1
|
Kowalczyk K, Mukherjee M, Malcolm P. Can a passive unilateral hip exosuit diminish walking asymmetry? A randomized trial. J Neuroeng Rehabil 2023; 20:88. [PMID: 37438846 DOI: 10.1186/s12984-023-01212-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/03/2023] [Indexed: 07/14/2023] Open
Abstract
BACKGROUND Asymmetric walking gait impairs activities of daily living in neurological patient populations, increases their fall risk, and leads to comorbidities. Accessible, long-term rehabilitation methods are needed to help neurological patients restore symmetrical walking patterns. This study aimed to determine if a passive unilateral hip exosuit can modify an induced asymmetric walking gait pattern. We hypothesized that a passive hip exosuit would diminish initial- and post-split-belt treadmill walking after-effects in healthy young adults. METHODS We divided 15 healthy young adults evenly between three experimental groups that each completed a baseline trial, an adaptation period with different interventions for each group, and a post-adaptation trial. To isolate the contribution of the exosuit we compared a group adapting to the exosuit and split-belt treadmill (Exo-Sb) to groups adapting to exosuit-only (Exo-only) and split-belt only (Sb-only) conditions. The independent variables step length, stance time, and swing time symmetry were analyzed across five timepoints (baseline, early- and late adaptation, and early- and late post-adaptation) using a 3 × 5 mixed ANOVA. RESULTS We found significant interaction and time effects on step length, stance time and swing time symmetry. Sb-only produced increased step length asymmetry at early adaptation compared to baseline (p < 0.0001) and an after-effect with increased asymmetry at early post-adaptation compared to baseline (p < 0.0001). Exo-only increased step length asymmetry (in the opposite direction as Sb-only) at early adaptation compared to baseline (p = 0.0392) but did not influence the participants sufficiently to result in a post-effect. Exo-Sb produced similar changes in step length asymmetry in the same direction as Sb-only (p = 0.0014). However, in contrast to Sb-only there was no significant after-effect between early post-adaptation and baseline (p = 0.0885). CONCLUSION The passive exosuit successfully diminished asymmetrical step length after-effects induced by the split-belt treadmill in Exo-Sb. These results support the passive exosuit's ability to alter walking gait patterns.
Collapse
Affiliation(s)
- Kayla Kowalczyk
- Department of Biomechanics and Center for Research in Human Movement Variability, University of Nebraska at Omaha, 6160 University Drive, Omaha, NE, 68182-0860, USA
- UGA Concussion Research Laboratory, Department of Kinesiology, University of Georgia, Athens, GA, USA
| | - Mukul Mukherjee
- Department of Biomechanics and Center for Research in Human Movement Variability, University of Nebraska at Omaha, 6160 University Drive, Omaha, NE, 68182-0860, USA
| | - Philippe Malcolm
- Department of Biomechanics and Center for Research in Human Movement Variability, University of Nebraska at Omaha, 6160 University Drive, Omaha, NE, 68182-0860, USA.
| |
Collapse
|
2
|
Akti S, Zeybek H. COMPARING GAIT AND HIP SCORES IN FEMORAL NECK AND INTERTROCHANTERIC FRACTURES. ACTA ORTOPEDICA BRASILEIRA 2023; 31:e261336. [PMID: 37323149 PMCID: PMC10263411 DOI: 10.1590/1413-785220233102e261336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 06/09/2022] [Indexed: 06/17/2023]
Abstract
Objective Treatment modality is controversial in the unstable IT fractures. Ideal hemiarthroplasty treatment for unstable IT fractures should be comparable to that for FN fractures. Therefore, the aim of this study was to compare patients who underwent cementless hemiarthroplasty for a diagnosis of FN and unstable IT in terms of clinical outcomes, functional scores, and smartphone-based gait analysis data. Methods Case matching was applied to 50 patients with FN fracture and 133 patients with IT fracture who underwent hemiarthroplasty treatment, they were compared in terms of, preoperative and postoperative walking status, and Harris hip scores. Smartphone-based gait analysis was applied to 12 patients in the IT group and 14 patients in the FN group who could walk without support. Results There was no significant difference between patients with IT and FN fractures regarding Harris hip scores, preoperative, and postoperative walking status. In the gait analysis, gait velocity, cadence, step time, step length, and step time symmetry values were observed to be significantly better in patients in the FN group. Conclusion Cementless hemiarthroplasty operations for unstable IT fractures have similar hip scores to FN fractures. However, the walking speed and walking symmetry data were seen to be worse. This result should be considered in the selection of appropriate treatment. Level of evidence III; Retrospective study.
Collapse
Affiliation(s)
- Sefa Akti
- . Cumhuriyet University, Department of Orthopaedics and Traumatology, Sivas, Turkey
| | - Hakan Zeybek
- . İzmir Katip Celebi University, Ataturk Training and Research Hospital, Department of Orthopaedics and Traumatology, İzmir, Turkey
| |
Collapse
|
3
|
Bonilla Yanez M, Kettlety SA, Finley JM, Schweighofer N, Leech KA. Gait speed and individual characteristics are related to specific gait metrics in neurotypical adults. Sci Rep 2023; 13:8069. [PMID: 37202435 PMCID: PMC10195830 DOI: 10.1038/s41598-023-35317-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 05/16/2023] [Indexed: 05/20/2023] Open
Abstract
Gait biofeedback is a well-studied strategy to reduce gait impairments such as propulsion deficits or asymmetric step lengths. With biofeedback, participants alter their walking to reach the desired magnitude of a specific parameter (the biofeedback target) with each step. Biofeedback of anterior ground reaction force and step length is commonly used in post-stroke gait training as these variables are associated with self-selected gait speed, fall risk, and the energy cost of walking. However, biofeedback targets are often set as a function of an individual's baseline walking pattern, which may not reflect the ideal magnitude of that gait parameter. Here we developed prediction models based on speed, leg length, mass, sex, and age to predict anterior ground reaction force and step length of neurotypical adults as a possible method for personalized biofeedback. Prediction of these values on an independent dataset demonstrated strong agreement with actual values, indicating that neurotypical anterior ground reaction forces can be estimated from an individual's leg length, mass, and gait speed, and step lengths can be estimated from individual's leg length, mass, age, sex, and gait speed. Unlike approaches that rely on an individual's baseline gait, this approach provides a standardized method to personalize gait biofeedback targets based on the walking patterns exhibited by neurotypical individuals with similar characteristics walking at similar speeds without the risk of over- or underestimating the ideal values that could limit feedback-mediated reductions in gait impairments.
