Effect Of Gait Speed Research Articles

The effect of gait speed on vertical force in late stance in children and adolescents with cerebral palsy

The effect of gait speed on vertical force in late stance in children and adolescents with cerebral palsy

Effects of gait speed on stability of walking revealed by simulated response to tripping perturbation

The objective of this work was to study stability of walking over a range of gait speeds by means of muscle-driven simulations. Fast walking has previously been related to high likelihood of falling due to tripping. Various measures of stability have shown different relationships between walking speed and stability. These measures may not be associated with tripping, so it is unclear whether the increase in likelihood of falling is explicable by an increase in instability. Here, stability with respect to a constant tripping perturbation was quantified as the immediate passive response of torso to the perturbation. Subject-specific muscle-driven simulations of eight young healthy subjects walking at four speeds, created by combining a generic musculoskeletal model with gait data, were analyzed. In the simulations, short perturbations were performed several times throughout the swing-phase by applying a constant backward force to the swing-foot of the model. Maxima of changes in the torso (angular) velocity components during the swing-phase were studied. These changes in the velocity components correlated with the walking speed as follows: anterior-posterior r=0.37 (p<0.05), vertical r=0.41 (p<0.05), and medio-lateral r=−0.40 (p<0.05). Of the angular velocity components, only the vertical component correlated statistically significantly with speed, r=0.52 (p<0.01). The weak and varying speed effects suggest that fast walking is not necessarily more unstable than slow walking, in the sense of response to a constant perturbation.

The influence of gait speed on co-activation in unilateral spastic cerebral palsy children

BackgroundPhysiological co-activation of antagonistic muscles during gait allows stability of loaded joints. Excessive co-activation restrains motion and increases energy expenditure. Co-activation is increased by gait speed and in the case of upper motor neuron lesions. This study aimed to assess the pathological component of co-activation in children with unilateral cerebral palsy. Methods10 children with unilateral cerebral palsy and 10 typically developing children walked at spontaneous, slow and fast speeds. The spatio-temporal parameters and electromyographic activity of the rectus femoris, vastus medialis, semi-tendinosus, tibialis anterior and soleus of both lower limbs were recorded. A co-activation index was computed from the EMG envelopes. A mixed linear model was used to assess the effect of walking speed on the index of the antagonistic muscle couples (rectus femoris/semi-tendinosus, vastus medialis/semi-tendinosus and tibialis anterior/soleus) in the different limbs. FindingsA greater effect of walking speed on co-activation was found in the involved limbs of children with cerebral palsy for all muscle couples, compared with their uninvolved limbs and the limbs of typically developing children. In typically developing children, but not in children with cerebral palsy, the effect of gait speed on the co-activation index was lower in the rectus femoris/semi-tendinosus than in the other agonist/antagonist muscle couples. InterpretationsIn children with cerebral palsy, a pathological component of muscle activation might be responsible for the greater increase in co-activation with gait speed in the involved limb. Altered motor control could explain why the co-activation in the rectus femoris/semi-tendinosus couple becomes more sensitive to speed.

Effect of Gait Speed on Muscle Activity Patterns and Magnitude During Stance

This study aims to assess the influence of gait speed (manipulated through cadence) on muscle activity patterns and activation degree during stance. Thirty-five healthy individuals participated in this study. Surface electromyographic activity from the gastrocnemius medialis (GM), gluteus maximus (GMax), biceps femoris (BF) and rectus femoris (RF) was acquired with subjects walking at three different speeds. Speed influenced: (1) relative motor activity patterns at heel strike, midstance-propulsion transition and propulsion; (2) the activity level of RF, GMax, GM and BF, in decreasing order, with higher activity at the fastest and slowest speeds. In general, muscle activity was higher at the fastest and slowest speeds than at the self-selected speed and only the activity of the main actions in each subphase remained stable. These findings suggest that gait speeds different from the self-selected speed influence not only activity levels but also relative muscle activity patterns. As a result, caution is advised when choosing standard speeds in gait studies, as this can lead to increased variability in relative muscle activity patterns.

The effect of gait speed on the knee adduction moment depends on waveform summary measures

The external knee adduction moment (KAM) is a useful proxy for medial knee loading. Though many studies examining the KAM report the peak value, recent studies have evaluated other measures from this waveform, including the stance impulse. It is important to understand the impact of varying gait speed on discrete values of the KAM waveform when evaluating differences between samples. The purpose of this study was to compare measures of the KAM waveform, including peak and impulse, during level walking at different speeds. Thirty-two healthy participants (mean age = 32 ± 8 years, 18 women) were recruited. The KAM peak and impulse were calculated over three ambulation speeds: self-selected, slow (15% slower than self-selected) and fast (15% faster than self-selected). To identify differences between these conditions, a one-way repeated measures analysis of variance was utilized. The peak KAM was greater in the fast compared to the slow condition ( p < 0.05). The KAM impulse was greater in the slow compared to both self-selected and fast conditions ( p < 0.05). The KAM impulse appeared more sensitive to changes in gait speed because the impulse reflects the duration of loading. These findings highlight that slowed gait speed increased loading exposure on the medial knee tissues, though the maximum magnitude of the exposure was reduced. This trade-off between the increase in duration and decrease in amplitude at slower gait speeds should be examined, particularly where loading exposure may lead to pathology, such as knee osteoarthritis.

