Gait Characteristics and Functional Ambulation Profile in Patients with Chronic Unilateral Stroke

Capacidade funcional de hemiparéticos crônicos submetidos a um programa de fisioterapia em grupo

Este estudo tem como objetivos analisar a eficácia da fisioterapia em grupo sobre a marcha, o equilíbrio corporal e o risco de queda, e verificar se há correlação entre a capacidade funcional da marcha e o equilíbrio em indivíduos com hemiparesia crônica. Participaram do estudo 21 adultos hemiparéticos, com idade média de 58,9±10,6 anos, com seqüela de no mínimo 1 ano após acidente vascular encefálico isquêmico ou hemorrágico. Os sujeitos foram submetidos a um programa de 1 hora de fisioterapia em grupo duas vezes por semana durante seis meses. Foram avaliados por meio da escala de equilíbrio de Berg (EEB) e do teste de levantar e caminhar cronometrado TLCC (TUG, na sigla em inglês de timed up & go) antes do programa, após 13 e ao fim de 26 semanas. Os resultados mostram uma redução progressiva, embora não-significativa, no tempo de execução do TLCC e aumento progressivo, também não-significativo, do escore na EEB. Foi observada forte correlação entre as duas escalas (r=0,7, p<0,05). Assim, a terapia não foi efetiva para produzir melhora nos escores dos testes, mas contribuiu para manter a mobilidade.

Stabilometry is a predictor of gait performance in chronic hemiparetic stroke patients

In patients with spastic hemiparesis, centre of foot pressure (CoP) is shifted toward the unaffected limb during quiet stance. We hypothesised that abnormal gait features would correlate with the degree of asymmetry during stance. In 15 patients and 17 normals we recorded CoP and body sway by a force platform and measured spatial-temporal variables of gait with pedobarography. In patients CoP was shifted toward the unaffected limb and sway was larger than in normals. CoP position was associated with the decrease in strength of the affected lower-limb muscles. Spatio-temporal variables of gait were also affected by the disease. Cadence and velocity were decreased, duration of single support on the unaffected limb and of double support were increased with respect to normals. The degree of impairment of gait variables correlated with CoP. We found a negative relationship between velocity or cadence and CoP, and a positive relationship between duration of single support and CoP in the unaffected but not in the affected limb. Duration of double support correlated positively with CoP. CoP asymmetry during both standing and walking suggests that postural and gait problems share some common neural origin in hemiparetic patients. This asymmetry affects gait performance by increasing the time and effort needed to shift body weight toward the affected limb. The degree of postural asymmetry measured by stabilometry is associated with the level of impairment of gait variables.

Agreement between temporospatial gait parameters of an electronic walkway and a motion capture system in healthy and chronic stroke populations

OBJECTIVES

To determine agreement between temporospatial gait parameters derived from an electronic walkway and a video-based motion capture system in healthy and chronic stroke subjects.

DESIGN

Data were acquired simultaneously by a walkway (GAITRite) and an eight-camera motion capture system (Motion Analysis Corporation) in 52 healthy subjects (age 47 +/- 15 yrs) and 20 people with stroke (age, 58 +/- 20 yrs; 4 +/- 7 yrs poststroke). Gait velocity, stride time, stride length, step length, percent single support, and percent total support were compared by the limits-of-agreement method.

RESULTS

The mean differences between the two methods were small and measured 1.5% or less of the parameter mean value. The velocity difference was significantly (P < 0.001) larger in healthy (1.37 +/- 0.93 cm/sec) than in stroke subjects (0.50 +/- 0.63) and in stroke subjects who did not use an assistive device (0.75 +/- 0.67 cm/sec) compared with those who did (0.13 +/- 0.32).

CONCLUSIONS

Electronic walkway and video-based gait analysis provide comparable temporospatial gait information in healthy and stroke subjects. The differences between the two methods were greater with increasing speed but overall still negligible considering expected changes resulting from stroke recovery, experimental manipulations, or therapeutic interventions. Therefore, electronic walkway and video-based gait analysis may be used interchangeably for evaluating temporospatial gait parameters after stroke for clinical and research purposes.

Should trunk movement or footfall parameters quantify gait asymmetry in chronic stroke patients?

