Muscle Contributions to Pre-Swing Biomechanical Tasks Influence Swing Leg Mechanics in Individuals Post-Stroke during Walking

Abstract Background Successful walking requires the execution of the pre-swing biomechanical tasks of body propulsion and leg swing initiation, which are often impaired post-stroke. While excess rectus femoris activity during swing is often associated with low knee flexion, previous work has suggested that deficits in propulsion and leg swing initiation may also contribute. The purpose of this study was to determine underlying causes of propulsion, leg swing initiation and knee flexion deficits in pre-swing and their link to stiff knee gait in stroke survivors. Methods Musculoskeletal models and forward dynamic simulations were developed for individuals post-stroke (n=15) and neurotypical participants (n=5). Linear regressions were used to evaluate the relationships between peak knee flexion, braking and propulsion symmetry, and individual muscle contributions to braking, propulsion, knee flexion in pre-swing, and leg swing initiation. Results 27% of individuals post-stroke had higher plantarflexor contributions to propulsion and 47% had higher vasti contributions to braking on their paretic leg relative to their nonparetic leg. Higher gastrocnemius contributions to propulsion were correlated to paretic propulsion symmetry (p=0.005) while soleus contributions were not. Higher vasti contributions to braking in pre-swing predicted lower knee flexion (p=0.022). The rectus femoris and iliopsoas did not directly contribute to lower knee flexion acceleration in pre-swing compared to contributions from the vasti. However, for some individuals with low knee flexion, during pre-swing the rectus femoris absorbed more power and the iliopsoas contributed less power to the paretic leg. Total muscle-tendon work done on the paretic leg in pre-swing was not correlated to knee flexion during swing. Conclusions These results emphasize the multiple causes of propulsion asymmetry in individuals post-stroke, including low plantarflexor contributions to propulsion, increased vasti contributions to braking and reliance on compensatory mechanisms. The results also show that the rectus femoris is not a major contributor to knee flexion in pre-swing, but absorbs more power from the paretic leg in pre-swing in some individuals with stiff knee gait. These results further highlight the heterogeneity of the post-stroke population and the need to identify individual causes of propulsion and knee flexion deficits to improve rehabilitation outcomes.

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Rectus femoris hyperreflexia predicts knee flexion angle in Stiff-Knee gait after stroke

10.1101/699108 ◽

2019 ◽

Cited By ~ 2

Author(s):

Tunc Akbas ◽

Kyoungsoon Kim ◽

Kathleen Doyle ◽

Kathleen Manella ◽

Robert Lee ◽

...

Keyword(s):

Knee Flexion ◽

Rectus Femoris ◽

H Reflex ◽

Flexion Angle ◽

Reflex Modulation ◽

Knee Flexion Angle ◽

Healthy Individuals ◽

Reflex Amplitude ◽

Post Stroke ◽

Stiff Knee

AbstractStiff-knee gait (SKG) after stroke is often accompanied by decreased knee flexion angle during the swing phase. The decreased knee flexion has been hypothesized to originate from excessive quadriceps activation. However, it is unclear whether this activation is due to poor timing or hyperreflexia, both common post-stroke impairments. The goal of this study was to investigate the relation between quadriceps hyperreflexia in post-stroke SKG with knee flexion angle during walking. The rectus femoris (RF) H-reflex was recorded in eleven participants with post-stroke SKG and ten healthy controls during standing and walking during toe-off. In order to separate the effects of poorly timed quadriceps muscle activation from hyperreflexia, healthy individuals voluntarily increased quadriceps activity using RF electromyographic (EMG) biofeedback during standing and pre-swing upon H-reflex stimulation. We observed a negative correlation (R = −0.92, p=0.001) between knee flexion angle and RF H-reflexes in post-stroke SKG. In contrast, H-reflex amplitude in healthy individuals in presence (R = 0.47, p = 0.23) or absence (R = −0.17, p = 0.46) of increased RF activity had no correlation with knee flexion angle. The RF H-reflex amplitude differed between standing and walking in healthy individuals, including when RF activity was increased voluntarily (d = 2.86, p = 0.007), but was not observed post-stroke (d =0.73, p = 0.296). Thus, RF reflex modulation is impaired in post-stroke SKG. Further, RF hyperreflexia, as opposed to overactivity, may play a role in knee flexion kinematics in post-stroke SKG. Interventions targeting self-regulated quadriceps hyperreflexia may be effective in promoting better neural control of the knee joint and thus better quality of walking post-stroke.