Collapse
Affiliation(s)
- Maryana Bonilla Yanez
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
| | - Sarah A Kettlety
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
| | - James M Finley
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA
| | - Nicolas Schweighofer
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA
| | - Kristan A Leech
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA.
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA.
| |
Collapse
|
4
|
Compagnat M, Daviet JC, Hermand E, Billot M, Salle JY, Perrochon A. Impact of a dual task on the energy cost of walking in individuals with subacute phase stroke. Brain Inj 2023; 37:114-121. [PMID: 36625007 DOI: 10.1080/02699052.2023.2165153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To assess the impact of cognitive Dual Task (DT) during walking on the energy cost of walking (Cw) in individuals with subacute stroke. The secondary objective was to determine whether there is an association between the Cw and cortical activity of the prefrontal area. METHODS Any individual with stroke localized in the temporal-parietal regions and able to walk without human assistance was included. Cw and prefrontal cortical activity, recorded by fNIRS, were measured during simple task walking activity and cognitive dual task during walking. RESULTS Nineteen individuals with stroke (age = 67.7 ± 9.6 yrs) were included. The cognitive DT during walking resulted in an increase in Cw of 23.1%; 95%CI [13.1%; 34.5%]. The increase in Cw in cognitive DT was correlated with the Cw for the single task walking activity (r = 0.48, p < 0.01) as well as the predominance of cortical activity of the prefrontal area in the contralesional hemisphere (r = -0.33, p < 0.01). CONCLUSION There is an increase in Cw during the cognitive DT. This increase is even more significant, as the Cw of the single task walking activity is high, and the cortical activity of the prefrontal areas predominates in the contralesional hemisphere.
Collapse
Affiliation(s)
- Maxence Compagnat
- HAVAE UR 20217 (Handicap, Aging, Autonomy, Environment), IFRH, University of Limoges, Limoges, France.,Department of Physical Medicine and Rehabilitation, Department of Physical Medicine and Rehabilitation in the University Hospital Center of Limoges, Limoges, France
| | - Jean Christophe Daviet
- HAVAE UR 20217 (Handicap, Aging, Autonomy, Environment), IFRH, University of Limoges, Limoges, France.,Department of Physical Medicine and Rehabilitation, Department of Physical Medicine and Rehabilitation in the University Hospital Center of Limoges, Limoges, France
| | - Eric Hermand
- URePSSS ULR 7369 (Unité de Recherche Pluridisciplinaire Sport, Santé, Société), Université du Littoral Côte d'Opale, Dunkerque, France
| | - Maxime Billot
- PRISMATICS Laboratory (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, Poitiers, France
| | - Jean Yves Salle
- HAVAE UR 20217 (Handicap, Aging, Autonomy, Environment), IFRH, University of Limoges, Limoges, France.,Department of Physical Medicine and Rehabilitation, Department of Physical Medicine and Rehabilitation in the University Hospital Center of Limoges, Limoges, France
| | - Anaick Perrochon
- HAVAE UR 20217 (Handicap, Aging, Autonomy, Environment), IFRH, University of Limoges, Limoges, France
| |
Collapse
|
5
|
McDonald KA, Cusumano JP, Hieronymi A, Rubenson J. Humans trade off whole-body energy cost to avoid overburdening muscles while walking. Proc Biol Sci 2022; 289:20221189. [PMID: 36285498 PMCID: PMC9597406 DOI: 10.1098/rspb.2022.1189] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/29/2022] [Indexed: 07/22/2023] Open
Abstract
Metabolic cost minimization is thought to underscore the neural control of locomotion. Yet, avoiding high muscle activation, a cause of fatigue, often outperforms energy minimization in computational predictions of human gait. Discerning the relative importance of these criteria in human walking has proved elusive, in part, because they have not been empirically decoupled. Here, we explicitly decouple whole-body metabolic cost and 'fatigue-like' muscle activation costs (estimated from electromyography) by pitting them against one another using two distinct gait tasks. When experiencing these competing costs, participants (n = 10) chose the task that avoided overburdening muscles (fatigue avoidance) at the expense of higher metabolic power (p < 0.05). Muscle volume-normalized activation more closely models energy use and was also minimized by the participants' decision (p < 0.05), demonstrating that muscle activation was, at best, an inaccurate signal for metabolic energy. Energy minimization was only observed when there was no adverse effect on muscle activation costs. By decoupling whole-body metabolic and muscle activation costs, we provide among the first empirical evidence of humans embracing non-energetic optimality in favour of a clearly defined neuromuscular objective. This finding indicates that local muscle fatigue and effort may well be key factors dictating human walking behaviour and its evolution.
