Double Support Time Research Articles

Usefulness of one-arm motorized gait device for chronic hemiplegic stroke survivors.

After stroke, gait training is a key component of rehabilitation, and most individuals use a variety of walking aids depending on their physical condition and environment. This study aimed to investigate the potential effect of a one-arm motorized gait device for gait assist of chronic hemiplegic stroke survivors through comparison with traditional gait devices (parallel bar and hemi-walker). This study was conducted on 14 chronic hemiplegic stroke survivors. The participants were asked to walk under three conditions using different gait devices, and their gait parameters during walking were collected and analyzed. The first condition involved walking on parallel bars; second condition, walking using hemi-walkers; and third condition, walking using one-arm motorized gait devices. With the use of a gait analysis system, the spatio-temporal gait parameters in each condition were collected, such as gait velocity, cadence, step length, stride length, single support time, and double support time. In the results by repeated-measures ANOVA or the Friedman test, a significant difference was found in the gait parameters among all three conditions (p< 0.05). The post-hoc test showed a significant change in the spatio-temporal gait parameters (especially, velocity, cadence and affected side single and double support time) when one-arm motorized gait device were used compared with parallel bars and hemi-walkers (p< 0.05). The results of this study suggest that one-arm motorized gait devices developed for hemiplegic stroke survivors may be more effective potentially than parallel bars and hemi-walkers in gait assistance of chronic hemiplegic stroke survivors.

Cognitive-motor interference during walking with modified leg mechanics: a dual-task walking study.

The use of mobile exoskeletons as assistive walking devices has the potential to affect the biomechanics of the musculoskeletal system due to their weight and restricted range of motion. This may result in physical and cognitive load for the user. Understanding how lower extremity loading affects cognitive-motor interference is crucial for the design of wearable devices, including powered exoskeletons, and the development of effective training interventions. This study aims to examine the effects of modified leg mechanics on cognitive-motor interference in dual-task walking. Gait variability, as an indicator of motor control, was analyzed to investigate its relation to cognitive task difficulty and to determine whether lower extremity loading modifies this relationship. Additionally, the impact on the gait pattern, as represented by the mean values of spatio-temporal gait parameters were investigated. Fifteen healthy young adults walked on a treadmill with and without weight cuffs bilaterally attached to their thighs and shanks while performing a visual-verbal Stroop test (simple task) and a serial subtraction task (difficult task). Dependent variables include mean values and variability (coefficients of variation) of step length, step width, stride time and double support time. Additionally, secondary task performance as correct response rates and perceived workload were assessed. Double support time variability decreased during dual-task walking, but not during walking with modified leg mechanics while performing the difficult secondary task. Walking with modified leg mechanics resulted in increased gait variability compared to normal walking, regardless of cognitive load. During walking with modified leg mechanics, step length, step width, and stride time increased, while double support time decreased. The secondary tasks did not affect the gait pattern. The interplay between an external focus of attention and competition for attentional resources may influence the variability of double support time. The findings suggest that walking with modified leg mechanics could increase cognitive-motor interference for healthy young adults in demanding dual-task situations. Therefore, it is important to analyze the underlying mechanisms of cognitive-motor interference in the context of human-exoskeleton interaction.

Global Sagittal Angle and T9-tilt seem to be the most clinically and functionally relevant global alignment parameters in patients with Adult Spinal Deformity

IntroductionRadiographic analysis is necessary for the assessment and the surgical planning in adults with spinal deformity (ASD). Restoration of global alignment is key to improving patient's quality of life. However, the large number of existing global alignment parameters can be confusing for surgeons. Research questionTo determine the most clinically and functionally relevant global alignment parameters in ASD. Material and methodsASD and controls underwent full body biplanar X-ray to calculate global alignment parameters: odontoid to hip axis angle (OD-HA), global sagittal angle (GSA), global tilt (GT), SVA, center of auditory meatus to hip axis (CAM-HA), SSA, T1-tilt and T9-tilt. All subjects filled HRQoL questionnaires: ODI, SF-36, VAS for pain and BDI (Beck's Depression Inventory). 3D gait analysis was performed to calculate kinematic and spatio-temporal parameters. A machine learning model predicted gait parameters and HRQoL scores from global alignment parameters. Results124 primary ASD and 47 controls were enrolled. T9 tilt predicted the most BDI (31%), hip flexion/extension during gait (36%), and double support time (39%). GSA predicted the most ODI (26%), thorax flexion/extension during gait (33%), and cadence (36%). Discussion and conclusionAmong all global alignment parameters, GSA, evaluating both trunk shift and knee flexion, and T9 tilt, evaluating the shift of the center of mass, were the best predictors for most of HRQoL scores and gait kinematics. Therefore, we recommend using GSA and T9 tilt in clinical practice when evaluating ASD because they represent the most quality of life and functional kinematic of these patients.

