Voluntary sway and rapid orthogonal transitions of voluntary sway in young adults,and low and high fall-risk older adults

Background

Falls amongst older people have been linked to reduced postural stability and slowed movement responses. The objective of this study was to examine differences in postural stability and the speed of response between young adults, low fall-risk older adults, and high fall-risk older adults during voluntary postural sway movements.

Methods

Twenty-five young adults (25 ± 4 years), and 32 low fall-risk (74 ± 5 years), and 16 high fall-risk (79 ± 7 years) older adults performed voluntary sway and rapid orthogonal transitions of voluntary sway between the anterior–posterior and medial–lateral directions. Measures included reaction and movement time and the amplitudes of the centre of pressure, centre of mass, and the separation distance between the centre of pressure and centre of mass.

Findings

Both fall-risk groups compared to the young had slower reaction and movement time, greater centre of pressure and/or centre of mass amplitude in the orthogonal (non-target) direction during voluntary sway, and reduced anterior–posterior and medial–lateral separation between the centre of pressure and centre of mass during voluntary sway and orthogonal transitions. High compared to low fall-risk individuals had slower reaction and movement time, increased non-target centre of mass amplitude during voluntary sway, and reduced medial–lateral centre of pressure and centre of mass separation during voluntary sway and orthogonal transitions.

Interpretation

Age-related deterioration of postural control resulted in slower reactive responses and reduced control of the direction of body movement during voluntary sway and orthogonal transitions. Slower postural reaction and movement time and reduced medial–lateral control of the centre of mass during voluntary sway movements are associated with increased fall-risk in community-living older people.     

The effect of post-stroke lower-limb spasticity on the control of standing balance: Inter-limb spatial and temporal synchronisation of centres of pressure

Background

Challenges in stability control are common post-stroke. Although lower-limb spasticity is a common sensorimotor consequence post-stroke, its potential to further complicate stability control among stroke-survivors remains largely unknown. Advancing such understanding can help inform strategies to reduce fall risk and increase independence among these individuals. The purpose of this study was to characterise the extent of limb-specific dyscontrol among individuals with spasticity.

Methods

A retrospective analysis of 131 patients assessed for spasticity was performed. Patients selected for inclusion were categorised into two groups, with (n = 19) or without (n = 63) unilateral lower-limb spasticity. Two force platforms were used to determine the individual-limb and net centres of pressure in both anteroposterior and mediolateral directions during 30 s of quiet standing. Limb-specific dyscontrol was assessed by calculating weight-bearing symmetry ratios, cross-correlation coefficients at zero phase-shift (temporal synchrony) and ratios of individual-limb root-mean-square displacements (spatial symmetry). Total body postural control was assessed by examining the root-mean-square of the net centre of pressure displacement.

Findings

The group with spasticity bore less weight on the affected limb and exhibited reduced temporal synchrony of centre of pressure displacements. There were no differences in inter-limb root-mean-square centre of pressure ratios or in the root-mean-square of the net centre of pressure displacement.

Interpretation

Individuals with lower-limb spasticity may have additional challenges with stability control, specifically linked to the ability to modify the location of the centre of pressure beneath the affected limb, in a time-sensitive manner so as to contribute beneficially to the control of whole body stability.     

Experimental calf muscle pain attenuates the postural stability during quiet stance and perturbation

Background

The purpose of this study was to evaluate how acute pain changes the postural control and stability during quiet standing and after unexpected perturbations.

Methods

Nine subjects stood as quiet as possible on a movable force platform that recorded the centre of pressure position and provided unexpected floor perturbations, before, during and after experimental calf muscle pain. Bilateral surface electromyography from the tibialis anterior and medial gastrocnemius muscles was recorded. The foot pressure distributions were measured using pressure insoles. Intramuscular injections of hypertonic saline were administrated (right leg) to induce acute pain in the tibialis anterior and/or medial gastrocnemius muscles, and an isotonic injection was used as control.

