Dynamic Gait Research Articles

Ultrasound of the plantar foot: a guide for the assessment of plantar intrinsic muscles.

Plantar intrinsic muscles play a pivotal role in posture control and gait dynamics. They help maintain the longitudinal and transverse arches of the foot, and they regulate the degree and velocity of arch deformation during walking or running. Consequently, pathologies affecting the plantar intrinsic muscles (for instance, acquired and inherited neuropathies) lead to foot deformity, gait disorders, and painful syndromes. Intrinsic muscle malfunctioning is also associated with multifactorial overuse or degenerative conditions such as pes planus, hallux valgus, and plantar fasciitis. As the clinical examination of each intrinsic muscle is challenging, ultrasound is gaining a growing interest as an imaging tool to investigate the trophism of these muscular structures and the pattern of their alterations, and potentially to follow up on the effects of dedicated rehabilitation protocols. The ten plantar intrinsic muscles can be dived into three groups (medial, central and lateral) and four layers. Here, we propose a regional and landmark-based approach to the complex sonoanatomy of the plantar intrinsic muscles in order to facilitate the correct identification of each muscle from the superficial to the deepest layer. We also summarize the pathological ultrasound findings that can be encountered when scanning the plantar muscles, pointing out the patterns of alterations specific to certain conditions, such as plantar nerves mononeuropathies.

Quantification of spinal ataxia in dogs with thoracolumbar spinal cord injury.

The clinical sign of ataxia is related to several neurological diseases and is seen in conjunction with paresis in dogs with spinal cord injury (SCI). Endeavours to objectify canine spinal ataxia in SCI remain limited. The aim of this clinical study was to determine and quantify differences between gait characteristics of ataxic dogs with thoracolumbar myelopathy and healthy control dogs using a computer-and treadmill-based gait analysis system. Five dogs with spinal ataxia and six healthy dogs underwent video-and computer-assisted gait analysis while walking on a four-ground reaction force plate treadmill system (maximum speed of 0.7 m/s). Spatio-temporal and kinetic gait characteristics regarding the dogs' locomotion were analysed with a focus on the individual coefficient of variation (CV), as a potential measure for quantification of the level of ataxia. Ataxic dogs with thoracolumbar SCI showed no effect on symmetry indices but higher variability in spatio-temporal and kinetic gait parameters mainly in the pelvic, but also in the thoracic limbs. Double support phase of the individual limb was prolonged in SCI dogs at the cost of the single support and swing phase. Reduced peaks of ground reaction forces (GRF) could potentially be explained by reduction of muscle strength, as a strategy of avoiding falling by taking enthusiastic steps, or by alteration of the rhythmogenic spinal circuits between the pelvic and thoracic limb pattern generators.

Absent loading response knee flexion: The impact on gait kinetics and centre of mass motion in individuals with unilateral transfemoral amputation, and the effect of microprocessor controlled knee provision

BackgroundIndividuals with unilateral transfemoral amputation walk with increased levels of asymmetry, and this is associated with reduced gait efficiency, back pain and overuse of the intact limb. This study investigated the effect of walking with a unilateral absence of loading response knee flexion on the symmetry of anterior-posterior kinetics and centre of mass accelerations. MethodsA retrospective cohort study design was used, assessing three-dimensional gait data from individuals with unilateral transfemoral amputation (n = 56). The anterior-posterior gait variables analysed included; peak ground reaction forces, impulse, centre of mass acceleration, as well as rate of vertical ground reaction force increase in early stance. With respect to these variables, this study assessed the symmetry between intact and prosthetic limbs, compared intact limbs against a healthy unimpaired control group, and evaluated effect on symmetry of microprocessor controlled knee provision. FindingsSignificant between-limb asymmetries were found between intact and prosthetic limbs across all variables (p < 0.0001). Intact limbs showed excessive loading when compared with control group limbs after speed normalisation across all variables (p < 0.0001). No improvement in kinetic symmetry following microprocessor controlled knee provision was found. InterpretationThe gait asymmetries for individuals with transfemoral amputation identified in this study suggest that more should be done by developers to address the resultant overloading of the intact limb, as this is thought to have negative long-term effects. The provision of microprocessor controlled knees did not appear to improve the asymmetries faced by individuals with transfemoral amputation, and clinicians should be aware of this when managing patient expectations.

