Uncontrolled manifold hypothesis: Organization of leg joint variance in humans while walking in a wide range of speeds.

This study aimed at investigating the organization of joint angle variability during walking by using the uncontrolled manifold (UCM) theory. We tested two hypotheses: i. the coordinative mechanism underlying joint angle variance during the stance phase is compatible with a kinematic synergy that stabilizes the centre of mass (CoM) position; ii. the walking speed affects the variance components onto and orthogonal to the UCM. Eight healthy subjects (26.0±2.0years old) steadily walked on a treadmill at five normalised speeds (from 0.62±0.03m/s to 1.15±0.07m/s). Joint angles and foot orientation, and components of the CoM position were, respectively, used as elemental variables and task performance for the UCM implementation. The effect of speed, time events, and variance components on the distribution of data variance in the space of joint angles was analyzed by the ANOVA test. Results corroborated the hypothesis that the variance of elemental variables is structured in order to minimize the stride-to-stride variability of the CoM position, at all speeds. Noticeably, both variance components increase during the propulsive phase, albeit that parallel to the UCM was always grater than the orthogonal one. Accordingly, the observed kinematic synergy is supposed to contribute to accomplishing an efficient transition between two steps. Results also revealed that the walking speed does not affect the partitioning of elemental variables-related variance onto and orthogonal to the UCM. Accordingly, the organization of leg joint variance underlying the stabilization of CoM position remains almost unaltered across speeds.

Spatio-temporal parameters and intralimb coordination patterns describing hemiparetic locomotion at controlled speed.

BACKGROUND: Comparison between healthy and hemiparetic gait is usually carried out while subjects walk overground at preferred speed. This generates bias due to the lack of uniformity across selected speeds because they reflect the great variability of the functional level of post-stroke patients. This study aimed at examining coordinative adaptations during walking in response to unilateral brain damage, while homologous participants walked at two fixed speeds. METHODS: Five patients with left and five with right chronic hemiparesis, characterized by similar level of motor functioning, were enrolled. Ten non-disabled volunteers were recruited as matched control group. Spatio-temporal parameters, and intralimb thigh-leg and leg-foot coordination patterns were used to compare groups while walking on a treadmill at 0.4 and 0.6 m/s. The likelihood of Continuous Relative Phase patterns between healthy and hemiparetic subjects was evaluated by means of the root mean square of the difference and the cross correlation coefficient. The effects of the group (i.e., healthy vs. hemiparetics), side (i.e., affected vs.unaffected), and speed (e.g., slow vs. fast) were analyzed on all metrics using the Analysis of Variance. RESULTS: Spatio-temporal parameters of all hemiparetic subjects did not significantly differ from those of healthy subjects nor showed any asymmetry between affected and unaffected limbs. Conversely, both thigh-leg and foot-leg coordination patterns appeared to account for pathology related modifications. CONCLUSION: Comparisons between hemiparetic and healthy gait should be carried out when all participants are asked to seek the same suitable dynamic equilibrium led by the same external (i.e., the speed) and internal (i.e., severity of the pathology) conditions. In this respect, biomechanical adaptations reflecting the pathology can be better highlighted by coordinative patterns of coupled segments within each limb than by the spatio-temporal parameters. Accordingly, a deep analysis of the intralimb coordination may be helpful for clinicians while designing therapeutic treatments.

Reported quality of randomized controlled trials in neglect rehabilitation.

The aim of this study is to assess the reported quality of randomized controlled trials (RCTs) on the effectiveness of neglect rehabilitation using a standardized scale. A search of seven electronic databases was carried out. Selected articles were scored using the PEDro scale and classified as high or low quality study both with the original cut off of 6 and a modified cut off of 5. A linear regression analysis between year of publication and quality rate was used to test whether the quality of the studies improved with time. A total of 18 RCTs were selected. Six articles (33.3%) and 10 articles (55.56%) were classified as having high quality when the original cut off or the modified cut off of the PEDro scale were used, respectively. Analysis shows no time-related changes in PEDro scores. The results show that reported quality is moderate for RCTs in neglect rehabilitation.

Types of article published in physiotherapy journals: a quantitative analysis.