Findings

Simultaneous pain in tibialis anterior and medial gastrocnemius altered the postural control. During quiet standing: higher medial-lateral centre of pressure speed and increased total sway displacement (P < 0.05), weight moved to the non-painful side, (P < 0.05) and plantar centre of pressure of the left foot was shifted towards the heel’s direction (P < 0.05). During forward perturbation: higher mean displacement in the medial-lateral direction (P < 0.05). After the perturbation: larger sway area (P < 0.05). Pain only in the medial gastrocnemius muscle increased medial-lateral centre of pressure speed (P < 0.05) during the quiet standing. Pain only in the tibialis anterior muscle increased peak pressure on the contralateral foot (P < 0.05).

Interpretation

These findings suggest that large acute painful areas on the calf muscles impair the postural control and potentially increase the risk factors for falls. Further strategies aiming to reduce pain in patients may lead to improvement in balance.     

Peripheral neuropathy may not be the only fundamental reason explaining increased sway in diabetic individuals

Background

Individuals with diabetic neuropathy sway more than control individuals while standing. This review specifically evaluated whether peripheral sensory neuropathy can be the only fundamental reason accounting for significant increased sway within this population.

Methods

Twenty-six experimental articles were selected using MEDLINE and reference lists of relevant articles. The articles chosen investigated kinematic data of postural behaviour in controls and individuals with diabetic neuropathy during stance. Results of literature were compared with four expectations related to the peripheral sensory neuropathy fundamental hypothesis.

Findings

Consistent with the peripheral sensory neuropathy hypothesis, the literature showed that individuals with diabetic neuropathy sway more than controls in quiet stance and even more so if their visual or vestibular systems were perturbed. Inconsistent with the hypothesis, individuals with diabetic neuropathy are more destabilised than controls in conditions altering sensation of the feet and legs (standing on a sway-referenced surface).

Interpretation

The review showed that the peripheral sensory neuropathy hypothesis may not be the only fundamental cause accounting for significant increased postural sway in individuals with diabetic neuropathy. Visual impairments and changes in postural coordination may explain the divergence between expectations and results. In order to develop interventions aimed at improving postural control in individuals with diabetic neuropathy, scientific exploration of these new expectations should be detailed. Also at the practical level, the review discussed which additional sensory information – at the level of the hands and feet – may be more beneficial in individuals with diabetic neuropathy to reduce their postural sway.     

Postural Response Latencies Are Related to Balance Control During Standing and Walking in Patients With Multiple Sclerosis

Objective

To understand and examine the relation between postural response latencies obtained during postural perturbations and representative measures of balance during standing (sway variables) and walking (trunk motion).

Design

Cross-sectional.

Setting

University medical center.

Participants

Persons with multiple sclerosis (MS) (n=40) were compared with similar aged control subjects (n=20). There were 20 subjects with MS in the normal walking velocity group and 20 subjects with MS who had slow walking velocity based on a timed 25-foot walk (T25FW) of <5 seconds.

Interventions

None.

Main Outcome Measures

Postural response latency, sway variables, trunk motion variables.

Results

We found that subjects with MS with both slow or normal walking velocities had significantly longer postural response latencies than the healthy control group. Postural response latency was not correlated with the T25FW. Postural response latency was significantly correlated with center of pressure sway variables during quiet standing (root mean square: ρ=.334, P=.04; range: ρ=.385, P=.017; mean velocity: ρ=.337, P=.038; total sway area: ρ=.393, P=.015). Postural response latency was also significantly correlated with motion of the trunk during walking (sagittal plane range of motion: ρ=.316, P=.05; SD of transverse plane range of motion: ρ=−.43, P=.006).

Conclusions

These findings clearly indicate that slow postural responses to external perturbations in patients with MS contribute to disturbances in balance control during both standing and walking.     

Standing Data Disproves Biomechanical Mechanism for Balance-Based Torso-Weighting

Objective

To test a proposed mechanism for the effect of balance-based torso-weighting (BBTW) in people with multiple sclerosis (MS) and healthy controls. The mechanism to be tested is that application of light weights to the trunk may result in a biomechanical shift of postural sway in the direction of weighting, mechanically facilitating maintenance of the center of mass over the base of support.

Design

Nonrandomized controlled trial.

Setting

Motion analysis laboratory.

Participants

Participants with MS (n=20; average Expanded Disability Status Scale score, 4.1) and controls matched for sex, age, height, and weight (n=18).