Different gait pattern in adolescence with patellofemoral instability

BackgroundPatellofemoral instability influences the gait pattern and activity level in adolescents. However, gait biomechanics to cope with recurrent patella instability and its relation to radiological findings has hardly been studied. MethodsWe retrospectively analyzed kinematic and kinetic gait analysis data, magnetic resonance images and X-ray of 32 adolescents with unilateral recurrent patellofemoral instability aged 12 to 18 years. Subjects were assigned to 3 groups based on their sagittal knee moment in the loading response and mid stance phase. Kinematic and kinetic differences among the groups were analyzed using a one-way ANOVA. A multinomial logistic regression model provided a further analysis of the relationship between gait biomechanics and MRI as well as X-ray parameters. FindingsAll three groups showed different characteristics of the knee kinematics during loading response and single stance: while the patella-norm-loading group showed a slightly reduced knee flexion (p 〈0,01), the patella-unloading group kept the knee nearly extended (p < 0,01) and patella-overloading group showed an increased knee flexion (p = 0,01) compared to the other groups. In single stance the patella-overloading group maintained increased knee flexion (p < 0,01) compared to patella-unloading group and patella-norm-loading group. None of the radiological parameters proved to be related to gait patterns. InterpretationThe paper describes different gait coping strategies and their clinical relevance in subjects with patellofemoral instability. However, we did not find any relation of gait biomechanics to skeletal morphology.

Accurate Real-Time Joint Torque Dynamic Prediction of Human Estimation for Locomotion.

Inverse dynamics is a common tool for determining human joint torques during walking. The traditional approaches rely on ground reaction force and kinematics measurements prior to analysis. A novel real-time hybrid method is proposed in this work by integrating a neural network and dynamic model that only requires kinematic data. An end-to-end neural network for direct joint torque estimation is also developed based on kinematic data. The neural networks are trained on a variety of walking conditions, including starting and stopping, sudden speed changes, and asymmetrical walking. The hybrid model is first tested in a detailed dynamic gait simulation (OpenSim) which results in root mean square errors less than 5 N.m and a correlation coefficient of greater than 0.95 for all the joints. Experiments demonstrate that the end-to-end model on average outperforms the hybrid model across the whole test when compared to the gold standard approach which requires both kinetic and kinematic information. The two torque estimators are also tested on one participant wearing a lower limb exoskeleton. In this case, the hybrid model (R>0.84) has significantly better performance than the end-to-end neural network (R>0.59). This indicates that the hybrid model is better applicable to scenarios which differ from the training data.

Dynamics and energetics of bottlenose dolphin (Tursiops truncatus) fluke-and-glide gait.

Intermittent locomotion composed of periods of active flapping/stroking followed by inactive gliding has been observed with species that inhabit both aerial and marine environments. However, studies on the energetic benefits of a fluke-and-glide (FG) gait during horizontal locomotion are limited for dolphins. This work presents a physics-based model of FG gait and an analysis of the associated cost of transport for bottlenose dolphins (Tursiops truncatus). New gliding drag coefficients for the model were estimated using measured data from free-swimming bottlenose dolphins. The data-driven approach used kinematic measurement from 84 h of biologging tag data collected from three animals to estimate the coefficients. A set of 532 qualifying gliding events were automatically extracted for estimation of the gliding drag coefficient. Next, data from 783 FG bouts were parameterized and used with the model-based dynamic analysis to investigate the cost benefits of FG gait. Experimental results indicate that FG gait was preferred at speeds of ∼2.2-2.7 m s-1. Observed FG bouts had an average duty factor of 0.45 and a gliding duration of 5 s. The average associated metabolic cost of transport (COT) and mechanical cost of transport (MECOT) of FG gait are 2.53 and 0.35 J m-1 kg-1, respectively, at the preferred speeds. This corresponded to a respective 18.9% and 27.1% reduction in cost when compared with model predictions of continuous fluking gait at the same average bout speed. Average thrust was positively correlated with fluking frequency and amplitude as animals accelerated during the FG bouts, whereas fluking frequency and amplitude were negatively correlated for a given thrust range. These results suggest that FG gait enhances the horizontal swimming efficiency of bottlenose dolphins and provides new insights into the gait dynamics of these animals.

