Swing Phase Research Articles

A sliding mode based foot-end trajectory consensus control method with variable topology for legged motion of heavy-duty robot

Rational foot-end trajectory planning and control are of great significance for stable-legged walking of heavy-duty multi-legged robots. To achieve a fast, active, and compliant response of the leg actuator to disturbances for improvement of the stability and flexibility of the heavy-duty legged robot system during continuous walking on rough roads, a legged consensus control method (LCC) is proposed. Firstly, the LCC includes a foot-end trajectory planner model for designing the trajectory during the swing phase to ensure that the robot’s feet are always in a safe workspace during legged motion with continuously variable direction. Secondly, LCC constructs a consensus control method for encoding foot-end position and velocity consensus error based on variable topology networks. Six legs are treated as six intelligent agents and divided into two fully connected networks: the swing phase and stance phase, to achieve smooth and consistent motion that satisfies the geometric constraints of the robot. The foot-end agent can switch between swing and stance groups according to the state of the contact with the environment accompanied by the amendment topology, to enhance the robustness of the robot system through fast compliance control of the foot-end kinematics state. Then, the sliding mode control method based on consensus velocity and position error is deduced in LCC. The sliding mode surface is designed to make the three control variables realize stable movement with a consistent state of foot-end in three X,Y,Z-axis respectively, thereby enhancing the stability of foot-end state and fuselage posture. Finally, simulation and experiments have verified that the proposed LCC can assist legged-robot perform relatively steady legged motion with continuously variable direction on various rugged roads. The body attitude Root Mean Square Error (RMSE) is quickly reduced by 81.0% compared with independent PI control. The LCC algorithm code is publicly available at https://github.com/bjmyX/LCC_code.

Using DeepLabCut-Live to probe state dependent neural circuits of behavior with closed-loop optogenetic stimulation.

Closed-loop behavior paradigms enable us to dissect the state-dependent neural circuits underlying behavior in real-time. However, studying context-dependent locomotor perturbations has been challenging due to limitations in molecular tools and techniques for real-time manipulation of spinal cord circuits. We developed a novel closed-loop optogenetic stimulation paradigm that utilizes DeepLabCut-Live pose estimation to manipulate primary sensory afferent activity at specific phases of the locomotor cycle in mice. A compact DeepLabCut model was trained to track hindlimb kinematics in real-time and integrated into the Bonsai visual programming framework. This allowed an LED to be triggered to photo-stimulate sensory neurons expressing channelrhodopsin at user-defined pose-based criteria, such as during the stance or swing phase. Optogenetic activation of nociceptive TRPV1 + sensory neurons during treadmill locomotion reliably evoked paw withdrawal responses. Photoactivation during stance generated a brief withdrawal, while stimulation during swing elicited a prolonged response likely engaging stumbling corrective reflexes. Comparison with Existing Methods: This new method allows for high spatiotemporal precision in manipulating spinal circuits based on the phase of the locomotor cycle. Unlike previous approaches, this closed-loop system can control for the state-dependent nature of sensorimotor responses during locomotion. Integrating DeepLabCut-Live with optogenetics provides a powerful new approach to dissect the context-dependent role of sensory feedback and spinal interneurons in modulating locomotion. This technique opens new avenues for uncovering the neural substrates of state-dependent behaviors and has broad applicability for studies of real-time closed-loop manipulation based on pose estimation. Highlights: Closed-loop system probes state-dependent behaviors at pose-modulated instancesBonsai integrates DeepLabCut models for real-time pose estimation during locomotion Phase-dependent TRPV1 + sensory afferent photostimulation elicits context-specific withdrawal responses.

Markerless three-dimensional gait analysis in healthy older adults: test–retest reliability and measurement error