BACKGROUND AND PURPOSE: The aim of this study was to quantify and assess the types of research and review articles published in physiotherapy professional journals with international circulations. METHOD: Selected articles from nine physiotherapy journals in a period of five years were classified according to their study design. RESULTS: A total number of 1627 articles were included in this study of which 205 (12.60%) were randomized controlled trial (RCT). Articles published with the highest frequency were 'observational/descriptive studies' (n = 305, 18.75%), whereas 'meta-analyses' were the rarest ones (n = 21, 1.29%). Many articles were validation studies (n = 216, 13.28%) and articles classified as 'others' (n = 217, 13.34%). High heterogeneity was found in terms of distribution over years and journals with an improvement of the number of RCTs among years. CONCLUSION: The distribution of different types of article in physiotherapy journals is similar to other disciplines. The improvement of RCTs represents an important move in the right direction for evidence-based physiotherapy research.

During walking elders increase efforts at proximal joints and keep low kinetics at the ankle.

BACKGROUND: Both ageing and speed definitely affect gait patterns. Since most of the comparisons between young and elderly people while walking have been carried out at different "self-selected" speeds, results might be biased by a lack of control of the effects of both the concomitant issues. Therefore, further investigations aimed at separating the influence of both the sources of variability are required. METHODS: Nine young and eight elderly healthy subjects walked on a treadmill at five normalised speeds according to the Froude Number, from 0.5 to 1.3 m/s. Step parameters and peaks belonging to kinematic and kinetic patterns have been compared between the groups and over the five speeds by the two-factor (Group and Speed) ANOVA. FINDINGS: After making walking speed comparable between the groups, in elders, hip and knee concentric powers during the stance phase were higher than in young subjects despite their decreased ankle plantarflexor kinetics. Kinematic differences occurred in conjunction with the modifications of the kinetic patterns. INTERPRETATION: Since proximal and distal extensor muscles contribute to the same functional tasks during walking (e.g., stabilisation, forward acceleration of the trunk, body support against gravity), ageing would involve a different sharing of muscle efforts among leg joints, increasing the work load of the proximal extensor muscles. Moreover, gait analysis, when carried out at controlled and comparable speeds, can better pinpoint features of each group of subjects than the comparison at self-selected speed.

Recovery from stroke in patients with diabetes mellitus.

BACKGROUND AND AIM: Diabetes mellitus (DM) is recognized as an important risk factor for stroke and might theoretically influence post-stroke level of disability, increasing the extension of the cerebral injured area. However, results of the few researches aimed at studying this influence are contradictory; moreover, the effect of DM on motor recovery has not been extensively studied. The aim of this study was to investigate the effect of DM on both functional and motor recovery. METHODS: A total of 395 acute patients with first stroke were selected in a rehabilitation department and divided into two groups on the basis of the presence or absence of DM (DM+ and DM-, respectively). Outcome measures were the Barthel Index, the Fugl-Meyer Assessment Scale, and the mobility part of the motor assessment chart according to Lindmark and Hamrin. Participants were assessed at admission to department (T1, 13.9+/-7.9 days from stroke onset), at discharge (T2, 40.1+/-13.4), and at follow-up (T3, 84.2+/-14.3). A 2 x 3 analysis of variance with repeated measures was performed to verify the effect of group and of phase of assessment on motor and functional measures and their interaction. RESULTS: DM+ and DM- groups included 93 and 302 patients, respectively. Both groups showed a significant and progressive improvement in all outcome measures (P<.001), but no interaction was found between group and phase of assessment, which means that motor and functional recovery was similar in the two groups. CONCLUSION: Results suggest that diabetes has no influence on motor and functional outcome within the acute and post-acute phase after stroke. Further research should investigate motor recovery in a longer-term period and with larger samples.

Pusher behaviour: a critical review of controversial issues.

Despite an increasing interest by researchers and clinicians, the pusher behaviour (PB) is still a poorly understood disorder, exhibited by some stroke patients, who push with their non-affected limbs towards the contralesional side and resist attempts at correction of their tilted posture. This review is aimed at critically summarizing findings on controversial issues regarding PB, namely correlation with neglect, neural correlates and underlying mechanisms. There is a growing agreement that PB reflects some misrepresentation of verticality. According to different findings, it has been suggested that PB may result from a conflict between an intact visual and an impaired somesthetic perception of vertical, or alternatively that it might result from a high-order disruption of somesthetic information processing from the paretic hemi-body, named graviceptive neglect. Although conflicting data have been reported, the association between PB and neglect seems to be confirmed, when a comprehensive assessment of neglect-related phenomena is performed. Localization of brain lesions is also controversial. Some investigations stressed the role of posterior lateral thalamus, but other findings revealed that different lesional sites may also be present. On the basis of these data we suggest the existence of a multicomponential network reliable for upright posture control. This model might also explain some different results in this area. Clinical implications and requirements for future research are discussed.