Impact of Pilates suspension with self-awareness on gait and metacognition in multiple sclerosis: Randomized, single-blinded and parallel-group trial

BackgroundExercise and self-awareness are popular in the management of people with MS (pwMS). The combination of these techniques for diminishing mental and cognitive imparements doesn't apply. Since the capacity to monitor one's mind and maintain balance and efficient mobility is fundamental for carrying out the daily affairs of pwMS, in this study we assess the effect of Pilates Suspension with Self-awareness on Gait and Metacognition of pwMS. We also evaluate whether metacognition is trainable and, if so, which component of self-awareness (mental and physical) would be instrumental in this improvement. MethodTwenty-four female PwMS who scored 2–6.5 on the EDSS were homogeneously divided into two intervention groups [one received pilates suspension training (PST) with Benson relaxation (PSBR), and the other received PST with Jacobson's progressive muscle relaxation (PSJR)] and one control group for 7 consecutive weeks. Relaxation training was used as a means to self-awareness. Due to the coronavirus pandemic around the world during the research process, baseline and postintervention tests and training sessions were held online. Dynamic Gait Index (DGI) and Metacognition Questionnaire-30 (MCQ-30), outcome measures were collected before and after the intervention. ResultsAnalysis of group data revealed significant improvement between baseline and intervention phases for Dynamic Gate Index (p = 0.002 for Benson relaxation and p = 0.001 for Jacobson's progressive muscle) and Metacognition Questionnaire-30 (p = 0.02 for Benson relaxation and p = 0.002 for Jacobson's progressive muscle).Conclusions: With regard to multidimensional disorders of pwMS, a combined training protocol is recommended for pwMS.

Changes in Navigation Controls and Field-of-View Modes Affect Cybersickness Severity and Spatiotemporal Gait Patterns After Exposure to Virtual Environments.

To examine the effects of navigation controls and field-of-view modes on cybersickness severity and gait dynamics after cessation of exposure to a virtual environment (VE). The applications of virtual reality are increasing in various fields; however, whether changes in interaction techniques and visual contents could mitigate the potential gait disturbance following VE exposure remains unclear. Thirty healthy adults wore a head-mounted display to complete six sessions of 12-min run-and-gun tasks using different navigation controls (gamepad, head, natural) and field-of-view modes (full, restricted). Forward and backward walking tasks were performed before and after VE exposure. The degrees of cybersickness and presence were evaluated using questionnaires, along with the in-session task performance. Spatiotemporal gait measures and their variabilities were calculated for each walking task. The participants experienced less cybersickness with the head and natural controls than with the gamepad. Natural control, based on matching body movements, was associated with the highest degree of presence and best performance. VE navigation using the gamepad showed reduced cadences and increased stride times during postexposure forward-walking tasks. When the VE was presented via the restricted field-of-view mode, increased gait variabilities were observed from backward-walking tasks after VE exposure. Body movement-based navigation controls may alleviate cybersickness. We observed gait adaptation during both ambulation tasks, which was influenced by the navigation control method and field-of-view mode. This study provides the first evidence for gait adaptation during balance-demanding tasks after VE exposure, which is valuable for designing guidelines for virtual reality interactions.

Deep Learning for Multiple Sclerosis Differentiation Using Multi-Stride Dynamics in Gait.