In older adults, gait analysis may detect changes that signal early disease states, yet challenges in biomechanical screening limit widespread use in clinical or community settings. Recently, a markerless method from multi-camera video data has become accessible, making screenings less challenging. This study evaluated the test–retest reliability and measurement error of markerless gait kinematics and kinetics in healthy older adults. Twenty-nine healthy older adults performed gait analysis on two occasions, at preferred walking speed, using their everyday clothes. Lower limb angles and moments were averaged from 8 gait cycles. Integrated pointwise indices [Intraclass Correlation Coefficient (ICCA,K) and Standard Error of Measurement (SEM)] were calculated for curve data, as well as ICCA,K, and SEM [95 % confidence intervals] for selected peaks. Generally, kinematic ICCs were good (>0.75) and reasonably stable throughout the gait cycle, except for the hip kinematics during the swing phase in the sagittal plane and pelvis tilt and rotation. The integrated and peaks SEM were <2.4°. The reliability of kinetics was similar (ICC>0.75), except for the transverse hip moment and abduction peak, fluctuating more during the swing than through the stance phase. SEM were < 0.07Nm/Kg. In conclusion, these results showed good overall test–retest reliability for markerless gait kinematics and kinetics for the hip, knee, and ankle joints, moderate for the pelvis angles, and error levels of ≤5°, and SEM%≤5% for the sagittal plane. This supports this method’s use in assessing gait in healthy older adults, including kinetics, for which reliability data from markerless systems is difficult to find reported.

Walking on Virtual Surface Patterns Leads to Changed Control Strategies.

Inclusive design does not stop at removing physical obstacles such as staircases. It also involves identifying architectural features that impose sensory burdens, such as repetitive visual patterns that are known to potentially cause dizziness or visual discomfort. In order to assess their influence on human gait and its stability, three repetitive patterns-random dots, repetitive stripes, and repetitive waves (Lisbon pattern)-were displayed in a coloured and greyscale variant in a virtual reality (VR) environment. The movements of eight participants were recorded using a motion capture system and electromyography (EMG). During all test conditions, a significant increase in the muscular activity of leg flexor muscles was identified just before touchdown. Further, an increase in the activity of laterally stabilising muscles during the swing phase was observed for all of the test conditions. The lateral and vertical centre of mass (CoM) deviation was statistically evaluated using a linear mixed model (LMM). The patterns did cause a significant increase in the CoM excursion in the vertical direction but not in the lateral direction. These findings are indicative of an inhibited and more cautious gait style and a change in control strategy. Furthermore, we quantified the induced discomfort by using both algorithmic estimates and self-reports. The Fourier-based methods favoured the greyscaled random dots over repetitive stripes. The colour metric favoured the striped pattern over the random dots. The participants reported that the wavey Lisbon pattern was the most disruptive. For architectural and structural design, this study indicates (1) that highly repetitive patterns should be used with care in consideration of their impact on the human visuomotor system and its behavioural effects and (2) that coloured patterns should be used with greater caution than greyscale patterns.

Behavior of the Coefficient of Friction of Textured Tibial Inserts of Total Knee Replacements under the Conditions Prescribed by ISO 14243-3:2014

This work investigates the effect of surface texturing on the coefficient of friction (COF) of tibial inserts (TIs), of total knee replacements (TKRs), using a servomechanical knee simulator operating under the conditions prescribed by ISO 14243-3:2014, which requires strict control of flexion/extension (FE), anterior/posterior displacement (AP), inward/outward rotation (IOR) movements, and load variation. Tests were carried out lubricating with fetal bovine serum solution with a protein concentration of 20 g/L at 37 ± 2 °C. TIs were manufactured by fused deposition modeling (FDM) using polylactic acid (PLA) because of the advantages associated with rapid prototyping and customization. The acquired COF data were analyzed using statistical parametric mapping (SPM) to determine how the surface of the TIs affects the COF, identifying ranges where significant differences occurred. Textured surfaces led to significant reductions in COF during the swing phase of the walking cycle.

How boots affect the kinematics and kinetics of lower limb joints during walking compared to casual footwear

Boots are widely used by many people for various purposes, but their impact on gait biomechanics and injury risk is not well understood. This study investigated the effects of boots on walking biomechanics, compared to casual footwear. The lower limb joint kinematics and kinetics of 20 healthy male participants aged 20 to 30 years old were compared during self-paced walking with boots and shoes. The results showed that walking with boots is associated with greater hip extensor (P = 0.009) and ankle dorsiflexor (P < 0.001) moments in early stance, hip power generation (P < 0.001) and knee power absorption (P < 0.001) in early swing phase, hip abductor (P < 0.001) and knee adduction (P < 0.001) moments in the entire stance, net concentric work for the hip joint in sagittal (13.9%, P = 0.001) and frontal (21.7%, P = 0.002) planes. In contrast, the subtalar supinator moment in the entire stance (P < 0.001), ankle angular velocity in late stance (P < 0.001), and net concentric (− 42.7%, P < 0.001) and eccentric (− 44.6%, P = 0.004) works of subtalar joint were significantly lower in the boot condition. The compensatory adjustments in the hip and knee joints may result from ankle restrictions. While boots may aid those with ankle disorders, lower limb loading and the risk of musculoskeletal injuries and osteoarthritis could be increased. This study offers new perspectives on the biomechanical impact of boots on gait, potential prevention and treatment strategies of related injuries, and advancing footwear design.