The Effect of Gait Speed on Three-Dimensional Analysis of Hindlimb Kinematics During Treadmill Locomotion in Rats

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The effect of gait speed and gender on perceived exertion, muscle activity, joint motion of lower extremity, ground reaction force and heart rate during normal walking

This study aims to investigate the effect of speed and gender on subjective perceived exertion, muscle activity, joint motion of lower extremity, vertical ground reaction force and heart rate during barefoot walking. Thirty healthy young adults, 15 females and 15 males, participated in this study. The Borg CR-10 scale was applied to evaluate the perceived exertion of whole body and 10 local areas. Objective measurements included electromyography (EMG), joint motion, vertical ground reaction force (VGRF) and heart rate. The results indicate that walking speed had significant influence on perceived exertion of whole body, as well as the buttock, rear thigh, front thigh and rear shank areas ( p < 0.05). Increased walking speed caused significant increase in the muscle activities of lumbar erector spinae, biceps femoris, and medial gastrocnemius, lumbar motion, as well as the vertical ground reaction force in the loading response and mid-stance phases. For gender effect, females showed significantly higher tibialis anterior muscle activity, ankle motion, vertical ground reaction force and average heart rate than males. Some systematic relations among the physiological, kinematics, kinetics and psychophysical responses were found for interpreting gait performance.

Effect of gait speed on gait rhythmicity in Parkinson's disease: variability of stride time and swing time respond differently

BackgroundThe ability to maintain a steady gait rhythm is impaired in patients with Parkinson's disease (PD). This aspect of locomotor dyscontrol, which likely reflects impaired automaticity in PD, can be quantified by measuring the stride-to-stride variability of gait timing. Previous work has shown an increase in both the variability of the stride time and swing time in PD, but the origins of these changes are not fully understood. Patients with PD also generally walk with a reduced gait speed, a potential confounder of the observed changes in variability. The purpose of the present study was to examine the relationship between walking speed and gait variability.MethodsStride time variability and swing time variability were measured in 36 patients with PD (Hoehn and Yahr stage 2–2.5) and 30 healthy controls who walked on a treadmill at four different speeds: 1) Comfortable walking speed (CWS), 2) 80% of CWS 3) 90% of CWS, and 4) 110% of CWS. In addition, we studied the effects of walking slowly on level ground, both with and without a walker.ResultsConsistent with previous findings, increased variability of stride time and swing time was observed in the patients with PD in CWS, compared to controls. In both groups, there was a small but significant association between treadmill gait speed and stride time variability such that higher speeds were associated with lower (better) values of stride time variability (p = 0.0002). In contrast, swing time variability did not change in response to changes in gait speed. Similar results were observed with walking on level ground.ConclusionThe present results demonstrate that swing time variability is independent of gait speed, at least over the range studied, and therefore, that it may be used as a speed-independent marker of rhythmicity and gait steadiness. Since walking speed did not affect stride time variability and swing time variability in the same way, it appears that these two aspects of gait rhythmicity are not entirely controlled by the same mechanisms. The present findings also suggest that the increased gait variability in PD is disease-related, and not simply a consequence of bradykinesia.

The effect of gait speed on lateral balance control during walking in healthy elderly.

The aim of this paper was to investigate the effect of speed dependency on lateral gait parameters. In 36 healthy elderly (mean age=72.5 years, S.D.=3.2 years), walking at four different self-administered speeds, mediolateral trunk acceleration and step width (SW), but not step-width variability (SWV), were found to have quadratic relations to gait speed. Normalizing for speed by curvilinear interpolation, and controlling for subject characteristics, disclosed smaller SW (adjusted R2=0.41, P<0.001), but larger SWV (adjusted R2=0.26, P=0.01) with increasing age in multiple regression models. These relations were camouflaged at preferred speed.

The effect of gait speed and load carrying on the reliability of ground reaction forces

Many risk factors for instability have been identified, but gait stability is difficult to measure and quantify. Conventional methods to assess gait stability are based on perturbing the subject until a fall is produced resulting in information about the boundary of stable gait patterns. Without perturbing the gait control, this study focuses on the reliability of successful weight transfers during various gait speed and load carrying. Participants walked on a treadmill under fifteen conditions (five load positions×three speeds) while vertical ground reaction forces were recorded for a number of consecutive steps. The first four statistical moments (i.e. mean, standard deviation, skewness and kurtosis) of the distributions of several kinetic parameters were calculated based on the series of recorded steps. Changes were seen in all four moments of various parameters for several speed and loading conditions. The results suggest that alterations are made in both the basic gait pattern and in the tradeoff point between accuracy of execution of the gait pattern and successful completion of the task. Changes in the higher moments suggest that some loading positions and higher speeds reduce the reliability of the execution of gait patterns while other loading positions may actually increase the reliability.

A model of foot placement during gait

Foot placement is known to affect balance during gait; however, how foot placements are chosen is unknown. Objectives of this research were to analyze swing trajectories of the foot during gait with respect to the pelvis, and to propose a model of foot placement control which provides a stable base of support. Effects of gait speed and vision on this model of foot placement were then examined. Foot trajectories were analyzed using spherical coordinates referenced to the pelvis, termed the pelvic spherical coordinates (PSCs). A model was developed based on this coordinate system which predicts foot placement in terms of position and velocity with respect to the pelvis. It is proposed that foot placements are chosen to minimize the sum of PSC coordinates of the stance and swing feet. Foot velocity at heel contact is proposed to minimize the sum of the PSC stance and swing angular velocities. Experimental data were collected to test this model during walking trials of different speeds, both with and without vision. Results showed that sums of stance and swing feet PSCs were very close to zero at heel contact, supporting the positional control hypothesis. Sums of PSC velocities, however, were not zero at heel contact. Rather, individual swing leg PSC velocities were zero at heel contact, suggesting independent swing leg velocity control. Vision did not have an effect on position or velocity variables at heel contact. Gait speed did have an effect, particularly on PSC velocities at heel contact. Results of this study support the proposition that foot placements are dependent upon location of the stance foot with respect to the pelvis in order to help maintain balance during gait.