Attentional control of postural stability in institutionalised elderly people: effects of a physical exercise program]

OBJECTIVE: We aimed to examine the effect of a physical activity program on postural sway and on the attentional control of postural abilities in elderly frail adults. METHOD: Twelve older adults (age 81.4+/-9 years) institutionalised in a geriatric care institution participated in the physical activity program posture-balance-mobility (PBM) twice a week (1 hour per session) for 12 weeks. We analysed stabilometric data for surface and length of the center of pressure (COP) sway, with eyes open and eyes closed, under single-task and dual-task conditions on a firm floor before and after the training program. During the static postural evaluation and under the dual-task condition, subjects performed an attention-demanding cognitive task, the random number generation task. RESULTS: Only the length of COP sway was more important under the dual-task condition than under the single-task condition (p=0.05). At baseline, cognitive performance was significantly weaker under the dual-task condition (standing) than under the single-task condition (seated), with eyes closed but not eyes open (p<0.05). However, after the training program, the performance of the cognitive task did not significantly differ between the dual-task condition with eyes closed and the single-task condition with eyes closed. CONCLUSION: The training program allowed elderly subjects to improve their ability to perform an attention-demanding cognitive task while standing still, in particular with their eyes closed. Although balance seemed to be less stable under the dual-task condition than under the single-task condition, these results could be interpreted as an improvement of the attentional control of postural stability.     

Reliability of postural control during double-leg standing in subjects with nonspecific chronic low back pain: Dual-task paradigm and manipulated visual and somatosensory inputs

BackgroundThe aim of this study is to evaluate the test-retest reliability of the Center of Pressure (COP) parameters in quiet double-leg standing in subjects with Non-Specific Chronic Low Back Pain (NSCLBP) during dual taking associated with manipulated visual and somatosensory inputs.Materials and methodsIn this observational cross-sectional study, the static balance of thirty NSCLBP patients were assessed during a double-leg stance by using the force platform. Subjects were accosted by manipulated somatosensory and visual inputs during dual taking in eight different conditions (with and without vibration, eyes-open and eyes-closed, and with and without auditory Stroop test). The COP parameters were recorded as follows: range sideways and range fore-aft as well as mean velocity and area variables. The cognitive task parameters included the reaction time and error ratio. The intra-class correlation coefficient (ICC) was computed to assess the intersession reliability of COP parameters.Resultsin intersession, range sideways, range fore-aft, and mean velocity measures possessed moderate to high ICC, but area owned high ICC only in one condition (double-leg stance, eyes-close, with vibration, and with auditory Stroop test). Notably, other conditions had low ICC, and moderate to high and low to very high ICC were reported for reaction time and error ratio.ConclusionAmong the parameters studied in the present study, the mean velocity measure seems to be the most reliable variable of postural control in the subjects with NSLBP especially in more challenging conditions, i.e., quiet double-leg standing with eyes closed and adding vibratory inputs during dual-tasking.     

Incidence and outcome of orthostatic hypotension in stroke patients undergoing rehabilitation

OBJECTIVES: To document the incidence and outcome of orthostatic hypotension in stroke patients undergoing rehabilitation and to determine clinical variables associated with it. DESIGN: Cohort study. SETTING: Inpatient setting of a tertiary rehabilitation center. PARTICIPANTS: Seventy-one stroke patients (41 men, 30 women; mean age, 58.4+/-10.7 y) with a first clinical stroke, admitted for rehabilitation within 4 weeks of the stroke. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patients' blood pressure was measured in supine position and on tilting at 90 degrees within 3 days of admission. Orthostatic hypotension was defined as a drop in systolic blood pressure (SBP) of 20 mmHg or more. RESULTS: Orthostatic hypotension was present in 37 (52.1%) patients, of whom 13 had severe hypotension (standing SBP, < or =100 mmHg). Twelve (32.4%) patients with orthostatic hypotension were positive for hypotensive symptoms and signs, with 2 patients experiencing near syncope. Orthostatic hypotension was significantly associated with older patients, a lower admission functional status (as measured on the Modified Barthel Index), and more severe hemiparesis. It was, however, not related with the site of stroke or the use of antihypertensives. On discharge, orthostatic hypotension had resolved in 23 patients. The presence of orthostatic hypotension did not influence functional outcome or the length of stay in rehabilitation. CONCLUSION: Orthostatic hypotension was common in stroke patients undergoing inpatient rehabilitation. It should be suspected in older patients who have more severe hemiparesis and a lower functional status.     

