Swing Phase Duration Research Articles

A Comparative Study on Running Gait Pattern of Sprinters and Distance Runners

Abstract: The biomechanics of running gait vary significantly between sprinters and distance runners, owing to the unique demands of their respective disciplines. Sprinting is an aggressive and intricate athletic activity that is primarily associated with power and speed, whereas distance running is concerned with efficiency and fluidity of movement. This study was formulated to determine whether sprinters and distance runners would exhibit differences in technique while running at the same speed. 20 male collegiate athletes—10 sprinters and 10 distance runners aged between 17-25 year were selected from the LNIPE. Each subject ran on treadmill at a set pace of 15 km/hr for 5 mins. Spatiotemporal variables (cadence, stride length, run cycle duration, stance phase duration, swing phase duration, propulsion speed) and pelvic kinematic variables (pelvic tilt, pelvic obliquity, and pelvic rotation) were measured using BTS G-Walk sensor. Collected data was analysed using independent t-test. The result of the study showed no significant differences (p > .05) between sprinters and distance runners for both the spatiotemporal and the pelvic kinematic variables which suggests that, despite their different training focuses and race distances, sprinters and distance runners exhibit similar gait patterns when running at the same speed.

Gait asymmetrical evaluation of lower limb amputees using wearable inertial sensors

This study presents an analysis and evaluation of gait asymmetry (GA) based on the temporal gait parameters identified using a portable gait event detection system, placed on the lateral side of the shank of both lower extremities of the participants. Assessment of GA was carried out with seven control subjects (CS), one transfemoral amputee (TFA) and one transtibial amputee (TTA) while walking at different speeds on overground (OG) and treadmill (TM). Gait cycle duration (GCD), stance phase duration (SPD), swing phase duration (SwPD), and the sub-phases of the gait cycle (GC) such as Loading-Response (LR), Foot-Flat (FF), and Push-Off (PO), Swing-1 (SW-1) and Swing-2 (SW-2) were evaluated. The results revealed that GCD showed less asymmetry as compared to other temporal parameters in both groups. A significant difference (p < 0.05) was observed between the groups for SPD and SwPD with lower limb amputees (LLA) having a longer stance and shorter swing phase for their intact side compared to their amputated side, resulting, large GA for TFA compared to CS and TTA. The findings could potentially contribute towards a better understanding of gait characteristics in LLA and provide a guide in the design and control of lower limb prosthetics/orthotics.

Gait Analysis in Patients with Symptomatic Pes Planovalgus Following Subtalar Arthroereisis with the Talus Screw.

Pes planovalgus is one of the most common pediatric skeletal deformities. There have been no studies to analyze in detail the spatiotemporal variables of gait following arthroereisis. The purpose of our study was to assess gait parameters in patients with symptomatic flexible flatfoot following treatment with the talus screw. This was a prospective study assessing the 22 patients treated surgically due to symptomatic flexible flatfoot with the talus screw. Patients underwent gait assessment with a G-Sensor. We analyzed the following gait parameters: gait cycle duration, step length, support phase duration, swing phase duration, double support duration, single support duration, cadence, velocity, step length. The post-operative gait parameter assessment for the operated and non-operated foot showed a significant difference only in terms of step length. Cadence increased from the pre-operative mean of 82.29 steps/min to a post-operative mean of 102.94 steps/min. Gait velocity increased significantly from 0.81m/s before to 0.96m/s after surgery. Arthroereisis with the talus screw helps improve gait parameters following surgery. Post-operatively, we observed increased gait velocity and cadence and decreased gait cycle duration in the operated limb. Short-term biomechanical outcomes of pes planovalgus treatment with the talus screw are good.

A hierarchical model for external electrical control of an insect, accounting for inter-individual variation of muscle force properties.

