Postural Control In Subjects Research Articles

Explicit training through neurodevelopmental therapy improves tone and postural control in hemiplegic stroke-A Systematic review protocol

Introduction Hemiplegia is the common term used to describe a multitude of clinical problems associated with a stroke. Hemiplegic stroke accounts for 70-85% of all first strokes. Trunk stability is impaired due to hypertonia and weakness in hemiplegia. Impaired trunk control leads to gait and postural abnormalities which if left untreated causes permanent disability in hemiplegics. Objective To investigate the scope of research on the benefits of explicit training using Neurodevelopmental Therapy (NDT) for enhancing tone and postural control in subjects with hemiplegic stroke. Methods In order to adhere to established protocols of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework, the systematic review will be carried out to find pertinent studies published up to the search date, and a thorough search strategy will be applied across popular electronic databases including PubMed/Medline, Scopus, and Cochrane Library. This systematic review methodology has been registered in PROSPERO for rigorous and transparent dissemination of study search, synthesis, and analysis. Discussion As the motor impairments due to abnormal tone and postural impairment in hemiplegic stroke substantially impact a stroke survivor’s quality of life, this study will provide a thorough and methodical approach to synthesize and report the merits and demerits on the effectiveness of NDT in enhancing tone and postural control, considering the potential variability in interventions and outcomes, and the methodological rigor of particular studies. The review also intends to provide significant insights for clinicians, researchers, and policymakers by critically analysing and summarizing the present state of research in this domain. This will facilitate evidence-based decision-making in rehabilitation techniques for patients with hemiplegic stroke. Systematic Review Registration number CRD42023476137

Efficacy of Different Types of Foot Orthoses on Postural Control in Subjects With Lateral Ankle Sprain: A Systematic Review

Objectives: Lateral ankle sprain is one of the most common injuries to the musculoskeletal system, especially among active people. This injury causes complex complications, such as recurrent sprain because of reduced postural control. Foot orthoses are among the interventions used to improve postural control in this population. This review aims to investigate foot orthoses to improve postural control among patients with an acute or chronic lateral ankle sprain. Methods: Four electronic databases (Scopus, PubMed, Web of Sciences, and Google scholar) were searched for experimental studies. Articles were selected using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) method. The articles were reviewed for their quality based on the standards for reporting diagnostic accuracy statements and then entered into this review. Results: The search results in all databases provided a total of 48 articles. After reviewing the documents, we excluded 38 articles that did not pass the inclusion criteria, resulting in 10 remaining articles. Data extraction from population, interventions, and outcome measures was done for these 10 articles. Discussion: Foot orthoses are effective in improving the postural control of individuals with an acute or chronic lateral ankle sprain. Considering the existence of mechanical and functional instability, foot orthosis which is made to affect the proprioception and follow the biomechanics of the body seems to be the most effective in this field; however, more studies are required to confirm this

COVID-19 and Postural Control-A Stabilographic Study Using Rambling-Trembling Decomposition Method.

Background and Objectives: Some respiratory viruses demonstrate neurotropic capacities. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has recently taken over the globe, causing coronavirus disease 2019 (COVID-19). The aim of the study was to evaluate the impact of COVID-19 on postural control in subjects who have recently recovered from the infection. Materials and Methods: Thirty-three convalescents who underwent COVID-19 within the preceding 2–4 weeks, and 35 healthy controls were enrolled. The ground reaction forces were registered with the use of a force platform during quiet standing. The analysis of the resultant center of foot pressure (COP) decomposed into rambling (RAMB) and trembling (TREMB) and sample entropy was conducted. Results: Range of TREMB was significantly increased in subjects who experienced anosmia/hyposmia during COVID-19 when the measurement was performed with closed eyes (p = 0.03). In addition, subjects who reported dyspnea during COVID-19 demonstrated significant increase of length and velocity of COP (p < 0.001), RAMB (p < 0.001), and TREMB (p < 0.001), indicating substantial changes in postural control. Conclusions: Subjects who had experienced olfactory dysfunction or respiratory distress during COVID-19 demonstrate symptoms of balance deficits after COVID-19 recovery, and the analysis using rambling-trembling decomposition method might point at less efficient peripheral control. Monitoring for neurological sequelae of COVID-19 should be considered.

