scholarly journals How Well Do Commonly Used Co-contraction Indices Approximate Lower Limb Joint Stiffness Trends During Gait for Individuals Post-stroke?

2021 ◽  
Vol 8 ◽  
Author(s):  
Geng Li ◽  
Mohammad S. Shourijeh ◽  
Di Ao ◽  
Carolynn Patten ◽  
Benjamin J. Fregly
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Sagittal Plane ◽  
Joint Stiffness ◽  
Energetic Cost ◽  
Electromechanical Delay ◽  
Antagonist Muscle ◽  
Post Stroke ◽  
Methodological Choices ◽  
Model Based

Muscle co-contraction generates joint stiffness to improve stability and accuracy during limb movement but at the expense of higher energetic cost. However, quantification of joint stiffness is difficult using either experimental or computational means. In contrast, quantification of muscle co-contraction using an EMG-based Co-Contraction Index (CCI) is easier and may offer an alternative for estimating joint stiffness. This study investigated the feasibility of using two common CCIs to approximate lower limb joint stiffness trends during gait. Calibrated EMG-driven lower extremity musculoskeletal models constructed for two individuals post-stroke were used to generate the quantities required for CCI calculations and model-based estimation of joint stiffness. CCIs were calculated for various combinations of antagonist muscle pairs based on two common CCI formulations: Rudolph et al. (2000) (CCI1) and Falconer and Winter (1985) (CCI2). CCI1 measures antagonist muscle activation relative to not only total activation of agonist plus antagonist muscles but also agonist muscle activation, while CCI2 measures antagonist muscle activation relative to only total muscle activation. We computed the correlation between these two CCIs and model-based estimates of sagittal plane joint stiffness for the hip, knee, and ankle of both legs. Although we observed moderate to strong correlations between some CCI formulations and corresponding joint stiffness, these associations were highly dependent on the methodological choices made for CCI computation. Specifically, we found that: (1) CCI1 was generally more correlated with joint stiffness than was CCI2, (2) CCI calculation using EMG signals with calibrated electromechanical delay generally yielded the best correlations with joint stiffness, and (3) choice of antagonist muscle pairs significantly influenced CCI correlation with joint stiffness. By providing guidance on how methodological choices influence CCI correlation with joint stiffness trends, this study may facilitate a simpler alternate approach for studying joint stiffness during human movement.

scholarly journals How Well Do Commonly Used Co-Contraction Indices Approximate Lower Limb Joint Stiffness Trends during Gait?

2020 ◽  
Author(s):  
Geng Li ◽  
Mohammad S. Shourijeh ◽  
Di Ao ◽  
Carolynn Patten ◽  
Benjamin J. Fregly
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Joint Stiffness ◽  
Reference Value ◽  
Energetic Cost ◽  
Electromechanical Delay ◽  
Methodological Choices ◽  
Model Based ◽  
Alternative Path ◽  
Antagonistic Muscle

AbstractMuscle co-contraction generates joint stiffness to improve stability and accuracy during limb movement but at the expense of higher energetic cost. The quantification of joint stiffness generated from muscle co-contraction is difficult through both experimental and computational means for its benefit and cost to be assessed. Quantification of muscle co-contraction may offer an alternative path for estimating joint stiffness. By choosing the commonly used Co-Contraction Indices (CCIs) to represent muscle co-contraction, this study investigated the feasibility of using CCI to approximate lower limb joint stiffness trends during gait. A calibrated EMG-driven musculoskeletal model of a hemiparetic individual post-stroke from a previous study was used to generate the quantities required for CCI calculation and model-based estimation of joint stiffness. A total of 14 classes of CCIs for various combinations of antagonistic muscle pairs were calculated based on two common CCI formulations, each with 7 types of quantities that included variations of electromyography (EMG) signals and joint moments from the muscles. Correlations between CCIs and model-based estimates of sagittal plane stiffness of the lower extremity joints (hip, knee, ankle) were computed. Although moderate to strong correlation was observed between some CCI formulations and the corresponding joint stiffness, these associations were highly dependent on the methodological choices made for CCI computation. The overall findings of this study were the following: (1) the formulation proposed by Rudolph et al. (2000), CCI1, was more correlated with joint stiffness than that of Falconer and Winter (1985); (2) Moment-based CCI1 from individual antagonistic muscle pairs was more correlated than EMG-based CCI1; (3) EMG signals with calibrated electromechanical delay and joint moment generated by individual muscle without normalization to a reference value were the most correlated for EMG-based CCI1 and moment-based CCI1, respectively. The combination of antagonistic muscle pairs for most correlated within each CCI class was also identified. By using CCI to approximate joint stiffness trends, this study may open an alternative path to studying joint stiffness.