Self-treatment of freezing of gait in Parkinson’s disease patients using silicone pads to apply Thai acupressure to plantar acupoints: A randomised, controlled trial

IntroductionFreezing of gait (FOG) involves dysfunction of the motor and sensory systems. Peripheral sensory stimuli, including Thai acupressure, can improve proprioceptive function and decrease FOG episodes. Here, we sought to determine the efficacy of acupressure as a self-treatment to alleviate FOG in patients with Parkinson’s disease (PD). MethodsWe conducted an open-label, controlled trial of 60 PD patients with FOG while medicated, randomised into two groups: an active-treatment group using silicone pads to apply pressure to plantar acupoints on the head of the big toe and the base of the first metatarsal bone on each foot for 6 s using patient body weight while seated, repeated four times for each acupoint bilaterally, and a sham-treatment group using a similar protocol without the silicone pads. The primary outcome was stride length. Secondary outcomes included FOG episodes, FOG duration, percent duration of FOG to total gait time (%FOG), and gait parameters. A baseline-adjusted analysis of covariance was used to compare outcomes between the two groups. ResultsCompared with the sham treatment, the active treatment increased stride length, gait velocity, and cadence (all p < 0.001), and decreased FOG episodes and duration (both p < 0.001), %FOG (p = 0.011), and double-support time (p < 0.001). No adverse effects were noted. ConclusionsAcupressure using silicone pads to stimulate plantar acupoints for self-treatment is a noninvasive, simple, safe way to improve gait and alleviate FOG in patients with PD. Clinical Trial RegistrationWe registered the study prospectively in the Thai Clinical Trial Registry No. TCTR20200317001.

Validation of algorithms for calculating spatiotemporal gait parameters during continuous turning using lumbar and foot mounted inertial measurement units

Spatiotemporal gait parameters such as step time and walking speed can be used to quantify gait performance and determine physical function. Inertial measurement units (IMUs) allow for the measurement of spatiotemporal gait parameters in unconstrained environments but must be validated against a gold standard.While many IMU systems and algorithms have been validated during treadmill walking and overground walking in a straight line, fewer studies have validated algorithms during more complex walking conditions such as continuous turning in different directions.This study explored the concurrent validity in a population of healthy adults (range 26–52 years) of three different algorithms using lumbar and foot mounted IMUs to calculate spatiotemporal gait parameters: two methods utilizing an inverted pendulum model, and one method based on strapdown integration. IMU data was compared to a Vicon twelve-camera optoelectronic system, using data collected from 9 participants performing straight walking and continuous walking trials at different speeds, resulting in 162 walking trials in total. Intraclass correlation coefficients (ICCA,1) for absolute agreement were calculated between the algorithm outputs and Vicon output.Temporal parameters were comparable in all methods and ranged from moderate to excellent, except double support time which was poor. Strapdown integration performed better for estimating spatial parameters than pendulum models during straight walking, but worse during turning. Selecting the most appropriate model should take into consideration both speed and walking condition.

