Anticipatory postural adjustment during gait initiation in multiple sclerosis patients: A systematic review

Impact of physical activity, physical fitness and exercises on cognitive impairment in patients with multiple sclerosis: A review of evidence and underlying mechanisms

Cognitive impairment in persons with MS (pwMS) occurs commonly, early and independently of other clinical features of the disease. MS-related cognitive impairment is mainly characterized by weakening of information processing speed, working memory and episodic memory. Much evidence, based on both neuropsychological and neuroimaging outcomes, highlights successful cognitive rehabilitation interventions. In this context, promotion of physical activity and exercise training could be a dual, motor and cognitive, rehabilitation method. The aim of this article is, firstly, to review existing evidence regarding the effects of exercise on cognition among pwMS, and secondly, to explore the possible mechanisms of action of the cognitive-motor coupling.

Cognitive-motor dual task to reveal gait impairments in multiple sclerosis patients at an early stage: A systematic review

BACKGROUND

Multiple sclerosis can cause locomotor and cognitive impairments even at lower levels of disability, which can impact daily life. The cognitive-motor dual task is commonly used to assess everyday locomotion. Thus, this study aimed to examine the effect of cognitive-motor dual tasks on gait parameters among patients with multiple sclerosis in the early disease stages and to determine whether dual tasks could be used as a clinical test to detect locomotion impairments.

METHODS

A systematic search of five databases was conducted in May 2024. The population of interest was patients with multiple sclerosis with an Expanded Disability Status Scale score of 4 or less. The following outcome measures were examined: spatiotemporal and kinematic parameters. The Newcastle-Ottawa Scale was used to assess the quality of the studies.

FINDINGS

Eleven studies including 270 patients with multiple sclerosis and 221 healthy controls. Three spatiotemporal parameters were modified both in patients with multiple sclerosis and healthy controls during dual-task performance: gait speed, stride length and the double support phase. No spatiotemporal parameter was affected during dual-task performance in patients with multiple sclerosis alone.

INTERPRETATION

Dual-task performance could be useful for assessing gait impairments in patients with multiple sclerosis provided that assessments and protocols are standardized. Nevertheless, the spatiotemporal parameters did not allow discrimination between patients with multiple sclerosis at an early stage and healthy controls. Three-dimensional gait analysis during dual-task performance could be a useful approach for detecting early gait impairments in patients with multiple sclerosis, assessing their progression and adjusting rehabilitation programs.

Gait initiation in multiple sclerosis patients with and without functional loss

BACKGROUND

Gait initiation (GI) is an important functional task related to balance and gait performance. In addition, it has predictive importance for falls and postural instability in patient with multiple sclerosis (MS). However, it is uncertain how GI is affected in patients in the early stage of MS (Expanded Disability Status Scale (EDSS) ≤3). In this study, it was aimed to investigate the anticipatory postural adjustments (APAs), posterior center of pressure (COPap) displacement, and spatiotemporal variability during GI in patients with and without functional loss in the early stage of MS.

METHODS

Forty-four participants (31 MS patients and 13 healthy subjects) involved in this prospective cross-sectional study were divided into three groups: Group-I: Patients without functional loss (EDSS 0 to 1.5) (n = 14), Group-II: Patients with functional loss (EDSS 2 to 3) (n = 17) and Group-III: Healthy subjects (n = 13). Electromyographic activity of the bilateral tibialis anterior (TA) and gastrocnemius medialis (GM) and COPap displacement were recorded during the postural phase of GI. Additionally, spatiotemporal parameters were recorded within the first three steps, and the coefficient of variation was calculated with 40 walks for variability.

RESULTS

There were significant differences in the Kruskal-Wallis tests of variables (p<0.05). Group-I demonstrated smaller APAs magnitudes in TA [stance (p = 0.01), swing (p = 0.01)], GM of swing limb (p<0.0001), and smaller COPap displacement (p<0.0001) compared to group-III. Group-II demonstrated smaller APAs magnitudes in all muscles (p<0.0001) compared to group-III and the smallest COPap displacement (p<0.0001). Group-I showed a significant increase in stride width variability compared to group-III (p = 0.01). Group-II showed a significant increase in several variabilities [first stride length (p<0.0001), second stride time (p<0.0001), first double support time (p<0.0001), stride width (p<0.0001)] compared to group-III.