scholarly journals Mechanism of anterior cruciate ligament loading during dynamic motor tasks

2020 ◽  
Author(s):  
Azadeh Nasseri ◽  
David G Lloyd ◽  
Adam L Bryant ◽  
Jonathon Headrick ◽  
Timothy Sayer ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Lower Limb ◽  
Muscle Activation ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Three Dimensional ◽  
Whole Body ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Anterior Cruciate

AbstractThis study determined anterior cruciate ligament (ACL) force and its contributors during a standardized drop-land-lateral jump task using a validated computational model. Healthy females (n=24) who were recreationally active performed drop-land-lateral jump and straight run tasks. Three-dimensional whole-body kinematics, ground reaction forces, and muscle activation patterns from eight lower limb muscles were collected concurrently during both tasks, but only the jump was analyzed computationally, with the run included for model calibration. External biomechanics, muscle-tendon unit kinematics, and muscle activation patterns were used to model lower limb muscle and ACL forces. Peak ACL force (2.3±0.5 BW) was observed at 13% of the stance phase during the drop-land-lateral jump task. The ACL force was primarily developed through the sagittal plane, and muscle was the dominant source of ACL loading. The gastrocnemii and quadriceps were main ACL antagonists (i.e., loaders), while hamstrings were the main ACL agonists (i.e., supporters).

Different Muscle-Recruitment Strategies Among Elite Breaststrokers

2015 ◽  
Vol 10 (8) ◽  
pp. 1061-1065 ◽  
Author(s):  
Brice Guignard ◽  
Bjørn H. Olstad ◽  
David Simbaña Escobar ◽  
Jessy Lauer ◽  
Per-Ludvik Kjendlie ◽  
...  
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Sagittal Plane ◽  
National Level ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Recovery Phase ◽  
Elite Group ◽  
Flexion Extension ◽  
High Level

Purpose:To investigate electromyographical (EMG) profiles characterizing the lower-limb flexion-extension in an aquatic environment in high-level breaststrokers.Methods:The 2-dimensional breaststroke kick of 1 international- and 2 national-level female swimmers was analyzed during 2 maximal 25-m swims. The activities of biceps femoris, rectus femoris, gastrocnemius, and tibialis anterior were recorded.Results:The breaststroke kick was divided in 3 phases, according to the movements performed in the sagittal plane: push phase (PP) covering 27% of the total kick duration, glide phase (GP) 41%, and recovery phase (RP) 32%. Intrasubject reproducibility of the EMG and kinematics was observed from 1 stroke cycle to another. In addition, important intersubject kinematic reproducibility was noted, whereas muscle activities discriminated the subjects: The explosive Pp was characterized by important muscle-activation peaks. During the recovery, muscles were likewise solicited for swimmers 1 (S1) and 2 (S2), while the lowest activities were observed during GP for S2 and swimmer 3 (S3), but not for S1, who maintained major muscle solicitations.Conclusions:The main muscle activities were observed during PP to perform powerful lower-limb extension. The most-skilled swimmer (S1) was the only 1 to solicit her muscles during GP to actively reach better streamlining. Important activation peaks during RP correspond to the limbs acting against water drag. Such differences in EMG strategies among an elite group highlight the importance of considering the muscle parameters used to effectively control the intensity of activation among the phases for a more efficient breaststroke kick.

scholarly journals Adjustments with running speed reveal neuromuscular adaptations during landing associated with high mileage running training

2017 ◽  
Vol 122 (3) ◽  
pp. 653-665 ◽  
Author(s):  
Jasper Verheul ◽  
Adam C. Clansey ◽  
Mark J. Lake
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Joint Stiffness ◽  
Thigh Muscle ◽  
Running Speed ◽  
Running Training ◽  
Knee Stiffness ◽  
Peak Knee ◽  
The Impact ◽  
Weight Acceptance

