Decreased Step Length Research Articles

Speeding up or slowing down?: Gait adaptations to preserve gait stability in response to balance perturbations

It has frequently been proposed that lowering walking speed is a strategy to enhance gait stability and to decrease the probability of falling. However, previous studies have not been able to establish a clear relation between walking speed and gait stability. We investigated whether people do indeed lower walking speed when gait stability is challenged, and whether this reduces the probability of falling.Nine healthy subjects walked on the Computer Assisted Rehabilitation ENvironment (CAREN) system, while quasi-random medio-lateral translations of the walking surface were imposed at four different intensities. A self-paced treadmill setting allowed subjects to regulate their walking speed throughout the trials. Walking speed, step length, step frequency, step width, local dynamic stability (LDS), and margins of stability (MoS) were measured.Subjects did not change walking speed in response to the balance perturbations (p=0.118), but made shorter, faster, and wider steps (p<0.01) with increasing perturbation intensity. Subjects became locally less stable in response to the perturbations (p<0.01), but increased their MoS in medio-lateral (p<0.01) and backward (p<0.01) direction.In conclusion, not a lower walking speed, but a combination of decreased step length and increased step frequency and step width seems to be the strategy of choice to cope with medio-lateral balance perturbations, which increases MoS and thus decreases the risk of falling.

Temporal-Spatial Gait Adaptations During Stair Ascent and Descent in Patients With Knee Osteoarthritis

Knee osteoarthritis (OA) accounts for more functional disability of the lower extremity than any other disease. We recruited 18 patients with knee OA and 18 healthy age-, height-, mass-, and gender-matched control subjects to investigate the effects knee OA has on select spatial and temporal gait variables during a stair climbing task. No group-by-direction interaction was observed; however, significant effects did occur for group and direction. Specifically, patients with knee OA demonstrated less time in single support, greater time in double support, decreased step length, greater step width, less stride length, decreased total gait velocity, greater total time in support, and less total time in swing, compared with controls. Early-stage knee OA directly influences specific temporal and spatial gait characteristics during stair climbing.

Conversion of Fused Hip to Total Hip Arthroplasty With Presurgical and Postsurgical Gait Studies

This case study presents a subject with a fused hip converted to total hip arthroplasty. Kinematic gait analysis was conducted on 3 occasions, presurgery, 4 months postsurgery, and 2.5 years postsurgery. Presurgery data showed decreased cadence and shorter step length; sound limb possessed increased hip, knee range of motion (ROM), and increased knee flexion during stance; the affected limb had minimal hip motion and normal knee ROM with abnormal pattern. At 4 months postsurgery, the sound limb showed decreased step length, whereas the affected limb showed increased knee extension during stance and increased hip ROM. Data obtained at 2.5 years postsurgery indicated decreased cadence and speed and increased ROM in both limbs. The total hip arthroplasty had provided relief of chronic back and affected hip pain and improved mobility. Gait-specific training is recommended.

Stepping characteristics and Centre of Mass control during stair descent: Effects of age, fall risk and visual factors

Stair edges provide important visual cues for appropriate foot placement on the stair and balance control during stair descent. Previous studies explored age-related changes in stepping performance and balance control during stair descent and included fit older adults. The present study investigates both age- and frailty-related changes to stepping parameters and Centre of Mass (COM) control during stair descent and how these measures are affected by visual factors. Older adults were split into two groups containing participants with the lowest (LROA, n = 7) and highest (HROA, n = 8) combined scores on tests of balance and confidence to negotiate stairs. Data were also collected from younger adult participants (YA, n = 8). Kinematic data were collected from participants while they descended stairs under combinations of ambient light (bright and dimmed) and stair edge contrast conditions (high and low). A three (group) × two (illumination) × two (contrast) ANCOVA was performed with average stair walking speed as covariate. HROA cleared the stair edge vertically ( p = 0.001) and horizontally ( p < 0.001) with less distance than LROA. Dimmed ambient light resulted in decreased step length in HROA ( p = 0.006) compared to bright lighting. High stair edge contrast led to reduced vertical COM acceleration variability in HROA ( p = 0.009) and increased distance between COM and anterior base of support ( p = 0.017) in LROA. YA increased horizontal foot clearance ( p = 0.011) when stair edge contrast was high. We conclude that the aforementioned differences in stepping behaviour shown by HROA may contribute towards an increased risk of tripping and that high stair edge contrast has a beneficial effect on balance control in older adults.