Effect of Combined Neuromuscular Electrical Stimulation and Disease-Modifying Antirheumatic Drug Therapy Versus Disease-Modifying Antirheumatic Drug Therapy Alone on Enhancing Gait and Reducing Fall Risks in Patients with Rheumatoid Arthritis and Peripheral Neuropathy

Background: Rheumatoid Arthritis (RA) with Peripheral Neuropathy (PN) significantly impacts gait and balance, posing challenges in patient management. While Disease-Modifying Antirheumatic Drug (DMARD) therapy is effective for RA, it may not fully address these functional impairments. Neuromuscular Electrical Stimulation (NMES) has been proposed as a complementary therapy to improve these outcomes. Objective: This study aimed to assess the effectiveness of combining NMES with DMARD therapy versus DMARD therapy alone in enhancing gait and reducing fall risks among RA patients with PN. Methods: In a randomized controlled trial, 66 RA patients with PN were allocated to either Group A (NMES + DMARD, n=33) or Group B (DMARD only, n=33). Baseline demographics (age, gender, BMI, RA duration) and clinical outcomes (stride length, gait speed, cadence, etc.) were measured. Assessments were conducted at the study’s onset and after an 8-week intervention period, with data analyzed using independent t-tests. Results: Baseline data revealed no significant differences between the groups. Post-intervention, Group A exhibited marked improvements: stride length reduced to 58.26 cm (± 5.0) compared to Group B’s 69.1 cm (± 5.2, p=0.036), gait speed decreased to 0.77 m/s (± 5.1) against Group B’s 0.94 m/s (± 5.2, p=0.020), and cadence lowered to 81.43 steps/min (± 4.5) versus Group B’s 97.06 steps/min (± 4.7, p=0.029). Significant improvements were also seen in step width, double support time, and balance scales in Group A. However, biochemical markers did not show significant differences post-intervention. Conclusion: The integration of NMES with DMARD therapy resulted in significant improvements in gait and balance parameters compared to DMARD therapy alone in RA patients with PN. These findings suggest that NMES could be an effective adjunct to DMARDs in managing functional impairments in this population.

Impact of deep brain stimulation on gait in Parkinson disease: A kinematic study

BackgroundThe effect of Deep Brain Stimulation (DBS) on gait in Parkinson’s Disease (PD) is poorly understood. Kinematic studies utilizing quantitative gait outcomes such as speed, cadence, and stride length have shown mixed results and were done mostly before and after acute DBS discontinuation. ObjectiveTo examine longitudinal changes in kinematic gait outcomes before and after DBS surgery. MethodWe retrospectively assessed changes in quantitative gait outcomes via motion capture in 22 PD patients before and after subthalamic (STN) or globus pallidus internus (GPi) DBS, in on medication state. Associations between gait outcomes and clinical variables were also assessed. ResultGait speed reduced from 110.7 ± 21.3 cm/s before surgery to 93.6 ± 24.9 after surgery (7.7 ± 2.9 months post-surgery, duration between assessments was 15.0 ± 3.8 months). Cadence, step length, stride length, and single support time reduced, while total support time, and initial double support time increased. Despite this, there was overall improvement in the Movement Disorder Society-Unified Parkinson Disease Rating Scale-Part III score “on medication/on stimulation” score (from 19.8 ± 10.7–13.9 ± 8.6). Change of gait speed was not related to changes in levodopa dosage, disease duration, unilateral vs bilateral stimulation, or target nucleus. ConclusionQuantitative gait outcomes in on medication state worsened after chronic DBS therapy despite improvement in other clinical outcomes. Whether these changes reflect the effects of DBS as opposed to ongoing disease progression is unknown.

Effects of Sport Participation on Gait Coordination, Symmetry, and Variability in Older Adults.

The aim of this study was to compare the interlimb coordination, asymmetry, and variability between older adults who participated in sports (n = 25; age = 72.6 ± 6.46years) and sedentary older adults (n = 20; age = 70.85 ± 3.82years). The sport participants were selected from tennis and badminton clubs, whereas the sedentary participants were recruited from local community centers. The participants walked at their preferred speed in a 10-m walkway for 2min. The interlimb coordination was measured by the phase coordination index. Other walking metrics were speed, cadence, swing time, stance time, double-support time, stride time, and swing time asymmetry. The results showed that the sport participants relative to the sedentary group had better interlimb coordination, higher walking speed and cadence, and less swing time variability. Young older adults also had a better interlimb coordination. In conclusion, the findings of this study showed that long-term participation in sports has some antiaging benefits on gait coordination and symmetry in older adults.

Comparison of gait and sagittal plane arm swing between individuals with adolescent idiopathic scoliosis and healthy individuals.