The purpose of this study was to investigate gait asymmetry in chronic stroke patients in comparison with subjects with no known asymmetries. Further, we wanted to decide which gait symmetry parameter has the best ability to discriminate between the two groups. Twenty subjects with hemiplegia (mean age 58 years, S.D.=8 years) and 57 subjects with no known gait asymmetry (mean age 77 years, S.D.=5 years) walked six times along a 7-m walkway at slow, preferred and fast speed. Measures of vertical, anteroposterior, and mediolateral trunk asymmetry were assessed from triaxial accelerometry data. The footfall parameters of single support (% of stride time) and step length (m) asymmetry were assessed from data obtained using an electronic walkway. Vertical (p<0.001), anteroposterior (p=0.01), mediolateral (p=0.01) trunk movement and single support (p=0.03) showed significant differences in asymmetry between the two groups. No difference in step length asymmetry was found between the two groups. Neither single support asymmetry nor step length asymmetry showed the ability to discriminate subjects with hemiplegic gait from subjects in the comparison group. Measures of trunk movement asymmetry, however, were able to discriminate between the two groups (p<or=0.001). The results indicate that trunk movement should be included in the assessment of gait asymmetry in chronic stroke patients.

Gait reveals bilateral adaptation of motor control in patients with chronic unilateral stroke

BACKGROUND AND AIMS

Functional brain imaging has shown that bilateral brain reorganization may occur after unilateral cerebral damage. The present study searched for evidence of bilateral motor control changes in gait in patients with chronic unilateral stroke.

METHODS

Gait variables (temporal and spatial parameters, footprint peak times (FPPT) and footfall times (FFT)) were recorded in 48 patients with chronic unilateral stroke at their preferred speed, and in 10 healthy volunteers walking from very slowly to very fast on a pressure sensor walkway. The data were divided into 4 groups according to gait velocity. The functional outcome of stroke was measured by the Barthel Index.

RESULTS

Patients' gait variables reflected their hemiparetic gait pattern. Slower patients had prolonged stance, FPPT and FFT on the non-affected side (NS), and prolonged swing and shorter FPPT and FFT on the affected side (AS). The magnitude of the asymmetry index of these parameters was inversely associated with velocity performance and, at the same time, it characterized how much the control of the clinically healthy (NS) side was altered during walking. Bilateral changes in kinetic and footfall variables in the chronic stage of unilateral stroke were present.

CONCLUSIONS

Patients chose their preferred walking velocity using stereotyped, alternative gait patterns, in which the contribution of the NS was larger than that of the AS. Alternative gait patterns may partly demonstrate compensatory behavioral strategies adapted by patients.

Bilateral foot center of pressure measures predict hemiparetic gait velocity

Stroke is a major cause of disability in the US, leaving most survivors with abnormal motor function, often resulting in hemiparetic gait. Quality of gait in this population has been well characterized by measures of velocity, though velocity alone provides only a general index of functional mobility. Researchers and clinicians should continue to develop a complete characterization of behavioral alterations, but should also work to identify the neuromechanical processes underlying the loss and recovery of locomotor function. We hypothesized that selected foot center of pressure (CoP) measures would show a predictive relationship with hemiparetic gait velocity, a standard clinical metric of locomotor capability, thus providing insight into the relationship between neuromotor control and function. Thirty-three chronic stroke survivors (67+/-10 years) were evaluated during walking at a self-selected speed. Patients wore pressure sensitive shoe insoles and completed 15 steady-state gait cycles over an instrumented gait mat. CoP parameters and walking velocity were measured during each cycle. Multiple regression analyses were used to model all combinations of CoP and interlimb symmetry parameters as predictor variables of gait velocity. Eleven CoP and symmetry parameters were selected in a final regression model, and provided a robust prediction of hemiparetic gait velocity (R(adj)(2)=0.90) in this group of chronic stroke patients. These results indicate that bilateral foot CoP measures, especially those representing variability of foot CoP control, not only index locomotor function, but may also have the potential to provide information about the underlying control properties of the stroke-injured neuromuscular system.

Interlimb coordination during locomotion: what can be adapted and stored?