Cyborg control of insect movement is promising for developing miniature, high-mobility, and efficient biohybrid robots. However, considering the inter-individual variation of the insect neuromuscular apparatus and its neural control is challenging. We propose a hierarchical model including inter-individual variation of muscle properties of three leg muscles involved in propulsion (retractor coxae), joint stiffness (pro- and retractor coxae), and stance-swing transition (protractor coxae and levator trochanteris) in the stick insect Carausius morosus. To estimate mechanical effects induced by external muscle stimulation, the model is based on the systematic evaluation of joint torques as functions of electrical stimulation parameters. A nearly linear relationship between the stimulus burst duration and generated torque was observed. This stimulus-torque characteristic holds for burst durations of up to 500ms, corresponding to the stance and swing phase durations of medium to fast walking stick insects. Hierarchical Bayesian modeling revealed that linearity of the stimulus-torque characteristic was invariant, with individually varying slopes. Individual prediction of joint torques provides significant benefits for precise cyborg control.

Biomechanical characteristics of transfemoral bone-anchored prostheses during gait: A review of literature.

Osseointegration (OI) is an emerging technique that allows a direct connection between the bone and a titanium metal implant, allowing the direct attachment of bone-anchored prostheses (BAP) to address the problems associated with socket prostheses. This review article aims to compare the biomechanical features of gait when using a transfemoral BAP in comparison to healthy gait, and in comparison to the gait of traditional transfemoral socket prosthesis users. A computer-based literature search of electronic databases since inception (ranging from 1967 to 2004 depending on the database) to June 14, 2022, identified peer-reviewed articles focusing on the temporal-spatial, kinematic, kinetic, and electromyography data related to transfemoral BAP gait. Eight articles were included that focused on these biomechanical features of gait in adults with BAP and were compared with socket prosthesis users or healthy gait. Compared with healthy participants, prosthesis users after OI surgery have slower speed and cadence, lower symmetry, longer duration of swing phase, increased pelvic and trunk motion, more hip extension, larger moments on the intact limb, and lower forces on the prosthetic side. Compared with transfemoral socket prosthesis gait, BAP gait shows faster cadence and longer duration of support phase. There are limited and inconsistent data on changes in trunk, pelvic, and hip motion with OI. Based on this review, transfemoral BAP improve spatial-temporal parameters closer to normal gait when compared to socket gait, but there are persisting deficits compared with healthy gait. Additional studies are needed to confirm the changes in kinematics and kinetics when walking with a BAP.

Relationship of Neural Correlates of Gait Characteristics and Cognitive Dysfunction in Patients with Mild Cognitive Impairment.

Background: Some patients with mild cognitive impairment (MCI) experience gait disturbances. However, there are few reports on the relationship between gait disturbance and cognitive function in patients with MCI. Therefore, we investigated the neural correlates of gait characteristics related to cognitive dysfunction. Methods: Eighty patients diagnosed with MCI from three dementia centers in Gangwon-do, Korea, were recruited for this study. We defined MCI as a Clinical Dementia Rating global score of 0.5 or higher, with a memory domain score of 0.5 or greater. The patients were classified as having either higher or lower MMSE and the groups were based on their Mini Mental Status Examination z-scores. Multiple logistic regression analysis was performed to examine the association between the gait characteristics and cognitive impairment. Analyses included variables such as age, sex, years of education, number of comorbidities, body mass index, and height. Results: Gait velocity, step count, step length, heel-to-heel base support, swing and stance phase duration, and support time were associated with cognitive function. A decrease in gray matter volume in the right pericalcarine area was associated with gait characteristics related to cognitive dysfunction. An increase in the curvature of gray matter in the right entorhinal, right lateral orbitofrontal, right cuneus, and right and left pars opercularis areas was also associated with gait characteristics related to cognitive dysfunction. Conclusion: Since gait impairment is an important factor in determining activities of daily living in patients with mild cognitive impairment, the evaluation of gait and cognitive functions in patients with mild cognitive impairment is important.