CONCLUSION

Patients in the early stage of MS had impairment in both the postural and locomotor phases of GI with more obvious in the patients with functional loss. The results indicate that MS patients without functional loss have difficulty initiating gait. Although there is no functional loss, the patients have a risk of falls, postural instability, and gait impairment due to their inability to initiate gait effectively. As a result, rehabilitation is necessary even if there is no functional loss in patients with MS.

Comparison of physical performance, gait, balance, falls efficacy, and step reaction time in individuals with multiple sclerosis

OBJECTIVE

The study aimed to investigate the physical performance, gait, balance, falls efficacy, and step reaction time in individuals with MS.

METHODS

A total of 60 individuals (30 individuals with MS and 30 age and sex-matched healthy controls) were enrolled. Individuals' physical performance was evaluated with the Timed Up and Go Test (TUG) and Five-Times-Sit-to-Stand Test (FTSTS). Activities-specific Balance Confidence (ABC) Scale, 12-item Multiple Sclerosis Walking Scale (MSWS-12v2) and Falls Efficacy Scale International (FES-I) were used to assess the balance, gait and fall efficacy of the participants. Individuals' step reaction time (SRT) was calculated with video-based software. The time between the step command and the first contact of the foot with the ground in the first step was recorded.

RESULTS

The mean age of the individuals with MS and the control group was 38.5 ± 9.4 years and 33.9 ± 11.7 years, respectively. Significant differences existed between the groups in SRT, FES-I, ABC, and FTSTS (p < 0.05). There was no significant correlation between SRT with any other parameter (p > 0.05). TUG was moderately correlated with MSWS-12 and FES-I (r1 =0.426, r2 =0.495, p < 0.05). Besides, there was a moderate correlation between ABC with TUG and FTSTS (r1 =-0.605, r2 =-0.468, p < 0.05). A high degree correlation was found between MSWS-12 with FES-I and ABC (r1 =0.843, r2 =-0.834, p < 0.05).

CONCLUSION

Individuals with MS have decreased SRTs. However, this condition was not found to be related to physical performance. Further studies should focus on the association of SRT with cognitive and psychosocial parameters.

Effect of Dynamic Neuromuscular Stabilization on Balance, Trunk Function, Falling, and Spasticity in People With Multiple Sclerosis: A Randomized Controlled Trial

OBJECTIVE

To compare the effects of core stabilization (CS) and dynamic neuromuscular stabilization (DNS) on balance, trunk function, mobility, falling, and spasticity, in people with multiple sclerosis (PWMS).

DESIGN

Two-group randomized controlled trial.

SETTING

General community and referral center.

PARTICIPANTS

A total of 64 PWMS, between 30 and 50 years old, and an expanded disability status scale between 2 and 5, participated in this study (N=64).

INTERVENTIONS

Participants were randomly assigned to CS (n=32) and DNS (n=32) groups. Both groups received a total of 15 sessions of CS or DNS exercises, 60 minutes per session, 3 times a week during the 5 weeks.

OUTCOME MEASURES

Balance function was measured as the primary outcome measure. Trunk function, postural stability, falling rate, fear of falling, falling index, mobility, and spasticity were measured as secondary outcomes.

RESULTS

DNS group had significant improvement in Berg balance scale, trunk impairment scale, postural stability, activities-specific balance confidence, reduced falling rate, the timed Up and Go (TUG), multiple sclerosis walking scale-12, and multiple sclerosis spasticity scale in PWMS compared with the CS group, (P<.0001) after 5 weeks of intervention and 17 weeks of follow-up. Except for the modified Ashworth scale (MAS), significant improvements were seen in all outcome measures in both groups after 5 weeks of intervention.

CONCLUSION

This is the first clinical evidence to support the importance of DNS exercise in improving balance, trunk function, and fall prevention in PWMS. This study provides clinical evidence that DNS may be more effective for PWMS than CS.