Multiple sclerosis (MS) is a chronic neurological condition of the central nervous system leading to various physical, mental and psychiatric complexities. Mobility limitations are amongst the most frequent and early markers of MS. We evaluated the effectiveness of a DeepMS2G (deep learning (DL) for MS differentiation using multistride dynamics in gait) framework, which is a DL-based methodology to classify multi-stride sequences of persons with MS (PwMS) from healthy controls (HC), in order to generalize over newer walking tasks and subjects. We collected single-task Walking and dual-task Walking-while-Talking gait data using an instrumented treadmill from a balanced collection of 20 HC and 20 PwMS. We utilized domain knowledge-based spatiotemporal and kinetic gait features along with two normalization schemes, namely standard size-based and multiple regression normalization strategies. To differentiate between multi-stride sequences of HC and PwMS, we compared 16 traditional machine learning and DL algorithms. Further, we studied the interpretability of our highest-performing models; and discussed the association between the lower extremity function of participants and our model predictions. We observed that residual neural network (ResNet) based models with regression-based normalization were the top performers across both task and subject generalization classification designs. Considering regression-based normalization, a multi-scale ResNet attained a subject classification accuracy and F 1-score of 1.0 when generalizing from single-task Walking to dual-task Walking-while-Talking; and a ResNet resulted in the top subject-wise accuracy and F 1 of 0.83 and 0.81 (resp.), when generalizing over unseen participants. We used advanced DL and dynamics across domain knowledge-based spatiotemporal and kinetic gait parameters to successfully classify MS gait across distinct walking trials and unseen participants. Our proposed DL algorithms might contribute to efforts to automate MS diagnoses.

Effect of a Virtual Reality-based Exercise Program on Balance and Risk of Falling in Older Women

Background and Aims This study aims to investigate the effect of a virtual reality-based exercise program on static and dynamic balance and the risk of falling in older women. Methods The study population consists of all older women in Tehran, Iran (Mean±SD age= 64.96±0.34 years, height=163.16±0.67 cm, and body mass index= 64.27±4.91 Kg/m2). Of these, 30 women were selected by a convenience sampling method based on the inclusion criteria and were randomly divided into two groups of exercise (n=15) and control (n=15). Their static and dynamic balances were assessed by Biodex balance system and their risk of falling was measured by the dynamic gait index. The women in the exercise group performed balance exercises based on virtual reality for six weeks (Three sessions per week, each for 30-45 minutes). Finally, the obtained data were analyzed by statistical tests such as t-test and analysis of covariance in SPSS software, version 21. The significance level was set at 0.05. Results Six weeks of virtual reality-based exercises had a positive and significant effect on static and dynamic balance and the risk of falling in older women (P=0.001). Conclusion The exercises based on virtual reality can improve static and dynamic balance and reduce the risk of falling in Aged women which are recommended to prevent balance disorders and its adverse outcomes in these women.

Correlation Between the Scores of Common Balance Tests for Patients With Multiple Sclerosis

Background and Aims One of the neurological challenges of people with multiple sclerosis (MS) is balance. Different balance tests are used for this purpose. This study aims to measure the association between the scores of common balance tests for patients with MS. Methods In this descriptive retrospective study, participants were 41 patients with MS (27 females and 14 males) with an expanded disability status scale score of 4.5 or less (Mean= 4.02±0.61). The balance tests including Berg balance test (BBS), functional reach test (FRT), activities-specific balance confidence (ABC) scale, timed up &amp; go (TUG) test, dynamic gait index (DGI), modified Romberg test-open eyes (RMTO), modified Romberg test-closed eyes (RMTC), and dizziness handicap inventory (DHI) were randomly performed in two days with sufficient rest interval between them. Pearson correlation test was used to measure the relationship between their scores. Results The DGI score had a high and significant correlation with the scores of ABC scale, BBS, and FRT (P&lt;0.001). Also, there was a high and significant correlation between the scores of ABC scale and BBS (P&lt;0.001). The correlation between the scores of BBS and FRT test was also high and significant (P&lt;0.001). Conclusion The BBS score، as one of the most widely used balance tests in patients with MS and other balance diseases، has a high correlation with the scores of DGI، ABC scale، and FRT. These tests are suggested as supplementary tests for BBS. The findings can help therapists and neurologists to choose valid balance tests at different conditions and levels of MS.