The Characteristics of Gait Disturbance and Its Relationship with Posterior Tibial Somatosensory Evoked Potentials in Patients with Cervical Myelopathy

Prospective case control study. This study is to investigate the gait characteristics of cervical myelopathy (CM) and to assess the relationship between presence of abnormality of posterior tibial somatosensory evoked potential (PTSEPs) and gait parameters. Many of CM patients suffer from gait disturbance so that the assessment of walking ability and its restoration are one of main concerns. The patients were recruited who had suffered from gait disturbance and were diagnosed as CM by cervical magnetic resonance image (MRI). All subjects underwent three-dimensional gait analysis and PTSEP. Normal persons were recruited as control groups and underwent gait analysis. The CM patients were divided into two groups such as normal and abnormal SEP groups, and two groups were compared as to presence of signal change in MRI and gait parameters. CM groups revealed significantly lower gait velocity, decreased step length and stride length, and increased double support time. They showed significantly decreased maximal knee flexion angle in swing phase, the decreased plantarflexion angle at push off, and the increased maximal dorsiflexion angle at swing phase in comparison with control group. Abnormal SEP group demonstrated the lower gait velocity and cadence, smaller plantarflexion angle at push off and the larger maximal dorsiflexion angle at swing phase in comparison with normal SEP group. There was no significant relationship between presence of SEP abnormality and signal change of MRI. CM patients compensated stabilizing balance by decreasing gait velocity and step length as well as increasing step width and double support time. Considering the presence of abnormality of PTSEP was closely related to typical gait characteristics of CM patient, the gait deviation of CM patients was attributed to impaired proprioception of lower limbs and poor stability.

4-Aminopyridine improves gait variability in cerebellar ataxia due to CACNA 1A mutation

The fall risk of patients with cerebellar ataxia is markedly increased and these falls often result in serious injuries or a fear of falling [13]. Patients with cerebellar ataxia typically walk with a broadened base of support, decreased step length and increased gait variability [4]. The latter is a critical parameter in the assessment of patients with gait disorders since increased variability is associated with a

Walking patterns in Parkinson's disease with and without freezing of gait

The pathophysiology underlying freezing of gait (FOG) in Parkinson's disease remains incompletely understood. Patients with FOG (“freezers”) have a higher temporal variability and asymmetry of strides compared to patients without FOG (“non-freezers”). We aimed to extend this view, by assessing spatial variability and asymmetry of steps and interlimb coordination between the upper and lower limbs during gait. Twelve freezers, 15 non-freezers, and 15 age-matched controls were instructed to walk overground and on a treadmill. Kinematic data were recorded with a motion analysis system. Both freezers and non-freezers showed an increased spatial variability of leg movements compared to controls. In addition, both patient groups had a deficit in interlimb coordination, not only between ipsilateral arms and legs, but also between diagonally positioned limbs. The only difference between freezers and non-freezers was a decreased step length during treadmill walking. We conclude that parkinsonian gait—regardless of FOG—is irregular, not only in the legs, but also with respect to interlimb coordination between the arms and legs. FOG is reflected by abnormal treadmill walking, presumably because this provides a greater challenge to the defective supraspinal control than overground walking, hampering the ability of freezers to increase their stride length when necessary.