Arm swing and energy consumption play an important role in the realization of an effective gait. However, research on arm swing and energy consumption during gait in individuals with adolescent idiopathic scoliosis (AIS) is limited. The aim of this study was to investigate the spatiotemporal characteristics of gait, arm swing angles in the sagittal plane, energy consumption in individuals with AIS, to compare them with their healthy peers in this regard. 26 diagnosed with AIS and 21 healthy were included in this study. Evaluation measures were based on the Cobb angle, axial trunk rotation, trunk symmetry, sagittal curve measurements, spatiotemporal characteristics of gait with the GAITRite electronic walkway, sagittal plane arm swing with two video-camera recordings, and energy consumption. There were a decrease in right- sided sagittal arm swing, an increase in energy consumption, in left-side step time and right-side double support time in the scoliosis group compared to the control group. The other spatiotemporal characteristics of the gait were similar in both groups. The evaluation of arm swing, energy consumption, and gait of individuals with AIS may contribute to the development of rehabilitation programs by better identifying the deficiencies of individuals with AIS.

Enhanced motor learning and motor savings after acute intermittent hypoxia are associated with a reduction in metabolic cost.

Breathing mild bouts of low oxygen air (i.e. acute intermittent hypoxia, AIH) has been shown to improve locomotor function in humans after a spinal cord injury. How AIH-induced gains in motor performance are achieved remains unclear. We examined the hypothesis that AIH augments motor learning and motor retention during a locomotor adaptation task. We further hypothesized that gains in motor learning and retention will be associated with reductions in net metabolic power, consistent with the acquisition of energetically favourable mechanics. Thirty healthy individuals were randomly allocated into either a control group or an AIH group. We utilized a split-belt treadmill to characterize adaptations to an unexpected belt speed perturbation of equal magnitude during an initial exposure and a second exposure. Adaptation was characterized by changes in spatiotemporal step asymmetry, anterior-posterior force asymmetry, and net metabolic power. While both groups adapted by reducing spatial asymmetry, only the AIH group achieved significant reductions in double support time asymmetry and propulsive force asymmetry during both the initial and the second exposures to the belt speed perturbation. Net metabolic power was also significantly lower in the AIH group, with significant reductions from the initial perturbation exposure to the second. These results provide the first evidence that AIH mediates improvements in both motor learning and retention. Further, our results suggest that reductions in net metabolic power continue to be optimized upon subsequent learning and are driven by more energetically favourable temporal coordination strategies. Our observation that AIH facilitates motor learning and retention can be leveraged to design rehabilitation interventions that promote functional recovery. KEY POINTS: Brief exposures to low oxygen air, known as acute intermittent hypoxia (AIH), improves locomotor function in humans after a spinal cord injury, but it remains unclear how gains in motor performance are achieved. In this study, we tested the hypothesis that AIH induces enhancements in motor learning and retention by quantifying changes in interlimb coordination, anterior-posterior force symmetry and metabolic cost during a locomotor adaptation task. We show the first evidence that AIH improves both motor learning and savings of newly learned temporal interlimb coordination strategies and force asymmetry compared to untreated individuals. We further demonstrate that AIH elicits greater reductions in metabolic cost during motor learning that continues to be optimized upon subsequent learning. Our findings suggest that AIH-induced gains in locomotor performance are facilitated by enhancements in motor learning and retention of more energetically favourable coordination strategies.

Altered gait parameters in distracted walking: a bio-evolutionary and prognostic health perspective on passive listening and active responding during cell phone use.

The underpinnings of bipedal gait are reviewed from an evolutionary biology and prognostic health perspective to better understand issues and concerns related to cell phone use during ambulation and under conditions of distraction and interference. We also consider gait-related health issues associated with the fear of or risk of falling and include prognostic dimensions associated with cognitive decline, dementia, and mortality. Data were acquired on 21 healthy young adults without hearing loss, vestibular, balance, otological or neurological dysfunction using a computerized walkway (GAITRite® Walkway System) combined with specialized software algorithms to extract gait parameters. Four experimental conditions and seven temporo-spatial gait parameters were studied: gait velocity, cadence, stride length, ambulatory time, single-support time, double-support time, and step count. Significant main effects were observed for ambulation time, velocity, stride velocity, and double-support time. The greatest impact of distraction and interference occurred during the texting condition, although other significant effects occurred when participants were verbally responding to queries and passively listening to a story. These experimental observations show that relatively simple distraction and interference tasks implemented through the auditory sensory modality can induce significant perturbations in gait while individuals were ambulating and using a cell phone. Herein, emphasis is placed on the use of quantifiable gait parameters in medical, psychological, and audiological examinations to serve as a foundation for identifying and potentially averting gait-related disturbances.