Collapse
Affiliation(s)
- Kirsty A. McDonald
- School of Health Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
- School of Human Sciences, The University of Western Australia, Crawley, Perth, Western Australia 6009, Australia
- Biomechanics Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Joseph P. Cusumano
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA
| | - Andrew Hieronymi
- School of Visual Arts, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jonas Rubenson
- School of Human Sciences, The University of Western Australia, Crawley, Perth, Western Australia 6009, Australia
- Biomechanics Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA
- Integrative and Biomedical Physiology, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| |
Collapse
|
6
|
Johnson RT, Bianco NA, Finley JM. Patterns of asymmetry and energy cost generated from predictive simulations of hemiparetic gait. PLoS Comput Biol 2022; 18:e1010466. [PMID: 36084139 PMCID: PMC9491609 DOI: 10.1371/journal.pcbi.1010466] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 09/21/2022] [Accepted: 08/03/2022] [Indexed: 11/18/2022] Open
Abstract
Hemiparesis, defined as unilateral muscle weakness, often occurs in people post-stroke or people with cerebral palsy, however it is difficult to understand how this hemiparesis affects movement patterns as it often presents alongside a variety of other neuromuscular impairments. Predictive musculoskeletal modeling presents an opportunity to investigate how impairments affect gait performance assuming a particular cost function. Here, we use predictive simulation to quantify the spatiotemporal asymmetries and changes to metabolic cost that emerge when muscle strength is unilaterally reduced and how reducing spatiotemporal symmetry affects metabolic cost. We modified a 2-D musculoskeletal model by uniformly reducing the peak isometric muscle force unilaterally. We then solved optimal control simulations of walking across a range of speeds by minimizing the sum of the cubed muscle excitations. Lastly, we ran additional optimizations to test if reducing spatiotemporal asymmetry would result in an increase in metabolic cost. Our results showed that the magnitude and direction of effort-optimal spatiotemporal asymmetries depends on both the gait speed and level of weakness. Also, the optimal speed was 1.25 m/s for the symmetrical and 20% weakness models but slower (1.00 m/s) for the 40% and 60% weakness models, suggesting that hemiparesis can account for a portion of the slower gait speed seen in people with hemiparesis. Modifying the cost function to minimize spatiotemporal asymmetry resulted in small increases (~4%) in metabolic cost. Overall, our results indicate that spatiotemporal asymmetry may be optimal for people with hemiparesis. Additionally, the effect of speed and the level of weakness on spatiotemporal asymmetry may help explain the well-known heterogenous distribution of spatiotemporal asymmetries observed in the clinic. Future work could extend our results by testing the effects of other neuromuscular impairments on optimal gait strategies, and therefore build a more comprehensive understanding of the gait patterns observed in clinical populations.
Collapse
Affiliation(s)
- Russell T. Johnson
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
| | - Nicholas A. Bianco
- Department of Mechanical Engineering, Stanford University, Palo Alto, California, United States of America
| | - James M. Finley
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California, United States of America
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, United States of America
| |
Collapse
|
7
|
Bacek T, Sun M, Liu H, Chen Z, Kulic D, Oetomo D, Tan Y. Varying Joint Patterns and Compensatory Strategies Can Lead to the Same Functional Gait Outcomes: A Case Study. IEEE Int Conf Rehabil Robot 2022; 2022:1-6. [PMID: 36176172 DOI: 10.1109/icorr55369.2022.9896497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
This paper analyses joint-space walking mechanisms and redundancies in delivering functional gait outcomes. Multiple biomechanical measures are analysed for two healthy male adults who participated in a multi-factorial study and walked during three sessions. Both participants employed varying intra- and inter-personal compensatory strategies (e.g., vaulting, hip hiking) across walking conditions and exhibited notable gait pattern alterations while keeping task-space (functional) gait parameters invariant. They also preferred various levels of asymmetric step length but kept their symmetric step time consistent and cadence-invariant during free walking. The results demonstrate the importance of an individualised approach and the need for a paradigm shift from functional (task-space) to joint-space gait analysis in attending to (a)typical gaits and delivering human-centred human-robot interaction.
Collapse
|
8
|
Michelini A, Sivasambu H, Andrysek J. The Short-Term Effects of Rhythmic Vibrotactile and Auditory Biofeedback on the Gait of Individuals After Weight-Induced Asymmetry. CANADIAN PROSTHETICS & ORTHOTICS JOURNAL 2022; 5:36223. [PMID: 37614474 PMCID: PMC10443516 DOI: 10.33137/cpoj.v5i1.36223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 01/22/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Biofeedback (BFB), the practice of providing real-time sensory feedback has been shown to improve gait rehabilitation outcomes. BFB training through rhythmic stimulation has the potential to improve spatiotemporal gait asymmetries while minimizing cognitive load by encouraging a synchronization between the user's gait cycle and an external rhythm. OBJECTIVE The purpose of this work was to evaluate if rhythmic stimulation can improve the stance time symmetry ratio (STSR) and to compare vibrotactile to auditory stimulation. Gait parameters including velocity, cadence, stride length, double support time, and step length symmetry, were also examined. METHODOLOGY An experimental rhythmic stimulation system was developed, and twelve healthy adults (5 males), age 28.42 ± 10.93 years, were recruited to participate in walking trials. A unilateral ankle weight was used to induce a gait asymmetry to simulate asymmetry as commonly exhibited by individuals with lower limb amputation and other clinical disorders. Four conditions were evaluated: 1) No ankle weight baseline, 2) ankle weight without rhythmic stimulation, 3) ankle weight + rhythmic vibrotactile stimulation (RVS) using alternating motors and 4) ankle weight + rhythmic auditory stimulation (RAS) using a singletone metronome at the participant's self-selected cadence. FINDINGS As expected the STSR became significantly more asymmetrical with the ankle weight (i.e. induced asymmetry condition). STSR improved significantly with RVS and RAS when compared to the ankle weight without rhythmic stimulation. Cadence also significantly improved with RVS and RAS compared to ankle weight without rhythmic stimulation. With the exception of double support time, the other gait parameters were unchanged from the ankle weight condition. There were no statistically significant differences between RVS and RAS. CONCLUSION This study found that rhythmic stimulation can improve the STSR when an asymmetry is induced. Moreover, RVS is at least as effective as auditory stimulation in improving STSR in healthy adults with an induced gait asymmetry. Future work should be extended to populations with mobility impairments and outside of laboratory settings.