Intervention

Light weights strategically placed according to the BBTW protocol were applied to all participants after at least 3 walking trials and 10 seconds of quiet standing with feet together and eyes open and then eyes closed. Measures were repeated after weighting.

Main Outcome Measure

Forceplate center of pressure (COP) changes >1 standard error of measurement.

Results

With BBTW, people with MS had larger maximum changes in COP than healthy controls in the left-right direction but not in the anterior-posterior direction. COP changes >1 standard error of measurement occurred in the same direction of weighting 20% of the time (95% confidence interval, 5–34), ranging from 10% to 28% across conditions and directions of postural sway. Direction of greatest weight placement did not match the direction of change in the average COP in most participants with MS or the healthy controls in eyes open or eyes closed conditions (P<.001).

Conclusions

If BBTW worked via a biomechanical shift of the center of mass, COP changes should match the direction of greatest weighting with BBTW. Our data allowed us to reject this hypothesis. Future research may explore alternative mechanisms of action underlying this intervention.     

Effect of tibial re-alignment surgery on single leg standing balance in patients with knee osteoarthritis

Background

Standing balance is impaired in individuals with knee osteoarthritis and is associated with disease severity. The effects of surgical interventions on standing balance have received little attention. The purpose of the present study was to examine measures of balance during tests of single-limb standing before and after medial opening wedge high tibial osteotomy – a lower limb re-alignment procedure for those with varus alignment and knee osteoarthritis.

Methods

Standing balance was assessed in 49 individuals prior to and 12 months following medial opening wedge high tibial osteotomy. Participants performed three trials of single-limb balance lasting 10 s each while standing on a force platform. Anteroposterior and mediolateral coordinates of the centre of pressure were obtained from the force platform and used to calculate the total centre of pressure path length as well as the range and variability (standard deviation) of the anteroposterior and mediolateral coordinates.

Findings

Though all centre of pressure measures were lower following high tibial osteotomy, none reached statistical significance (P > 0.05) and effect sizes were small (d < 0.34). The largest mean improvement was 7.6% (95% confidence interval: −0.7–15.8%).

Interpretation

Results indicate that standing balance in individuals with knee osteoarthritis is not significantly different following high tibial osteotomy surgery. Standing balance in this patient population is a complex process not entirely dictated by disease symptoms or structural factors such as alignment.     

Recovery Process of Standing Postural Control in Hemiplegia after Stroke

[Purpose] The aim of this study was to investigate the recovery process of standing postural control in hemiplegia after stroke. [Subjects and Methods] Thirty-four inpatients with hemiparesis after first-onset stroke were included in this study. We measured the center of pressure fluctuations during quiet standing using a force platform at 2, 4, and 6 weeks after admission. We assessed weight-bearing asymmetry, and velocity and amplitude of body sway. [Results] Weight-bearing asymmetry diminished in the first 2 weeks of observation. Velocity of body sway also decreased significantly in the first 2 weeks, though its amplitude only decreased significantly after 4 weeks of observation. [Conclusion] Amplitude of body sway requires a longer time for significant improvement than weight-bearing asymmetry and velocity of body sway. Although the loading function of the paretic lower limb improved at an early stage, attainment of optimum postural control, including management of the affected paretic lower limb, requires much time.Key words: Postural balance, Hemiplegia, Recovery of function     

Randomized Comparison Trial of Balance Training by Using Exergaming and Conventional Weight-Shift Therapy in Patients With Chronic Stroke

Objective

To compare the effects of exergaming with conventional weight-shift training on balance function in patients with chronic stroke.

Design

Single-blind randomized controlled trial.

Setting

Medical center.

Participants

Patients (N=30) with chronic stroke and balance deficits.

Interventions

Twelve weeks of Wii Fit training or conventional weight-shift training.

Main Outcome Measures

Static balance was assessed using posturography. We recorded the stability index and percentage of weight bearing on the affected leg in 8 positions. We also used the timed Up and Go and forward reach tests for dynamic balance evaluation, Falls Efficacy Scale-International for fear of falling assessment, and Physical Activity Enjoyment Scale for estimating the enjoyment of training.