It remains to be determined whether running training influences the amplitude of lower limb muscle activations before and during the first half of stance and whether such changes are associated with joint stiffness regulation and usage of stored energy from tendons. Therefore, the aim of this study was to investigate neuromuscular and movement adaptations before and during landing in response to running training across a range of speeds. Two groups of high mileage (HM; >45 km/wk, n = 13) and low mileage (LM; <15 km/wk, n = 13) runners ran at four speeds (2.5–5.5 m/s) while lower limb mechanics and electromyography of the thigh muscles were collected. There were few differences in prelanding activation levels, but HM runners displayed lower activations of the rectus femoris, vastus medialis, and semitendinosus muscles postlanding, and these differences increased with running speed. HM runners also demonstrated higher initial knee stiffness during the impact phase compared with LM runners, which was associated with an earlier peak knee flexion velocity, and both were relatively unchanged by running speed. In contrast, LM runners had higher knee stiffness during the slightly later weight acceptance phase and the disparity was amplified with increases in speed. It was concluded that initial knee joint stiffness might predominantly be governed by tendon stiffness rather than muscular activations before landing. Estimated elastic work about the ankle was found to be higher in the HM runners, which might play a role in reducing weight acceptance phase muscle activation levels and improve muscle activation efficiency with running training. NEW & NOTEWORTHY Although neuromuscular factors play a key role during running, the influence of high mileage training on neuromuscular function has been poorly studied, especially in relation to running speed. This study is the first to demonstrate changes in neuromuscular conditioning with high mileage training, mainly characterized by lower thigh muscle activation after touch down, higher initial knee stiffness, and greater estimates of energy return, with adaptations being increasingly evident at faster running speeds.

Design and validation of a lower limb exoskeleton employing the recumbent cycling modality for post-stroke rehabilitation

2014 ◽  
Vol 228 (18) ◽  
pp. 3517-3525 ◽  
Author(s):  
Hua Yan ◽  
Canjun Yang
Keyword(s):  
Lower Limb ◽  
Muscle Power ◽  
Sagittal Plane ◽  
Kinematic Model ◽  
Stroke Patients ◽  
Post Stroke ◽  
Lower Limb Exoskeleton ◽  
Exoskeleton Robot ◽  
Limited Range Of Motion ◽  
Custom Made

This paper presents the design and validation of a lower limb exoskeleton robot for post-stroke patients at the early stage of neurorehabilitation. Instead of the usual walking gait, the popular exercise, recumbent cycling, is adopted to provide a safe and comfortable movement training to the patients who lost active motor abilities due to a very low muscle power. The exoskeleton robot mounted on a commercial wheelchair possesses two pairs of hip and knee joints on the right and left legs, respectively, and each joint has one degree of freedom actuated by a custom-made linear actuator in the sagittal plane. Additionally, two passive ankle joints are added to provide a limited range of motion for human comfort. The hip and knee joint motion profiles were calculated based on a simplified kinematic model of the recumbent cycling modality, and implemented through the motor position–velocity–time trajectory. Clinical trials were conducted on six stable post-stroke patients with a low muscle power under the supervision of a skilled therapist. The preliminary results validated the functionality and feasibility of the new exoskeleton robot and showed a promising application of the recumbent cycling modality in robot-assisted neurorehabilitation.

scholarly journals Effect of Stretching of Spastic Elbow Under Intelligent Control in Chronic Stroke Survivors—A Pilot Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Sanjana Rao ◽  
Meizhen Huang ◽  
Sun Gun Chung ◽  
Li-Qun Zhang
Keyword(s):  
Elbow Joint ◽  
Sagittal Plane ◽  
Biceps Tendon ◽  
Joint Stiffness ◽  
Elbow Flexion ◽  
Passive Movement ◽  
Chronic Stroke ◽  
Stroke Survivors ◽  
Short Term ◽  
Post Stroke