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Neuromusculoskeletal simulation reveals abnormal rectus femoris-gluteus medius reflex coupling in post-stroke gait

10.1101/501072 ◽

2018 ◽

Cited By ~ 1

Author(s):

Tunc Akbas ◽

Richard R. Neptune ◽

James Sulzer

Keyword(s):

Knee Flexion ◽

Latency Period ◽

Rectus Femoris ◽

Gluteus Medius ◽

Coordination Pattern ◽

Healthy Controls ◽

Post Stroke ◽

Reflex Latency ◽

Stiff Knee ◽

Muscle Activations

ABSTRACTPost-stroke gait is often accompanied by muscle impairments that result in adaptations such as hip circumduction to compensate for lack of knee flexion. Our previous work robotically enhanced knee flexion in individuals post-stroke with Stiff-Knee Gait (SKG), however, this resulted in greater circumduction, suggesting the existence of abnormal coordination in SKG. The purpose of this work is to investigate two possible mechanisms of the abnormal coordination: 1) an involuntary coupling between stretched quadriceps and abductors, and 2) a coupling between volitionally activated knee flexors and abductors. We used previously collected kinematic, kinetic and EMG measures from nine participants with chronic stroke and five healthy controls during walking with and without the applied knee flexion torque perturbations in the pre-swing phase of gait in the neuromusculoskeletal simulation. The measured muscle activity was supplemented by simulated muscle activations to estimate the muscle states of the quadriceps, hamstrings and hip abductors. We used linear mixed models to investigate two hypotheses: H1) association between quadriceps and abductor activation during an involuntary period (reflex latency) following the perturbation and H2) association between hamstrings and abductor activation after the perturbation was removed. We observed significantly higher rectus femoris (RF) activation in stroke participants compared to healthy controls within the reflex latency period following the perturbation based on both measured (H1, p < 0.001) and simulated (H1, p = 0.022) activity. Simulated RF and gluteus medius (GMed) activations were correlated only in those with SKG, which was significantly higher compared to healthy controls (H1, p = 0.030). There was no evidence of voluntary synergistic coupling between any combination of hamstrings and hip abductors (H2, p > 0.05) when the perturbation was removed. The RF-GMed coupling suggests an underlying abnormal reflex coordination pattern in post-stroke SKG. These results challenge earlier assumptions that hip circumduction in stroke is simply a kinematic adaptation due to reduced toe clearance. Instead, abnormal coordination may underlie circumduction, illustrating the deleterious role of abnormal coordination in post-stroke gait.

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Hip circumduction is not a compensation for reduced knee flexion angle during gait

10.1101/520684 ◽

2019 ◽

Author(s):

Tunc Akbas ◽

Sunil Prajapati ◽

David Ziemnicki ◽

Poornima Tamma ◽

Sarah Gross ◽

...

Keyword(s):

Knee Flexion ◽

Frontal Plane ◽

Pelvic Obliquity ◽

Flexion Angle ◽

Knee Flexion Angle ◽

Compensatory Mechanisms ◽

Ankle Foot Orthosis ◽

Post Stroke ◽

Hip Abduction ◽

Stiff Knee

AbstractIt has long been held that hip abduction compensates for reduced swing-phase knee flexion angle, especially in those after stroke. However, there are other compensatory motions such as pelvic obliquity (hip hiking) that could also be used to facilitate foot clearance with greater energy efficiency. Our previous work suggested that hip abduction may not be a compensation for reduced knee flexion after stroke. Previous study applied robotic knee flexion assistance in people with post-stroke Stiff-Knee Gait (SKG) during pre-swing, finding increased abduction despite improved knee flexion and toe clearance. Thus, our hypothesis was that hip abduction is not a compensation for reduced knee flexion. We simulated the kinematics of post-stroke SKG on unimpaired individuals with three factors: a knee orthosis to reduce knee flexion, an ankle-foot orthosis commonly worn by those post-stroke, and matching gait speeds. We compared spatiotemporal measures and kinematics between experimental factors within healthy controls and with a previously recorded cohort of people with post-stroke SKG. We focused on frontal plane motions of hip and pelvis as possible compensatory mechanisms. We observed that regardless of gait speed, knee flexion restriction significantly increased pelvic obliquity (2.79°, p<0.01) compared to unrestricted walking (1.5°, p<0.01), but similar to post-stroke SKG (3.4°). However, those with post-stroke SKG had significantly greater hip abduction (8.2°) compared to unimpaired individuals with restricted knee flexion (4.2°, p<0.05). These results show that pelvic obliquity, not hip abduction, compensates for reduced knee flexion angle. Thus, other factors, possibly neural, facilitate exaggerated hip abduction observed in post-stroke SKG.