Interlimb coordination is critically important during bipedal locomotion and often must be adapted to account for varying environmental circumstances. Here we studied adaptation of human interlimb coordination using a split-belt treadmill, where the legs can be made to move at different speeds. Human adults, infants, and spinal cats can alter walking patterns on a split-belt treadmill by prolonging stance and shortening swing on the slower limb and vice versa on the faster limb. It is not known whether other locomotor parameters change or if there is a capacity for storage of a new motor pattern after training. We asked whether adults adapt both intra- and interlimb gait parameters during split-belt walking and show aftereffects from training. Healthy subjects were tested walking with belts tied (baseline), then belts split (adaptation), and again tied (postadaptation). Walking parameters that directly relate to the interlimb relationship changed slowly during adaptation and showed robust aftereffects during postadaptation. These changes paralleled subjective impressions of limping versus no limping. In contrast, parameters calculated from an individual leg changed rapidly to accommodate split-belts and showed no aftereffects. These results suggest some independence of neural control of intra- versus interlimb parameters during walking. They also show that the adult nervous system can adapt and store new interlimb patterns after short bouts of training. The differences in intra- versus interlimb control may be related to the varying complexity of the parameters, task demands, and/or the level of neural control necessary for their adaptation.

Effect of Intrathecal Baclofen Bolus Injection on Temporospatial Gait Characteristics in Patients With Acquired Brain Injury

OBJECTIVE

To evaluate changes in temporospatial gait parameters after intrathecal baclofen (ITB) bolus administration in patients with spasticity resulting from acquired brain injury by using computerized gait analysis.

DESIGN

Case series; before-after intervention. Walking performance and spasticity in lower-extremity muscles were assessed before and at 2, 4, and 6 hours after ITB bolus injection.

SETTING

Tertiary care free-standing rehabilitation hospital.

PARTICIPANTS

Consecutive sample of 28 adults with acquired brain injury due to stroke, trauma, or anoxia.

INTERVENTION

A 50-microg ITB bolus injection (2 subjects received 75 microg and 100 microg, respectively).

MAIN OUTCOME MEASURES

Ashworth Scale scores, self-selected gait velocity, stride length, cadence, step length symmetry, step width, and percentage of single support on the more involved side.

RESULTS

Ashworth score decreased from 2.0+/-0.5 at baseline to 1.3+/-0.3 at peak response ( P <.001), whereas gait velocity increased from 41+/-26 to 47+/-31 cm/s ( P <.001). Significant improvements also occurred in stride length ( P <.05) and step width ( P <.001). Gait velocity was the most sensitive temporospatial outcome measure for differentiating functional response to ITB bolus injection. Sixteen patients increased velocity by an average of 12 cm/s, representing a mean gain of 33% over their baseline walking speed, while 5 decreased (mean loss, -6 cm/s [52% of baseline]) and 7 were unchanged. There was a significant correlation between baseline velocity and peak change in velocity after ITB bolus ( r =.39, P <.05). Baseline Ashworth score correlated inversely with velocity, stride length, cadence, and percentage single support (r range, -.46 to -.57). No significant correlations were found between change in Ashworth score and change in any temporospatial outcome measure.

CONCLUSIONS

ITB bolus injection consistently reduces spasticity in ambulatory patients with acquired brain injury but may result in a range of changes in walking performance that can be reliably detected using computerized motion analysis. Velocity appears to be the most sensitive parameter with which to classify individual patient response. The relation between baseline gait velocity and peak change in velocity after bolus administration may have application in predicting the outcome of screening trials for pump implantation; it warrants further investigation.

Footprint analysis of gait using a pressure sensor system

The purpose of this study was to investigate if the detailed pressure data of the footprints of normal gait add essential information to the spatio-temporal variables of gait. The gait of 62 healthy adult subjects was investigated using GAITRite pressure sensor system. Each footprint was divided into 12 equal trapezoids and after that the hindfoot, midfoot and forefoot analysis was developed. A typical activation pattern of the sensors with two peaks of active area and peak pressure distribution during normal walking was obtained. The first peak reflected the heel strike, and the second peak reflected push-off at the end of the stance phase. The lowest pressure values were in the midfoot, where the lateral part of the foot activated sensors more than the medial part. The footprint patterns of right and left legs were symmetrical and corresponded with the symmetry found in the spatio-temporal variables of gait. The variability for the active area and the peak pressure were more pronounced for the lateral part of the midfoot and a smaller variation was seen in areas with concentrated observations (e.g. 1st, 2nd and 5th lateral trapezoids). Increasing active area in the forefoot was associated with decreasing pressure sensor activity in the midfoot. The footprint patterns identified the symmetry between the legs and at the same time revealed the velocity performance.