Collapse
Affiliation(s)
- A. Michelini
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada
- Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Canada
| | - H. Sivasambu
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada
- Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Canada
| | - J. Andrysek
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada
- Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Canada
| |
Collapse
|
9
|
Kulmala JP, Haakana P, Nurminen J, Ylitalo E, Niemelä T, Marttinen Rossi E, Mäenpää H, Piitulainen H. A test of the effort equalization hypothesis in children with cerebral palsy who have an asymmetric gait. PLoS One 2022; 17:e0262042. [PMID: 35061756 PMCID: PMC8782512 DOI: 10.1371/journal.pone.0262042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 12/15/2021] [Indexed: 11/18/2022] Open
Abstract
Healthy people can walk nearly effortlessly thanks to their instinctively adaptive gait patterns that tend to minimize metabolic energy consumption. However, the economy of gait is severely impaired in many neurological disorders such as stroke or cerebral palsy (CP). Moreover, self-selected asymmetry of impaired gait does not seem to unequivocally coincide with the minimal energy cost, suggesting the presence of other adaptive origins. Here, we used hemiparetic CP gait as a model to test the hypothesis that pathological asymmetric gait patterns are chosen to equalize the relative muscle efforts between the affected and unaffected limbs. We determined the relative muscle efforts for the ankle and knee extensors by relating extensor joint moments during gait to maximum moments obtained from all-out hopping reference test. During asymmetric CP gait, the unaffected limb generated greater ankle (1.36±0.15 vs 1.17±0.16 Nm/kg, p = 0.002) and knee (0.74±0.33 vs 0.44±0.19 Nm/kg, p = 0.007) extensor moments compared with the affected limb. Similarly, the maximum moment generation capacity was greater in the unaffected limb versus the affected limb (ankle extensors: 1.81±0.39 Nm/kg vs 1.51±0.34 Nm/kg, p = 0.033; knee extensors: 1.83±0.37 Nm/kg vs 1.34±0.38 Nm/kg, p = 0.021) in our force reference test. As a consequence, no differences were found in the relative efforts between unaffected and affected limb ankle extensors (77±12% vs 80±16%, p = 0.69) and knee extensors (41±17% vs 38±23%, p = 0.54). In conclusion, asymmetric CP gait resulted in similar relative muscle efforts between affected and unaffected limbs. The tendency for effort equalization may thus be an important driver of self-selected gait asymmetry patterns, and consequently advantageous for preventing fatigue of the weaker affected side musculature.
Collapse
Affiliation(s)
- Juha-Pekka Kulmala
- Motion Laboratory, Children’s Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
- JAMK University of Applied Sciences, Jyväskylä, Finland
- * E-mail:
| | - Piia Haakana
- Motion Laboratory, Children’s Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Jussi Nurminen
- Motion Laboratory, Children’s Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Elina Ylitalo
- Motion Laboratory, Children’s Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Tuula Niemelä
- Motion Laboratory, Children’s Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Essi Marttinen Rossi
- Motion Laboratory, Children’s Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Helena Mäenpää
- Motion Laboratory, Children’s Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Harri Piitulainen
- Motion Laboratory, Children’s Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| |
Collapse
|
10
|
Estimation of Walking Speed and Its Spatiotemporal Determinants Using a Single Inertial Sensor Worn on the Thigh: From Healthy to Hemiparetic Walking. SENSORS 2021; 21:s21216976. [PMID: 34770283 PMCID: PMC8587282 DOI: 10.3390/s21216976] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 09/24/2021] [Accepted: 09/24/2021] [Indexed: 11/16/2022]
Abstract
We present the use of a single inertial measurement unit (IMU) worn on the thigh to produce stride-by-stride estimates of walking speed and its spatiotemporal determinants (i.e., stride time and stride length). Ten healthy and eight post-stroke individuals completed a 6-min walk test with an 18-camera motion capture system used for ground truth measurements. Subject-specific estimation models were trained to estimate walking speed using the polar radius extracted from phase portraits produced from the IMU-measured thigh angular position and velocity. Consecutive flexion peaks in the thigh angular position data were used to define each stride and compute stride times. Stride-by-stride estimates of walking speed and stride time were then used to compute stride length. In both the healthy and post-stroke cohorts, low error and high consistency were observed for the IMU estimates of walking speed (MAE < 0.035 m/s; ICC > 0.98), stride time (MAE < 30 ms; ICC > 0.97), and stride length (MAE < 0.037 m; ICC > 0.96). This study advances the use of a single wearable sensor to accurately estimate walking speed and its spatiotemporal determinants during both healthy and hemiparetic walking.
Collapse
|
11
|
Lee H, Eizad A, Lee G, Afzal MR, Yoon J, Oh MK, Yoon J. Comparative Study on Overground Gait of Stroke Survivors With a Conventional Cane and a Haptic Cane. IEEE Trans Neural Syst Rehabil Eng 2021; 29:2183-2192. [PMID: 34665734 DOI: 10.1109/tnsre.2021.3121412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The conventional cane (single cane) is widely used to promote gait ability of stroke survivors as it provides postural stability by extending the base of support. However, its use can reduce muscle activity in the user's paretic side and cause upper limb neuropathies due to the intermittent and excessive loading of the upper limb. The provision of low magnitude support and speed regulation may result in collective improvement of gait parameters such as symmetry, balance and muscle activation. In this paper, we developed a robotic Haptic Cane (HC) that is composed of a tilted structure with motorized wheels and sensors to allow continuous haptic contact with the ground while moving at a regulated speed, and carried out gait experiments to compare the HC with an Instrumented conventional Cane (IC). The results show that use of the HC involved more continuous ground support force of a comparatively lesser magnitude than the IC, and resulted in greater improvements in the swing symmetry ratio and significant improvements in the step length symmetry ratio. Percentage of Non-Paretic Activity (%NPA) of paretic muscles (vastus medialis obliquus (VMO), semitendinosus (SMT), tibialis anterior (TBA) and gastrocnemius medialis (GCM)) in swing phase was significantly improved by the use of either device at fast speed. However, the use of HC improved %NPA of paretic VMO and SMT more than the use of IC at both preferred and fast speeds. It also significantly improved %NPA of paretic GCM in stance phase. Furthermore, comfortable speed with the HC was higher than with the IC and exhibited better RMS of anteroposterior (AP) tilt. Thus, the developed device with a simple and intuitive mechanism can provide efficient assistance for overground gait of stroke patients with a high possibility of widespread use.