Results

The exergaming group showed more improvement in stability index than the control group in head straight with eyes open while standing on a foam surface, eyes closed while standing on a solid surface with head turned 30° to the left, and eyes closed while standing on a solid surface with head turned up positions (time-group interaction P=.02, .04, and .03, respectively); however, the effects were not maintained. At 3-month follow-up, the control group showed more improvement in weight-bearing symmetry in the head straight with eyes open while standing on a solid surface position than the exergaming group (time-group interaction P=.03). Both groups showed improvement in the timed Up and Go test, forward reach test, and fear of falling. The improvement in fear of falling was not maintained. The exergaming group enjoyed training more than the control group (P=.03).

Conclusions

Exergaming is enjoyable and effective for patients with chronic stroke.     

Recruitment of the plantar intrinsic foot muscles with increasing postural demand

Background

The aim of this study was to determine the difference in activation patterns of the plantar intrinsic foot muscles during two quiet standing tasks with increasing postural difficulty. We hypothesised that activation of these muscles would increase with increasing postural demand and be correlated with postural sway.

Methods

Intra-muscular electromyographic (EMG) activity was recorded from abductor hallucis, flexor digitorum brevis and quadratus plantae in 10 healthy participants while performing two balance tasks of graded difficulty (double leg stance and single leg stance). These two standing postures were used to appraise any relationship between postural sway and intrinsic foot muscle activity.

Findings

Single leg stance compared to double leg stance resulted in greater mean centre of pressure speed (0.24 m s^− 1 versus 0.06 m s^− 1, respectively, P ≤ 0.05) and greater mean EMG amplitude for abductor hallucis (P ≥ 0.001, ES = 0.83), flexor digitorum brevis (P ≤ 0.001, ES = 0.79) and quadratus plantae (P ≤ 0.05, ES = 0.4). EMG amplitude waveforms for all muscles were moderate to strongly correlated to centre of pressure (CoP) medio-lateral waveforms (all r ≥ 0.4), with muscle activity amplitude increasing with medial deviations of the CoP. Intra-muscular EMG waveforms were all strongly correlated with each other (all r ≥ 0.85).

Interpretations

Activation of the plantar intrinsic foot muscles increases with increasing postural demand. These muscles are clearly important in postural control and are recruited in a highly co-ordinated manner to stabilise the foot and maintain balance in the medio-lateral direction, particularly during single leg stance.     

The evaluation of walking footwear on postural stability in healthy older adults: an exploratory study

Background

It has been proposed that walking footwear enhances postural stability in healthy older adults. The aim of the study is to evaluate differences between two different types of athletic footwear in relation to postural stability in healthy older adults.

Methods

A convenience sample of 21 healthy older adults with mean (SD) of 74 (5) years was recruited. Postural stability was measured using a force plate for anterior–posterior (AP) and mediolateral (ML) centre of pressure excursion for 30 s with eyes closed and open using two different types of athletic footwear. Each participant performed three repetitions of bipedal standing. Two-way analysis of variance tested the interaction effect of the footwear and eye conditions on anterior–posterior (AP) and mediolateral (ML) postural sway.

Findings

There was no significant footwear–eye condition interaction for anterior-posterior(AP) postural sway but there were significant main effects for both the footwear and eye conditions (P < 0.05). The significant main effects for the footwear conditions occurred between barefeet and the two shoe conditions, but not between the two shoe conditions. For mediolateral (ML) postural sway there was no significant interaction effect and no main effects for the footwear and eye conditions (P > 0.05).

Interpretation

The results suggest that older adults demonstrate an initial destabilisation effect which could possibly be of benefit to functional ability but the long-term effects of ability of athletic footwear to enhance postural stability requires further investigation.     

Effects of toning shoes on lower extremity gait biomechanics

Background

The Reebok Easy Tone shoe concept was developed to induce instability during walking and standing with the primary purpose of increasing muscle activity of the lower extremity muscles. To the authors' knowledge, no scientific work has been published, which analyzed neuromuscular and biomechanical effects when walking and standing with Reebok Easy Tone shoes. Therefore, the purpose of this study was to investigate the immediate effects of using such footwear on gait biomechanics for the lower extremity in healthy participants.

Methods

Five healthy female and seven healthy male participants volunteered to participate in this study. During quiet standing, centre of pressure excursion was determined. 3D gait analyses were performed with simultaneously collecting surface electromyography data of the leg muscles when walking with regular shoes and with Reebok Easy Tone shoes.

