Neuromuscular Reflexes Contribute to Knee Stiffness During Valgus Loading

2005 ◽  
Vol 93 (5) ◽  
pp. 2698-2709 ◽  
Author(s):  
Y. Y. Dhaher ◽  
A. D. Tsoumanis ◽  
T. T. Houle ◽  
W. Z. Rymer
Keyword(s):  
Knee Joint ◽  
Muscle Activation ◽  
Joint Stiffness ◽  
Muscle Contractions ◽  
Emg Activity ◽  
Lateral Direction ◽  
Reflex Responses ◽  
Torque Response ◽  
Joint Dynamics ◽  
Periarticular Tissue

We have previously shown that abduction angular perturbations applied to the knee consistently elicit reflex responses in knee joint musculature. Although a stabilizing role for such reflexes is widely proposed, there are as of yet no studies quantifying the contribution of these reflex responses to joint stiffness. In this study, we estimate the mechanical contributions of muscle contractions elicited by mechanical excitation of periarticular tissue receptors to medial-lateral knee joint stiffness. We hypothesize that these reflex muscle contractions will significantly increase knee joint stiffness in the adduction/abduction direction and enhance the overall stability of the knee. To assess medial-lateral joint stiffness, we applied an abducting positional deflection to the fully extended knee using a servomotor and recorded the torque response using a six degree-of-freedom load-cell. EMG activity was also recorded in both relaxed and preactivated quadriceps and hamstrings muscles with surface electrodes. A simple, linear, second-order, delayed model was used to describe the knee joint dynamics in the medial/lateral direction. Our data indicate that excitation of reflexes from periarticular tissue afferents results in a significant increase of the joint’s adduction-abduction stiffness. Similar to muscle stretch reflex action, which is modulated with background activation, these reflexes also show dependence on muscle activation. The potential significance of this reflex stiffness during functional tasks was also discussed. We conclude that reflex activation of knee muscles is sufficient to enhance joint stabilization in the adduction/abduction direction, where knee medial-lateral loading arises frequently during many activities.

scholarly journals Functional assessments of the knee joint biomechanics by using pendulum test in adults with Down syndrome

2012 ◽  
Vol 113 (11) ◽  
pp. 1747-1755 ◽  
Author(s):  
Antonino Casabona ◽  
Maria Stella Valle ◽  
Mariangela Pisasale ◽  
Maria Rosita Pantò ◽  
Matteo Cioni
Keyword(s):  
Down Syndrome ◽  
Knee Joint ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Emg Activity ◽  
Pendulum Test ◽  
Joint Resistance ◽  
Leg Flexion ◽  
Joint Biomechanics ◽  
Muscle Hypotonia

In this study, we assessed kinematics and viscoelastic features of knee joint in adults with Down syndrome (DS) by means of the Wartenberg pendulum test. This test allows the measuring of the kinematics of the knee joint during passive pendular motion of leg under the influence of gravity. In addition, by a combination of kinematic and anthropometric data, pendulum test provides estimates of joint viscoelastic properties by computing damping and stiffness coefficients. To monitor the occurrences of muscle activation, the surface electromyogram (EMG) of muscle rectus femoris was recorded. The experimental protocol was performed in a group of 10 adults with DS compared with 10 control adults without DS. Joint motion amplitude, velocity, and acceleration of the leg during the first knee flexion significantly decreased in persons with DS with respect to those without DS. This behavior was associated with the activation of rectus femoris in subjects with DS that resulted in increasing of joint resistance shortly after the onset of the first leg flexion. The EMG bursts mostly occurred between 50 and 150 ms from the leg flexion onset. During the remaining cycles of pendular motion, persons with DS exhibited passive leg oscillations with low tonic EMG activity and reduced damping coefficient compared with control subjects. These results suggest that adults with DS might perform preprogrammed contractions to increase joint resistance and compensate for inherent joint instability occurring for quick and unpredictable perturbations. The reduction of damping coefficients observed during passive oscillations could be a predictor of muscle hypotonia.

Changes in Muscle Activity in Response to Different Impact Forces Affect Soft Tissue Compartment Mechanical Properties

2006 ◽  
Vol 129 (4) ◽  
pp. 594-602 ◽  
Author(s):  
Katherine A. Boyer ◽  
Benno M. Nigg
Keyword(s):  
Mechanical Properties ◽  
Soft Tissue ◽  
Muscle Activity ◽  
Muscle Activation ◽  
Joint Stiffness ◽  
Heel Strike ◽  
Emg Activity ◽  
Tissue Compartment ◽  
Tissue Compartments ◽  
The Impact