Scale for contraversive pushing: cutoff scores for diagnosing "pusher behavior" and construct validity.

BACKGROUND AND PURPOSE: Considerable disagreement exists among researchers with regard to the prevalence, pathophysiology, and treatment of "pusher behavior" (PB), partly because of different testing procedures. This study was primarily aimed at establishing cutoff scores for and the construct validity of the Scale for Contraversive Pushing (SCP). The prevalence of PB in people with right- and left-brain lesions also was investigated. SUBJECTS AND METHODS: The study subjects were 105 consecutive patients with recent stroke. Two methods were used to diagnose PB: clinical examination and SCP score with 3 different cutoff points--an SCP total score of greater than 0 (Crit_1), subscores in each section of the scale of greater than 0 (Crit_2), and subscores in each section of the scale of > or =1 (Crit_3). Clinical and SCP diagnoses were independently made by different examiners. The Cohen kappa coefficient was used to determine the agreement between clinical and SCP diagnoses. The construct validity of the SCP was estimated by calculation of Spearman rank correlation coefficients for SCP and balance, mobility, and functional scores. RESULTS: The agreement between clinical and SCP diagnoses was low (kappa=.212) when Crit_1 was used. Crit_2 led to the highest agreement with the clinical diagnosis (kappa=.933). However, only Crit_3, although globally less accurate (kappa=.754), ensured no false-positive results. The construct validity of the SCP was demonstrated by significant (P<.001) moderate to high correlations with mobility (rho=.595), functional (rho=.632), and balance (rho=.666) scores. The prevalence of PB was not influenced by the side of the lesion. A limitation of the study was that the reliability of the clinical examination method was not investigated. DISCUSSION AND CONCLUSION: The results support the validity of the SCP and suggest the need to choose different SCP cutoff criteria (Crit_2 or Crit_3) according to the aim of the evaluation.

Subtle neurological abnormalities as risk factors for cognitive and functional decline, cerebrovascular events, and mortality in older community-dwelling adults.

BACKGROUND: Subtle, but clinically detectable, neurological abnormalities (SNAs) are associated with impaired physical performance in elderly persons without overt neurological diseases. We investigated whether SNAs were prospectively associated with cognitive and functional status, death, and cerebrovascular events (CVEs) in older community-dwelling individuals. METHODS: In participants without history of stroke, parkinsonism and dementia, or cognitive impairment, a score (N(SNA)) was obtained by summing SNAs detected with a simple neurological examination. Cognitive status and disability were reassessed 4 years later, and deaths and CVEs were documented over 8 years. RESULTS: Of 506 participants free of neurological diseases (mean [SEM] age, 71.9 [0.3] years; 42% were men), 59% had an N(SNA) of 1 or more (mean [SEM], 1.1 [0.06]; range, 0-8). At baseline, the N(SNA) increased with age and with declining cognitive and physical performance, depressive symptoms, and disability, after adjusting for several covariates, but did not increase with falls and urinary incontinence. The N(SNA) prospectively predicted worsening cognitive status and disability, adjusting for demographics and for baseline comorbidity and cognitive and physical performance. The mortality rates were 22.6, 23.3, 23.9, 58.6, and 91.9 per 1000 person-years in participants with an N(SNA) of 0, 1, 2, 3, and 4 or higher, respectively. Compared with an N(SNA) of less than 3, having an N(SNA) of 3 or higher was associated with an increased adjusted risk of death (hazard ratio, 1.77; 95% confidence interval [CI], 1.25-2.74) and of CVE (hazard ratio, 1.94; 95% CI, 1.07-3.54) over 8 years. CONCLUSION: In this sample of older community-dwelling persons without overt neurological diseases, multiple SNAs were associated with cognitive and functional decline and independently predicted mortality and CVEs.

Cognitive and functional impairment in hypertensive brain microangiopathy.

Brain microangiopathy, whose neuroimaging expression is represented by age-related white matter changes (ARWMC), is largely due to hypertension and it is, in turn, responsible for geriatric syndromes, including decline in cognitive, functional and motor/gait abilities. This review analyzes the link between hypertension and ARWMC, as well as the complex relationships between ARWMC and cognitive impairment, executive dysfunction, and movement/gait abnormalities. The available evidence supports the hypothesis that these functional consequences of ARWMC are responsible for substantial disability in the elderly. Thus, adequate treatment of hypertension may represent a feasible way to reduce the burden of disability in late life.