Collapse
|
12
|
Padmanabhan P, Sreekanth Rao K, Gonzalez AJ, Pantelyat AY, Chib VS, Roemmich RT. The Cost of Gait Slowness: Can Persons with Parkinson's Disease Save Energy by Walking Faster? JOURNAL OF PARKINSONS DISEASE 2021; 11:2073-2084. [PMID: 34511512 DOI: 10.3233/jpd-212613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Gait slowing is a common feature of Parkinson's disease (PD). Many therapies aim to improve gait speed in persons with PD, but goals are often imprecise. How fast should each patient walk? And how do persons with PD benefit from walking faster? There is an important need to understand how walking speed affects fundamental aspects of gait-including energy cost and stability-that could guide individualized therapy decisions in persons with PD. OBJECTIVE We investigated how changes in walking speed affected energy cost and spatiotemporal gait parameters in persons with PD. We compared these effects between dopaminergic medication states and to those observed in age-matched control participants. METHODS Twelve persons with PD and twelve control participants performed treadmill walking trials spanning at least five different speeds (seven speeds were desired, but not all participants could walk at the fastest speeds). Persons with PD participated in two walking sessions on separate days (once while optimally medicated, once after 12-hour withdrawal from dopaminergic medication). We measured kinematic and metabolic data across all trials. RESULTS Persons with PD significantly reduced energy cost by walking faster than their preferred speeds. This held true across medication conditions and was not observed in control participants. The patient-specific walking speeds that reduced energy cost did not significantly affect gait variability metrics (used as proxies for gait stability). CONCLUSION The gait slowing that occurs with PD results in energetically suboptimal walking. Rehabilitation strategies that target patient-specific increases in walking speed could result in a less effortful gait.
Collapse
Affiliation(s)
- Purnima Padmanabhan
- Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD, USA.,Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Keerthana Sreekanth Rao
- Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Anthony J Gonzalez
- Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Alexander Y Pantelyat
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Vikram S Chib
- Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Ryan T Roemmich
- Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD, USA.,Departmentof Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
13
|
McAllister MJ, Blair RL, Donelan JM, Selinger JC. Energy optimization during walking involves implicit processing. J Exp Biol 2021; 224:272119. [PMID: 34521117 DOI: 10.1242/jeb.242655] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 08/02/2021] [Indexed: 11/20/2022]
Abstract
Gait adaptations, in response to novel environments, devices or changes to the body, can be driven by the continuous optimization of energy expenditure. However, whether energy optimization involves implicit processing (occurring automatically and with minimal cognitive attention), explicit processing (occurring consciously with an attention-demanding strategy) or both in combination remains unclear. Here, we used a dual-task paradigm to probe the contributions of implicit and explicit processes in energy optimization during walking. To create our primary energy optimization task, we used lower-limb exoskeletons to shift people's energetically optimal step frequency to frequencies lower than normally preferred. Our secondary task, designed to draw explicit attention from the optimization task, was an auditory tone discrimination task. We found that adding this secondary task did not prevent energy optimization during walking; participants in our dual-task experiment adapted their step frequency toward the optima by an amount and at a rate similar to participants in our previous single-task experiment. We also found that performance on the tone discrimination task did not worsen when participants were adapting toward energy optima; accuracy scores and reaction times remained unchanged when the exoskeleton altered the energy optimal gaits. Survey responses suggest that dual-task participants were largely unaware of the changes they made to their gait during adaptation, whereas single-task participants were more aware of their gait changes yet did not leverage this explicit awareness to improve gait adaptation. Collectively, our results suggest that energy optimization involves implicit processing, allowing attentional resources to be directed toward other cognitive and motor objectives during walking.
Collapse
Affiliation(s)
| | - Rachel L Blair
- Simon Fraser University, Burnaby, BC, Canada, V5A 1S6.,University of British Columbia, Department of Anesthesiology, Vancouver, BC, Canada, V6T 1Z3
| | | | | |
Collapse
|
14
|
Clites TR, Shepherd MK, Ingraham KA, Wontorcik L, Rouse EJ. Understanding patient preference in prosthetic ankle stiffness. J Neuroeng Rehabil 2021; 18:128. [PMID: 34433472 PMCID: PMC8390224 DOI: 10.1186/s12984-021-00916-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 07/21/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND User preference has the potential to facilitate the design, control, and prescription of prostheses, but we do not yet understand which physiological factors drive preference, or if preference is associated with clinical benefits. METHODS Subjects with unilateral below-knee amputation walked on a custom variable-stiffness prosthetic ankle and manipulated a dial to determine their preferred prosthetic ankle stiffness at three walking speeds. We evaluated anthropomorphic, metabolic, biomechanical, and performance-based descriptors at stiffness levels surrounding each subject's preferred stiffness. RESULTS Subjects preferred lower stiffness values at their self-selected treadmill walking speed, and elected to walk faster overground with ankle stiffness at or above their preferred stiffness. Preferred stiffness maximized the kinematic symmetry between prosthetic and unaffected joints, but was not significantly correlated with body mass or metabolic rate. CONCLUSION These results imply that some physiological factors are weighted more heavily when determining preferred stiffness, and that preference may be associated with clinically relevant improvements in gait.
Collapse
Affiliation(s)
- Tyler R Clites
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
- Robotics Institute, University of Michigan, Ann Arbor, MI, 48109, USA
- Neurobionics Lab, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Max K Shepherd
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
- Shirley Ryan Ability Lab, Chicago, IL, 60611, USA
- Neurobionics Lab, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kimberly A Ingraham
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
- Robotics Institute, University of Michigan, Ann Arbor, MI, 48109, USA
- Neurobionics Lab, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Leslie Wontorcik
- Department of Physical Medicine and Rehabilitation, Michigan Medicine, University of Michigan Orthotics and Prosthetics Center, Ann Arbor, MI, 48104, USA
| | - Elliott J Rouse
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA.
- Robotics Institute, University of Michigan, Ann Arbor, MI, 48109, USA.