Postural Control in Subjects with Incomplete Partition Inner Ear Malformations: A Comparison of Incomplete Partition Types

Introduction: Children with inner ear malformation (IEM) are at risk of vestibular loss as well as hearing loss. Incomplete partition (IP) anomalies constitute about 41% of all IEMs. This study aimed to investigate the postural control in subjects with the same type of IP on both sides and to compare their results with cochlear implant (CI) users without IEM and healthy peers. Methods: The study group consists of 17 subjects with the same IP types on both sides and using auditory implants on at least one side, with the following 3 groups: 6 IP-I subjects (mean age 12.28 ± 6.25), 6 IP-II subjects (mean age 12.90 ± 3.23), and 5 IP-III subjects (mean age 6.98 ± 3.10). Six unilateral CI users (mean age 11.38 ± 3.57) with normal inner ear structures were included in the CI control group, and 6 healthy peers (10.20 ± 4.79) were included in the healthy control group. The postural control was measured using the Bruininks-Oseretsky Test of Motor Proficiency Second Edition (BOT-2) balance subtest. All devices were turned off during the balance test. Results: The BOT-2 balance scale scores were observed to be significantly different between the IP-I and healthy control group (medians of balance scores being 3.00 and 16.00, respectively, p < 0.001) and the IP-III and healthy control group (medians of balance scores being 6.60 and 16.00, respectively, p = 0.04). The IP-II group had better balance scores (median = 8.00) than those of the other IP groups, although there were no significant differences between the IP-II and other groups (p > 0.05). Conclusion: This study demonstrated that subjects with the same IP type on both sides and with early implantation may differ in terms of their postural control abilities depending on their IP type. Subjects with IP should be regularly followed up by the vestibular assessment and supported by their postural control ability by vestibular rehabilitation.

The Impact of Visual Input and Support Area Manipulation on Postural Control in Subjects after Osteoporotic Vertebral Fracture.

Osteoporosis is a prevalent health concern among older adults and is associated with an increased risk of falls that may result in fracture, injury, or even death. Identifying the risk factors for falls and assessing the complexity of postural control within this population is essential for developing effective regimes for fall prevention. The aim of this study was to assess postural control in individuals recovering from osteoporotic vertebral fractures while performing various stability tasks. Seventeen individuals with type II osteoporosis and 17 healthy subjects participated in this study. The study involved maintaining balance while standing barefoot on both feet for 20 s on an Advanced Mechanical Technology Inc. (AMTI) plate, with eyes open, eyes closed, and eyes closed in conjunction with a dual-task. Another three trials lasting 10 s each were undertaken during a single-leg stance under the same conditions. Fall risk was assessed using the Biodex Balance platform. Nonlinear measures were used to assess center of pressure (CoP) dynamics in all trials. Reducing the support area or elimination of the visual control led to increased sample entropy and fractal dimension. Results of the nonlinear measurements indicate that individuals recovering from osteoporotic vertebral fractures are characterized by decreased irregularity, mainly in the medio-lateral direction and reduced complexity.