COGNITIVE MUSCULAR THERAPY FOR LOW BACK PAIN

PurposeCognitive Muscular Therapy (CMT) is a new treatment for low back pain which integrates psychological techniques for pain management alongside training to improve postural control. Rather than focus on postural alignment or strength, CMT aims to improve the regulation of postural tone (low-level activity which supports the body against gravity). This is achieved by teaching patients an awareness of compensatory paraspinal activation, which can be triggered by overactivity of the abdominal muscles.The aim of this study was to understand whether CMT could reduce symptoms associated with low back pain and improve paraspinal muscle activation.Methods and resultsFifteen patients with chronic low back pain received seven weekly sessions of CMT from a physiotherapist. Clinical data was captured at baseline and two weeks after the intervention using the Roland-Morris questionnaire and the pain catastrophising scale. Activation of the erector spinae muscle during walking was also measured at baseline and after the final intervention session. Change data were analysed using paired t-tests.There was a 75% reduction (p&lt;0.001) in the Roland-Morris score from a mean (SD) of 9.3(2.9) to 2.3(2.6), along with a 78% reduction in pain catastrophising (p&lt;0.002) from 16.6(13) to 3.7(4.8). Activation of the contralateral erector spinae muscles reduced by 30% (p&lt;0.01) during the contralateral swing phase of walking.ConclusionIn this small sample, CMT delivered large clinical improvements and reduced activation of the low back muscles during walking. Larger randomised trials are now required to confirm whether CMT could outperform existing physiotherapy treatments for chronic back pain.Conflict of interestNo conflicts of interestSource of fundingUniversity of Salford

The correlation of gait and muscle activation characteristics with locomotion dysfunction grade in elderly individuals.

To investigate the differences and regularity of gait and muscle activation characteristics parameters in the Locomotion Dysfunction Grade (LDG) scale assessment in elderly individuals, and analyse the correlation between objective parameters and scale grading. Thus, to propose a novel detection mode for elderly individuals, which combined the LDG scale with objective detection. It can not only provide quantitative data for intelligent evaluation and rehabilitation, but also provided more accurate reference for the classification of care levels in elderly care policies. Elderly individuals (n = 159) who underwent gait analysis and sEMG at the Chinese Rehabilitation Research Center from January 2019 to September 2023 were included. According to the LDG scale, the elderly individuals were divided into four groups, namely, the LDG4, LDG5, LDG6 groups and the healthy control group. Four indicators, namely, spatiotemporal, kinematic, dynamic gait parameters and muscle activation characteristics data, were collected. Changes in these characteristics of elderly individuals with lower extremity motor dysfunction were evaluated and analysed statistically. The spatiotemporal gait parameters were significantly lower in the LDG4, LDG5, LDG6 groups than in the healthy control group. The double support phase was positively correlated with the LDG, while the swing phase, step length and velocity were negatively correlated (P < 0.05). The movement angles of both hips, knees and ankles were significantly limited and negatively correlated with the LDG (P < 0.05). Compared with those in the healthy control group, the centre of pressure (COP) path length were greater, and the average COP velocity was significantly lower (P < 0.05) in the LDG4, LDG5, LDG6 groups. The regularity of muscle activation clearly changed. The root mean square of the gastrocnemius medialis was positively correlated with LDG (P < 0.05), while the tibialis anterior showed no regularity. As the LDG increased, the differences in spatiotemporal, kinematic and dynamic gait parameters between elderly individuals with motor dysfunction and the healthy individuals gradually increased. The muscle activation characteristics parameters showed an abnormal activation pattern. These parameters were correlated with the LDG, providing a more comprehensive and objective assessment of lower extremity motor function in elderly individuals, improve assessment accuracy, and help accurate rehabilitation.