Electromyographic (EMG) activity is associated with several tasks prior to landing in walking and running including positioning the leg, developing joint stiffness and possibly control of soft tissue compartment vibrations. The concept of muscle tuning suggests one reason for changes in muscle activity pattern in response to small changes in impact conditions, if the frequency content of the impact is close to the natural frequency of the soft tissue compartments, is to minimize the magnitude of soft tissue compartment vibrations. The mechanical properties of the soft tissue compartments depend in part on muscle activations and thus it was hypothesized that changes in the muscle activation pattern associated with different impact conditions would result in a change in the acceleration transmissibility to the soft tissue compartments. A pendulum apparatus was used to systematically administer impacts to the heel of shod male participants. Wall reaction forces, EMG of selected leg muscles, soft tissue compartment and shoe heel cup accelerations were quantified for two different impact conditions. The transmissibility of the impact acceleration to the soft tissue compartments was determined for each subject/soft tissue compartment/shoe combination. For this controlled impact situation it was shown that changes in the damping properties of the soft tissue compartments were related to changes in the EMG intensity and/or mean frequency of related muscles in response to a change in the impact interface conditions. These results provide support for the muscle tuning idea—that one reason for the changes in muscle activity in response to small changes in the impact conditions may be to minimize vibrations of the soft tissue compartments that are initiated at heel-strike.

scholarly journals Immediate Effects of Acupuncture on Explosive Force Production and Stiffness in Male Knee Joint

2021 ◽  
Vol 18 (18) ◽  
pp. 9518
Author(s):  
Jun Wang ◽  
I-Lin Wang ◽  
Rui Hu ◽  
Shun Yao ◽  
Yu Su ◽  
...  
Keyword(s):  
Knee Joint ◽  
Muscle Activation ◽  
Average Power ◽  
Joint Stiffness ◽  
Force Production ◽  
Sham Acupuncture ◽  
Significant Interaction Effect ◽  
Average Maximum ◽  
Explosive Force ◽  
The Right

Acupuncture can improve explosive force production and affect joint stiffness by affecting muscle activation levels. This study aims to explore the effects of true acupuncture (TA) compared with sham acupuncture (SA) on the explosive force production and stiffness of the knee joint in healthy male subjects. Twenty subjects were randomly divided into the TA group (n = 10) and SA group (n = 10) to complete isokinetic movement of the right knee joint at a speed of 240°/s before and after acupuncture. Futu (ST32), Liangqiu (ST34), Zusanli (ST36), Xuehai (SP10), and Chengshan (BL57) were selected for acupuncture. The intervention of SA is that needles with a blunt tip were pushed against the skin, giving an illusion of insertion. The results showed that acupuncture and the intervention time had a significant interaction effect on knee joint explosive force and joint stiffness (p < 0.05). The average maximum (max) torque, average work, average power, average peak power and total work of the TA group increased significantly after acupuncture (p < 0.05), while the SA group did not (p > 0.05). Therefore, true acupuncture can immediately improve the explosive force and joint stiffness of the male knee joint by inducing post-activation potentiation (PAP) and/or De-Qi.

Device for Assessing Knee Joint Dynamics During Magnetic Resonance Imaging

2021 ◽  
Author(s):  
Sandeep P. Jogi ◽  
Rafeek Thaha ◽  
Sriram Rajan ◽  
Vidur Mahajan ◽  
Vasantha K. Venugopal ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Knee Joint ◽  
Resonance Imaging ◽  
Joint Dynamics

scholarly journals Knee Kinematics Estimation Using Multi-Body Optimisation Embedding a Knee Joint Stiffness Matrix: A Feasibility Study

PLoS ONE ◽  
2016 ◽  
Vol 11 (6) ◽  
pp. e0157010 ◽  
Author(s):  
Vincent Richard ◽  
Giuliano Lamberto ◽  
Tung-Wu Lu ◽  
Aurelio Cappozzo ◽  
Raphaël Dumas
Keyword(s):  
Knee Joint ◽  
Feasibility Study ◽  
Stiffness Matrix ◽  
Joint Stiffness ◽  
Knee Kinematics ◽  
Multi Body

Development of an Apparatus for Bilateral Rhythmical Training of Arm Movement Via Linear and Elliptical Trajectories of Various Directions

2014 ◽  
Vol 8 (3) ◽  
Author(s):  
Zlatko Matjačić ◽  
Matjaž Zadravec ◽  
Jakob Oblak
Keyword(s):  
Muscle Activation ◽  
Arm Movement ◽  
Emg Activity ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Arm Cycling ◽  
Arm Reaching ◽  
Direction Of Movement ◽  
Muscle Groups ◽  
Neurologically Intact