Walking Performance during Concurrent Cognitive and Motor Tasks in Individuals with Nonspecific Chronic Low Back Pain: A Case-Control Study.

The present study aimed to compare the effects of simultaneous cognitive and motor tasks on walking performance between individuals with nonspecific chronic low back pain (NSCLBP) and healthy controls. A total of 20 patients with NSCLBP and 20 healthy controls participated in this study. They walked at their self-selected speed on a treadmill under 3 walking conditions in a randomized order: walking only, walking while performing a concurrent cognitive task, and walking while performing a concurrent motor task. Two-way repeated measure analysis of variance with additional post hoc comparison (Bonferroni test) was used to evaluate the effects of group and walking conditions on gait parameters. The result showed a significant main effect of the group for swing time ( P = 0.012) and double support time (P = 0.021) in those with NSCLBP compared with healthy controls. Moreover, there was a significant interaction between the group and condition for cadence ( P = 0.004) and step width variability (P = 0.016).Regarding stride length variability and stride time variability, the analysis indicated a significant effect of condition (P = 0.002 and P = 0.030, respectively). In both groups, no significant differences were observed in gait parameters between motor dual task and single walking ( P > 0.05). Our findings indicated that those with NSCLBP adapted successfully to walking performance to maintain the performance of the concurrent cognitive task under the cognitive dual-task walking condition. Moreover, the present study observed no dual-task interference under the motor dual-task condition.

Gait Analysis in Idiopathic Normal Pressure Hydrocephalus: A Meta-Analysis.

Gait analysis objectively quantifies gait impairment in idiopathic normal pressure hydrocephalus (iNPH), may improve diagnosis and evaluation for surgical candidacy. This meta-analysis aims to understand which objective gait parameters improve after tap-test (TT) and CSF shunt surgery (CSS), also comparing responders (R) with non-responders (NR) and to assess if gait restores within the range of healthy controls after procedures. Studies enrolling iNPH with at least one instrumented gait measure were selected. Three time points of gait assessment were defined: PRE, POST-TT, and POST-CSS. Gait velocity, cadence, step length, stride length, and double limb support time were evaluated. Patients were categorized based on responsiveness to CSF diversion procedures. Seventeen studies including 527 patients were selected. iNPH improved significantly in almost all gait parameters POST-TT, and to a greater extent POST-CSS. Gait parameters consistently discriminated iNPH from healthy controls. Despite the aforementioned improvements, iNPH's gait did not completely normalize after CSF diversion procedures. Meta-regression analysis also revealed that TT's effect on gait velocity plateaus after 24-48 hr and returns to baseline in 90-100 hr. Gait analysis is a reliable quantitative instrument to assess gait impairment in iNPH, demarking a net differentiation from healthy controls, according to the notion that the iNPH CSF dynamic alteration also leads to an irreversible damage. Specific gait parameters improve among TT-R, providing an opportunity to select patients that will respond to CSS. Future studies validating a standardized reporting method including criteria of responsiveness, specific gait parameters, and timeframe of assessment are needed.

Gait stability and the relationship with energy cost of walking in polio survivors with unilateral plantarflexor weakness