Effects of basic movements and gait in the case of homolateral imitative synkinesis

BackgroundHomolateral Imitative Synkinesis (HIS) is a rare form of associative movement between the ipsilateral upper and lower limbs. The incidence of HIS or its correlation with various movements remains uninvestigated. This study expounds on the characteristics of HIS, the frequency at which it occurs, and its relationship with movement, particularly walking. MethodsThis study included 1328 patients with acute stroke admitted to our healthcare facility between October 2019 and February 2022. We evaluated the severity of motor paralysis and sensory impairment in instances where HIS manifested, and assessed the relationship between HIS, basic activities, and gait. ResultsHIS was observed in 13/1328 patients. Motor paralysis was mild in all the cases. Each patient displayed a degree of sensory impairment, albeit of varying severity. HIS did not manifest during basic activities but was evident during walking movements in five instances. These patients displayed involuntary repetitive lifting of their upper limbs during the swing phase of their gait. Some individuals expressed discontent with involuntary upper-limb movements, citing them as contributors to a suboptimal gait. ConclusionsThis study identified HIS as a rare syndrome, manifesting at a rate of 0.9%. Focus was more common in patients with damage to the thalamus and parietal lobe. No manifestations of the HIS occurred during basic activities, suggesting a weak correlation between the HIS and such activities. Certain patients exhibit HIS during gait, report suboptimal gait, and have an increased risk of falls, potentially influencing their gait proficiency.

Quantitative gait markers and the TUG time in chronic kidney disease

BackgroundPoor gait performance results in more fall incidents among people with chronic kidney disease (CKD). It is unknown what specific quantitative gait markers contribute to high fall risk in CKD and the size of their mediation effects. MethodsWe included 634 participants from the Taizhou Imaging Study who had complete gait and laboratory data. Quantitative gait assessment was conducted with a wearable insole-like device. Factor analysis was utilized to summarize fifteen highly correlated individual parameters into five independent gait domains. Prevalent CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 m2, which was calculated based on cystatin C. Regression models were created to examine the associations of prevalent CKD with quantitative gait markers and the TUG time. Mediation analysis was used to investigate whether poor quantitative gait parameters could be mediators and the proportion of their mediation effects. ResultsParticipants with prevalent CKD had a higher TUG time (odds ratio = 2.02, P = 0.025) and poor gait performance in the phase domain (standardized β = −0.391, FDR = 0.009), including less time in the swing phase (standardized β = −0.365, FDR = 0.027) and greater time in the double-support phase (standardized β = 0.367, FDR = 0.027). These abnormalities mediated the association of prevalent CKD with a high TUG time (for the swing phase: 31.6 %, Pmediation = 0.044; for the double-support phase: 29.6 %, Pmediation = 0.042; for the phase domain: 26.9 %, Pmediation = 0.048). ConclusionPoor phase-related gait abnormalities mediated the relationship between CKD and a high TUG time, suggesting that incorporating quantitative gait markers in specific domains may improve fall prevention programs for individuals with CKD.

Morphological Changes in the Infrapatellar Fat Pad During Walking Detected by Dynamic Ultrasound in Healthy Volunteers.

Aim This study aimed to verify specific morphological changes in the infrapatellar fat pad (IFP) during walking in healthy young participants. Methods A total of 17 healthy young participants (mean age, 22.8 ± 0.9 years) were recruited in this cross-sectional study. The IFP was evaluated using ultrasonography in three conditions: supine, standing, and walking. The IFP value was described as the thickness of the distal section of the IFP. Additionally, in the walking condition, the IFP was captured in video mode on ultrasonography, and its dynamics were recorded. The waveform of the IFP was produced using the sequence of the IFP thickness on each image. The morphological change of IFP (ΔIFP) was calculated in the IFP waveform and was shown as the difference in IFP thickness between the maximum and minimum at the beginning of the early stance phase. Moreover, kinematics and kinetic data were evaluated using a three-dimensional motion system, and the knee flexion angle (KFA) and knee flexion moment (KFM) were obtained. Results The thickness of the IFP during walking was significantly greater than that during the supine and standing conditions (p < 0.001 for both). The IFP waveform during walking showed a gradual increase during the stance phaseand a decrease during the swing phase of the gait cycle. ΔIFP was 1.35 ± 0.42 mm and significantly correlated with the KFM (r = 0.59, p = 0.007). Conclusions Dynamic ultrasonography revealed a specific morphological change in the IFP during walking, which correlated with the KFM.