Reliability of traditional and fractal dimension measures of quiet stance center of pressure in young, healthy people

OBJECTIVES: To assess reliability of traditional and fractal dimension measures of quiet stance center of pressure (COP). DESIGN: Cross-sectional study. SETTING: University laboratory. PARTICIPANTS: Thirty young healthy men (n=20) and women (n=10) (mean age, 23 y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: COP was recorded for 3 trials across 4 conditions: eyes open and eyes closed standing on firm and foam surfaces. Traditional COP variables--peak sway velocity and range of sway, both in the anteroposterior (AP) and mediolateral (ML) directions, and total excursion area, and fractal dimension of the COP in the AP and ML directions--were calculated. Reliability statistics were calculated. RESULTS: Range of sway (AP) was the most reliable traditional variable (intraclass correlation coefficient model 2,1 [ICC(2,1)] range -.28 to .72.). Peak sway velocity (AP) had poorest reliability (ICC(2,1) range, .05-.29). Only 1 of the traditional variables had excellent reliability; total excursion area (firm, eyes closed) (ICC(2,1)=.95). All bar 1 fractal dimension measures had excellent ICCs. Relative technical error of measurement ranged from 4% to 7% for the fractal dimension measures. Coefficients of variation were also very good, ranging from 1.8% to 6.7%. CONCLUSIONS: Fractal dimension measures were more reliable than traditional measures of COP. Although traditional measures are used extensively to assess COP, their reliability is questionable. Fractal dimension measures show promise to reliably quantify COP and warrant further investigation.     

Effects of an ankle-foot orthosis on balance performance in patients with hemiparesis of different durations

OBJECTIVE: To examine the effects of an ankle-foot orthosis (AFO) on balance performance in patients with hemiparesis of short and long duration. DESIGN: Within-subject random order of intervention, cross-sectional study design. SETTINGS: Medical centres and district hospitals. SUBJECTS: Forty-two subjects with hemiparesis of short duration (< six months) and 61 subjects of long duration ( > 12 months). MEASUREMENTS: The balance and gait ability of subjects were evaluated both with an AFO and without. The static and dynamic balance activities were evaluated by the Balance Master System, whereas the functional balance was assessed with the Berg Balance Scale. The speed and cadence were also measured during a 10-metre walk. Paired t-test was used to determine the effect of the AFO. RESULTS: In subjects with hemiparesis of short duration, we found that subjects wearing an AFO showed significant improvements in (1) weight-bearing distribution during quiet standing (p = 0.042, 95% confidence interval (CI) 0.521, 7.325), (2) body sway during standing on foam surface with eyes open (p = 0.020, 95% CI 0.020, 0.680) and eyes closed (p = 0.041, 95% CI 0.023, 0.921), (3) movement velocity during limit of stability test (LOS)--toward the affected side (p = 0.037, 95% CI - 0.978, - 0.042) and nonaffected side (p = 0.008, 95% CI -2.223, - 0.377), (4) maximal excursion toward the affected side (p= 0.042, 95% CI -19.546, -0.071), and (5) speed (p=0.028, 95% CI -0.204, -0.017) and cadence (p= 0.021, 95% CI - 22.983, - 1.864). Such effects were not observed in subjects with hemiparesis of long duration. CONCLUSIONS: For the subjects with hemiparesis of short duration, the AFO improves the symmetry in quiet and dynamic standing balances. It also increases speed and cadence. However, its effectiveness is minimal for patients of long duration.     