Kinetic gait analysis in a small sized dog with congenital shoulder luxation

Kinetic gait analysis in a small sized dog with congenital shoulder luxation

A mental workload and biomechanical assessment during split-belt locomotor adaptation with and without optic flow.

Adaptive human performance relies on the central nervous system to regulate the engagement of cognitive-motor resources as task demands vary. Despite numerous studies which employed a split-belt induced perturbation to examine biomechanical outcomes during locomotor adaptation, none concurrently examined the cerebral cortical dynamics to assess changes in mental workload. Additionally, while prior work suggests that optic flow provides critical information for walking regulation, a few studies have manipulated visual inputs during adaption to split-belt walking. This study aimed to examine the concurrent modulation of gait and Electroencephalography (EEG) cortical dynamics underlying mental workload during split-belt locomotor adaptation, with and without optic flow. Thirteen uninjured participants with minimal inherent walking asymmetries at baseline underwent adaptation, while temporal-spatial gait and EEG spectral metrics were recorded. The results revealed a reduction in step length and time asymmetry from early to late adaptation, accompanied by an elevated frontal and temporal theta power; the former being well corelated to biomechanical changes. While the absence of optic flow during adaptation did not affect temporal-spatial gait metrics, it led to an increase of theta and low-alpha power. Thus, as individuals adapt their locomotor patterns, the cognitive-motor resources underlying the encoding and consolidation processes of the procedural memory were recruited to acquire a new internal model of the perturbation. Also, when adaption occurs without optic flow, a further reduction of arousal is accompanied with an elevation of attentional engagement due to enhanced neurocognitive resources likely to maintain adaptive walking patterns.

Effects of Curved-Path Gait Training on Gait Ability in Middle-Aged Patients with Stroke: Protocol for a Randomized Controlled Trial.

(1) Introduction: This study aimed to investigate the effects of curved-path stride gait training on the gait ability of patients with stroke. (2) Materials and Methods: Thirty patients with stroke were randomly assigned to curved-path stride gait training (n = 15) and general gait training groups (n = 15). Both groups underwent training for 30 min five times a week for 8 weeks. The gait ability of each was assessed using the Dynamic Gait Index (DGI), Timed-Up-and-Go (TUG) test, 10-meter walk test, and Figure-of-8 walk test (F8WT). (3) Results: The curved-path gait training group showed significant differences in the DGI, TUG test, 10-m walk test, and F8WT pre- versus post- intervention (p < 0.05). The general gait training group showed no significant difference in F8WT pre- versus post-intervention (p > 0.05). Additionally, there was a statistically significant intergroup difference in gait ability (p < 0.05). (4) Conclusions: Curved-path gait training resulted in greater improvement in gait ability than general gait training. Therefore, curved-path gait training can be a meaningful intervention for improving the gait ability of patients with stroke.

Taekwondo Poomsae practise in slow motion and the balance of healthy older adults: A Pre-Experimental Study.