- Neurobionics Lab, University of Michigan, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
15
|
McCain EM, Berno ME, Libera TL, Lewek MD, Sawicki GS, Saul KR. Reduced joint motion supersedes asymmetry in explaining increased metabolic demand during walking with mechanical restriction. J Biomech 2021; 126:110621. [PMID: 34284306 DOI: 10.1016/j.jbiomech.2021.110621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 06/28/2021] [Accepted: 07/05/2021] [Indexed: 10/20/2022]
Abstract
Recent research has highlighted the complex interactions among chronic injury- or disease-induced joint limitations, walking asymmetry, and increased metabolic cost. Determining the specific metabolic impacts of asymmetry or joint impairment in clinical populations is difficult because of concurrent neurological and physiological changes. This work investigates the metabolic impact of gait asymmetry and joint restriction by unilaterally (asymmetric) and bilaterally (symmetric) restricting ankle, knee, and combined ankle and knee ranges of motion in unimpaired individuals. We calculated propulsive asymmetry, temporal asymmetry, and step-length asymmetry for an average gait cycle; metabolic rate; average positive center of mass power using the individual limbs method; and muscle effort using lower limb electromyography measurements weighted by corresponding physiological cross-sectional areas. Unilateral restriction caused propulsive and temporal asymmetry but less metabolically expensive gait than bilateral restriction. Changes in asymmetry did not correlate with changes in metabolic cost. Interestingly, bilateral restriction increased average positive center of mass power compared to unilateral restriction. Further, increased average positive center of mass power correlated with increased energy costs, suggesting asymmetric step-to-step transitions did not drive metabolic changes. The number of restricted joints reduces available degrees of freedom and may have a larger metabolic impact than gait asymmetry, as this correlated significantly with increases in metabolic rate for 7/9 participants. These results emphasize symmetry is not by definition metabolically optimal, indicate that the mechanics underlying symmetry are meaningful, and suggest that available degrees of freedom should be considered in designing future interventions.
Collapse
Affiliation(s)
- Emily M McCain
- North Carolina State University, Raleigh, NC, North Carolina State University, 911 Oval Drive, USA.
| | - Matthew E Berno
- North Carolina State University, Raleigh, NC, North Carolina State University, 911 Oval Drive, USA.
| | - Theresa L Libera
- North Carolina State University, Raleigh, NC, North Carolina State University, 911 Oval Drive, USA.
| | - Michael D Lewek
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | | | - Katherine R Saul
- North Carolina State University, Raleigh, NC, North Carolina State University, 911 Oval Drive, USA.
| |
Collapse
|
16
|
Sanchez N, Schweighofer N, Finley JM. Different Biomechanical Variables Explain Within-Subjects Versus Between-Subjects Variance in Step Length Asymmetry Post-Stroke. IEEE Trans Neural Syst Rehabil Eng 2021; 29:1188-1198. [PMID: 34138713 PMCID: PMC8290879 DOI: 10.1109/tnsre.2021.3090324] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Step length asymmetry (SLA) is common in most stroke survivors. Several studies have shown that factors such as paretic propulsion can explain between-subjects differences in SLA. However, whether the factors that account for between-subjects variance in SLA are consistent with those that account for within-subjects, stride-by-stride variance in SLA has not been determined. SLA direction is heterogeneous, and different impairments likely contribute to differences in SLA direction. Here, we identified common predictors between-subjects that explain within-subjects variance in SLA using sparse partial least squares regression (sPLSR). We determined whether the SLA predictors differ based on SLA direction and whether predictors obtained from within-subjects analyses were the same as those obtained from between-subjects analyses. We found that for participants who walked with longer paretic steps paretic double support time, braking impulse, peak vertical ground reaction force, and peak plantarflexion moment explained 59% of the within-subjects variance in SLA. However the within-subjects variance accounted for by each individual predictor was less than 10%. Peak paretic plantarflexion moment accounted for 4% of the within-subjects variance and 42% of the between-subjects variance in SLA. In participants who walked with shorter paretic steps, paretic and non-paretic braking impulse explained 18% of the within-subjects variance in SLA. Conversely, paretic braking impulse explained 68% of the between-subjects variance in SLA, but the association between SLA and paretic braking impulse was in the opposite direction for within-subjects vs. between-subjects analyses. Thus, the relationships that explain between-subjects variance might not account for within-subjects stride-by-stride variance in SLA.
Collapse
|
17
|
Stenum J, Choi JT. Disentangling the energetic costs of step time asymmetry and step length asymmetry in human walking. J Exp Biol 2021; 224:269113. [PMID: 34115860 DOI: 10.1242/jeb.242258] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 04/26/2021] [Indexed: 11/20/2022]
Abstract
The metabolic cost of walking in healthy individuals increases with spatiotemporal gait asymmetries. Pathological gait, such as post-stroke, often has asymmetry in step length and step time which may contribute to an increased energy cost. But paradoxically, enforcing step length symmetry does not reduce metabolic cost of post-stroke walking. The isolated and interacting costs of asymmetry in step time and step length remain unclear, because previous studies did not simultaneously enforce spatial and temporal gait asymmetries. Here, we delineate the isolated costs of asymmetry in step time and step length in healthy human walking. We first show that the cost of step length asymmetry is predicted by the cost of taking two non-preferred step lengths (one short and one long), but that step time asymmetry adds an extra cost beyond the cost of non-preferred step times. The metabolic power of step time asymmetry is about 2.5 times greater than the cost of step length asymmetry. Furthermore, the costs are not additive when walking with asymmetric step time and asymmetric step length: the metabolic power of concurrent asymmetry in step length and step time is driven by the cost of step time asymmetry alone. The metabolic power of asymmetry is explained by positive mechanical power produced during single support phases to compensate for a net loss of center of mass power incurred during double support phases. These data may explain why metabolic cost remains invariant to step length asymmetry in post-stroke walking and suggest how effects of asymmetry on energy cost can be attenuated.