MULTİPL SKLEROZLU BİREYLERDE STABİLİTE LİMİTLERİ VE DÜŞME RİSKİ ARASINDAKİ İLİŞKİNİN İNCELENMESİ

Amaç: Bu çalışmanın amacı, Multipl Skleroz (MS)’lu bireylerde stabilite limitleri (SL) ile düşme riski arasındaki ilişkiyi incelemektir. Yöntem: Çalışmaya 18-50 yaş aralığında, Expanded Disability Status Scale (EDSS) skoru ≤ 4, son 6 ay içerisinde atak geçirmeyen ve son 6 ay içerisinde düşme hikâyesi olan 30 MS’li birey dâhil edildi. Bireylerin demografik bilgileri kaydedildi. Dört yöndeki (anterior, posterior, lateral- sol, sağ) SL, Bertec Balance Check ScreenerTM (Model BP5050; Bertec Corporation, Columbus, OH, USA) ile değerlendirildi. Düşme riski ise Zamanlı Kalk ve Yürü Testi (ZKYT) ile değerlendirildi. Dört yöndeki SL ile ZKYT skoru arasındaki ilişkileri incelemek için Spearman korelasyon testi kullanıldı. Sonuçlar: Çalışmaya katılan 30 bireyin (18 kadın, 12 erkek) yaş ortalaması 37,66±8,86 yıl idi. Anterior-posterior SL ile ZKYT skorları arasında negatif yönde iyi derecede (r =-0,616), lateral sol-sağ SL ile ZKYT skorları arasında negatif yönde orta derecede (r =-0,463) anlamlı bir ilişki bulundu (p&lt;0,05). Stabilite Limitleri Stabilite Skoru (SLSS) ile ZKYT skorları arasında ise negatif yönde iyi derecede (r =-0,683) anlamlı bir ilişki bulundu (p&lt;0,05). Tartışma: MS’li bireylerde SL, düşme için önemli bir faktördür. Biyomekanik yeterliliğin ve dinamik dengenin önemli bir göstergesi olan SL azaldıkça düşme riski artmaktadır. Düşme yaşayan MS’li bireyler SL açısından mutlaka değerlendirilmeli ve rehabilitasyon programında SL’nin geliştirilmesine de yer verilmelidir.

Anticipatory postural adjustments in older versus young adults: a systematic review and meta-analysis

BACKGROUND

Anticipatory postural adjustments (APAs) are a feedforward mechanism triggered in advance to a predictable perturbation, to help the individual counteract mechanical effects that the disturbance may cause. Whether or not this strategy is compromised in the elderly is not a consensus in the literature.

METHODS

In this systematic review with meta-analysis, we investigated aging effects on postural control, based on anticipatory postural adjustments (APAs). We selected 11 eligible articles of the following databases: Lilacs, SciELO, PubMed, Cochrane Central, Embase, and CINAHL, involving 324 research participants, assessing their methodological quality and extracting electromyographic, posturographic, and kinematic measurements. We included studies that investigated the occurrence of APAs in healthy younger and older adults, published before 10th August 2022, in English. Studies involving participant with conditions that may affect balance or that did not report measures of onset or amplitude of electromyography (EMG), COP, or kinematics were excluded. To analyze the aggregated results from these studies, we performed the analysis based on the outcome measures (EMG, COP, or kinematic measures) used in individual studies. We calculated differences between younger and older adult groups as the mean differences between the groups and the estimated effect. Egger's test was conducted to evaluate whether this meta-analysis had publication bias.

RESULTS

Through this review, older adults showed no significant difference in the velocity to perform a movement compared to the younger adults (MD 0.95, 95% CI -0.86, 2.76, I2 = 82%), but both muscle onset and center of pressure (COP) onset were significantly more delayed in older than in younger adults: erector spinae (MD -31.44, 95% CI -61.79, -1.09, I2 = 95%); rectus abdominis (RA) (MD -31.51, 95% CI -70.58, -3.57, I2 = 85%); tibialis anterior (TA) (MD -44.70, 95% CI -94.30, 4.91, I2 = 63%); soleus (SOL) (MD -37.74, 95% CI -65.43, -10.05, I2 = 91%); gastrocnemius (GAS) (MD -120.59, 95% CI -206.70, -34.49, I2 = 94%); quadriceps (Q) (MD -17.42, 95% CI -34.73, -0.12, I2 = 0%); biceps femoris (BF) (MD -117.47, 95% CI -192.55, -42.70, I2 = 97%); COP onset (MD -45.28, 95% CI -89.57, -0.98, I2 = 93%), and COP apa (COPapa) (MD 2.35, 95% CI -0.09, 4.79, I2 = 64%). These changes did not seem to be linked to the speed of movement but possibly to age-related physiological changes that indicated decreased motor control during APAs in older adults.

CONCLUSIONS

Older adults use different postural strategies that aim to increase the safety margin and stabilize the body to perform the movement, according to the requirements imposed, and this should be considered in rehabilitation protocols.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD420119143198.