Paediatric Prosthetic Knee Design: The Technical Requirements of a Swing Phase Control Mechanism are Correlated with Parameters of Childhood Growth.

There is a lack of innovation in affordable prosthetic knee joints for children. One significant reason is the absence of technical requirements which consider the foundation of childhood: growth. This study aims to develop and use a modelling tool to determine the technical requirements throughout childhood growth for one prosthetic knee design feature, a swing phase control mechanism (SPCM). 3D gait data of 31 able-bodied children across a range of physical maturities were analyzed. For each participant 2 models were created from a validated paediatric able-bodied musculoskeletal model. The model was first linearly scaled, then a corresponding unilateral right knee-disarticulation amputation model produced by removing segments below the knee and replacing with prosthetic componentry. Long established low-cost prosthetic componentry and a novel polycentric knee were implemented. For each participant, inverse dynamics were conducted and the SPCM torque requirements defined. Prosthetic knee SPCM torque requirements were significantly less than the able-bodied knee to emulate able-bodied gait at free speed: 17.9% (± 10.2) and 66.3% (± 17.0) reduction in maximum extension and flexion torque, respectively. Maximum knee extension torque showed the strongest negative correlation with intact body mass (ρ = -0.6251) whereas flexion torque showed the strongest correlation with height (ρ = 0.6611). Corresponding linear regression fits produced RMSE of 1.91and 1.73 Nm, respectively. Results were also determined for slow and fast speeds. The torque requirements of an affordable paediatric prosthetic knee SPCM are defined and found to strongly correlate with parameters of childhood growth (body mass, height, and age). Current results recommend low-cost paediatric prosthetic SPCM designs can be tailored to accommodate growth. The creation of musculoskeletal models facilitate multiple future studies.

Energy Flow during Baseball Machine Hitting.

The primary aims of the study were to perform a descriptive analysis of hitting energetics off a pitching machine and to compare between the rear- and lead-side lower and upper extremities. Eighty-five high school to minor league baseball athletes participated. Five full-effort swings off a pitching machine with the fastest exit velocity were used for analysis. Energy flow was quantified using a segment power analysis. Wilcoxon signed-rank test revealed significant differences between rear- and lead-side energetics during both swing phases. During the stride, the rear knee and shoulder generated more energy than the lead side. Throughout the swing phase the lead knee, hip, and elbow generated more energy than the rear side, but at the shoulder the rear side generated significantly more energy than the lead. Most intriguing, differing energy transfer directions between the rear and lead knee and shoulder joints were reported. Furthermore, descriptive results revealed energy is predominantly transferred across the knee, shoulder, and elbow joints, while the hips primarily display energy generation. The descriptive nature of the study provides a foundation for future research and can be used as a resource for training personnel to design effective training protocols aimed at maximizing performance.

Unraveling stroke gait deviations with movement analytics, more than meets the eye: a case control study.

This study aimed to identify and quantify the kinematic and kinetic gait deviations in post-stroke hemiplegic patients with matched healthy controls using Statistical Parametric Mapping (SPM). Fifteen chronic stroke patients [4 females, 11 males; age 53.7 (standard deviation 12.2) years; body mass 65.4 (10.4) kg; standing height 168.5 (9.6) cm] and 15 matched healthy controls [4 females, 11 males; age 52.9 (11.7) years; body weight 66.5 (10.7) years; standing height 168.3 (8.8) cm] were recruited. In a 10-m walking task, joint angles, ground reaction forces (GRF), and joint moments were collected, analyzed, and compared using SPM for an entire gait cycle. Generally, when comparing the stroke patients' affected (hemiplegic) and less-affected (contralateral) limbs with the control group, SPM identified significant differences in the late stance phase and early swing phase in the joint angles and moments in bilateral limbs (all p < 0.005). In addition, the vertical and anteroposterior components of GRF were significantly different in various periods of the stance phase (all p < 0.005), while the mediolateral component showed no differences between the two groups. SPM was able to detect abnormal gait patterns in both the affected and less-affected limbs of stroke patients with significant differences when compared with matched controls. The findings draw attention to significant quantifiable gait deviations in the less-affected post-stroke limb with the potential impact to inform gait retraining strategies for clinicians and physiotherapists.