Objective: To assess the short-term effects of strenuous dynamic stretching of the elbow joint using an intelligent stretching device in chronic spastic stroke survivors.Methods: The intelligent stretching device was utilized to provide a single session of intensive stretching to the spastic elbow joint in the sagittal plane (i.e., elbow flexion and extension). The stretching was provided to the extreme range, safely, with control of the stretching velocity and torque to increase the joint range of motion (ROM) and reduce spasticity and joint stiffness. Eight chronic stroke survivors (age: 52.6 ± 8.2 years, post-stroke duration: 9.5 ± 3.6 years) completed a single 40-min stretching intervention session. Elbow passive and active ROM, strength, passive stiffness (quantifying the non-reflex component of spasticity), and instrumented tendon reflex test of the biceps tendon (quantifying the reflex component of the spasticity) were measured before and after stretching.Results: After stretching, there was a significant increase in passive ROM of elbow flexion (p = 0.021, r = 0.59) and extension (p = 0.026, r = 0.59). Also, elbow active ROM and the spastic elbow flexors showed a trend of increase in their strength.Conclusion: The intelligent stretching had a short-term positive influence on the passive movement ROM. Hence, intelligent stretching can potentially be used to repeatedly and regularly stretch spastic elbow joints, which subsequently helps to reduce upper limb impairments post-stroke.

Load Carriage During Walking Increases Dynamic Stiffness at Distal Lower Limb Joints

2021 ◽  
pp. 1-7
Author(s):  
Thiago R.T. Santos ◽  
Sergio T. Fonseca ◽  
Vanessa L. Araújo ◽  
Sangjun Lee ◽  
Fabricio Saucedo ◽  
...  
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Dynamic Stiffness ◽  
Regression Line ◽  
Joint Stiffness ◽  
Movement Pattern ◽  
Load Carriage ◽  
Linear Slope ◽  
The Moment ◽  
Loaded Walking

The addition of a load during walking requires changes in the movement pattern. The investigation of the dynamic joint stiffness behavior may help to understand the lower limb joints’ contribution to these changes. This study aimed to investigate the dynamic stiffness of lower limb joints in response to the increased load carried while walking. Thirteen participants walked in two conditions: unloaded (an empty backpack) and loaded (the same backpack plus added mass corresponding to 30% of body mass). Dynamic stiffness was calculated as the linear slope of the regression line on the moment–angle curve during the power absorption phases of the ankle, knee, and hip in the sagittal plane. The results showed that ankle (P = .002) and knee (P < .001) increased their dynamic stiffness during loaded walking compared with unloaded, but no difference was observed at the hip (P = .332). The dynamic stiffness changes were different among joints (P < .001): ankle and knee changes were not different (P < .992), but they had a greater change than hip (P < .001). The nonuniform increases in lower limb joint dynamic stiffness suggest that the ankle and knee are critical joints to deal with the extra loading.

scholarly journals Lower Limb Joint Kinetics During a Side-Cutting Task in Participants With or Without Chronic Ankle Instability

2020 ◽  
Vol 55 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Jeffrey D. Simpson ◽  
Ethan M. Stewart ◽  
Alana J. Turner ◽  
David M. Macias ◽  
Harish Chander ◽  
...  
Keyword(s):  
Hip Joint ◽  
Lower Limb ◽  
Stance Phase ◽  
Sagittal Plane ◽  
Ankle Instability ◽  
Reaction Force ◽  
Joint Stiffness ◽  
Control Group ◽  
Joint Kinetics ◽  
3 Dimensional