Effects of the speed on the webbed foot kinematics of mallard (Anas platyrhynchos).

In this study, the effect of the speed on the webbed foot locomotion of the mallard was analyzed based on a considerable number of reliable indoor test data. Four adult male mallards were selected for analysis, and the locomotion speed of the mallard was controlled using the treadmill at an accurate and adjustable speed. The locomotion pattern of the webbed foot of the mallard at different speeds was recorded using a high-speed camera. The changes in the position and conformation of the webbed foot during locomotion on a treadmill were tracked and analyzed using Simi-Motion kinematics software. The results indicated that the stride length of the mallard increased, and the stance phase duration was shortened with the increase of the speed, whereas the swing phase duration did not vary significantly. The duty factor decreased with the increase of the mallard speed but not drop below to 0.5, because the mallards flew with their wings, or moved backward relative to the treadmill with the further increase of the speed. Using the energy method to further distinguish gait, and through the percentage of congruity analysis, it was found that between 0.73 and 0.93 m/s, the gait experienced a transition from walking to grounded running, with no significant changes in spatiotemporal parameters. At speeds between 0.93 and 1.6 m/s, mallards adopt a grounded running gait. The instantaneous changes of the tarsometatarso-phalangeal joint (TMTPJ) angle and the intertarsal joint (ITJ) angle at touch-down, mid-stance and lift-off concomitant with the change of the speed were examined with the TMTPJ and ITJ angle as the research objects. Moreover, the continuous changes of the joint angles were examined in a complete stride cycle. The result indicated that the increase of the speed will also make the TMTPJ and ITJ angle change ahead of time in a stride cycle, proving the shortened stance phase duration. The ITJ angle changed much more than the TMTPJ. Thus, the above result reveals that the mallard primarily responds with the increase of the speed by adjusting the ITJ, instead of the TMTPJ. The vertical displacement of the toe joint points and the toe joint angle was studied (α joint angle is between the second toe and the third toe; β joint angle is between the third toe and the fourth toe) with a complete stride cycle as the research object. The distal phalanxes of the second, third and fourth toes first contacted the ground, and the proximal phalanx touched the ground in turn during the early stance phase duration of the mallard, as indicated by the result of this study. However, the toes got off the ground in turn from the proximal phalanxes when the mallard foot got off the ground. With the decrease of the interphalangeal α and β joint angles, the foot web tended to be close and rapidly recovered before the next touch-down. The above result reveals that the webbed foot of the mallard is a coupling system that plays a role in the adjustment of speed.

Unilaterally Applied Resistance to Swing Leg Shows a Different Adaptation Pattern Compared to Split-Belt Treadmill in Patients with Stroke.

Persons with chronic stroke (PwCS) have a decreased ability to ambulate and walk independently. We aimed to investigate the differences between the motor adaptation process for two different perturbation methods: split-belt treadmill walking and unilaterally applied resistance to the swing leg during walking. Twenty-two PwCS undergo split-belt treadmill walking and unilaterally applied resistance to the swing leg during walking, each one week apart. The test included three phases: the baseline period, the early-adaptation period and the late-adaptation period, as well as the early-de-adaptation period and the late-de-adaptation period. The average step length, swing duration, double-limb support duration, and coefficient of variance (CV) of these parameters were measured. During the split-belt treadmill walking, PwCS showed an adaptation of double-limb support duration symmetry (p = 0.004), specifically a trend between baseline versus early-adaptation (p = 0.07) and an after-effect (late-adaptation compare to early-de-adaptation, p = 0.09). In unilaterally applied resistance to the swing leg during walking, PwCS showed lower swing phase duration CV, in the adaptation period (baseline compare to adaptation, p = 0.006), and a trend toward increased variability of gait in the de-adaptation period compare to the adaptation periods (p = 0.099). The rate of adaptation and de-adaptation were alike between the two perturbation methods. Our findings show that the learning process happening in the central nervous system of PwCS may be dependent on the nature of the perturbation (mechanical resistance vs. split-belt) and that PwCS are able to adapt to two types of errors.