Trunk kinematics and limb movement of horses walking backwards and forwards in hand and lifting a single limb

Equine physiotherapy commonly includes basic exercises such as walking backward (BW) and voluntary lifting of single limbs (SLL), but trunk movements during these have not been studied. In order to compare the trunk kinematics during BW and SLL with forward walking (FW), nine horses were measured in FW, BW and during SLL triggered by tactile cue. Kinematics were obtained from skin markers captured by ten high-speed video cameras. Trunk angles were calculated in sagittal and horizontal planes from withers, dorsal to spinous processes of the 16th thoracic vertebra (T16), 2nd and 4th sacral vertebrae (S2, S4), WT16S2 and T16S2S4 respectively. From the hooves, maximum hoof height during swing phase and horizontal distance between hoof and median body plane during swing and stance phases were determined.Dorsoventral range of motion (ROM) and maximum flexion of WT16S2 was significantly larger in BW than in FW, while laterolateral ROM was significantly smaller during hindlimb swing phase in BW and SLL than in FW. In contrast, dorsoventral ROM of T16S2S4 was significantly smaller during stance and swing phases of hindlimbs in BW compared to FW, and throughout the movement. During forelimb swing phase, T16S2S4 ROM was significantly larger in BW than SLL. Hindhoof height in SLL was significantly higher than in FW. Distance between median body plane and hooves was significantly larger in BW than in FW, and significantly larger in BW than in SLL for hindlimb swing phase. In BW, increased lumbosacral stabilisation and the larger area of support created by fore- and hindlimbs may represent a strategy to enhance body stabilisation, as BW entails some insecurity.

Relationship between metabolic cost, muscle moments and co-contraction during walking and running

BackgroundThe metabolic cost of locomotion is a key factor in walking and running performance. It has been studied by analysing the activation and co-activation of the muscles of the lower limbs. However, these measures do not comprehensively address muscle mechanics, in contrast to approaches using muscle moments and co-contraction. Research questionWhat is the effect of speed and type of locomotion on muscle moments and co-contraction, and their relationship with metabolic cost during walking and running? MethodsEleven recreational athletes (60.5 ± 7.1 kg; 169.0 ± 6.6 cm; 23.6 ± 3.3 years) walked and ran on a treadmill at different speeds, including a similar speed of 1.75 m.s−1. Metabolic cost was estimated from gas exchange measurements. Muscle moments and co-contraction of ankle and knee flexors and extensors during the stance and swing phases were estimated using an electromyographic-driven model. ResultsBoth the slowest and fastest walking speeds had significantly higher metabolic costs than intermediate ones (p < 0.05). The metabolic cost of walking was correlated with plantarflexors moment during swing phase (r = 0.62 at 0.5 m.s−1, r = 0.67 at 1,25 m.s−1), dorsiflexors moment during stance phase (r = 0.65 at 1.25 m.s−1, r = 0.67 at 1.5 and 1.75 m.s−1), and ankle co-contraction during the stance phase (r = 0.63 at 1.25 and 1.75 m.s−1). The metabolic cost of running at 3.25 m.s−1 during the swing phase was correlated with the dorsiflexors moment (r = 0.63), plantarflexors moment (r = 0.61) and ankle co-contraction (r = 0.60). Discussion and conclusionFluctuations in metabolic cost of walking and running could be explained, at least in part, by increased ankle antagonist moments and co-contraction.