Restoration of weight-shifting capacity in patients with postacute stroke: a rehabilitation cohort study

OBJECTIVES: To identify and interrelate recovery characteristics of voluntary weight shifting after stroke and to examine whether the assessment of weight shifting adds information about balance recovery compared with the assessment of quiet standing. DESIGN: Exploratory study using an inception cohort with findings related to reference values from healthy elderly persons. SETTING: Dutch rehabilitation center. PARTICIPANTS: Thirty-six inpatients (mean age, 61.8 y; mean time poststroke, 10 wk) with a first hemispheric intracerebral infarction or hematoma who were admitted to retrain standing balance and walking. INTERVENTION: Individualized therapy. MAIN OUTCOME MEASURES: Center of pressure (COP) displacements were registered during voluntary frontal-plane weight shifting guided by visual COP feedback using a dual-plate force platform. Besides the speed (number of weight shifts) and imprecision (normalized average lateral COP displacement per weight shift), the weight-transfer time asymmetry and the spatiotemporal distribution were determined. Assessments took place as soon as patients could stand unassisted for at least 30 seconds and at 2, 4, 8, and 12 weeks later. RESULTS: During the 12-week training period, the stroke patients increased both their speed (2.3 hits/30 s; 95% confidence interval [CI], 1.1-3.4) and precision (37.7 mm/hit; 95% CI, 10.4-65.0) of weight shifting. Although the speed appeared to stabilize at a suboptimal level after 8 weeks, precision reached normal reference values after 12 weeks. Both older age (>/=65 y) and the presence of visuospatial hemineglect negatively affected weight-shifting speed but not its relative improvement in time. During the training period, a small degree of weight-transfer time asymmetry persisted (mean change, .07; 95% CI, -.21 to .36), with an average of 23% slower weight shifts toward the paretic leg, but the spatiotemporal distribution remained symmetrical. The correlations between weight-shifting and quiet-standing control at the end of training were moderate (Spearman rho range, .50-.77). CONCLUSIONS: Even subjects with severe stroke who are selected for inpatient rehabilitation are able to improve their speed and precision of weight shifting by reducing the weight-transfer time toward both legs in a proportionate manner. The observed correlations between weight shifting and quiet standing indicate that the assessment of weight-shifting capacity provides unique information about balance recovery after stroke.     

Reliability of the measures of weight-bearing distribution obtained during quiet stance by digital scales in subjects with and without hemiparesis

Abstract

Described as an alternative way of assessing weight-bearing asymmetries, the measures obtained from digital scales have been used as an index to classify weight-bearing distribution. This study aimed to describe the intra-test and the test/retest reliability of measures in subjects with and without hemiparesis during quiet stance. The percentage of body weight borne by one limb was calculated for a sample of subjects with hemiparesis and for a control group that was matched by gender and age. A two-way analysis of variance was used to verify the intra-test reliability. This analysis was calculated using the differences between the averages of the measures obtained during single, double or triple trials. The intra-class correlation coefficient (ICC) was utilized and data plotted using the Bland–Altman method. The intra-test analysis showed significant differences, only observed in the hemiparesis group, between the measures obtained by single and triple trials. Excellent and moderate ICC values (0.69–0.84) between test and retest were observed in the hemiparesis group, while for control groups ICC values (0.41–0.74) were classified as moderate, progressing from almost poor for measures obtained by a single trial to almost excellent for those obtained by triple trials. In conclusion, good reliability ranging from moderate to excellent classifications was found for participants with and without hemiparesis. Moreover, an improvement of the repeatability was observed with fewer trials for participants with hemiparesis, and with more trials for participants without hemiparesis.     

Effects of age on balance control during walking

OBJECTIVE: To determine the effects of aging on balance control during walking. DESIGN: Two-group repeated-measures design. SETTING: Gait laboratory in Australia. PARTICIPANTS: Convenience sample of 20 healthy older subjects (mean age, 72y) and 20 healthy young subjects (mean age, 24y). INTERVENTIONS: Changes in locomotor performance in response to perturbations to balance were quantified for healthy older adults compared with healthy young adults for (1) straight line walking at preferred speed, (2) straight line walking at fast speed, (3) figure-of-eight walking at preferred speed, and (4) figure-of-eight walking while performing a secondary motor task. MAIN OUTCOME MEASURES: Gait speed, stride length, cadence, and double-limb support duration, using a footswitch system. RESULTS: Healthy older people screened for pathology had gait patterns comparable to young adults for straight line walking at preferred speed. However, multivariate analysis of variance (MANOVA) showed a significant interaction between age and speed when balance was perturbed by requiring subjects to change from walking at preferred to fast speeds (Pillai-Bartlett trace=.259, F(4,35)=3.06, P<.029, partial eta(2)=.259). This occurred because older people did not increase their speed (F(1,38)=7.65, P<.01, partial eta(2)=.168) or stride length (F(1,38)=12.23, P<.01, partial eta(2)=.243) as much as did the young adults. MANOVAs did not show statistically significant interactions between age and turning conditions or age and dual task conditions, although older people walked more slowly and with shorter steps when turning or performing a secondary task. CONCLUSIONS: Balance strategies during gait are task specific and vary according to age. In response to challenges to balance imposed by the requirement to change from preferred to fast walking, older people did not increase their speed and stride length to the same extent as did younger adults. This was possibly a strategy to maintain their stability.     