Daily Outdoor Cycling by Older Adults Preserves Reactive Balance Behavior: A Case-Control Study.

We examined whether older adults who cycle outdoors regularly have better reactive balance control than noncycling older adults. Sixteen cyclist older adults and 24 age-, sex-, and health-matched controls who did not cycle (noncyclists) were exposed to unannounced perturbations of increased magnitudes in standing. We evaluated the strategies and kinematics employed at each perturbation magnitude. We found that cyclists exhibited a significantly higher stepping threshold, lower probability of stepping at each perturbation magnitude, and lower number of trials in which the participant needed to make a step to retain their balance. Cyclists also tended to recover balance using unloaded leg strategies in the first recovery step rather than a loaded leg strategy; they showed faster swing phase duration in the first recovery step, better controlling the displacement of center of mass than noncyclists. Older adults who cycle regularly outdoors preserve their reactive balance functions, which may reduce fall risks.

Ai Chi for Balance and Gait in Individuals with Parkinson's Disease: A Pilot Study

Background and Purpose: Parkinson disease (PD) has effects on an individual's balance, and Ai Chi can be used to improve balance and gait performance. The aim of this study was to investigate the effectiveness of Ai Chi in improving the balance and gait of individuals with idiopathic PD. Method: Ten individuals with PD at Hoehn and Yahr stages 1-3 were included in this 6-week study. Participants underwent a structured Ai Chi program (1 hour per session, twice weekly) for 6 weeks (12 sessions in total). Balance was assessed at baseline and week 6 using the Timed Up and Go (TUG) test, the Five Times Sit-to-Stand (FTSTS) test, the Four Square Step Test (FSST), the Ten Meter Walk Test (10MWT), and the Sensory Organization Test (SOT). Gait parameters were measured by inertial measurement units and videotaping for 2-dimentional motion analysis. Surface electromyography was used for measuring muscle activity during gait in the bilateral rectus femoris, biceps femoris, gastrocnemius, and tibialis anterior. Results: In a pre- and postintervention comparison, significant improvements were observed in the FTSTS, FSST, and TUG scores as well as in the composite, vision, and vestibular scores in the 10MWT and SOT (P &lt; .005). The results indicated improvement in balance. As for the gait analysis, no significant differences were observed in spatiotemporal parameters, including speed, cadence, step length, stride length, step duration, stride duration, swing-phase duration, stance-phase duration, and double support duration. Insignificant changes in the percentage maximum voluntary contraction of all the muscles examined were found, while a significant decrease in maximum voluntary contraction was identified in the left biceps femoris. Conclusions: The Ai Chi program produced a significant improvement in balance in individuals with PD, with insignificant results shown in gait. Ai Chi is an appropriate intervention to improve balance in individuals with PD.

Validity of Spatio-Temporal Gait Parameters in Healthy Young Adults Using a Motion-Sensor-Based Gait Analysis System (ORPHE ANALYTICS) during Walking and Running.

Motion sensors are widely used for gait analysis. The validity of commercial gait analysis systems is of great interest because calculating position/angle-level gait parameters potentially produces an error in the integration process of the motion sensor data; moreover, the validity of ORPHE ANALYTICS, a motion-sensor-based gait analysis system, has not yet been examined. We examined the validity of the gait parameters calculated using ORPHE ANALYTICS relative to those calculated using conventional optical motion capture. Nine young adults performed gait tasks on a treadmill at speeds of 2−12 km/h. The three-dimensional position data and acceleration and angular velocity data of the feet were collected. The gait parameters were calculated from motion sensor data using ORPHE ANALYTICS, and optical motion capture data. Intraclass correlation coefficients [ICC(2,1)] were calculated for relative validities. Eight items, namely, stride duration, stride length, stride frequency, stride speed, vertical height, stance phase duration, swing phase duration, and sagittal angleIC exhibited excellent relative validities [ICC(2,1) > 0.9]. In contrast, sagittal angleTO and frontal angleIC demonstrated good [ICC(2,1) = 0.892−0.833] and moderate relative validity [ICC(2,1) = 0.566−0.627], respectively. ORPHE ANALYTICS was found to exhibit excellent relative validities for most gait parameters. These results suggest its feasibility for gait analysis outside the laboratory setting.