BackgroundPolio survivors often exhibit plantarflexor weakness, which impairs gait stability, and increases energy cost of walking. Quantifying gait stability could provide insights in the control mechanisms polio survivors use to maintain gait stability and in whether impaired gait stability is related to the increased energy cost of walking. Research QuestionIs gait stability impaired in polio survivors with plantarflexor weakness compared to able-bodied individuals, and does gait stability relate to energy cost of walking? MethodsWe retrospectively analyzed barefoot biomechanical gait data of 31 polio survivors with unilateral plantarflexor weakness and of 24 able-bodied individuals. We estimated gait stability by calculating variability (SD) of step width, step length, double support time, and stance time, and by the mean and variability (SD) of the mediolateral and anteroposterior margin of stability (MoSML and MoSAP). In addition, energy cost of walking (polio survivors only) at comfortable speed was analyzed. ResultsComfortable speed was 31% lower in polio survivors compared to able-bodied individuals (p < 0.001). Corrected for speed differences, step width variability was significantly larger in polio survivors (+41%), double support time variability was significantly smaller (−27%), MoSML (affected leg) was significantly larger (+80%), and MoSAP was significantly smaller (affected leg:−17% and non-affected leg:−15%). Step width and step length variability (affected leg) were positively correlated with energy cost of walking (r = 0.502 and r = 0.552). MoSAP (non-affected leg) was negatively correlated with energy cost of walking (r = −0.530). SignificancePolio survivors with unilateral plantarflexor weakness demonstrated an impaired gait stability. Increased step width and step length variability and lower MoSAP could be factors related to the elevated energy cost of walking in polio survivors. These findings increase our understanding of stability problems due to plantarflexor weakness, which could be used for the improvement of (orthotic) interventions to enhance gait stability and reduce energy cost in polio survivors.

Effect of anti-gravity treadmill (Alter G) training on gait characteristics and postural stability in adult with healed burns: A single blinded randomized controlled trial

BackgroundBurns constitute one of the foremost contributors to premature mortality and morbidity, and the recovery process from burn injuries is characterized by its intricate and protracted nature. ObjectiveThe principal aim of this study was to assess the influence of an anti-gravity treadmill (Alter G) training program on both gait characteristics and postural stability indices (PSI) in adult individuals who have recovered from burns. DesignThis study followed a single-blind, randomized, controlled design. MethodsA total of 45 adults, aged 18–35 years, with healed lower extremity burns that were circumferential and encompassed 35–50% of their total body surface area (TBSA) were randomly allocated to either the anti-gravity treadmill (Alter G) Training group (n = 22) or the traditional physical therapy program (TPTP) group (n=23). The TPTP group received conventional physical therapy, while the anti-gravity treadmill (Alter G) training group engaged in anti-gravity treadmill exercises alongside the traditional physical therapy program. The primary outcome measures, evaluated at both baseline and the conclusion of the 12-week intervention, included gait characteristics assessed using the GAITRite system and PSI measured by the Biodex Balance System (BBS). ResultsThe anti-gravity treadmill (Alter G) training group exhibited significantly greater enhancements than the TPTP group in terms of mean values and percentage changes in gait characteristics and PSI. Specifically, the percentage changes for the Alter G group were as follows: stride length (20.57%), step time (22.58%), step length (20.47%), velocity (15.67%), cadence (23.28%), and double support time (29.03%). In contrast, the TPTP group’s percentage changes were: 6.73%, 8.19%, 7.65%, 7.75%, 8.89%, and 9.37%, respectively. Concerning PSI, the Alter G group exhibited percentage changes of 55.17% for the medio-lateral stability index (MLI), 48.21% for antero-posterior stability index (API), and 48.48% for the overall stability index (OSI). The TPTP group’s corresponding percentage changes were 20%, 14.03%, and 16.41%. ConclusionsThe amalgamation of anti-gravity treadmill training with the traditional physical therapy program yields greater efficacy than TPTP in isolation. Consequently, the findings underscore the efficiency of anti-gravity treadmill (Alter G) Training as a valuable tool for rehabilitating patients with burn injuries.

Overground gait adaptability in older adults with type 2 diabetes in response to virtual targets and physical obstacles.