Evaluating static postural control in subjects with controlled-diabetes mellitus II

Diabetes and neuropathy have been linked to postural instability. Aims: The purpose of this study is to determine how each system involved in balance is affected when challenged in a static standing posture. The goal was to identify postural instability by measuring balance through the amount of sway and weight bearing distribution in non-neuropathic controlled type II diabetics. Methods: Twelve participants (five males and seven females) with controlled type II diabetes mellitus and no history of peripheral neuropathy (Non-PN cDMII) formed the diabetic group, whereas eighteen participants (7 males and 11 females) without type II diabetes formed the control group. The exclusion criteria was applied via a series of screening tests (Berg Balance Scale, Five Times Sit To Stand Test, Functional Reach Test and Monofilament Test). Postural stability and weight distribution during quiet standing were measured using a Tekscan Matscan pressure mat, which measured the amount of sway and weight distribution. Static postural control was evaluated during eight sensory conditions that perturbed or stimulated the visual, proprioceptive, and vestibular systems. Results: Postural control was found to be significantly deficient when the vestibular system was stimulated, whereas the proprioceptive system was perturbed. After the data analysis, there was a significant difference in antero-posterior sway (P=0.05) with the following tasks: eyes open with head movements on an unstable surface, and eyes closed with head movements on a firm surface. Conclusions: The results revealed that the experimental group with type II diabetes had greater postural instability when compared to the control group during tasks with the vestibular system on an unstable surface. This demonstrates that, due to their deficits, individuals with non-PN cDMII are unable to maintain their balance when the vestibular and proprioceptive systems are challenged simultaneously.

The effect of Kinesio Taping on postural control in subjects with non-specific chronic low back pain

PurposeThe aim of this study was to investigate the possible alterations in postural control during upright standing in subjects with non-specific chronic low back pain and the effect of Kinesio taping on the postural control. MethodsTwenty subjects with non-specific chronic low back pain and twenty healthy subjects participated in this study. The center of pressure excursion was evaluated before the intervention for both groups, and immediately after intervention for the low back pain group. Independent sample t-test, Mann-Whitney test and repeated measure ANOVA were used for the statistical analysis of the data. ResultsThere were significant differences in the center of pressure excursion between the low back pain group versus the healthy group. The results of the ANOVA demonstrated a statistically significant difference in the mean COP displacement and velocity before Kinesio Taping, immediately after, and 24 h after in the low back pain group. ConclusionsThere are poor postural control mechanisms in subjects with non-specific chronic low back pain. Kinesio taping seems to change postural control immediately and have lasting effects until the day after.

Effect of elastic bandage on postural control in subjects with chronic ankle instability: a randomised clinical trial

Purpose: To report the immediate and prolonged (one week) effects of elastic bandage (EB) on balance control in subjects with chronic ankle instability.Material and methods: Twenty-eight individuals successfully completed the study protocol, of whom 14 were randomly assigned to the EB group (7 men, 7 women) and 14 were assigned to the non-standardised tape (NST) group (9 men, 5 women). To objectively measure postural sway we used computerised dynamic posturography (CDP) with sensory organisation test (SOT) and unilateral stance (US) test. We analysed the following SOT parameters: the composite SOT score, the composite SOT strategy and the SOT condition 2 and its strategy. In addition, we studied the centre of gravity (COG) sway velocity with open eyes and close eyes during the US test.Results: Repeated measures ANOVA showed a significant effect for time in composite SOT score (F= 34.98; p= <0.01), composite SOT strategy (F= 12.082; p= 0.02), and COG sway with open eyes (F= 3.382; p= 0.039) in EB group and NST group. Therefore, there were improvements in balance control after bandage applications (defined as better scores in SOT parameters and decreased COG sway in US test). However, no differences between groups were observed in the most relevant parameters.Conclusions: This study did not observe differences between EB and NST during the follow-up in the majority of measurements. Several outcome measures for SOT and US tests improved in both groups immediately after bandage applications and after one week of use. EB of the ankle joint has no advantage as compared to the non-standardised tape.Implications for rehabilitationElastic bandage (EB) of the ankle joint has no advantage as compared to the non-standardised tape.The effects of the bandages could be due to a greater subjective sense of security.It is important to be prudent with the use of bandage, since a greater sense of safety could also bring with it a greater risk of injury.The application of the bandage on subjects with chronic ankle instability (CAI) should be prolonged and used alongside other physiotherapy treatments.

The influence of thermoplastic thoraco lumbo sacral orthoses on standing balance in subjects with idiopathic scoliosis.