Collapse
Affiliation(s)
- Jan Stenum
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, MA 01003, USA.,Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD 21205, USA.,Department of Physical Medicine and Rehabilitation, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Julia T Choi
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, MA 01003, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA
| |
Collapse
|
18
|
Browne MG, Smock CS, Roemmich RT. The human preference for symmetric walking often disappears when one leg is constrained. J Physiol 2020; 599:1243-1260. [PMID: 33231294 DOI: 10.1113/jp280509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 10/30/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS We hypothesized that minimization of metabolic power could drive people to walk asymmetrically when one leg is constrained We studied healthy young adults and independently constrained one or both step lengths to be markedly shorter or longer than preferred using visual feedback When one leg was constrained to take a shorter or longer step than preferred, asymmetric walking patterns were less metabolically costly than symmetric walking patterns When one leg was constrained to take a shorter or longer step than preferred and the other leg was allowed to move freely, most participants naturally adopted an asymmetric gait People may prefer to walk asymmetrically to minimize metabolic power when the function of one leg is constrained during fixed-speed treadmill walking ABSTRACT: The bilateral symmetry inherent in healthy human walking is often disrupted in clinical conditions that primarily affect one leg (e.g. stroke). This seems intuitive: with one leg constrained, gait becomes asymmetric. However, the emergence of asymmetry is not inevitable. Consider that symmetric walking could be preserved by matching the movement of the unconstrained leg to that of the constrained leg. While this is theoretically possible, it is rarely observed in clinical populations. Here, we hypothesized that minimization of metabolic power could drive people to walk asymmetrically when one leg is constrained, even when symmetric walking remains possible. We tested this hypothesis by performing two experiments in healthy adults. In Experiment 1, we constrained one step to be markedly shorter or longer than preferred. We observed that participants could significantly reduce metabolic power by adopting an asymmetric gait (one short/long step, one preferred step) rather than maintaining a symmetric gait (bilateral short/long steps). Indeed, when allowed to walk freely in this situation, participants naturally adopted a less effortful asymmetric gait. In Experiment 2, we applied a milder constraint that more closely approximated magnitudes of step length asymmetry that are observed in clinical populations. Responses in this experiment were more heterogeneous, though most participants adopted an asymmetric gait. These findings support two central conclusions: (1) symmetry is not necessarily energetically optimal in constrained human walking, and (2) people may prefer to walk asymmetrically to minimize metabolic power when one leg is constrained during fixed-speed treadmill walking, especially when the constraint is large.
Collapse
Affiliation(s)
- Michael G Browne
- Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD, USA.,Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Cameron S Smock
- Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD, USA.,Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ryan T Roemmich
- Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD, USA.,Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
19
|
Nguyen TM, Jackson RW, Aucie Y, de Kam D, Collins SH, Torres-Oviedo G. Self-selected step length asymmetry is not explained by energy cost minimization in individuals with chronic stroke. J Neuroeng Rehabil 2020; 17:119. [PMID: 32847596 PMCID: PMC7450572 DOI: 10.1186/s12984-020-00733-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 07/26/2020] [Indexed: 11/24/2022] Open
Abstract
Background Asymmetric gait post-stroke is associated with decreased mobility, yet individuals with chronic stroke often self-select an asymmetric gait despite being capable of walking more symmetrically. The purpose of this study was to test whether self-selected asymmetry could be explained by energy cost minimization. We hypothesized that short-term deviations from self-selected asymmetry would result in increased metabolic energy consumption, despite being associated with long-term rehabilitation benefits. Other studies have found no difference in metabolic rate across different levels of enforced asymmetry among individuals with chronic stroke, but used methods that left some uncertainty to be resolved. Methods In this study, ten individuals with chronic stroke walked on a treadmill at participant-specific speeds while voluntarily altering step length asymmetry. We included only participants with clinically relevant self-selected asymmetry who were able to significantly alter asymmetry using visual biofeedback. Conditions included targeting zero asymmetry, self-selected asymmetry, and double the self-selected asymmetry. Participants were trained with the biofeedback system in one session, and data were collected in three subsequent sessions with repeated measures. Self-selected asymmetry was consistent across sessions. A similar protocol was conducted among unimpaired participants. Results Participants with chronic stroke substantially altered step length asymmetry using biofeedback, but this did not affect metabolic rate (ANOVA, p = 0.68). In unimpaired participants, self-selected step length asymmetry was close to zero and corresponded to the lowest metabolic energy cost (ANOVA, p = 6e-4). While the symmetry of unimpaired gait may be the result of energy cost minimization, self-selected step length asymmetry in individuals with chronic stroke cannot be explained by a similar least-effort drive. Conclusions Interventions that encourage changes in step length asymmetry by manipulating metabolic energy consumption may be effective because these therapies would not have to overcome a metabolic penalty for altering asymmetry.
Collapse
Affiliation(s)
- Thu M Nguyen
- Department of Mechanical Engineering, Stanford University, Stanford, USA
| | - Rachel W Jackson
- Department of Bioengineering, Stanford University, Stanford, USA
| | - Yashar Aucie
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, USA
| | - Digna de Kam
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, USA
| | - Steven H Collins
- Department of Mechanical Engineering, Stanford University, Stanford, USA
| | | |
Collapse
|
20
|
Persons post-stroke improve step length symmetry by walking asymmetrically. J Neuroeng Rehabil 2020; 17:105. [PMID: 32746886 PMCID: PMC7397591 DOI: 10.1186/s12984-020-00732-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 07/22/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND AND PURPOSE Restoration of step length symmetry is a common rehabilitation goal after stroke. Persons post-stroke often retain the ability to walk with symmetric step lengths ("symmetric steps"); however, the resulting walking pattern remains effortful. Two key questions with direct implications for rehabilitation have emerged: 1) how do persons post-stroke generate symmetric steps, and 2) why do symmetric steps remain so effortful? Here, we aimed to understand how persons post-stroke generate symmetric steps and explored how the resulting gait pattern may relate to the metabolic cost of transport. METHODS We recorded kinematic, kinetic, and metabolic data as nine persons post-stroke walked on an instrumented treadmill under two conditions: preferred walking and symmetric stepping (using visual feedback). RESULTS Gait kinematics and kinetics remained markedly asymmetric even when persons post-stroke improved step length symmetry. Impaired paretic propulsion and aberrant movement of the center of mass were evident during both preferred walking and symmetric stepping. These deficits contributed to diminished positive work performed by the paretic limb on the center of mass in both conditions. Within each condition, decreased positive paretic work correlated with increased metabolic cost of transport and decreased walking speed across participants. CONCLUSIONS It is critical to consider the mechanics used to restore symmetric steps when designing interventions to improve walking after stroke. Future research should consider the many dimensions of asymmetry in post-stroke gait, and additional within-participant manipulations of gait parameters are needed to improve our understanding of the elevated metabolic cost of walking after stroke.