Context Individuals with chronic ankle instability (CAI) demonstrate altered lower limb movement dynamics during jump landings, which can contribute to recurrent injury. However, the literature examining lower limb movement dynamics during a side-cutting task in individuals with CAI is limited. Objective To assess lower limb joint kinetics and sagittal-plane joint stiffness during the stance phase of a side-cutting task in individuals with or without CAI. Design Cohort study. Setting Motion-capture laboratory. Patients or Other Participants Fifteen physically active, young adults with CAI (7 men, 8 women; age = 21.3 ± 1.6 years, height = 171.0 ± 11.2 cm, mass = 73.4 ± 15.2 kg) and 15 healthy matched controls (7 men, 8 women; age = 21.5 ± 1.5 years, height = 169.9 ± 10.6 cm, mass = 75.5 ± 13.0 kg). Intervention(s) Lower limb 3-dimensional kinematic and ground reaction force data were recorded while participants completed 3 successful trials of a side-cutting task. Net internal joint moments, in addition to sagittal-plane ankle-, knee-, and hip-joint stiffness, were computed from 3-dimensional kinematic and ground reaction force data during the stance phase of the side-cutting task and analyzed. Main Outcome Measure(s) Data from each participant's stance phase were normalized to 100% from initial foot contact (0%) to toe-off (100%) to compute means, standard deviations, and Cohen d effect sizes for all dependent variables. Results The CAI group exhibited a reduced ankle-eversion moment (39%–81% of stance phase) and knee-abduction moment (52%–75% of stance phase) and a greater ankle plantar-flexion moment (3%–16% of stance phase) than the control group (P range = .009–.049). Sagittal-plane hip-joint stiffness was greater in the CAI than in the control group (t28 = 1.978, P = .03). Conclusions Our findings suggest that altered ankle-joint kinetics and increased hip-joint stiffness were associated when individuals with CAI performed a side-cutting task. These lower limb kinetic changes may contribute to an increased risk of recurrent lateral ankle sprains in people with CAI. Clinicians and practitioners can use these findings to develop rehabilitation programs for improving maladaptive movement mechanics in individuals with CAI.

scholarly journals Kinematic Analysis of Lower Limb Joint Asymmetry during Gait in People with Multiple Sclerosis

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 598
Author(s):  
Massimiliano Pau ◽  
Bruno Leban ◽  
Michela Deidda ◽  
Federica Putzolu ◽  
Micaela Porta ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Cross Sectional Study ◽  
Camera Motion ◽  
Cross Sectional ◽  
Temporal Parameters ◽  
Wide Range ◽  
Edss Score ◽  
Spatio Temporal

The majority of people with Multiple Sclerosis (pwMS), report lower limb motor dysfunctions, which may relevantly affect postural control, gait and a wide range of activities of daily living. While it is quite common to observe a different impact of the disease on the two limbs (i.e., one of them is more affected), less clear are the effects of such asymmetry on gait performance. The present retrospective cross-sectional study aimed to characterize the magnitude of interlimb asymmetry in pwMS, particularly as regards the joint kinematics, using parameters derived from angle-angle diagrams. To this end, we analyzed gait patterns of 101 pwMS (55 women, 46 men, mean age 46.3, average Expanded Disability Status Scale (EDSS) score 3.5, range 1–6.5) and 81 unaffected individuals age- and sex-matched who underwent 3D computerized gait analysis carried out using an eight-camera motion capture system. Spatio-temporal parameters and kinematics in the sagittal plane at hip, knee and ankle joints were considered for the analysis. The angular trends of left and right sides were processed to build synchronized angle–angle diagrams (cyclograms) for each joint, and symmetry was assessed by computing several geometrical features such as area, orientation and Trend Symmetry. Based on cyclogram orientation and Trend Symmetry, the results show that pwMS exhibit significantly greater asymmetry in all three joints with respect to unaffected individuals. In particular, orientation values were as follows: 5.1 of pwMS vs. 1.6 of unaffected individuals at hip joint, 7.0 vs. 1.5 at knee and 6.4 vs. 3.0 at ankle (p < 0.001 in all cases), while for Trend Symmetry we obtained at hip 1.7 of pwMS vs. 0.3 of unaffected individuals, 4.2 vs. 0.5 at knee and 8.5 vs. 1.5 at ankle (p < 0.001 in all cases). Moreover, the same parameters were sensitive enough to discriminate individuals of different disability levels. With few exceptions, all the calculated symmetry parameters were found significantly correlated with the main spatio-temporal parameters of gait and the EDSS score. In particular, large correlations were detected between Trend Symmetry and gait speed (with rho values in the range of –0.58 to –0.63 depending on the considered joint, p < 0.001) and between Trend Symmetry and EDSS score (rho = 0.62 to 0.69, p < 0.001). Such results suggest not only that MS is associated with significantly marked interlimb asymmetry during gait but also that such asymmetry worsens as the disease progresses and that it has a relevant impact on gait performances.

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