Walking asymmetry and its relation to patient-reported and performance-based outcome measures in individuals with unilateral lower limb loss

ABSTRACT Gait asymmetry persists for most people after lower limb amputation and is associated with slower walking speeds. However, the relationship between gait asymmetry and patient-reported function remains unclear because they are not commonly assessed together. The purpose of this study was to determine relationships between gait asymmetries in people with lower limb loss and (1) patient-reported outcomes and (2) performance-based prosthetic functional measures. This cross-sectional analysis included nine people with unilateral limb loss aged 48.2 ± 13.1 years of mixed amputation etiology. Patient-reported outcomes included the Prosthetic Evaluation Questionnaire mobility subscale and Activities-specific Balance Confidence scale. Performance outcomes included the Berg Balance Scale and the 30-second sit-to-stand test. Walking performance measures included the 2-Minute Walk Test, during which APDM Opal sensors recorded spatiotemporal gait parameters, and daily step-counts from StepWatch4 activity monitors. The study found that the most asymmetric gait symmetry ratios (prosthetic-limb divided by intact-limb) could be attributed to prosthetic foot dorsiflexion-plantarflexion and rotation motion limitations: prosthetic-limb trailing double support (0.789 ± 0.052), toe-off (0.760 ± 0.068) and toe-out angle (0.653 ± 0.256). Single limb stance, and stance and swing phase durations were most strongly associated with balance and walking performance measures. Notably, no symmetry ratio was significantly associated with patient-reported prosthetic function (unadjusted Pearson correlation coefficients r < 0.50, P > 0.05). More gait symmetry was associated with better balance and walking performance but had no significant relationship with patient-reported function. Although achieving gait symmetry after lower limb loss is a common walking goal, symmetry was unrelated to the perception of functional mobility for people with lower limb loss.

Predictors of ambulatory recovery and walking proficiency in community-dwelling stroke survivors: a cross-sectional study

BackgroundAlthough the major goal of rehabilitation is to return a stroke survivor (SSv) to as close to their pre-stroke functioning, limitation in ambulatory recovery and walking proficiency is the major impediment. Despite the importance of walking to the outcomes in stroke, factors predicting its recovery remain unclear. This study therefore was aimed at exploring the predictors of ambulatory recovery and walking proficiency in community-dwelling SSv.MethodsThis study involved 164 (83females) SSv from four tertiary health institutions in Nigeria. Ambulatory level and status was assessed using Functional Ambulatory Classification, motor function using the Fugl-Myer Assessment scale (lower limb), and ambulatory/waking endurance using the 6-min walk test. Ambulatory capability was assessed using the Lower Extremity Functional Scale, ambulatory self-confidence using the Ambulatory Self-Confidence Questionnaire, and functional ambulatory profile using the Modified Emory Functional Ambulation Profile. Mobility was assessed using the Modified Rivermead Mobility Index, functional mobility using Time Up and Go, balance using the Berg Balance Scale, and cognitive function using the modified Mini-Mental State Examination. Spatial indexes were assessed using the Footprint method and temporal variables using a stopwatch and gait speed on a 10-m walkway. Data was analyzed using multiple regression analysis at p ≤ 0.05.ResultsParticipants (mean age = 54.3±11.36 years) have had stroke for 12.9 ± 17.39 months and spent 9.82 ± 13.19 months in hospital admissions. More (65.2%) had ischemic stroke with 54.3% of them having left hemispheric stroke. The predictors of ambulatory onset in SSv were stroke duration and length of stay in hospital admission contributing 40.3% (β = 0.403) and 17.6% (β = 0.176) respectively to the variance. Mobility (β = 0.249, p < 0.001), gait speed (β = 0.185, p = 0.012), paretic double-limb support time (β = 0.155, p = 0.03), balance (β = 0.334, p < 0.001), and cognition (β = 0.155, p = 0.01) were predictors of ambulatory self-confidence contributing 59.5% to the variance. Balance (β = 0.363, p < 0.001) and mobility (β = 0.155, p = 0.015) were predictors of ambulatory capability contributing 52.9% to the variance. Balance (β = −0.489, p < 0.001), paretic double-limb support time (β = 0.223, p = 0.003), gait speed (β = −0.181, p = 0.022), and paretic swing phase duration (β = 0.177, p = 0.01) were predictors of functional ambulatory profile (p < 0.05) contributing 52.9% to the variance. Gait speed (β = −0.648, p < 0.001) and step length (β = −0.157, p = 0.003) were predictors of walking endurance contributing 76.5% to the variance.ConclusionAmbulatory recovery and walking proficiency depend on the interplay among duration of stroke and length of hospitalization on the one hand and balance performance, cognitive function, and the spatiotemporal integrity of the affected limb on the other hand.