To step over an unexpected obstacle, individuals adapt gait; they adjust step length in the anterior-posterior direction prior to the obstacle and minimum toe clearance height in the vertical direction during obstacle avoidance. Inability to adapt gait may lead to falls in older adults with diabetes as the results of the effects of diabetes on the sensory-motor control system. Therefore, this study aimed to investigate gait adaptability in older adults with diabetes. Would diabetes impair gait adaptability and increase sagittal foot adjustment errors? Three cohorts of 16 people were recruited: young adults (Group I), healthy older adults (Group II), and older adults with diabetes (Group III). Participants walked in baseline at their comfortable speeds. They then walked and responded to what was presented in gait adaptability tests, which included 40 trials with four random conditions: step shortening, step lengthening, obstacle avoiding, and walking through. Virtual step length targets were 40% of the baseline step length longer or shorter than the mean baseline step length; the actual obstacle was a 5-cm height across the walkway. A Vicon three-dimensional motion capture system and four A.M.T.I force plates were used to quantify spatiotemporal parameters of a gait cycle and sagittal foot adjustment errors (differences between desired and actual responses). Analyses of variance (ANOVA) repeated measured tests were used to investigate group and condition effects on dependent gait parameters at a significance level of 0.05. Statistical analyses of Group I (n = 16), Group II (n = 14) and Group III (n = 13) revealed that gait parameters did not differ between groups in baseline. However, they were significantly different in adaptability tests. Group III significantly increased their stance and double support times in adaptability tests, but these adaptations did not reduce their sagittal foot adjustment errors. They had the greatest step length errors and lowest toe-obstacle clearance, which could cause them to touch the obstacle more. The presented gait adaptability tests may serve as entry tests for falls prevention programs.

Gait initiation in multiple sclerosis patients with and without functional loss

BackgroundGait initiation (GI) is an important functional task related to balance and gait performance. In addition, it has predictive importance for falls and postural instability in patient with multiple sclerosis (MS). However, it is uncertain how GI is affected in patients in the early stage of MS (Expanded Disability Status Scale (EDSS) ≤3). In this study, it was aimed to investigate the anticipatory postural adjustments (APAs), posterior center of pressure (COPap) displacement, and spatiotemporal variability during GI in patients with and without functional loss in the early stage of MS. MethodsForty-four participants (31 MS patients and 13 healthy subjects) involved in this prospective cross-sectional study were divided into three groups: Group-I: Patients without functional loss (EDSS 0 to 1.5) (n = 14), Group-II: Patients with functional loss (EDSS 2 to 3) (n = 17) and Group-III: Healthy subjects (n = 13). Electromyographic activity of the bilateral tibialis anterior (TA) and gastrocnemius medialis (GM) and COPap displacement were recorded during the postural phase of GI. Additionally, spatiotemporal parameters were recorded within the first three steps, and the coefficient of variation was calculated with 40 walks for variability. ResultsThere were significant differences in the Kruskal-Wallis tests of variables (p<0.05). Group-I demonstrated smaller APAs magnitudes in TA [stance (p = 0.01), swing (p = 0.01)], GM of swing limb (p<0.0001), and smaller COPap displacement (p<0.0001) compared to group-III. Group-II demonstrated smaller APAs magnitudes in all muscles (p<0.0001) compared to group-III and the smallest COPap displacement (p<0.0001). Group-I showed a significant increase in stride width variability compared to group-III (p = 0.01). Group-II showed a significant increase in several variabilities [first stride length (p<0.0001), second stride time (p<0.0001), first double support time (p<0.0001), stride width (p<0.0001)] compared to group-III. ConclusionPatients in the early stage of MS had impairment in both the postural and locomotor phases of GI with more obvious in the patients with functional loss. The results indicate that MS patients without functional loss have difficulty initiating gait. Although there is no functional loss, the patients have a risk of falls, postural instability, and gait impairment due to their inability to initiate gait effectively. As a result, rehabilitation is necessary even if there is no functional loss in patients with MS.