Idiopathic scoliosis patients have postural equilibrium problems. The objective of this study was to assess postural control in subjects with idiopathic scoliosis following a 4-month intervention in an unbraced position. Quasi-experimental. Eight healthy girls and eight girls with idiopathic scoliosis took part. A Kistler force platform was used with a frequency of 100 Hz for recording data. The center of pressure was recorded in different positions out of brace for scoliosis and healthy subjects. Test conditions were single limb and double limb stance, with eyes open and closed, and foam and rigid surfaces. The data reflected a weak balance of idiopathic scoliosis subjects compared to healthy subjects. After 1 and 4 months of wearing the brace, center of pressure and center of gravity sway increased in the majority of the tests, although there were no significant differences in any of the test conditions (p > 0.05). While the center of pressure sway in medio-lateral direction decreased after 4 months of wearing a brace, in other variables center of pressure and center of gravity sway increased. Idiopathic scoliosis patients have weak balance in comparison to healthy subjects. In addition, following a period of 4 months of wearing a brace, balance parameters in the scoliosis subjects did not improve. The results show that we need more follow-up of orthoses wearing in idiopathic scoliosis subjects and suggest more studies at least 1-year follow-up to identify the efficiency of brace wear on balance. Scoliosis can alter postural stability and balance performance during quiet standing. Spinal deformity can alter a subject's ability to compensate for postural changes and cause gait deviations. This study investigated balance differences between the healthy and idiopathic scoliosis patients and the results of thoraco lumbo sacral orthosis brace wear. It might provide some new insight into the conservative treatment of idiopathic scoliosis patients for clinicians and researchers.

An impaired dynamic postural control in subjects with chronic ankle instability: a difference in strategy

An impaired dynamic postural control in subjects with chronic ankle instability: a difference in strategy

Nociceptive capacity of plantar irritating stimulus reduction influences postural control in children, teenagers, and adults.

Introduction: Sensory information from vestibular, visual, proprioception, and feet contribute on postural control. Plantar afferent contribution comes from the tactile and nociceptive cues of the plantar sole. Nociceptive capacity of plantar irritating stimulus (NCPIS) is one of the foot problems that induce nociception. Objective: Was to determine the postural impact of sensory input flow modifications induced by foam in people with and without nociceptive plantar irritating stimuli in different ages (children, adolescents, and adults). Method: 120 participants with (NP) and X without (Ct) NCPIS in different age group were evaluated (20 subjects in each age group and conditions). Postural balance assessment was performed during two-legged stance test using a force platform. Postural recoding was performed with eyes open in two conditions: on a hard surface and on a foam surface. The postural balance parameter analyzed was center of pressure area and variance of speed. Results: Area and variance of speed in control group increased, whereas decreased in NP subjects. No differences were observed for mean speed. In the Ct group, nociceptor and mechanoreceptor afferent sensations on foam induced postural variation with more oscillations (area and speed). Conclusion: NCPIS influenced postural control, and this foam neutralization of afferent nociception induced a new sensory organization. Foam surface imitated afferent plantar sensory information, induced postural variation as measured by CoP parameters with increasing postural control in subjects without NCIPS and decreasing postural control in subjects with NCPIS.

Nociceptive capacity of plantar irritating stimulus reduction influences postural control in children, teenagers, and adults.