Perturbations of ground support alter posture and locomotion coupling during step initiation in Parkinson’s disease

During the initiation of stepping, anticipatory postural adjustments (APAs) for lateral weight transfer and propulsion normally precede the onset of locomotion. In Parkinson's disease (PD), impaired step initiation typically involves altered APA ground force production with delayed step onset and deficits in stepping performance. If, as in stance and gait, sensory information about lower limb load is important for the control of stepping, then perturbations influencing loading conditions could affect the step initiation process. This study investigated the influence of changes in lower limb loading during step initiation in patients with PD and healthy control subjects. Participants performed rapid self-triggered step initiation with the impending single stance limb positioned over a pneumatically actuated platform. In perturbation trials, the stance limb ground support surface was either moved vertically downward (DROP) or upward (ELEVATE) by 1.5 cm shortly after the onset of the APA phase. Overall, PD patients demonstrated a longer APA duration, longer time to first step onset, and slower step speed than controls. In both groups, the DROP perturbation reinforced the intended APA kinetic changes for lateral weight transfer and resulted in a significant reduction in APA duration, increase in peak amplitude, and earlier time to first step onset compared with other conditions. During ELEVATE trials that opposed the intended weight transfer forces both groups rapidly adapted their stepping to preserve standing stability by decreasing step length and duration, and increasing step height and foot placement laterally. The findings suggested that sensory information associated with limb load and/or foot pressure modulates the spatial and temporal parameters of posture and locomotion components of step initiation in interaction with a centrally generated feedforward mode of neural control. Moreover, impaired step initiation in PD may at least acutely be enhanced by augmenting the coupling between posture and locomotion.

Step length appears to be a strong discriminant gait parameter for elderly females highly concerned about falls: a cross-sectional observational study

Objective To determine if gait parameters and the Timed Up and Go test can discriminate between elderly females with high and low concern about falls. Knowledge of these parameters could help in the development of rehabilitation programmes focused on the prevention of falls, fear of falling and functional decline. Design Cross-sectional, observational study. Setting Human motion laboratory. Participants One hundred and fifty-four elderly females (aged 64 to 83 years), divided into two groups based on their Falls Efficacy Scale International score: high concern ( n = 81) and low concern ( n = 73) about falls. Main outcome measures Eight gait parameters recorded with the GAITRite system and the Timed Up and Go test score. Results Factor 2 (composed of step length, gait velocity and Timed Up and Go mobility test) explained 20% of the variability of the data and was the only factor to discriminate between the groups, with 63% correct classifications. Step length proved to be the variable with the greatest discriminant ability, with a much higher discriminant coefficient (0.889) than the Timed Up and Go test (−0.369) and gait velocity (−0.268). Conclusions High concern about falls is primarily associated with decreased step length. Step length could be used as a screening tool to identify elderly women with low and high concern about falls in order to target these groups in a rehabilitation programme aimed to slow reduction in gait velocity and mobility.

Adult age differences in familiarization to treadmill walking within virtual environments

We assessed age-related differences in adults in familiarization to treadmill walking within virtual environments (VE), and examined whether treadmill walking after familiarization resembles overground walking. Seventeen younger and 17 older adults walked at preferred speed on an overground walkway and afterwards walked at the same speed for 20 min on a treadmill coupled to a VE. A motion capture system was used to measure spatio-temporal gait parameters. On the treadmill, both younger and older adults initially displayed decreased step length and increased step width, cadence, and time in double support relative to overground walking. Except for time in double support, step characteristics approached overground walking-behavior with a negatively accelerated trend. After 15 min of treadmill walking, changes became minor corresponding to less than 1% deviations to individuals’ overground walking. At the end of familiarization, average differences in step length, cadence, and double support relative to overground walking were reduced to less than 5 percent in both age groups. For step width, younger adults approximated overground walking after 20 min more closely than older adults, probably reflecting larger initial differences between treadmill and overground walking among older adults. We conclude (a) that 20 min of familiarization to treadmill walking in a VE are sufficient to reach stable walking patterns resembling those observed in overground walking, but that some differences between the two settings remain, especially in older adults; (b) that sufficient familiarization to the treadmill is needed to ascertain the validity and generalizability of comparisons between younger and older adults.