Gait analysis algorithm for lower limb rehabilitation robot applications

Abstract. When patients with lower limb dyskinesia use robots for rehabilitation training, gait parameters are of great significance for disease diagnosis and rehabilitation evaluation. Gait measurement is usually carried out by using optical motion capture systems, pressure plates and so on. However, it is difficult to apply these systems to lower limb rehabilitation robots due to their high price, limited scope and wearing requirements. At the same time, most of the current applications in robots focus on the basic gait parameters (such as step length and step speed) for robot control or user intention recognition. Therefore, this paper proposes an online gait analysis algorithm for lower limb rehabilitation robots, which uses a lidar sensor as the gait data acquisition sensor. The device is installed on the lower limb rehabilitation robot, which not only avoids the problems of decline in the detection accuracy and failure of leg tracking caused by lidar placement on the ground, but it also calculates seven gait parameters, such as step length, stride length, gait cycle and stance time, with high precision in real time. At the same time, the walking track of the patient may not be straight, and the lidar coordinate system is also changed due to the movement of the lower limb rehabilitation robot when the patient moves forward. In order to overcome this situation, a spatial parameter-splicing algorithm based on a time series is proposed to effectively reduce the error impact on gait spatiotemporal parameters. The experimental results show that the gait analysis algorithm proposed in this paper can measure the gait parameters effectively and accurately. Except for the swing time and double support time, which are calculated with large relative errors due to their small values, the relative errors of the remaining gait parameters are kept below 8 %, meeting the requirements of clinical applications.

Effects of muscular and mental fatigue on spatiotemporal gait parameters in dual task walking in young, non-frail and frail older adults.

Dual-task (DT) walking is of great interest in clinical evaluation to evaluate frailty or cognitive declines in older adults. Frail older adults are known to adopt different walking strategy to overcome fatigue. However, no studies evaluated the effect of muscular or mental fatigue on dual-task walking strategy and the difference between frail and non-frail older adults. Evaluate the effect of mental and muscular fatigue on spatio-temporal parameters in dual-task walking in young, non-frail and frail older adults. 59 participants divided into 20 young (Y) (24.9 ± 3years old), 20 non-frail (NF) (75.8 ± 4.9years old) and 19 frail older adults (F) (81 ± 4.7years old) performed single-task (ST) walking, single-task cognitive (serial subtraction of 3), and dual-task (subtraction + walking) for 1min at their fast pace. Gait speed, step length, step length variability, stance and swing phase time, single and double support time, cadence, gait speed variability were recorded in single- and dual-task walking. The dual-task effect (DTE) was calculated as ((DT-ST)/ST)×100). Generalized linear mixed models (GLMM) were used to compare the effects of mental and muscular fatigue on gait and cognitive variables between the groups. The DTE walking parameters were worse in F compared to NF or Y but no significant effect of fatigue were highlighted except for swing time and single support time DTEs. The results were mitigated but a clear difference in dual-task spatio-temporal parameters was found between F and NF which brings hope into the capacity of DT to better reveal frailty.

Eight weeks of a lower limb resistance training protocol and gait performance in patients with symptomatic mild to moderate knee osteoarthritis

BackgroundThe role of strengthening the lower limbs to optimize the biomechanics of the hip, knee and ankle during walking in patients with knee osteoarthritis, is still unclear. This study aimed to analyse the walking biomechanics of individuals with symptomatic mild to moderate knee osteoarthritis before and after a simplified lower limb resistance training protocol, focused on knee joint exercises with individualized load. MethodsForty-one patients with symptomatic and radiographic mild to moderate knee osteoarthritis underwent 3D gait analysis pre-post 8 weeks lower limb resistance training protocol performed 3 times a week. Parameters investigated were spatiotemporal, sagittal range of motion, flexion and extension minimum and maximum values, power and moment of hip, knee and ankle, as well as self-reported pain and physical function by the Western Ontario MacMaster University Osteoarthritis Index. Paired t test, Wilcoxon, Spearman's correlation and a logistic model were used for statistical analysis, with p < 0.05. Pain improvement more than 2 points was considered clinically relevant. The effect size (ES) was calculated using Cohen's d. ResultsPost protocol walking speed increased 6.7% (ES: 0.711), cadence 3.7% (ES: 0.655), stride length 2.6% (ES: 0.542), and double support time reduced 6.9% (ES:0.459). It was also observed a significant increase in one maximum repetition test for legpress 46%, knee extension 23% and knee flexion chair 27% (p < 0.001). Patients reported a 62.5% reduction in pain (ES:1.518) and 64.9% improvement in physical function (ES:1.376). 82% of the patients presented more than 2 points improvement in pain. No evidence of strong correlations between pain, strength gains and gait parameters were found. ConclusionsThere was a significant and clinical improvement of spatiotemporal gait parameters, pain, physical function, and strength after 8-week lower limb resistance training protocol. Patients who had a clinically relevant pain improvement presented better gait performance.