Introduction: Sensory information from vestibular, visual, proprioception, and feet contribute on postural control. Plantar afferentcontribution comes from the tactile and nociceptive cues of the plantar sole. Nociceptive capacity of plantar irritating stimulus (NCPIS) isone of the foot problems that induce nociception. Objective: Was to determine the postural impact of sensory input flow modificationsinduced by foam in people with and without nociceptive plantar irritating stimuli in different ages (children, adolescents, and adults).Method: 120 participants with (NP) and X without (Ct) NCPIS in different age group were evaluated (20 subjects in each age group andconditions). Postural balance assessment was performed during two-legged stance test using a force platform. Postural recoding wasperformed with eyes open in two conditions: on a hard surface and on a foam surface. The postural balance parameter analyzed wascenter of pressure area and variance of speed. Results: Area and variance of speed in control group increased, whereas decreased inNP subjects. No differences were observed for mean speed. In the Ct group, nociceptor and mechanoreceptor afferent sensations onfoam induced postural variation with more oscillations (area and speed). Conclusion: NCPIS influenced postural control, and this foamneutralization of afferent nociception induced a new sensory organization. Foam surface imitated afferent plantar sensory information,induced postural variation as measured by CoP parameters with increasing postural control in subjects without NCIPS and decreasingpostural control in subjects with NCPIS.

Effect of a Home-based Balance Training Protocol on Dynamic Postural Control in Subjects with Chronic Ankle Instability.

The aim of this study was to establish the presence of postural deficits in subjects with chronic ankle instability (CAI) and to assess the effect of an 8-week balance training program on dynamic postural control. A total of 43 subjects with CAI and 31 controls participated in this case-control study. Participants with CAI performed an 8-week home-based balance training, including 3 sessions a week. As main outcome measure, postural control was quantified after a vertical drop by means of the dynamic postural stability index (DPSI). Perceptual outcomes were documented using the FADI, FADI-Sport and VAS scales. At baseline, subjects with CAI displayed higher anterior/posterior and vertical postural instability, a poorer DPSI, and lower subjective stability scores compared to the control group. After balance training, all subjective stability scores improved significantly, although no changes were noted for the stability indices. In conclusion, subjects with CAI have an impaired postural control. As a treatment modality, balance training exhibits the capability of improving the subjective feeling of instability in subjects with CAI. However, there was no effect on dynamic postural control. Further research on the explanatory mechanisms of balance training is warranted, and other training modalities should be considered.

Complexity of human postural control in subjects with unilateral peripheral vestibular hypofunction

Complexity is a new measure for identifying the adaptability of a complex system to meet possible challenges. For a center of pressure (COP) time series, the complexity measure represents the stability of postural control. In this study, multiscale entropy (MSE) was used to evaluate the complexity of COP time series in six test conditions of sensory organization test (SOT). Complexity index (CI) is defined as the summation of entropies with coarse-graining scales 1–20 by MSE. A total of 51 subjects belonging to 3 groups – healthy-young, healthy-elderly and dizzy – were recruited in this study. The COP signals in both anteroposterior (AP) and mediolateral (ML) directions were analyzed respectively. According to our results, the CI of AP-direction COP time series is significantly correlated to the equilibrium score, which represents the stability of postural control in SOT. The AP-direction sway is significant larger than the ML-direction sway, particularly in the test conditions with sway-surface. In additions, the CI of AP-direction COP for the healthy-elderly and dizzy groups are significantly lower than those for the healthy young group in the test conditions 1–4. The CI of ML-direction COP for the healthy-elderly group is significantly lower than those for the healthy-young and dizzy groups under test conditions 3 and 6. These results show that the complexity loss is a common status of AP-direction COP time series for both healthy-elderly and dizzy groups, and the complexity of ML-direction COP time series for subjects with unilateral vestibular dysfunction is higher than that for the healthy-elderly group specifically under test conditions 3 and 6.

The effect of light touch on the amplitude of cutaneous reflexes in the arms during treadmill walking.