Synchronized Cyclograms to Assess Inter-Limb Symmetry during Gait in Post-Stroke Patients

The aim of this study was to assess the inter-limb symmetry during gait in post-stroke patients using the synchronized cyclograms technique. In total, 41 individuals with stroke (21 left and 20 right hemiplegic patients; age: 57.9 ± 12.8 years; time stroke event 4.6 ± 1.8 years) and 48 age-, sex-, and height-matched individuals (control group: CG; age: 54.4 ± 12.5 years) were assessed via 3D gait analysis. Raw kinematic data were processed to compute spatio-temporal parameters (speed, stride length, cadence, stance, swing, and double support phases duration) and angle–angle diagrams (synchronized cyclograms), which were characterized in terms of area, orientation, and trend symmetry indices. The results reveal that all spatio-temporal parameters are characterized by abnormal values, with reduced speed, stride length, cadence, and swing phase duration and increased stance and double support phases duration. With respect to inter-limb symmetry, higher values were found in post-stroke individuals for all the considered parameters as patients generally exhibited a cyclogram characterized by larger areas, higher orientation, and trend symmetry parameters with respect to CG. The described alterations of gait asymmetry are important from a clinical point of view as the achievement of symmetry in gait represents a crucial objective in the rehabilitation of hemiplegic people.

Different modulation of oscillatory common neural drives to ankle muscles during abrupt and gradual gait adaptations.

Different neural contributions to motor learning might be involved when different error sizes of perturbation are introduced. Although the corticospinal drive contributes to abrupt gait adaptation processes, no studies have investigated whether cortical involvement during gait differs between perturbations applied abruptly and gradually. This study aimed to investigate the differences in oscillatory common neural drives to ankle muscles during gait between abrupt and gradual adaptations, using coherence analyses of paired surface electromyographic (EMG) recordings. Sixteen healthy young adults performed the treadmill gait with perturbation resisting forward movement of the swing leg for 10min under two conditions: abrupt (a large perturbation from the beginning of the adaptation period) and gradual (a series of small perturbations that gradually increased). Swing phase duration and step length showed significantly greater asymmetry in the abrupt condition than in the gradual condition in the early adaptation period (p < 0.01), despite no significant differences in gait symmetries between the two conditions in the early post-adaptation period. EMG-EMG coherence calculated from the tibialis anterior muscle in the beta band (15-35Hz) on the perturbed side was significantly higher in the early adaptation period in the abrupt condition (p < 0.05), but not in the gradual condition. There were significant relationships between changes in temporal gait symmetry and EMG-EMG coherence during the different adaptation periods between the two conditions (p < 0.05). The abrupt large perturbation seems to require a cortical involvement, whereas a gradual adaptation with small gait asymmetry requires no modulation of cortical involvement.