Collapse
|
21
|
Stenum J, Choi JT. Step time asymmetry but not step length asymmetry is adapted to optimize energy cost of split‐belt treadmill walking. J Physiol 2020; 598:4063-4078. [DOI: 10.1113/jp279195] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 07/13/2020] [Indexed: 11/08/2022] Open
Affiliation(s)
- Jan Stenum
- Department of Kinesiology University of Massachusetts Amherst Amherst MA 01003 USA
- Center for Movement Studies Kennedy Krieger Institute Baltimore MD 21205 USA
- Department of Physical Medicine and Rehabilitation The Johns Hopkins University School of Medicine Baltimore MD 21205 USA
| | - Julia T. Choi
- Department of Kinesiology University of Massachusetts Amherst Amherst MA 01003 USA
- Department of Applied Physiology and Kinesiology University of Florida Gainesville FL 32611 USA
| |
Collapse
|
22
|
Balbinot G, Schuch CP, Bianchi Oliveira H, Peyré-Tartaruga LA. Mechanical and energetic determinants of impaired gait following stroke: segmental work and pendular energy transduction during treadmill walking. Biol Open 2020; 9:9/7/bio051581. [PMID: 32694152 PMCID: PMC7390624 DOI: 10.1242/bio.051581] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Systems biology postulates the balance between energy production and conservation in optimizing locomotion. Here, we analyzed how mechanical energy production and conservation influenced metabolic energy expenditure in stroke survivors during treadmill walking at different speeds. We used the body center of mass (BCoM) and segmental center of mass to calculate mechanical energy production: external and each segment's mechanical work (Wseg). We also estimated energy conservation by applying the pendular transduction framework (i.e. energy transduction within the step; Rint). Energy conservation was likely optimized by the paretic lower-limb acting as a rigid shaft while the non-paretic limb pushed the BCoM forward at the slower walking speed. Wseg production was characterized by greater movements between the limbs and body, a compensatory strategy used mainly by the non-paretic limbs. Overall, Wseg production following a stroke was characterized by non-paretic upper-limb compensation, but also by an exaggerated lift of the paretic leg. This study also highlights how post-stroke subjects may perform a more economic gait while walking on a treadmill at preferred walking speeds. Complex neural adaptations optimize energy production and conservation at the systems level, and may fundament new insights onto post-stroke neurorehabilitation. This article has and associated First Person interview with the first author of the paper. Summary: Walking after a stroke may be energetically consuming. Here, we show how compensations and asymmetries may contribute to increasing the amount of work needed to walk following a stroke.
Collapse
Affiliation(s)
- Gustavo Balbinot
- Exercise Research Laboratory, Universidade Federal do Rio Grande do Sul, 750 Felizardo Street, Porto Alegre, 90690-200, RS, Brazil.,KITE - Toronto Rehabilitation Institute - University Health Network, Lyndhurst Centre, 520 Sutherland Drive, Toronto, M4G 3V9, ON, Canada
| | - Clarissa Pedrini Schuch
- Exercise Research Laboratory, Universidade Federal do Rio Grande do Sul, 750 Felizardo Street, Porto Alegre, 90690-200, RS, Brazil
| | - Henrique Bianchi Oliveira
- Exercise Research Laboratory, Universidade Federal do Rio Grande do Sul, 750 Felizardo Street, Porto Alegre, 90690-200, RS, Brazil
| | - Leonardo A Peyré-Tartaruga
- Exercise Research Laboratory, Universidade Federal do Rio Grande do Sul, 750 Felizardo Street, Porto Alegre, 90690-200, RS, Brazil
| |
Collapse
|
23
|
Improving Spatiotemporal Gait Asymmetry Has Limited Functional Benefit for Individuals Poststroke. J Neurol Phys Ther 2020; 44:197-204. [DOI: 10.1097/npt.0000000000000321] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
24
|
Tesio L, Rota V. The Motion of Body Center of Mass During Walking: A Review Oriented to Clinical Applications. Front Neurol 2019; 10:999. [PMID: 31616361 PMCID: PMC6763727 DOI: 10.3389/fneur.2019.00999] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 09/02/2019] [Indexed: 01/04/2023] Open
Abstract
Human walking is usually conceived as the cyclic rotation of the limbs. The goal of lower-limb movements, however, is the forward translation of the body system, which can be mechanically represented by its center of mass (CoM). Lower limbs act as struts of an inverted pendulum, allowing minimization of muscle work, from infancy to old age. The plantar flexors of the trailing limbs have been identified as the main engines of CoM propulsion. Motion of the CoM can be investigated through refined techniques, but research has been focused on the fields of human and animal physiology rather than clinical medicine. Alterations in CoM motion could reveal motor impairments that are not detectable by clinical observation. The study of the three-dimensional trajectory of the CoM motion represents a clinical frontier. After adjusting for displacement due to the average forward speed, the trajectory assumes a figure-eight shape (dubbed the “bow-tie”) with a perimeter about 18 cm long. Its lateral size decreases with walking velocity, thus ensuring dynamic stability. Lateral redirection appears as a critical phase of the step, requiring precise muscle sequencing. The shape and size of the “bow-tie” as functions of dynamically equivalent velocities do not change from child to adulthood, despite anatomical growth. The trajectory of the CoM thus appears to be a promising summary index of both balance and the neural maturation of walking. In asymmetric gaits, the affected lower limb avoids muscle work by pivoting almost passively, but extra work is required from the unaffected side during the next step, in order to keep the body system in motion. Generally, the average work to transport the CoM across a stride remains normal. In more demanding conditions, such as walking faster or uphill, the affected limb can actually provide more work; however, the unaffected limb also provides more work and asymmetry between the steps persists. This learned or acquired asymmetry is a formerly unsuspected challenge to rehabilitation attempts to restore symmetry. Techniques of selective loading of the affected side, which include constraining the motion of the unaffected limb or forcing the use of the affected limb on split-belt treadmills which impose a different velocity and power to either limb, are now under scrutiny.
Collapse
Affiliation(s)
- Luigi Tesio
- Department of Biomedical Sciences for Health, Università degli Studi, Milan, Italy.,Department of Neurorehabilitation Sciences, Istituto Auxologico Italiano, IRCCS, Milan, Italy
| | - Viviana Rota
- Department of Neurorehabilitation Sciences, Istituto Auxologico Italiano, IRCCS, Milan, Italy
| |
Collapse
|