Psychometric properties of a modified Wolf Motor Function test for people with mild and moderate upper-extremity hemiparesis

OBJECTIVE: To test the necessity of videotaping, test-retest reliability, and item stability and validity of a modified Wolf Motor Function Test (WMFT) for people with mild and moderate chronic upper-extremity (UE) hemiparesis caused by stroke. DESIGN: Raters of videotape versus direct observation; test-retest reliability over 3 observations, item stability, and criterion validity with upper-extremity Fugl-Meyer Assessment (FMA) in the mildly and moderately impaired groups. SETTING: Academic research center. PARTICIPANTS: Sixty-six subjects with chronic UE hemiparesis who participated in a large intervention study. Subjects were classified into mild and moderate groups for additional analyses. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Mean and median times of task completion, functional ability, and strength (weight to box) measures of the WMFT. FMA scores for validity assessment. RESULTS: In a subgroup of 10 subjects, the intraclass correlation coefficient (ICC) for videotape versus direct observation ranged from .96 to .99. For the whole group, test-retest reliability using ICC2,1 ranged from .97 to .99; stability of the test showed that administration 1 differed from administrations 2 and 3 but administrations 2 and 3 did not differ; item analysis showed that 4 of 17 items changed across time, and validity, using a correlation with UE FMA, ranged from .86 to .89. Separate mild- and moderate-group analyses were similar to whole-group results. CONCLUSIONS: Videotaping the modified WMFT was not necessary for accurate scoring. The modified WMFT is reliable and valid as an outcome measure for people with chronic moderate and mild UE hemiparesis and is stable, but 1 repeat testing is recommended when practical.     

Test position and hip strength in healthy adults and people with chronic stroke

Barbic S, Brouwer B. Test position and hip strength in healthy adults and people with chronic stroke.

Objective

To determine if peak torques generated by the hip flexors and extensors are dependent on test position in healthy adults and in people with chronic stroke.

Design

Cross-sectional study.

Setting

Motor performance laboratory.

Participants

Volunteers were 10 young (20.7±1.5y), 10 older adults (62.1±7y), and 10 stroke survivors (60.6±10y) who were an average of 5 years poststroke.

Interventions

Not applicable.

Main Outcome Measures

Isokinetic (60°/s) peak concentric hip flexor and extensor torques (in Nm/kg) generated in supine and standing positions.

Results

Peak flexor torques measured in standing were generally higher than in supine (P=.018); a pattern evident in all groups, but significant only in stroke. An interaction between test position and group for hip extensor strength (P=.016) reflected 2 distinct patterns in which torques were highest in standing among the young subjects and highest in supine after stroke.

Conclusions

Isokinetic hip flexor and extensor strength measured in standing and supine are comparable in young and older healthy people. In chronic stroke, the test position may over or underestimate maximum peak torque depending on the muscle group tested, particularly on the side ipsilateral to the lesion. These findings may have implications for predicting functional ability from strength measurements.     

Short-term effects of whole-body vibration on postural control in unilateral chronic stroke patients: preliminary evidence

The short-term effects of whole-body vibration as a novel method of somatosensory stimulation on postural control were investigated in 23 chronic stroke patients. While standing on a commercial platform, patients received 30-Hz oscillations at 3 mm of amplitude in the frontal plane. Balance was assessed four times at 45-min intervals with a dual-plate force platform, while quietly standing with the eyes opened and closed and while performing a voluntary weight-shifting task with visual feedback of center-of-pressure movements. Between the second and third assessments, four repetitions of 45-sec whole-body vibrations were given. The results indicated a stable baseline performance from the first to the second assessment for all tasks. After the whole-body vibration, the third assessment demonstrated a reduction in the root mean square (RMS) center-of-pressure velocity in the anteroposterior direction when standing with the eyes closed (P < 0.01), which persisted during the fourth assessment. Furthermore, patients showed an increase in their weight-shifting speed at the third balance assessment (P < 0.05) while their precision remained constant. No adverse effects of whole-body vibration were observed. It is concluded that whole-body vibration may be a promising candidate to improve proprioceptive control of posture in stroke patients.     