Findings

Centre of pressure excursion did not show any significant differences. For walking, only slight differences were found in kinematics and kinetics. When walking with Reebok Easy Tone shoes, the first vertical peak of the ground reaction force was significantly increased as well as the maximum plantarflexion moment during initial contact and loading response. Mean muscle activation for vastus medialis and lateralis showed an increase during the second half of stance, but failed to reach significance.

Interpretation

Results of this study did not show any increased instability during standing and only a slight increase of vastii activity during stance. Thus, the marketing claims that “toning shoes” could serve as a sort of training devices for lower limb muscles during walking, cannot be supported.     

The influence of an auditory-memory attention-demanding task on postural control in blind persons

Background

In order to evaluate the effect of an auditory–memory attention-demanding task on balance control, nine blind adults were compared to nine age–gender-matched sighted controls. This issue is particularly relevant for the blind population in which functional assessment of postural control has to be revealed through “real life” motor and cognitive function. The study aimed to explore whether an auditory–memory attention-demanding cognitive task would influence postural control in blind persons and compare this with blindfolded sighted persons.

Methods

Subjects were instructed to minimize body sway during narrow base upright standing on a single force platform under two conditions: 1) standing still (single task); 2) as in 1) while performing an auditory–memory attention-demanding cognitive task (dual task). Subjects in both groups were required to stand blindfolded with their eyes closed. Center of Pressure displacement data were collected and analyzed using summary statistics and stabilogram-diffusion analysis.

Findings

Blind and sighted subjects had similar postural sway in eyes closed condition. However, for dual compared to single task, sighted subjects show significant decrease in postural sway while blind subjects did not.

Interpretation

The auditory–memory attention-demanding cognitive task had no interference effect on balance control on blind subjects. It seems that sighted individuals used auditory cues to compensate for momentary loss of vision, whereas blind subjects did not. This may suggest that blind and sighted people use different sensorimotor strategies to achieve stability.     

Between-Limb Kinematic Asymmetry During Gait in Unilateral and Bilateral Mild to Moderate Knee Osteoarthritis

Objective

To compare lower-limb kinematic asymmetries during gait in individuals with unilateral and bilateral symptomatic osteoarthritis and controls.

Design

Cross-sectional.

Setting

Laboratory.

Participants

Participants (N=54) had symptomatic unilateral (n=18) or bilateral (n=18) knee osteoarthritis. Healthy controls were sex- and age-matched and similar in height and weight to osteoarthritis groups (n=18).

Intervention

Three-dimensional motion analysis was conducted while participants walked on a treadmill at 1.1m/s.

Main Outcome Measures

Maximum joint angles and velocities of the knee and hip during stance, knee flexion, knee adduction, and hip adduction at initial contact, pelvic drop, stride length, and average toe out.

Results

There was a significant limb effect for knee flexion at initial contact (P=.01). The bilateral osteoarthritis group demonstrated the largest between-limb asymmetry (2.83°; 95% confidence interval, .88–4.78; effect size [ES]=.67). The bilateral osteoarthritis group also displayed tendencies toward between-limb asymmetry in hip adduction at initial contact and peak knee adduction during stance; ESs were small (ES=.33 and .48). Lower-limb kinematics was symmetrical in the control and unilateral knee osteoarthritis groups.

Conclusions

Between-limb asymmetries are present even at mild to moderate stages of knee osteoarthritis. During this stage, between-limb asymmetry appears to be more prevalent in patients with bilateral symptomatic disease, suggesting that patients with unilateral disease maintain kinematic symmetry for longer in the knee osteoarthritis process. Further, early treatment strategies should target the restoration of gait symmetry and involve kinematics changes in both lower limbs. Future research is needed to determine the efficacy of such strategies with respect to kinematic asymmetry, pain, and disease progression.     

Effects of experimentally induced pain of the plantar soles on centre of foot pressure displacements during unperturbed upright stance

Background

Although impaired balance control during quiet standing has repeatedly been reported in persons suffering from foot pain, a better understanding of the effect of foot pain on unperturbed postural control is needed in order to propose and implement efficient podiatry treatments/interventions into clinical practice. The present study was hence designed to address this issue.