Effectiveness of fingertip light contact in reducing postural sway in older people.

BACKGROUND AND OBJECTIVE: haptic cues from fingertip light touch (LT) with a stationary surface reduce postural sway even at non-mechanically supportive force levels. Aim of this study was to determine the effects of LT on postural sway in older compared with younger persons. SUBJECTS: twenty young (age 20-29, mean 23.9 + 2.5) and 20 older participants (age 65-83, mean 74.3 + 6.4). METHODS: subjects stood in the semi-tandem position on a firm surface, and their postural sway was quantified using a force platform. Experimental trials, randomised across subjects, included two sight conditions (vision and no vision) and three contact conditions (no touch, NT; light touch, LT; and force touch, FT). The measured parameters were the length and the area of centre of pressure sway (COP-L and COP-A) and the mean velocity of COP displacements in the anterior-posterior (COP-AP) and medial-lateral (COP-ML) direction. RESULTS: for all variables, the analysis showed significant differences between contact conditions, sight conditions and age. Contact-age interaction was significant between NT and LT conditions, with older participants showing greater decrease in postural sway than younger participants, but not between FT and LT conditions. CONCLUSIONS: results indicate that the effectiveness of LT in reducing postural sway may be greater in older than in younger persons, perhaps because in older persons haptic cues from upper extremity might counterbalance sub-clinical sensory loss in the lower extremities. This finding supports the hypothesis that older people may sometimes use a walking aid as an informative device and suggests that during balance training external aids should not be used.

The scale for contraversive pushing: A reliability and validity study.

OBJECTIVE: Pushing toward the hemiplegic side can interfere with mobility training after stroke. This study estimated the internal consistency, interrater reliability, and validity of the Scale for Contraversive Pushing (SCP). METHODS: Twenty-six patients with recent stroke were diagnosed with pusher behavior (PB). Two testers, randomly selected from 3 other examiners, independently assessed each patient using the SCP on the same day within 3 days of admission for rehabilitation. Cohen kappa coefficient was used to determine the agreement between the clinical and SCP diagnosis. The interrater reliability of the scale was estimated by calculation of the intraclass correlation coefficient. Cronbach's alpha coefficient and Pearson's coefficients were used to estimate the internal consistency of the scale and correlations between the subscores and the total score. RESULTS: The agreement between SCP and clinical diagnosis was very low when the original cutoff criterion for SCP diagnosis was used but was almost perfect with a modified criterion. The interrater reliability was good to excellent with regard both to each sub-score and to the total score. The internal consistency was very high, along with correlations between subscores and total score of the scale. CONCLUSIONS: The results provide support for use of the SCP based on its reliability and validity using a modified cutoff criterion to make a diagnosis of PB.

Glenohumeral subluxation in hemiplegia: An overview.

This review summarizes the recent advances in glenohumeral subluxation (GHS) in hemiplegic patients and analyzes the reliability and validity of clinical evaluation and the effectiveness of different treatment approaches. GHS, a common complication of stroke, can be considered an important risk factor for shoulder pain and other problems. GHS is a complex phenomenon, and its pathomechanics are not yet fully understood. Radiographic measurements are considered the best method of quantifying GHS. Clinical evaluation can be useful as screening assessment. Functional electrical stimulation and strapping are effective in an acute stage of hemiplegia; some types of slings have been shown to be effective and may be used together with other strategies.

[Cardiac rehabilitation in the elderly]. / Riabilitazione cardiologica nell'anziano.

Cardiac rehabilitation is an integral component of secondary prevention, and is indicated for patients with a wide variety of cardiac conditions, ranging from coronary artery disease to chronic heart failure. Best results are obtained with integrated, multicomponent cardiac rehabilitation programs, which include exercise training together with counseling and psychosocial measures that may help patients maintain sustained changes toward a more healthy lifestyle. Evidence from randomized controlled trials and meta-analyses supports the efficacy of cardiac rehabilitation on clinically relevant outcomes such as reduced long-term morbidity and mortality, enhanced functional profile and improved control of cardiovascular risk factors. However, the vast majority of this evidence derives from trials with only small numbers of patients > 70 years of age. In elderly patients the goal of cardiac rehabilitation may differ from those of younger patients, and include the preservation of mobility, self-sufficiency and mental function. Cardiac rehabilitation my represent an opportunity to provide effective health care and achieve a high quality of life for older patients. Future research programs should therefore be aimed at specifically investigating the efficacy and effectiveness of cardiac rehabilitation in older, frail cardiac patients.