Light touch contact of the tip of one finger can influence the postural control of subjects standing or walking on a treadmill. It is suggested that haptic cues from the finger provide an important sensory cue for the control of posture. In the current study, we used intra-limb cutaneous reflexes in the arms to test the hypothesis that transmission in sensory pathways relevant to the light touch contact would be modulated when light touch is used to increase stability during walking in an unstable environment. Subjects walked on a treadmill and received periodic pulls to the waist. Cutaneous reflexes were evoked from stimulation of the median and radial nerves while the subjects either (a) lightly touched or (b) did not touch a stable contact with the tip of their index finger, while the eyes were either (c) open or (d) closed. The results showed that cutaneous reflexes were modulated by both touch and vision. The effect of touch depended on the nerve being stimulated. The provision of touch in the absence of vision resulted in facilitation of median nerve reflexes evoked in the posterior deltoid and the triceps brachii, but resulted in the suppression of radial nerve reflexes. The nerve-specific influence of touch observed in the responses suggests that cutaneous afferent pathways are facilitated in the presence of touch if they transport sensory information from functionally relevant sensory cues.

Immediate effect of nonspecific mandibular mobilization on postural control in subjects with temporomandibular disorder: a single-blind, randomized, controlled clinical trial

Temporomandibular disorder (TMD) is considered multifactorial and is defined as a group of pain conditions characterized by functional stomatognathic system alterations, which may be affected by or related disrupted postural control. Assess the immediate effect of nonspecific mandibular mobilization (NMM) on the postural control of subjects diagnosed or not with TMD. A simple-blind, randomized, controlled clinical trial was performed involving 50 subjects of both genders assigned to two groups: the TMD group and the control group. TMD was diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). A stabilometric assessment was performed by testing subjects in a quiet stance on a dual force platform under two visual conditions (eyes open and eyes closed). The Center of Pressure (CoP)-related variables analyzed were displacement, amplitude, speed of anterior-posterior (AP) and medial-lateral (ML) displacements and CoP sway area. The mean values of each variable were compared, considering the accepted significance value of p<0.05. A significant difference between the pre- and post-NMM means could be observed in subjects diagnosed with TMD under the closed-eyes visual condition. There was a statistically significant difference in the CoP sway area (p<0.03) in the ML displacement COPML (p<0.006) and ML amplitude COPML (p<0.01) and in the variable speed in the AP COPAP (p<0.03) and ML COPML (p<0.03) directions, simultaneously. These results indicate that nonspecific temporomandibular joint mobilization contributes to the immediate improvement of postural control in patients with TMD.

Effect of medication and STN-DBS on postural control in subjects with Parkinson’s disease

Aims and objectivesTo assess the effect of disease severity, dopaminergic medication (med) and STN-DBS on postural stability in Parkinson’s disease (PD). MethodsPostural sway in quiet stance, and the Unified Parkinson’s Disease Rating Scale (motor) (UPDRS III) were evaluated in 129 subjects in the off-med state. A subgroup of 28 subjects was studied on-med and after STN-DBS. Postural sway was measured using center of pressure (CoP) root mean square displacement (RMSCoP) and mean velocity (VCoP) in the anterior-posterior (AP) and medial-lateral (ML) directions. ResultsAll CoP parameters were larger in moderate/advanced subjects vs controls (P < 0.001) and early subjects. Only RMSCoPML was larger in early subjects vs controls (P < 0.05). Med, DBS and DBS + med decreased UPDRS III compared to off-med (P < 0.001). RMSCoPML and VCoPML were larger on-med vs off-med and vs DBS (P < 0.001). Compared to controls and PD subjects with normal CoP sway off-med, med increased all CoP parameters (P < 0.01) but DBS returned VCoPML to normal values. For ‘abnormal’ PD subjects, STN-DBS improved the excessive VCoP in ML compared to off and on-med pre-DBS (P < 0.05). ConclusionsPostural sway in quiet stance increased with disease severity. Only ML CoP displacement was abnormal in early stage PD, and this may be a compensatory mechanism. Medication increased ML postural sway. In ‘normal’ PD subjects, STN-DBS reversed medication induced postural instability. Subjects with abnormal balance in quiet stance did not benefit from medication or DBS, except for improvement in ML CoP velocity from DBS. This may serve to reduce postural instability and falling.