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Effectiveness of botulinum toxin in rectus femoris in patients post-stroke with stiff-knee gait

Gait & Posture ◽

10.1016/j.gaitpost.2012.12.021 ◽

2013 ◽

Vol 37 ◽

pp. S1-S2

Author(s):

M. Bacchini ◽

C. Rovacchi ◽

F. Chiampo ◽

M. Rossi

Keyword(s):

Botulinum Toxin ◽

Rectus Femoris ◽

Post Stroke ◽

Stiff Knee

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Can non-disabled adults reproduce the stiff-knee gait of individuals with stroke?

10.1101/2020.12.02.20242966 ◽

2020 ◽

Author(s):

Odair Bacca ◽

Melissa Celestino ◽

José Barela ◽

Anna Lima ◽

Ana Barela

Keyword(s):

Lower Limb ◽

Knee Flexion ◽

Muscle Activation ◽

Rectus Femoris ◽

Biceps Femoris ◽

Gait Pattern ◽

Activation Level ◽

Stiff Knee ◽

Mechanical Constraint ◽

Disabled Adults

AbstractThis study investigated whether a mechanical constraint of knee flexion in non-disabled individuals could help with reproducing the gait pattern of individuals with stroke. Eleven non-disabled adults (26.6±6.5 years old) and 12 individuals with stroke (52.0±12.8 years old) walked at a self-selected comfortable speed as kinematic and electromyographic data were acquired. Non-disabled adults also walked with an orthosis that limited to 45 degrees of knee flexion. The hip, knee, and ankle joint angles and the muscle activation of the rectus femoris, vastus medialis and lateralis, tibialis anterior, semitendinosus, biceps femoris, and gastrocnemius medialis and lateralis were analyzed. The results demonstrated that non-disabled adults presented similar lower limb excursion to individuals with stroke that affects most joints, although, they displayed a different muscle activation level for most muscles. These results suggest that a mechanical constraint of knee flexion leads to temporal and joint excursion alterations in the lower limb of non-disabled individuals, thereby enabling the reproduction of a gait pattern similar to individuals with stroke. It is also observed that these individuals use different strategies to control muscle activation, which might be related to the lack of control in coordinating muscle activation during gait that is present in individuals with stroke.

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Investigating On-Road Lane Maintenance and Speed Regulation in Post-Stroke Driving: A Pilot Case–Control Study

Geriatrics ◽

10.3390/geriatrics6010016 ◽

2021 ◽

Vol 6 (1) ◽

pp. 16

Author(s):

Heng Zhou ◽

Qian (Chayn) Sun ◽

Alison Blane ◽

Brett Hughes ◽

Torbjörn Falkmer ◽

...

Keyword(s):

Cognitive Abilities ◽

Speed Control ◽

Executive Dysfunction ◽

Case Control ◽

Older Drivers ◽

Control Performance ◽

Post Stroke ◽

Speed Regulation ◽

Stroke Population ◽

Lane Keeping

Stroke can adversely affect the coordination and judgement of drivers due to executive dysfunction, which is relatively common in the post-stroke population but often undetected. Quantitatively examining vehicle control performance in post-stroke driving becomes essential to inspect whether and where post-stroke older drivers are risky. To date, it is unclear as to which indicators, such as lane keeping or speed control, can differentiate the driving performance of post-stroke older drivers from that of normal (neurotypical) older drivers. By employing a case–control design using advanced vehicle movement tracking and analysis technology, this pilot study aimed to compare the variations in driving trajectory, lane keeping and speed control between the two groups of older drivers using spatial and statistical techniques. The results showed that the mean standard deviation of lane deviation (SDLD) in post-stroke participants was higher than that of normal participants in complex driving tasks (U-turn and left turn) but almost the same in simple driving tasks (straight line sections). No statistically significant differences were found in the speed control performance. The findings indicate that, although older drivers can still drive as they need to after a stroke, the decline in cognitive abilities still imposes a higher cognitive workload and more effort for post-stroke older drivers. Future studies can investigate post-stroke adults’ driving behaviour at more challenging driving scenarios or design driving intervention programs to improve their executive function in driving.