The effect of immediate decreasing of weight bearing asymmetry on quiet standing postural control in individuals with chronic stroke

The main patterns characterizing standing posture of hemiparetic patients include: weight-bearing asymmetry (WBA), larger postural sway, asymmetrical contribution of lower limbs to balance control, and increased visual dependency to balance control. The aim of this study was to evaluate the effect of decreasing WBA with the use of a shoe lift, on quiet standing postural control in patients with chronic stroke. Twenty-seven patients participated in this study. Patients completed two tests: 1) quiet standing; and 2) quiet standing while a lift was placed under the non-paretic limb. The following tests were completed on force plates for evaluation: asymmetry of the balance measures (weight bearing, root mean square (RMS) of anterior-posterior (AP) and medial-lateral (ML) center of pressure (COP) velocity), RMS of total AP and ML COP velocity, and AP and ML Romberg quotients. Paired t-tests were used to analyze the data. The mean value of WBA index decreased significantly after using a lift (p < 0.05). However, the changes of the mean value of other postural control parameters were not significant (p > 0.05). The results indicate that there may not be an association between decreased WBA and improved postural control during quiet standing in patients with stroke.     

Intrasession reliability of center of pressure measures of postural steadiness in healthy elderly people

OBJECTIVES: To estimate the immediate test-retest reliability of a single measure of several center of pressure (COP) variables, to report the number of trials to be averaged to obtain a reliable measurement of postural steadiness, and to determine the minimal metrically detectable change (MMDC). DESIGN: Cross-sectional study. SETTING: University biomechanics laboratory. PARTICIPANTS: Seven community-living, healthy elderly people over the age of 60 years (range, 62-73y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The COP was estimated from 2 force platforms and the following measures were calculated: (1) root mean square (RMS), (2) COP range, (3) COP mean velocity, (4) mean power frequency (MPF), (5) median power frequency (MedPF), and (6) sway area. Intraclass correlation coefficients (ICCs) were determined by using 9 successive quiet standing trials. RESULTS: The ICCs obtained for 1 measure of 120 seconds were.58 and.58 for the RMS,.83 and.94 for the COP mean velocity,.52 and.62 for the COP range,.44 and.30 for the MPF, and.34 and.47 for the MedPF in anteroposterior (AP) and mediolateral (ML) directions, respectively. The ICC of the COP sway area obtained for 1 measure was.41. Only 2 trials had to be averaged to obtain an ICC over.90 for the COP mean velocity associated with an MMDC of +/-1.2mm/s (AP) and +/-0.6mm/s (ML). CONCLUSIONS: Mean velocity was the most reliable COP measure and using 2 repetitions allowed for reliable measurement of postural steadiness. For the other COP variables, 3 trials of 120 seconds were needed to obtain an ICC over.80.     

老年人平衡功能的脑网络变化：基于功能性近红外线光谱研究

目的 探究老年人完成平衡控制任务的脑网络特征。方法 2022年1月至4月,于广州医科大学附属第五医院和社区招募22例健康年轻人和20例健康老年人,两组站在足底压力测试板上,完成睁眼或闭眼站立任务,功能性近红外光谱测量左、右前额叶皮质(PFC)和初级运动区(PMC)功能连接强度。结果 老年人闭眼状态下的椭圆面积(Z=-2.884, P <0.01)和最大摆动范围(Z=-2.481, P <0.05)大于年轻人;站立任务时,老年人左侧(t=2.978, P <0.01)和右侧PFC(Z=-3.123, P <0.01)内部功能连接降低;右PMC-左PFC (t=2.087, P <0.05)和右PFC-左PFC (t=3.471, P <0.001)间功能连接降低。结论 与年轻人相比,老年人在平衡控制任务中出现PFC功能连接降低,可能与早期脑老化有关。     

Standing balance after vestibular stimulation in Tai Chi-practicing and nonpracticing healthy older adults