Fractal dimension approach in postural control of subjects with Prader-Willi Syndrome

BackgroundStatic posturography is user-friendly technique suitable for the study of the centre of pressure (CoP) trajectory. However, the utility of static posturography in clinical practice is somehow limited and there is a need for reliable approaches to extract physiologically meaningful information from stabilograms. The aim of this study was to quantify the postural strategy of Prader-Willi patients with the fractal dimension technique in addition to the CoP trajectory analysis in time and frequency domain.Methods11 adult patients affected by Prader-Willi Syndrome (PWS) and 20 age-matched individuals (Control group: CG) were included in this study. Postural acquisitions were conducted by means of a force platform and the participants were required to stand barefoot on the platform with eyes open and heels at standardized distance and position for 30 seconds. Platform data were analysed in time and frequency domain. Fractal Dimension (FD) was also computed.ResultsThe analysis of CoP vs. time showed that in PWS participants all the parameters were statistically different from CG, with greater displacements along both the antero-posterior and medio-lateral direction and longer CoP tracks. As for frequency analysis, our data showed no significant differences between PWS and CG. FD evidenced that PWS individuals were characterized by greater value in comparison with CG.ConclusionsOur data showed that while the analysis in the frequency domain did not seem to explain the postural deficit in PWS, the FD method appears to provide a more informative description of it and to complement and integrate the time domain analysis.

Postural Control in Subjects with Visual Impairment

To investigate the effect of long-term, not experimentally induced visual impairment on balance, and to clarify which means are used to compensate for this sensory deficit. Posturography was examined in 50 visually impaired subjects (11 with congenital blindness and 39 with acquired visual impairment) and 50 healthy controls. Examination was performed in 4 testing conditions: while standing on firm surface or foam pads (which decreases the somatosensory input) and with open or closed eyes (manipulating visual input). Subjects with acquired visual impairment were significantly less stable than controls when tested with open eyes, especially when standing on foam pads, but equal to controls when eyes were closed. Congenitally blind subjects performed equally to normal controls in all test conditions when tested with eyes open, and performed significantly better than controls with eyes closed. In comparison to subjects with acquired visual impairment, the congenitally blind were significantly more stable in all test conditions. Fourier analysis revealed that the visually impaired subjects showed decreased intensity values within the lowest frequency range of 0.1 Hz and below, a range believed to be sensitive to the function of the visual system. We have found that vision impairment influenced postural control, especially if acquired and not congenital. The somatosensory and vestibular systems serve as compensatory mechanisms, which is utilized most effectively by the congenitally blind.

Multiple Sclerosis and Postural Control: The Role of Spasticity

Sosnoff JJ, Shin S, Motl RW. Multiple sclerosis and postural control: the role of spasticity. Objectives To examine the association between spasticity and postural control in subjects with multiple sclerosis (MS). Design Cross-sectional. Setting Motor control laboratory. Participants Subjects with MS (n=16, 2 male) and age and sex-matched subjects (n=16) participated in the investigation. All subjects with MS had Expanded Disability Status Scale scores between 0 and 4.5 and modified Ashworth scale scores between 1 and 3. Interventions Not applicable. Main Outcome Measures Postural control was measured with a force platform that quantifies ground reaction forces and moments in mediolateral and anteroposterior directions. Postural control was indexed with anterior-posterior sway range, medial-lateral sway range, 95% elliptical area of the deviations of center of pressure (COP), velocity of COP sway, and the frequency at which 95% of spectral profile was contained. Participants with MS further underwent assessment of the soleus Hoffman reflex (H-reflex) as an index of spasticity. Results Cluster analysis on H-reflex data identified groups of MS participants with high spasticity (n=7) and low spasticity (n=9). There were no differences in age, duration of MS, and disease severity between MS groups. There were no differences in anterior-posterior sway range between any of the groups. The high spasticity group had greater COP area, velocity, and mediolateral sway compared with the low spasticity and control group, and the low spasticity group had postural control values between the high spasticity and control groups. Conclusions The pattern of results suggests that spasticity contributes to postural deficits observed in MS.