Poor balance confidence and functional balance can lead to falls in community-dwelling older adults. Exercises utilising slow movements have been shown to improve balance in this population. It is hypothesised that by superimposing the use of slow movements onto Taekwondo Poomsae, there could be similar benefits in improving balance confidence and functional balance in older adults. This was a pre - experimental study. Fifteen community-dwelling older adults received 11weeks of Slow Poomsae (SP) training using a proposed 50-min protocol. Pre- and post-intervention scores of the Activities-Specific Balance Confidence Simplified Scale (ABC-S), Berg Balance Scale (BBS), Dynamic Gait Index (DGI), and 'Timed Up and Go' test (TUG) assessments were recorded and compared. Fifteen eligible participants with mean and standard deviation (SD) of age 73.8 (6.05) years completed the study. Significant improvements (p<0.05) were seen in the pre-post differences between ABC-S, BBS, DGI, and TUG, with median score changes of 15 points (Z=-3.408), 3 points (Z=-3.306), 3 points (Z=-2.852), and 3.5s (Z=-3.296) respectively. The preliminary findings support the efficacy of SP as a potential balance training programme that is safe for healthy older adults to improve their balance confidence and functional balance. More research is required on this topic that leans towards a large population blinded randomised controlled trial with a longer intervention period and inclusion of a follow-up to further elucidate the effects of long-term practice and novelty of SP.

Titanium alloy cannulated screws and biodegrade ceramic nails for treatment of femoral neck fractures: A finite element analysis

BackgroundOur previous studies have demonstrated the mechanical effect of sclerosis around screw paths on the healing of femoral neck fractures (FNF) after internal fixation. Furthermore, we discussed the possibility of using bioceramic nails (BNs) to prevent sclerosis. However, all these studies were conducted under static conditions as the patient was standing on one leg, while the effect of the stress generated during movement is unknown. The purpose of this study was to evaluate the stress and displacement under dynamic stress loading conditions. MethodsTwo types of internal fixation, namely cannulated screws and bioceramic nails, were utilized in conjunction with various finite element models of the femur. These models included the femoral neck fracture healing model, the femoral neck fracture model, and the sclerosis around screws model. The resulting stress and displacement were analyzed by applying the contact forces associated with the most demanding activities during gait, including walking, standing, and knee bending. The present study establishes a comprehensive framework for investigating the biomechanical properties of internal fixation devices in the context of femoral fractures. ResultsThe stress at the top of the femoral head in the sclerotic model was increased by roughly 15 MPa during the knee bend and walking phases and by about 30 MPa during the standing phase compared to the healing model. The area of high stress at the top of the femoral head was increased during the sclerotic model's walking and standing phases. Additionally, the stress distribution throughout the dynamic gait cycle was comparable before and after the removal of internal fixations following the healing of the FNF. The overall stress distribution of the entire fractured femoral model was lower and more evenly distributed in all combinations of internal fixation. Furthermore, the internal fixation stress concentration was lower when more BNs were used. In the fractured model with three cannulated screws (CSs), however, the majority of the stress was concentrated around the ends of the fractures.The maximal stress in the healing model with one CS and two BNs was the highest at all stages of gait over three combinations of internal fixation, and the stress was mainly carried by CS. ConclusionsThe presence of sclerosis around screw paths increases the risk of femoral head necrosis. Removal of CS has little effect on the mechanics of the femur after healing of the FNF. BNs have several advantages over conventional CSs after FNF. Replacing all internal fixations with BNs after the healing of FNF may solve the problem of sclerosis formation around CSs to improve bone reconstruction owing to their bioactivity.

Modeling of Walking-Gait Parameters and Walking Strategy for Quadruped Robots

The inspiration for the footed robot was originally derived from biology, and it was an imitation of biological form and movement. In this paper, a bionic-robot dog is designed to reveal the motion characteristics of a quadruped robot mechanism through modeling, model kinematic analysis, and other methods. First, the structural characteristics and movement characteristics of the developed bionic-dog model are studied. The first step is to study the physiological structure of the dog, analyze the function of the dog’s limbs, and then use a high-speed camera to capture the motion of the marked bionic-robot dog and shoot motion video of the bionic-robot dog in different motion states. The effective data of the marked points in the video are extracted using PHOTRON 1.0 software, and the extracted data are analyzed and processed in the software MATLAB R2020a, and finally the structural characteristics and motion laws of the bionic-robot dog are obtained. Then, a bionic-robot-dog experimental platform is built to conduct experiments with three planned gaits (dynamic gait, static gait, and gait transition). The experiments showed that the three gaits were consistent with the planned movements and the bionic-robot dog could perform stable fast-gait walking, slow-gait walking, and quickly complete gait transitions. All three gaits were simulated in ADAMS 2019 software, and the simulation results showed that all three gaits caused the bionic dog robot to move smoothly.