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Kinematic Comparison between Medially Congruent and Posterior-Stabilized Third-Generation TKA Designs

Journal of Functional Morphology and Kinesiology ◽

10.3390/jfmk6010027 ◽

2021 ◽

Vol 6 (1) ◽

pp. 27

Author(s):

Stefano Ghirardelli ◽

Jessica L. Asay ◽

Erika A. Leonardi ◽

Tommaso Amoroso ◽

Thomas P. Andriacchi ◽

...

Keyword(s):

Knee Flexion ◽

Knee Kinematics ◽

Primary Total Knee Arthroplasty ◽

Flexion Angle ◽

Heel Strike ◽

Third Generation ◽

Knee Flexion Angle ◽

Posterior Stabilized ◽

Rotational Angle ◽

Peak Knee

Background: This study compares knee kinematics in two groups of patients who have undergone primary total knee arthroplasty (TKA) using two different modern designs: medially congruent (MC) and posterior-stabilized (PS). The aim of the study is to demonstrate only minimal differences between the groups. Methods: Ten TKA patients (4 PS, 6 MC) with successful clinical outcomes were evaluated through 3D knee kinematics analysis performed using a multicamera optoelectronic system and a force platform. Extracted kinematic data included knee flexion angle at heel-strike (KFH), peak midstance knee flexion angle (MSKFA), maximum and minimum knee adduction angle (KAA), and knee rotational angle at heel-strike. Data were compared with a group of healthy controls. Results: There were no differences in preferred walking speed between MC and PS groups, but we found consistent differences in knee function. At heel-strike, the knee tended to be more flexed in the PS group compared to the MC group; the MSKFA tended to be higher in the PS group compared to the MC group. There was a significant fluctuation in KAA during the swing phase in the PS group compared to the MC group, PS patients showed a higher peak knee flexion moment compared to MC patients, and the PS group had significantly less peak internal rotation moments than the MC group. Conclusions: Modern, third-generation TKA designs failed to reproduce normal knee kinematics. MC knees tended to reproduce a more natural kinematic pattern at heel-strike and during axial rotation, while PS knees showed better kinematics during mid-flexion.

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Quadriceps Strength Symmetry Does Not Modify Gait Mechanics After Anterior Cruciate Ligament Reconstruction, Rehabilitation, and Return-to-Sport Training

The American Journal of Sports Medicine ◽

10.1177/0363546520980079 ◽

2020 ◽

pp. 036354652098007

Author(s):

Elanna K. Arhos ◽

Jacob J. Capin ◽

Thomas S. Buchanan ◽

Lynn Snyder-Mackler

Keyword(s):

Knee Flexion ◽

Cruciate Ligament ◽

Return To Sport ◽

Quadriceps Muscle ◽

Quadriceps Strength ◽

Flexion Angle ◽

Knee Flexion Angle ◽

Sport Training ◽

Gait Biomechanics ◽

Peak Knee

Background: After anterior cruciate ligament (ACL) reconstruction (ACLR), biomechanical asymmetries during gait are highly prevalent, persistent, and linked to posttraumatic knee osteoarthritis. Quadriceps strength is an important clinical measure associated with preoperative gait asymmetries and postoperative function and is a primary criterion for return-to-sport clearance. Evidence relating symmetry in quadriceps strength with gait biomechanics is limited to preoperative and early rehabilitation time points before return-to-sport training. Purpose/Hypothesis: The purpose was to determine the relationship between symmetry in isometric quadriceps strength and gait biomechanics after return-to-sport training in athletes after ACLR. We hypothesized that as quadriceps strength symmetry increases, athletes will demonstrate more symmetric knee joint biomechanics, including tibiofemoral joint loading during gait. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Of 79 athletes enrolled in the ACL-SPORTS Trial, 76 were participants in this study after completing postoperative rehabilitation and 10 return-to-sport training sessions (mean ± SD, 7.1 ± 2.0 months after ACLR). All participants completed biomechanical walking gait analysis and isometric quadriceps strength assessment using an electromechanical dynamometer. Quadriceps strength was calculated using a limb symmetry index (involved limb value / uninvolved limb value × 100). The biomechanical variables of interest included peak knee flexion angle, peak knee internal extension moment, sagittal plane knee excursion at weight acceptance and midstance, quadriceps muscle force at peak knee flexion angle, and peak medial compartment contact force. Spearman rank correlation (ρ) coefficients were used to determine the relationship between limb symmetry indexes in quadriceps strength and each biomechanical variable; alpha was set to .05. Results: Of the 76 participants, 27 (35%) demonstrated asymmetries in quadriceps strength, defined by quadriceps strength symmetry <90% (n = 23) or >110% (n = 4) (range, 56.9%-131.7%). For the biomechanical variables of interest, 67% demonstrated asymmetry in peak knee flexion angle; 68% and 83% in knee excursion during weight acceptance and midstance, respectively; 74% in internal peak knee extension moment; 57% in medial compartment contact force; and 74% in quadriceps muscle force. There were no significant correlations between quadriceps strength index and limb symmetry indexes for any biomechanical variable after return-to-sport training ( P > .129). Conclusion: Among those who completed return-to-sport training after ACLR, subsequent quadriceps strength symmetry was not correlated with the persistent asymmetries in gait biomechanics. After a threshold of quadriceps strength is reached, restoring strength alone may not ameliorate gait asymmetries, and current clinical interventions and return-to-sport training may not adequately target gait.