Postural Adjustments in HTLV-1 Infected Patients during a Self-Initiated Perturbation

BACKGROUND

Human T-cell lymphotropic virus type 1 (HTLV-1) infection can be associated with tropical spastic paraparesis (TSP/HAM), which causes neurological myelopathy and sensory and muscle tone alterations, leading to gait and balance impairments. Once trunk perturbation is predicted, the motor control system uses anticipatory and compensatory mechanisms to maintain balance by recruiting postural muscles and displacement of the body's center of mass.

METHODS

Twenty-six participants (control or infected) had lower limb muscle onset and center of pressure (COP) displacements assessed prior to perturbation and throughout the entire movement.

RESULTS

Semitendinosus (ST) showed delayed onset in the infected group compared to the control group. The percentage of trials with detectable anticipatory postural adjustment was also lower in infected groups in the tibialis anterior and ST. In addition, COP displacement in the infected group was delayed, had a smaller amplitude, and took longer to reach the maximum displacement.

CONCLUSIONS

HTLV-1 infected patients have less efficient anticipatory adjustments and greater difficulty recovering their postural control during the compensatory phase. Clinical assessment of this population should consider postural stability during rehabilitation programs.

Effect of dynamic neuromuscular stabilization on balance and trunk function in people with multiple sclerosis: protocol for a randomized control trial

Background

Multiple sclerosis is a chronic and disabling neurological disease among young people. One of the major complaints in patients with multiple sclerosis (PWMS) is falling. There are a number of factors that risk factors for falling, including balance disorder and spasticity. Core stability (CS) exercises such as trunk muscle strengthening exercises can improve balance and mobility and reduce falling. Dynamic neuromuscular stabilization (DNS) exercise is a new functional rehabilitation strategy that optimizes motor function based on the principles of developmental kinesiology. This trial will evaluate the effectiveness of DNS in comparison to CS on balance, spasticity, and falling in PWMS.

Methods

A total of 64 PWMS, between 30 and 50 years old and expanded disability status scale (EDSS) between 2 to 5, will be recruited from neurophysiotherapy clinic, Faculty of Rehabilitation Sciences, Iran University of Medical Sciences to participate in this 2-armed parallel study. Participants will be randomly divided into two groups to receive CS exercise or DNS exercise. All participants will receive exercise treatment for 15 sessions during a period of 5 weeks (3 sessions per week). Primary outcome measures will be balance. Falling rate, fear of falling, patient mobility, as well as spasticity, will be measured as secondary outcomes. All outcome measures will be measured at baseline, the day after the completion of the 15th session, and after 17 weeks.

Discussion

Dynamic neurostabilization exercises utilize the subconscious stimulation of special zones to reflexively mediate the diaphragm and other core stabilization muscles, which is extremely effective for individuals with reduced somatosensory or movement awareness. Findings from the proposed study are expected to benefit the knowledge base of the physiotherapist, and it can be a good alternative for the rehabilitation program and even reduce medication use in patients with multiple sclerosis. These exercises are easy to understand and applicable for these patients and their partners as well.

Trial registration

The trial was registered in the Iran registry organization with code IRCT20140222016680N5 and was approved on April 7^th, 2020. Address: IRCT administration team, Central Library Building, Iran University Campus, Hemmat Freeway, next to Milad tower, Tehran, Iran. postal code:14496-14535.

Simplified stance limb kinetics patterns revealed during gait initiation in early stage of multiple sclerosis

BACKGROUND

Although patients with an early stage of Multiple Sclerosis (MS) commonly complain about balance and gait impairments, their troubles remain misunderstood. The objective was to compare body kinematics and lower limb kinetics during gait initiation between patients with MS with an EDSS score ≤ 4 and healthy participants.

METHODS

Sixteen patients with MS with a median EDSS score of 2.5 [0-4] and disease duration of 7.4 ± 4.2 years, as well as 16 healthy participants were included, and 3-D motion analysis was performed during gait initiation to calculate spatiotemporal, kinematic and kinetic parameters.

FINDINGS

The center of pressure position at the beginning of the gait initiation was more anterior (p = 0.02) in patients with MS than healthy participants. The kinetic parameters of the stance limb were highly affected in patients with MS compared to healthy participants during gait initiation. The net muscular moments for each joint were significantly different during the anticipatory postural adjustment phase with smoother variations for patients with MS compared to healthy participants.

INTERPRETATION

Early stage MS strongly affects the motor modulation of stance limb kinetics during the anticipatory postural adjustment of gait initiation, without alteration of the execution phase. The net muscular moments are sensitive in detecting unobservable balance impairments and can be used to assess disease progression at the early stage. These results suggest that early rehabilitation programs aimed at improving motor modulation and flexibility in gait initiation should be implemented.