Planned stopping in people with Parkinson

The aim of this study was to quantify gait termination in people with Parkinson (PwP) as the basis for understanding the underlying pathophysiology of stopping difficulties. Fourteen PwP and 14 age- and gender-matched comparisons completed five trials each of four walking tasks: preferred walk, preferred walk with secondary motor task, coming to a planned stop, and planned stop with a secondary motor task. Spatio-temporal data of walks were compared to steady state walking in stopping trials. Results showed that PwP walked with shorter step length, slower speed, yet similar cadence to comparisons. Both groups decreased step length and step speed when performing a secondary task. Neither group showed changes of gait characteristics in steady state walking prior to stopping. For stopping trials, the number of steps, time, and distance taken to stop were compared for PwP and controls. In planned stops PwP used more steps and took a longer time to stop, but both groups stopped within a similar distance. A secondary motor task did not alter stopping distance or number of steps to stop, but stopping time increased in the comparisons. The results indicate that central control mechanisms regulating planned stopping appear to be intact in people with mild to moderate Parkinson.

Gait and balance disorders in Parkinson's disease: Impaired active braking of the fall of centre of gravity

Gait and balance disorders are common in Parkinson's disease (PD), but its pathophysiology is still poorly understood. Step length, antero-posterior, and vertical velocities of the center of gravity (CG) during gait initiation were analyzed in 32 controls and 32 PD patients, with and without levodopa, using a force platform. Brain volumes and mesencephalic surface area were measured in PD patients. During the swing limb period, controls showed a fall in the CG, which was reversed before foot-contact indicating active braking of the CG fall. In PD patients, without levodopa, step length and velocity were significantly reduced and no braking occurred before foot-contact in 22 patients. With levodopa, step length and velocity increased in all patients and 7 patients improved their braking capacity. PD patients with normal braking (n = 17) had significantly lower gait and balance disorder scores and higher normalized-mesencephalic surface areas compared to patients with impaired braking (n = 15). The decreased step length and velocity, characteristic of PD, mainly result from degeneration of central dopaminergic systems. The markedly decreased braking capacity observed in half the PD patients contributes to their gait disorders and postural instability, perhaps as a result of nondopaminergic lesions, possibly at the mesencephalic level.

Effects of weighted vests and sled towing on sprint kinematics

In this study, we compared sprint kinematics of sled towing and vest sprinting with the same relative loads. Twenty athletes performed 30-m sprints in three different conditions: (a) un-resisted, (b) sled towing, and (c) vest sprinting. During sled towing and vest sprinting, external loads of 15% and 20% of body mass were used. Sprint times were recorded over 10 and 30 m. Sagittal-plane high-speed video data were recorded at 5, 15, and 25 m from the start. Relative to the un-resisted condition, sprint time increased (7.5 to 19.8%) in both resisted conditions, resulting mainly from decreased step length ( − 5.2 to − 16.5%) with small decreases in step frequency ( − 2.7 to − 6.1%). Sled towing increased stance phase duration (14.7 to 26.0%), trunk angle (12.5 to 71.5%), and knee angle (10.3 to 22.7%), and decreased swing phase duration ( − 4.8 to − 15.2%) relative to the un-resisted condition. Vest sprinting increased stance phase duration (12.8 to 24.5%) and decreased swing phase duration ( − 8.4 to − 14.4%) and trunk angle ( − 1.7 to − 13.0%). There were significant differences between the two resisted conditions in trunk, thigh, and knee angles. We conclude that sled towing and vest sprinting have different effects on some kinematics and hence change the overload experienced by muscle groups.

Gait characteristics of patients with claudication

Objective: Intermittent claudication of the lower extremity vessels produces pain during walking. This study differentiates walking patterns of patients with claudication from walking patterns of healthy individuals. Design: Nonrandomized case control study performed in a teaching university hospital outpatient setting. Patients: The sample of convenience involved male patients with lower extremity claudication ( n = 19) and 11 healthy men of similar ages. Interventions: Subjects were asked to walk at self-selected speed for 20 meters on a level, indoor surface. Outcome Measures: Walking velocity and number of steps were averaged over each of five trials, and step length was calculated from these measures. Results: Patients with claudication walked slower and had decreased step length and decreased cadence compared with controls ( p < .001). No positive relationship was found between disease severity, peak walking time, and step length, cadence, or speed. Conclusion: All patients with claudication, regardless of disease severity, demonstrated abnormal gait parameters compared with controls. Further studies should evaluate whether the abnormal gait parameters significantly curtail walking ability.