Clinical rehabilitation of individuals with various neurological disorders requires a significant number of movement repetitions in order to improve coordination and restoration of appropriate muscle activation patterns. Arm reaching movement is frequently practiced via motorized arm cycling ergometers where the trajectory of movement is circular thus providing means for practicing a single and rather nonfunctional set of muscle activation patterns, which is a significant limitation. We have developed a novel mechanism that in the combination with an existing arm ergometer device enables nine different movement modalities/trajectories ranging from purely circular trajectory to four elliptical and four linear trajectories where the direction of movement may be varied. The main objective of this study was to test a hypothesis stating that different movement modalities facilitate differences in muscle activation patterns as a result of varying shape and direction of movement. Muscle activation patterns in all movement modalities were assessed in a group of neurologically intact individuals in the form of recording the electromyographic (EMG) activity of four selected muscle groups of the shoulder and the elbow. Statistical analysis of the root mean square (RMS) values of resulting EMG signals have shown that muscle activation patterns corresponding to each of the nine movement modalities significantly differ in order to accommodate to variation of the trajectories shape and direction. Further, we assessed muscle activation patterns following the same protocol in a selected clinical case of hemiparesis. These results have shown the ability of the selected case subject to produce different muscle activation patterns as a response to different movement modalities which show some resemblance to those assessed in the group of neurologically intact individuals. The results of the study indicate that the developed device may significantly extend the scope of strength and coordination training in stroke rehabilitation which is in current clinical rehabilitation practice done through arm cycling.

scholarly journals Backward walking highlights gait asymmetries in children with cerebral palsy

2018 ◽  
Vol 119 (3) ◽  
pp. 1153-1165 ◽  
Author(s):  
Germana Cappellini ◽  
Francesca Sylos-Labini ◽  
Michael J. MacLellan ◽  
Annalisa Sacco ◽  
Daniela Morelli ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Muscle Activation ◽  
Pattern Generation ◽  
Comprehensive Assessment ◽  
Emg Activity ◽  
Backward Walking ◽  
Spinal Circuitry ◽  
Children With Cerebral Palsy ◽  
Control Circuits ◽  
The Brain

To investigate how early injuries to developing motor regions of the brain affect different forms of gait, we compared the spatiotemporal locomotor patterns during forward (FW) and backward (BW) walking in children with cerebral palsy (CP). Bilateral gait kinematics and EMG activity of 11 pairs of leg muscles were recorded in 14 children with CP (9 diplegic, 5 hemiplegic; 3.0–11.1 yr) and 14 typically developing (TD) children (3.3–11.8 yr). During BW, children with CP showed a significant increase of gait asymmetry in foot trajectory characteristics and limb intersegmental coordination. Furthermore, gait asymmetries, which were not evident during FW in diplegic children, became evident during BW. Factorization of the EMG signals revealed a comparable structure of the motor output during FW and BW in all groups of children, but we found differences in the basic temporal activation patterns. Overall, the results are consistent with the idea that both forms of gait share pattern generation control circuits providing similar (though reversed) kinematic patterns. However, BW requires different muscle activation timings associated with muscle modules, highlighting subtle gait asymmetries in diplegic children, and thus provides a more comprehensive assessment of gait pathology in children with CP. The findings suggest that spatiotemporal asymmetry assessments during BW might reflect an impaired state and/or descending control of the spinal locomotor circuitry and can be used for diagnostic purposes and as complementary markers of gait recovery.NEW & NOTEWORTHY Early injuries to developing motor regions of the brain affect both forward progression and other forms of gait. In particular, backward walking highlights prominent gait asymmetries in children with hemiplegia and diplegia from cerebral palsy and can give a more comprehensive assessment of gait pathology. The observed spatiotemporal asymmetry assessments may reflect both impaired supraspinal control and impaired state of the spinal circuitry.

The Spatial Dependency of Shoulder Muscle Demands for Seated Lateral Hand Force Exertions

2014 ◽  
Vol 30 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Alison C. McDonald ◽  
Elora C. Brenneman ◽  
Alan C. Cudlip ◽  
Clark R. Dickerson
Keyword(s):  
Repeated Measures ◽  
Muscle Activation ◽  
Three Dimensional ◽  
Emg Activity ◽  
Hand Position ◽  
Individual Muscle ◽  
Repeated Measures Analysis ◽  
Spatial Parameters ◽  
Shoulder Complex ◽  
The Right

As the modern workplace is dominated by submaximal repetitive tasks, knowledge of the effect of task location is important to ensure workers are unexposed to potentially injurious demands imposed by repetitive work in awkward or sustained postures. The purpose of this investigation was to develop a three-dimensional spatial map of the muscle activity for the right upper extremity during laterally directed submaximal force exertions. Electromyographic (EMG) activity was recorded from fourteen muscles surrounding the shoulder complex as the participants exerted 40N of force in two directions (leftward, rightward) at 70 defined locations. Hand position in both push directions strongly influenced total and certain individual muscle demands as identified by repeated measures analysis of variance (P< .001). During rightward exertions individual muscle activation varied from 1 to 21% MVE and during leftward exertions it varied from 1 to 27% MVE with hand location. Continuous prediction equations for muscular demands based on three-dimensional spatial parameters were created with explained variance ranging from 25 to 73%. The study provides novel information for evaluating existing and proactive workplace designs, and may help identify preferred geometric placements of lateral exertions in occupational settings to lower muscular demands, potentially mitigating fatigue and associated musculoskeletal risks.

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