Stimulation of the pedunculopontine and cuneiform nuclei for freezing of gait and falls in Parkinson disease: Cross-over single-blinded study and long-term follow-up

IntroductionDeep brain stimulation (DBS) of the mesencephalic locomotor region, composed of the pedunculopontine (PPN) and cuneiform (CuN) nuclei, has been proposed to treat dopa-resistant gait and balance disorders in Parkinson's disease (PD). Here, we report the long-term effects of PPN- or CuN-DBS on these axial disorders. MethodsIn 6 PD patients operated for mesencephalic locomotor region DBS and prospectively followed for more than 2 years, we assessed the effects of both PPN- and CuN-DBS (On-dopa) in a cross-over single-blind study by using clinical scales and recording gait parameters. Patients were also examined Off-DBS. ResultsMore than 2 years after surgery, axial and Tinetti scores were significantly aggravated with both PPN- or CuN-DBS relative to before and one year after surgery. Gait recordings revealed an increased double-stance duration with both PPN- or CuN-DBS, higher swing phase duration with CuN-DBS and step width with PPN-DBS. With PPN- versus CuN-DBS, the step length, velocity and cadence were significantly higher; and the double-stance and turn durations significantly lower. Irrespective the target, we found no significant change in clinical scores Off-DBS compared to On-DBS. The duration of anticipatory postural adjustments as well as step length were lower with versus without PPN-DBS. We found no other significant changes in motor, cognitive or psychiatric scores, except an increased anxiety severity. ConclusionIn this long-term follow-up study with controlled assessments, PPN- or CuN-DBS did not improve dopa-resistant gait and balance disorders with a worsening of these axial motor signs with time, thus indicating no significant clinical effect.

Allometry in desert ant locomotion (Cataglyphis albicans and Cataglyphis bicolor) - does body size matter?

Desert ants show a large range of adaptations to their habitats. They can reach extremely high running speeds, for example, to shorten heat stress during foraging trips. It has recently been examined how fast walking speeds are achieved in different desert ant species. It is intriguing in this context that some species exhibit distinct intraspecific size differences. We therefore performed a complete locomotion analysis over the entire size spectrum of the species Cataglyphis bicolor, and we compared this intraspecific dataset with that of the allometrically similar species Cataglyphis albicans. Emphasis was on the allometry of locomotion: we considered the body size of each animal and analysed the data in terms of relative walking speed. Body size was observed to affect walking parameters, gait patterns and phase relationships in terms of absolute walking speed. Unexpectedly, on a relative scale, all ants tended to show the same overall locomotion strategy at low walking speeds, and significant differences occurred only between C. albicans and C. bicolor at high walking speeds. Our analysis revealed that C. bicolor ants use the same overall strategy across all body sizes, with small ants reaching the highest walking speeds (up to 80 body lengths s-1) by increasing their stride length and incorporating aerial phases. By comparison, C. albicans reached high walking speeds mainly by a high synchrony of leg movement, lower swing phase duration and higher stride frequency ranging up to 40 Hz.

Wearable inertial sensors are highly sensitive in the detection of gait disturbances and fatigue at early stages of multiple sclerosis