Assessing balance in people with bilateral vestibulopathy using the Mini-Balance Evaluation Systems Test (Mini-BESTest): feasibility and comparison with healthy control data

ObjectivesBilateral vestibulopathy (BVP) leads to unsteadiness when walking, which worsens in darkness or on uneven ground, as well as falls. Since simple balance tests struggle to distinguish between BVP and healthy participants, we aimed (1) to test if the Mini-BESTest is feasible in BVP, (2) how people with BVP perform on the Mini-BESTest and (3) to compare these scores with healthy reference data.MethodsFifty participants with BVP completed the Mini-BESTest. 12-month falls incidence was obtained by questionnaire. To compare the overall and sub-scores between our participants with BVP and those of healthy participants from the literature (n = 327; obtained via PubMed searches), Mann–Whitney U tests were used. Sub scores within the BVP group were also compared. Spearman correlations were used to investigate the relationships between Mini-BESTest score and age.ResultsNo floor or ceiling effects were observed. Participants with BVP had significantly lower Mini-BESTest total scores than the healthy group. Anticipatory, reactive postural control and sensory orientation sub scores of the Mini-BESTest were significantly lower in BVP, while dynamic gait sub scores were not significantly different. A stronger negative correlation between age and Mini-BESTest total score was found in BVP than in the healthy group. Scores did not differ between patients with different falls history.ConclusionThe Mini-BESTest is feasible in BVP. Our results confirm the commonly reported balance deficits in BVP. The stronger negative association between age and balance in BVP might reflect the age-related decline in the remaining sensory systems with which people with BVP compensate.

Achilles Tendon Gait Dynamics After Rupture: A Three-Armed Randomized Controlled Trial Comparing An Individualized Treatment Algorithm Vs. Operative Or Non-Operative Treatment

Achilles Tendon Gait Dynamics After Rupture: A Three-Armed Randomized Controlled Trial Comparing An Individualized Treatment Algorithm Vs. Operative Or Non-Operative Treatment

Frailty Syndrome as a Transition from Compensation to Decompensation: Application to the Biomechanical Regulation of Gait.

Most gait parameters decrease with age and are even more importantly reduced with frailty. However, other gait parameters exhibit different or even opposite trends for aging and frailty, and the underlying reason is unclear. Literature focuses either on aging, or on frailty, and a comprehensive understanding of how biomechanical gait regulation evolves with aging and with frailty seems to be lacking. We monitored gait dynamics in young adults (19-29 years, n = 27, 59% women), middle-aged adults (30-59 years, n = 16, 62% women), and non-frail (>60 years, n = 15, 33% women) and frail older adults (>60 years, n = 31, 71% women) during a 160 m walking test using the triaxial accelerometer of the Zephyr Bioharness 3.0 device (Zephyr Technology, Annapolis, MD, USA). Frailty was evaluated using the Frail Scale (FS) and the Clinical Frailty Scale (CFS). We found that in non-frail older adults, certain gait parameters, such as cadence, were increased, whereas other parameters, such as step length, were decreased, and gait speed is maintained. Conversely, in frail older adults, all gait parameters, including gait speed, were decreased. Our interpretation is that non-frail older adults compensate for a decreased step length with an increased cadence to maintain a functional gait speed, whereas frail older adults decompensate and consequently walk with a characteristic decreased gait speed. We quantified compensation and decompensation on a continuous scale using ratios of the compensated parameter with respect to the corresponding compensating parameter. Compensation and decompensation are general medical concepts that can be applied and quantified for many, if not all, biomechanical and physiological regulatory mechanisms of the human body. This may allow for a new research strategy to quantify both aging and frailty in a systemic and dynamic way.