Inter-joint coordination with and without dopaminergic medication in Parkinson’s disease: a case-control study

BackgroundHow the joints exactly move and interact and how this reflects PD-related gait abnormalities and the response to dopaminergic treatment is poorly understood. A detailed understanding of these kinematics can inform clinical management and treatment decisions. The aim of the study was to investigate the influence of different gait speeds and medication on/off conditions on inter-joint coordination, as well as kinematic differences throughout the whole gait cycle in well characterized pwPD.Methods29 controls and 29 PD patients during medication on, 8 of them also during medication off walked a straight walking path in slow, preferred and fast walking speeds. Gait data was collected using optical motion capture system. Kinematics of the hip and knee and coordinated hip-knee kinematics were evaluated using Statistical Parametric Mapping (SPM) and cyclograms (angle-angle plots). Values derived from cyclograms were compared using repeated-measures ANOVA for within group, and ttest for between group comparisons.ResultsPD gait differed from controls mainly by lower knee range of motion (ROM). Adaptation to gait speed in PD was mainly achieved by increasing hip ROM. Regularity of gait was worse in PD but only during preferred speed. The ratios of different speed cyclograms were smaller in the PD groups. SPM analyses revealed that PD participants had smaller hip and knee angles during the swing phase, and PD participants reached peak hip flexion later than controls. Withdrawal of medication showed an exacerbation of only a few parameters.ConclusionsOur findings demonstrate the potential of granular kinematic analyses, including > 1 joint, for disease and treatment monitoring in PD. Our approach can be extended to further mobility-limiting conditions and other joint combinations.Trial registrationThe study is registered in the German Clinical Trials Register (DRKS00022998, registered on 04 Sep 2020).

Effectiveness of canine training using suit-mounted feeder

Enhancing Canine–Human communication during training is an important research. We aim to strengthen the communication between canines and humans during the training of canine remote control using robotic technology. Training using rewards is a widely known technique to boost canine ability. So far, this method has consisted of giving rewards from humans, thus creating a strong connection between humans and canines; however, this method can also cause canines to become overly fixated on the people who feed them. Fixation prevents canines from performing behaviors away from people. For that reason, this study explores the possibility of using robotic technology to reduce canine fixation on their trainer. This paper evaluates dog behavior during training with reduced human intervention using a backpack-like device, which provides food as a reward. This method of training is assessed in two dogs by comparing the training time, number of feedings, and number of times the dog looks at nearby humans, as compared to the traditional method. The suit-mounted feeder was used to train the two dogs to follow a spot-light, achieving a success rate of 96.4% in feeding during training. There was no significant difference in training time or number of feedings required for training with this method compared to traditional human-rewarded training methods. On the other hand, it was suggested that the device could reduce the number of times the dogs looked at their trainer by up to 84.7%. Changes in gait caused by the suit and feeder were also evaluated based on the percentage of the swing phase of gait. The results indicate that the presence or absence of the feeder device does not affect the dog's gait. Continued canine training without fixation on the feeder or the trainer could allow the working dogs to demonstrate its abilities in remote areas.

Concurrent Validity of Depth-Sensor-Based Quantification of Compensatory Movements during the Swing Phase of Gait in Healthy Individuals

The advancement in depth-sensor technology increased the potential for the clinical use of markerless three-dimensional motion analysis (3DMA); however, the accurate quantification of depth-sensor-based 3DMA on gait characteristics deviating from normal patterns is unclear. This study investigated the concurrent validity of the measurements of compensatory movements measured by depth-sensor-based 3DMA compared to those measured by marker-based 3DMA. We induced swing-phase compensatory movements due to insufficient toe clearance by restricting unilateral ankle and knee joint movements in healthy individuals. Thirty-two healthy young adults (nineteen males, aged 20.4 ± 2.0 years, height 164.4 ± 9.8 cm, weight 60.0 ± 9.3 kg [average ± standard deviation]) walked the 6 m walkway in slow speed, very slow speed, and knee–ankle–foot orthosis (KAFO; participants wore KAFOs on the right leg) conditions. Gait kinematics were measured with marker-based and depth-sensor-based 3DMA systems. The intraclass correlation coefficient (ICC3,1) was used to measure the relative agreement between depth-sensor-based and marker-based 3DMA and demonstrated good or moderate validity for swing-phase compensatory movement measurement. Additionally, the ICC2,1 measured absolute agreement between the systems and showed lower validity than the ICC3,1. The measurement errors for contralateral vaulting, trunk lateral flexion, hip hiking, swing-side hip abduction, and circumduction between instruments were 0.01 m, 1.30°, 1.99°, 2.37°, and 1.53°, respectively. Depth-sensor-based 3DMA is useful for determining swing-phase compensatory movements, although the possibility of missing a slight measurement error of 1–2° must be considered.

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 &gt; .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.