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Healthy subjects with lax knees use less knee flexion rather than muscle control to limit anterior tibia translation during landing

Journal of Experimental Orthopaedics ◽

10.1186/s40634-020-00246-6 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Michèle N. J. Keizer ◽

Juha M. Hijmans ◽

Alli Gokeler ◽

Anne Benjaminse ◽

Egbert Otten

Keyword(s):

Knee Flexion ◽

Muscle Activation ◽

Reaction Force ◽

Rectus Femoris ◽

Knee Laxity ◽

Biceps Femoris ◽

Level Of Evidence ◽

Jump Landing ◽

Muscle Activation Patterns ◽

Healthy Participants

Abstract Purpose It has been reported that there is no correlation between anterior tibia translation (ATT) in passive and dynamic situations. Passive ATT (ATTp) may be different to dynamic ATT (ATTd) due to muscle activation patterns. This study aimed to investigate whether muscle activation during jumping can control ATT in healthy participants. Methods ATTp of twenty-one healthy participants was measured using a KT-1000 arthrometer. All participants performed single leg hops for distance during which ATTd, knee flexion angles and knee flexion moments were measured using a 3D motion capture system. During both tests, sEMG signals were recorded. Results A negative correlation was found between ATTp and the maximal ATTd (r = − 0.47, p = 0.028). An N-Way ANOVA showed that larger semitendinosus activity was seen when ATTd was larger, while less biceps femoris activity and rectus femoris activity were seen. Moreover, larger knee extension moment, knee flexion angle and ground reaction force in the anterior-posterior direction were seen when ATTd was larger. Conclusion Participants with more ATTp showed smaller ATTd during jump landing. Muscle activation did not contribute to reduce ATTd during impact of a jump-landing at the observed knee angles. However, subjects with large ATTp landed with less knee flexion and consequently showed less ATTd. The results of this study give information on how healthy people control knee laxity during jump-landing. Level of evidence III

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Age- and Activity-Related Differences in the Mechanisms Underlying Maximal Power Production in Young and Older Adults

Journal of Applied Biomechanics ◽

10.1123/jab.2013-0037 ◽

2014 ◽

Vol 30 (1) ◽

pp. 12-20 ◽

Cited By ~ 6

Author(s):

Thomas Korff ◽

Ann H. Newstead ◽

Renate van Zandwijk ◽

Jody L. Jensen

Keyword(s):

Older Adults ◽

Knee Flexion ◽

Power Production ◽

Activity Level ◽

Maximum Power ◽

Maximal Power ◽

Joint Power ◽

Age Related ◽

Peak Knee ◽

Active Adults

The purpose of this study was to examine the interactions between aging, activity levels and maximal power production during cycling. Participants were divided into younger adults (YA), older active adults (OA,) and older sedentary adults (OS). Absolute maximum power was significantly greater in YA compared with OS and OA; no differences were found between OA and OS. The age-related difference in maximum power was accompanied by greater absolute peak knee extension and knee flexion powers. Relative joint power contributions revealed both age- and activity-related differences. YA produced less relative hip extension power than older adults, regardless of activity level. The OS participants produced less relative knee flexion power than active adults, regardless of age. The results show the age-related decline in muscular power production is joint specific and that activity level can be a modifier of intersegmental coordination, which has implications for designing interventions for the aging population.

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