Characterization of Anticipatory Postural Adjustments in Lateral Stepping: Impact of Footwear and Lower Limb Preference

Lateral stepping is a motor task that is widely used in everyday life to modify the base of support, change direction, and avoid obstacles. Anticipatory Postural Adjustments (APAs) are often analyzed to describe postural preparation prior to forward stepping, however, little is known about lateral stepping. The aim of the study is to characterize APAs preceding lateral steps and to investigate how these are affected by footwear and lower limb preference. Twenty-two healthy young participants performed a lateral step using both their preferred and non-preferred leg in both barefoot and shod conditions. APA spatiotemporal parameters (size, duration, and speed) along both the anteroposterior and mediolateral axes were obtained through force plate data. APAs preceding lateral stepping showed typical patterns both along the anteroposterior and mediolateral axis. RM-ANOVA highlighted a significant effect of footwear only on medio-lateral APAs amplitude (p = 0.008) and velocity (p = 0.037). No differences were found for the limb preference. APAs in lateral stepping presented consistent features in the sagittal component, regardless of limb/shoe factors. Interestingly, the study observed that footwear induced an increase in the medio-lateral APAs size and velocity, highlighting the importance of including this factor when studying lateral stepping.

Variability in the Center of Mass State During Initiation of Accurate Forward Step Aimed at Targets of Different Sizes

Motor control for forward step initiation begins with anticipatory postural adjustments (APAs). During APAs, the central nervous system controls the center of pressure (CoP) to generate an appropriate center of mass (CoM) position and velocity for various task requirements. In this study, we investigated the effect of required stepping accuracy on the CoM and CoP parameters during APA for a step initiation task. Sixteen healthy young participants stepped forward onto the targets on the ground as soon as and as fast as possible in response to visual stimuli. Two target sizes (small: 2 cm square and large: 10 cm square) and two target distances (short: 20% and long: 40% of the body height) were tested. CoP displacement during the APA and the CoM position, velocity, and extrapolated CoM at the timing of the takeoff of the lead leg were compared among the conditions. In the small condition, comparing with the large condition, the CoM position was set closer to the stance limb side during the APA, which was confirmed by the location of the extrapolated center of mass at the instance of the takeoff of the lead leg [small: 0.09 ± 0.01 m, large: 0.06 ± 0.01 m, mean and standard deviation, F _{(1, 15)} = 96.46, p < 0.001, η² = 0.87]. The variability in the mediolateral extrapolated center of mass location was smaller in the small target condition than large target condition when the target distance was long [small: 0.010 ± 0.002 m, large: 0.013 ± 0.004 m, t(15) = 3.8, p = 0.002, d = 0.96]. These findings showed that in the step initiation task, the CoM state and its variability were task-relevantly determined during the APA in accordance with the required stepping accuracy.

Straighten your back! Self-correction posture and postural balance in "non rehabilitative instructed" multiple sclerosis patients

BACKGROUD

Patients with MS, regardless of the complexity of the activity or sensory conditions, commonly present a significant postural control deficit compared to healthy subjects.

OBJECTIVE

To investigate which postural self-correction strategies are adopted by patients with Multiple Sclerosis versus a group of healthy-subjects and how self-correction can influence the control of postural balance.

METHODS

A case-control prospective observational study was conducted. Person with Multiple Sclerosis and a group of healthy volunteers were enrolled. Patients included were instructed with vocal commands, to reach a self-correction posture, and they were compared to healthy subjects. Clinical assessments including Balance, Stabilometry and Postural evaluation of the spine were performed.

RESULTS

Sixty patients (30: control-group; 30: treatment-group) were enrolled. In the treatment group, the analysis reported a significant statistical difference between path length and center of pressure speed in self-correction posture with closed-eyes (p = 0,049; 0,047) and an improvement in C7 and L3 levels in self-correction posture (p < 0,01-C7; p < 0,01-L3). There are significant statistical differences about path length between the two groups in all examined conditions (p = 0,0001). At sagittal plane evaluation, results show an increase of all measurements in both posture (C7-neutral posture p = 0,0001; L3-neutral posture p = 0,0001; C7-self-correction posture p = 0,0001; L3-self-correction posture p = 0,0001).

CONCLUSION

Further study should investigate dynamic situations and different Multiple Sclerosis forms to complete balance analysis and to establish a correct rehabilitative program with self-correction exercise as powerful focus.