using the Rivermead Assessment of Somatosensory Performance. Vibration duration was assessed using a tuning fork. Duration for the Timed Up and Go Test and reaching distance of the Functional Reach Test were measured to assess balance limitations. The normative range of sensory modalities was defined using cut-off points in the healthy participants. The multivariate linear regression was used to identify the significant predictors of balance in people with multiple sclerosis.ResultsProprioceptive impairments (66.7%) were more common than tactile (60.8%) and vibration impairments (44.9%). Somatosensory impairments were more frequent in the lower limb (78.2%) than the upper limb (64.1%). All sensory modalities were significantly associated with the Timed Up and Go and Functional Reach tests (p < 0.05). The Timed Up and Go test was independently predicted by the severity of the neurological lesion, Body Mass Index, ataxia, and tactile sensation (R2 = 0.58), whereas the Functional Reach test was predicted by the severity of the neurological lesion, lower limb strength, and vibration sense (R2 = 0.49).ConclusionsSomatosensory impairments are very common in people with multiple sclerosis. These impairments are independent predictors of balance limitation.