OBJECTIVE: To compare the effects of vestibular stimulation on standing balance control between Tai Chi practitioners and older subjects. DESIGN: Cross-sectional study. SETTING: University-based rehabilitation center. PARTICIPANTS: Tai Chi practitioners (n=24; age +/- standard deviation, 69.3+/-5.0y) and control subjects (n=24; age, 71.6+/-6.1y) were recruited. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Subjects stood on a force platform with eyes closed before and after stimulation of their horizontal semicircular canals, applied by means of whole head-and-body rotation at 80 degrees /s for 60 seconds, with subjects seated in a rotational chair. Body sway during stance was measured as total sway path, peak amplitudes, and mean velocities of sway in both anteroposterior (AP) and mediolateral (ML) directions. RESULTS: After head-and-body rotation, significant within-group increases were found in all measures in both AP and ML directions during stance with eyes closed in older control subjects but not in Tai Chi practitioners along the AP direction. In fact, significantly smaller increases in total sway path, peak amplitude, and mean velocity of body sway in the AP direction were found in the Tai Chi practitioners when compared with those of control subjects. CONCLUSIONS: Our results show that long-term Tai Chi practitioners had better AP standing balance control after vestibular stimulation than older control subjects.     

Gender differences in balance performance at the time of retirement

BACKGROUND: Impairments in balance performance are a commonly accepted risk factor for falling in older people. Since there is a higher reported incidence of falling in women, it is of interest to test whether this correlates with poorer balance performance in women than men at the time of retirement in order to plan health promotional strategies. The purpose of this study was to investigate whether any gender differences exist in balance performance in people approaching retirement age. METHODS: Ninety-seven healthy volunteers (44 males, 53 females) planning to retire shortly were enrolled in the study (age range 50-67 years). Balance assessments during quiet standing were performed under various conditions; feet together eyes open, feet together eyes closed and single limb stance eyes open. The range of centre of pressure displacement in both the anterior-posterior and medial-lateral planes was collected for each task using a force platform. FINDINGS: For several of the balance tasks the men exhibited a statistically significant larger range of centre of pressure displacement than the women (P<0.01). However, after normalising the data for height, no gender differences were seen. Over half of the group failed to complete all three single limb stance trials on both limbs. INTERPRETATION: When the data was normalised for height, no differences were found in static balance performance between men and women of retirement age. A number of participants demonstrated balance impairments whilst performing the single limb stance likely to affect functional activities. Health promotional messages should be targeted equally at men and women.     

Joint position sense in elderly fallers: a preliminary investigation of the validity and reliability of the SENSERite measure

OBJECTIVES: To establish the validity and reliability of the SENSERite system and to determine and compare proprioceptive acuity thresholds (PATs) among 3 groups. DESIGN: Between groups, repeated measures, with randomized sequence. SETTING: University research laboratory. PARTICIPANTS: Forty-six adults recruited into 1 of 3 groups: group 1, 10 healthy young adults (mean age, 22.20y); group 2, 22 healthy older adults (mean age, 73.12y); and group 3, 14 older adults with a history of falls (mean age, 73.21y). INTERVENTIONS: The validity of SENSERite's joint position measure was determined by comparing the system's performance with a validated goniometer measure. The test-retest reliability was determined by repeatedly measuring the established joint positions for the neutral, inversion, eversion, plantarflexion, and dorsiflexion on 2 separate occasions, approximately 24 hours apart. In addition, PATs were measured to determine group differences. Data were analyzed by means of a univariate analysis of variance (ANOVA), intraclass correlation coefficient (ICC(2,k)), and paired t tests. MAIN OUTCOME MEASURES: Error in active reproduction of position and PAT derived from the 5 respective joint position sense tests. RESULTS: Excellent clinical goniometer and SENSERite correlation (ICC(2,k)=1.0, P<.05) was found. The test-retest reliability for the 5 respective position sense tests were excellent (ICC(2,k) range, .88-.99; P<.05). ANOVA revealed a significant difference in PATs among the 3 groups. Post hoc analysis indicated that PAT was greater in groups 2 and 3 than in group 1. No significant difference in PAT was observed between groups 2 and 3. CONCLUSIONS: The ability of the SENSERite to measure joint angular position was as good as that of a clinical goniometer; it had an adequate reliability when tested on 2 separate occasions. The device detected differences between elderly and young subjects, but it did not discriminate differences between fallers and nonfallers. This finding indicates that there is no significant difference between the fallers and nonfallers in proprioceptive acuity.     