BackgroundThe aim of the current study was to examine multiple gait parameters obtained by wearable inertial sensors and their sensitivity to clinical status in early multiple sclerosis (MS). Further, a potential correlation between gait parameters and subjective fatigue was explored.MethodsAutomated gait analyses were carried out on 88 MS patients and 31 healthy participants. To measure gait parameters (i.e. walking speed, stride length, stride duration, duration of stance and swing phase, minimal toe-to-floor distance), wearable inertial sensors were utilized throughout a 6-min 25-ft walk. Additionally, self-reported subjective fatigue was assessed.ResultsMean gait parameters consistently revealed significant differences between healthy participants and MS patients from as early as an Expanded Disability Status Scale (EDSS) value of 1.5 onwards. Further, MS patients showed a significant linear trend in all parameters, reflecting continuously deteriorating gait performance throughout the test. This linear deterioration trend showed significant correlations with fatigue.ConclusionsWearable inertial sensors are highly sensitive in the detection of gait disturbances, even in early MS, where global scales such as the EDSS do not provide any clinical information about deviations in gait behavior. Moreover, these measures provide a linear trend parameter of gait deterioration that may serve as a surrogate marker of fatigue. In sum, these results suggest that classic timed walking tests in routine clinical practice should be replaced by readily and automatically applicable gait assessments, as provided by inertial sensors.

Acute effects of short-term stretching of the triceps surae on ankle mobility and gait initiation in patients with Parkinson's disease

BackgroundAnkle mobility is known to be of uttermost importance to generate propulsive forces and control balance during gait initiation. Impaired mobility of the postural chain occurs with normal ageing and is exacerbated in patients with Parkinson's disease. This study questions whether short-term stretching session applied to the triceps surae improves ankle mobility and, consequently, dynamical postural control in patients with Parkinson's disease performing gait initiation. MethodNineteen patients with Parkinson's disease participated in this study and were randomly assigned to an “intervention group” or a “sham group”. In the intervention group, patients were exposed to a 4 × 60 seconds triceps surae stretching. In the sham group, they were exposed to forearm stretching. Additionally, ten age-matched healthy elderly, who were not exposed to any stretching-treatment, were assigned to a “control group”. Participants performed series of gait initiation on a force-plate before and after their treatment. FindingsAnkle mobility was improved in the intervention group after triceps surae stretching. The forward velocity of the center-of-mass at heel-off and motor performance related-parameters (progression velocity, center-of-mass velocity at foot-contact and swing phase duration) were also improved in the intervention group, with large effect sizes (d ≥ 0.8). None of the stability parameters were modified by the treatments. InterpretationShort-term triceps surae stretching is an efficient method to increase ankle mobility and improve the capacity to generate forward propulsive forces in patients with Parkinson's disease. These findings are congruent with the “posturo-kinetics capacity” theory according to which dynamical postural control depends on postural chain mobility.

Efficacy of a novel walking assist device with auxiliary laser illuminator in stroke Patients~ a randomized control trial

Task-oriented functional walking is important in stroke patients. We aimed to investigate effects of a quad-cane with auxiliary laser illuminator (laser-cane) among stroke patients. This was a randomized-prospective study. Patients in the experimental group (EG) received 15-min of walking training with laser-cane and 15-min of traditional physical therapy. Patients in the control group (CG) received the same rehabilitation without laser-cane. The rehabilitation lasted for 4 weeks, twice per week. Primary outcome were gait parameters. Secondary outcomes were Berg Balance Scale (BBS), Timed Up and Go Test (TUG), and Barthel index (BI). Outcomes were measured at baseline, at the end of the rehabilitation (visit-1), and 4 weeks later (visit-2). Both the groups (both n=15) showed improvement of cadence, relative stance and swing phase duration of non-paretic side, BBS, and TUG at both visits. In the intragroup comparison, the EG additionally improved at stride length, relative stance and swing phase duration of paretic side, and gait speed at both visits; temporal swing symmetry, and toe-off angle of non-paretic side at the visit-2. Intergroup comparing for changing of outcomes with the CG, stride length and gait speed increased, relative stance phase duration of the non-paretic site decreased, and the temporal swing symmetry improved at the visit-1; relative stance phase duration of the paretic side decreased and the temporal stance symmetry improved at the visit-2 in the EG. Rehabilitation with laser-cane improved the balance, activity of daily living, gait symmetry and gait parameters of stroke patients.