Methods

Ten young healthy adults were asked to stand upright, eyes closed, as still as possible in three experimental conditions: (1) a no-pain condition, (2) a condition when a painful stimulation was applied to the plantar surfaces of both feet, and (3) a condition in which painful stimulation was applied to another body part, the palms of both hands. The centre of foot pressure displacements was recorded using a force platform.

Findings

For the same perceived intensity of the pain, the severe painful stimulation applied to the plantar surfaces of both feet increased centre of foot pressure displacements, whereas the severe painful stimulation applied to the palms of both hands did not.

Interpretation

These results reveal the deleterious effect of experimentally induced pain on the plantar soles on unperturbed bipedal postural control. At this point, it is conceivable that these effects of experimental pain could generalise to the effects of pain in patients. Accordingly, the present findings suggest that clinical and/or instrumental interventions designed to mitigate pain in patients suffering from plantar foot pain (e.g., podiatry treatments/interventions) could improve postural control.     

The influence of thoracolumbosacral orthoses on standing balance in patients with adolescent idiopathic scoliosis: a pilot study

Background and aim: The objective of this study was to assess the effect of thoracolumbosacral orthoses (TLSOs) on antero-posterior (AP) sway, medio-lateral (ML) sway and displacement of the center of pressure (COP) during a longitudinal study in patients with adolescent idiopathic scoliosis (AIS). Methods: Eight females aged between 12 and 14.5 years participated in this study. Evaluations were performed prior to the TLSO intervention as a baseline condition, after 1 month, and after 4 months of orthosis use by assessing balance when standing statically on different surfaces. Results: When standing on both lower limbs on a solid surface there were significant differences in ML sway with the eyes both open and closed, and also in A/P sway but only when standing on a solid surface with the eyes open and also when standing on a foam surface with the eyes closed with TLSO use. When standing on the dominant leg, ML sway significantly improved, but AP sway only improved with a foam base surface with the eyes open. Conclusion: This study demonstrated positive effects of wearing a TLSO in improving quiet standing balance and standing on the dominant lower extremity in subjects with AIS after 4 months of brace use.

• Implications for Rehabilitation

• Due to a change in body shape such as that caused by scoliosis, human posture changes and spinal deformities affect the position of the center of support, and thus balance ability may change.

• AIS subjects have poor standing stability compared to a healthy matched control group.

• Brace wearing had positive effect in improving quiet standing balance and standing on the dominant lower extremity in subjects with AIS undergoing brace treatment after 4 months of TLSO use.

     

Postural control is altered in patients with ankylosing spondylitis

Background

Ankylosing spondylitis is a chronic inflammatory disorder that can lead to increased axial and peripheral joint stiffness, impairing joint mobility. Impaired axial mobility due to vertebral ankylosis may result in changes in standing postural control. Little research has addressed changes in standing postural control in the ankylosing spondylitis population, nor how these issues might affect clinical understanding and treatment.

Methods

Sixteen ankylosing spondylitis patients, and 17 healthy controls participated. Each individual completed two 120-second quiet standing trials with eyes open and eyes closed, while standing upon two force platforms. Net center of pressure displacement and mean power frequency in the frontal and sagittal planes were calculated. A Spearman's rank correlation analysis was performed between net center of pressure measures and several clinical measures of disease activity.

Findings

Frontal plane net center of pressure displacement and frequency content, and sagittal plane net center of pressure displacement were significantly greater within the ankylosing spondylitis patient group. Ankylosing spondylitis patients demonstrated a significant increase in frontal plane net center of pressure displacement in the eyes-closed condition. Net center of pressure displacement and frequency were significantly correlated to the Bath Ankylosing Spondylitis Functional Index, and individual components of the Bath Ankylosing Spondylitis Metrology Index.

Interpretation

Quiet standing postural control was altered particularly so in the frontal plane in patients with ankylosing spondylitis, which may be associated with increased fall risk. Posturographic measures of postural control may serve as valuable clinical tools for the monitoring of disease progression and disease status in ankylosing spondylitis.     

Apathy and Health-Related Quality of Life in Stroke

Objective

To examine differences in health-related quality of life (HRQOL) in stroke survivors with and without apathy.

Design

Cross-sectional study.

Setting

Acute stroke unit in a regional hospital.