Differences in developmental movement patterns used by active versus sedentary middle-aged adults coming from a supine position to erect stance.

The purpose of this study was twofold: (1) to further validate categories for the movement pattern of supine to standing in adults and (2) to evaluate the influence physical activity might have on the movement patterns used for rising. Seventy-two adults, between 30 and 39 years of age (mean = 34.1, SD = 2.8), performed the rising task while being videotaped. Subjects were divided into three groups by self-reports of level of physical activity (daily to rarely). Individual videotaped trials were classified using the previously described categories. Comparisons among the activity-level groups revealed that more active subjects demonstrated more developmentally advanced movement patterns in the righting task, consistent with earlier research on older adults. Results suggest that lifestyle patterns of regular, moderate physical activity may influence how a person performs the basic righting task of coming from a supine to a standing position. This investigation also provided additional support for the use of developmental sequences for the movement pattern of supine to standing.     

The effect of shoe wedges and lifts on symmetry of stance and weight bearing in hemiparetic individuals

OBJECTIVE: To determine the effect of shoe wedges and lifts on symmetry of stance and weight bearing in hemiparetic individuals. DESIGN: Weight bearing on the paretic side was measured in patients with hemiparesis during quiet standing and in conditions of compelled weight shift. SETTING: Free-standing acute inpatient rehabilitation hospital. PARTICIPANTS: Nine individuals with hemiparesis as a result of unilateral stroke who were able to stand for 3 to 5 minutes without assistance or rest, and satisfied other inclusion criteria. INTERVENTIONS: Compelled shift of the body weight was induced with different shoe wedges (5 degrees, 7.5 degrees, 12.5 degrees) or shoe lifts (0.6, 0.9, 1.2cm), which extended under the entire shoe of the unaffected limb. Weight-bearing symmetry scores were used to characterize the symmetry of stance. MAIN OUTCOME MEASURES: Weight-bearing symmetry scores. RESULTS: Without a shoe wedge or a shoe lift, weight-bearing symmetry was characterized by underloading of the paretic limb (39.90% +/-.80% of body weight). Weight shift induced by shoe wedges or shoe lifts applied to the unaffected limb promoted improved symmetry of weight bearing and stance. A shoe wedge of 5 degrees provided the most symmetrical weight distribution (51.44% +/- 1.88% of body weight). CONCLUSION: Shoe wedges and shoe lifts under the unaffected limb induced compelled weight shift toward the paretic limb, resulting in improved symmetry of stance of individuals with mild hemiparesis. We suggest that improved symmetry of bipedal standing obtained with a shoe wedge or a shoe lift applied to the unaffected limb can help overcome the learned disuse of the affected limb. We further suggest that weight distribution induced by shoe wedges or shoe lifts may help in the treatment of ambulatory hemiparetic individuals with asymmetrical stance caused by unilateral stroke.     

Reliability of three commercially available heart rate variability instruments using short-term (5-min) recordings

AIM: To assess the reliability of heart rate variability (HRV) measures made by three commercially available analysers in healthy subjects. METHODS: Twenty-nine volunteers (20 males, mean age 35 +/- 13 years and nine females, mean age 29 +/- 11 years) underwent repeated HRV measures under three conditions: lying supine, standing, lying supine with controlled breathing. HRV was measured simultaneously by three instruments. Reliability was assessed statistically by calculating coefficient of variation (CV), intraclass correlation coefficient (ICC) and limits of agreement (LoA). RESULTS: A wide range of values were found for CV (1-235%) and ICC (R = 0.16-0.99) dependent on the HRV measure assessed and the position in which the measurement was made. For the most part the analysers gave similar values in each condition. The values for CV and ICC were high but within the range reported in the literature. Values for LoA were also high and showed a wide range of values. CONCLUSIONS: The similarity in measures between systems indicates that biological variation and experimental error play a major role in determining the repeatability of HRV measurements. It is therefore recommended that population-specific reliability coefficients should be published where possible and that authors should take into account the reliability of measures when making sample size calculations.