Surgical hip fusion: Gait kinematics and kinetics

This case study presents a subject with a fused hip converted to total hip arthroplasty. Kinematic gait analysis was conducted on 3 occasions, presurgery, 4 months postsurgery, and 2.5 years postsurgery. Presurgery data showed decreased cadence and shorter step length; sound limb possessed increased hip, knee range of motion (ROM), and increased knee flexion during stance; the affected limb had minimal hip motion and normal knee ROM with abnormal pattern. At 4 months postsurgery, the sound limb showed decreased step length, whereas the affected limb showed increased knee extension during stance and increased hip ROM. Data obtained at 2.5 years postsurgery indicated decreased cadence and speed and increased ROM in both limbs. The total hip arthroplasty had provided relief of chronic back and affected hip pain and improved mobility. Gait-specific training is recommended.

Relationship of plantar-flexor peak torque and dorsiflexion range of motion to kinetic variables during walking.

Limited ankle plantar-flexor moments and power during walking have been documented in several patient populations and are believed to contribute to gait deviations. The primary purpose of this study was to determine the relationship of plantar-flexor peak torque (PFPT) and dorsiflexion range of motion (ROM) to peak ankle moments and power during walking in a group of subjects without diabetes mellitus (DM) and in a group of subjects with DM and associated peripheral neuropathies. Nineteen subjects, 9 with DM and associated peripheral neuropathies (mean age = 58 years, SD = 14, range = 35-75 years) and 10 without DM (mean age = 57 years, SD = 11, range = 37-68 years), were evaluated. The following data were collected on all subjects: PFPT, dorsiflexion ROM, and ankle moments and power during walking (using a two-dimensional link-segment model). Hierarchical multiple regression was used for data analysis. Plantar-flexor peak torque made substantial contributions to the ankle moment (40%) and ankle plantar-flexor power (53%) during walking. There also was a high correlation between PFPT and dorsiflexion ROM (r = .78) and between dorsiflexion ROM and ankle power (r = .72). Plantar-flexor peak torque and dorsiflexion ROM are interrelated and appear to be important factors that contribute to ankle plantar-flexor moments and power during walking. This finding suggests that increasing PFPT and dorsiflexion ROM may help decrease gait deviations such as decreased step length and walking speed. When increasing PFPT is not possible, the natural occurrence of limited dorsiflexion ROM may help to maximize ankle moments during walking. Further research is needed to test whether these proposed treatment strategies can have a clinically useful effect. [Mueller MJ, Minor SD, Schaaf JA, et al. Relationship of plantar-flexor peak torque and dorsiflexion range of motion to kinetic variables during walking.

Hip and ankle walking strategies: effect on peak plantar pressures and implications for neuropathic ulceration.

Treatment of neuropathic plantar ulcers often is directed at reducing excessive, repeated peak plantar pressures (PPP). The purposes of this study were to determine whether instructing a subject to walk using a hip strategy would reduce forefoot PPP and change the kinematics of walking during a single session of testing. Thirteen subjects, 7 with peripheral neuropathy and a history of a recent plantar ulcer, and 6 controls participated. PPPs were measured with an in-shoe pressure monitoring system. Kinematics were measured with a computer-assisted motion analysis system. After data were collected as subjects walked using their normal walking pattern, subjects were instructed to walk using the hip strategy by decreasing their push-off, pulling their leg forward from their hips, decreasing step length, and maintaining their normal walking velocity. Compared with using the normal (ankle) strategy, using the hip strategy showed a significant 27% decrease in forefoot PPP and a 24% increase in heel PPP. Kinematic changes were decreased plantar flexion angular velocity, hip extension range-of motion (ROM), and step length, increased dorsiflexion ROM, and hip flexion ROM, but no change in walking velocity. These findings indicate that a change in walking pattern can result in lower forefoot PPP during a single session. Assuming patients can maintain the alterations in their walking pattern, these adaptations may help to heal plantar ulcers in some patients with peripheral neuropathy.