Participants

Stroke survivors (N=391) recruited from the acute stroke unit.

Interventions

Not applicable.

Main Outcome Measures

Participants were divided into apathy and nonapathy groups. Participants who scored ≥36 on the Apathy Evaluation Scale, clinician's version formed the apathy group. HRQOL was measured with the 2 component scores, mental component summary (MCS) and physical component summary (PCS), of the Medical Outcomes Study 12-Item Short-Form Health Survey (SF-12). Demographic and clinical information were obtained with the National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), Mini-Mental State Examination (MMSE), and Geriatric Depression Scale (GDS).

Results

Thirty-six (9%) participants had apathy. The apathy group had significantly lower MCS and PCS scores. After adjusting for sex, education, diabetes mellitus, and NIHSS, MMSE, GDS, and BI scores, the MCS score in the apathy group remained significantly lower.

Conclusions

Apathy has a significant negative effect on HRQOL in stroke survivors, particularly on their mental health. Interventions for apathy could improve the HRQOL of stroke survivors.     

The effects of sandals on postural stability in patients with rheumatoid arthritis: An exploratory study

Background

Rheumatoid arthritis results in postural instability, pain and functional limitations. As rheumatoid arthritis progresses, localised forefoot deformities such as hallux valgus and clawing of the lesser toes occur, leading to a high proportion of people with rheumatoid arthritis wearing sandals. Sandals may affect postural stability due to poor motion control. The aim was to assess two different open-toe sandals on postural stability in people with rheumatoid arthritis.

Methods

Twenty women with rheumatoid arthritis were assessed in quiet standing under four conditions: (1) open-back sandal; (2) closed-back sandal; (3) own footwear and (4) bare feet. Postural stability was assessed as postural sway in the anterior-posterior and medial-lateral directions, with eyes open and eyes closed, using a pressure mat. Repeated measures analysis of variance tested the interaction effect of the footwear and eye conditions on anterior-posterior and medial-lateral sway.

Findings

In eyes-open, there was no significant difference in anterior–posterior sway (P = .169) and medial-lateral sway (P = .325) for footwear conditions. In eyes-closed testing, compared with barefoot conditions, increased anterior–posterior sway was observed with participants' footwear (P < .0001), the open-back sandal (P = .005), and the closed-back sandal (P = .017). With eyes closed, increased anterior–posterior sway was also observed with the participants' footwear compared with the closed-back sandal (P = .041). Increased medial-lateral sway was observed with the closed-back sandal compared with bare feet (P = .014).

Interpretation

Sandals may be detrimental to older women with well-established rheumatoid arthritis when eyes are closed. Further investigation is needed to evaluate the effect of sandals on dynamic tasks.     

Ankle-foot orthoses in stroke: Effects on functional balance,weight-bearing asymmetry and the contribution of each lower limb to balance control

Background

Ankle-foot orthoses are often provided to improve walking in stroke patients, although the evidence of effects on walking and balance control is still inconsistent. This could be caused by a lack of insight into the influence of orthoses on the underlying impairments. These impairments can be assessed with dual plate posturography to determine the relative contribution of each lower limb to balance control and weight-bearing. This study examined the effects of ankle-foot orthoses on functional balance, static and dynamic weight-bearing asymmetry and dynamic balance control of the paretic and non-paretic lower limbs.

Methods

Twenty stroke subjects (time since stroke 5–127 months) completed the study. Subjects were assessed with and without ankle-foot orthosis. Functional balance was assessed using the Berg Balance Scale, Timed Up & Go test, Timed Balance Test, 10-m walking test and Functional Ambulation Categories. Weight-bearing asymmetry and dynamic balance control were assessed with force plates on a movable platform.

Findings

No significant effects of ankle-foot orthoses were found for weight-bearing asymmetry and dynamic balance control, but significant differences in favour of ankle-foot orthosis use were found for most functional tests.

Interpretation

Although ankle-foot orthoses had no effect on weight-bearing asymmetry or dynamic balance contribution of the paretic lower limb, functional tests were performed significantly better with orthoses. Apparently, improvements at functional level cannot be readily attributed to a greater contribution of the paretic lower limb to weight-bearing or balance control. This finding suggests that ankle-foot orthoses influence compensatory mechanisms.