Joint Torque Modeling of Knee Extension and Flexion

2011 ◽  
pp. 79-88 ◽  
Author(s):  
Fabian Guenzkofer ◽  
Florian Engstler ◽  
Heiner Bubb ◽  
Klaus Bengler
Keyword(s):  
Knee Extension ◽  
Joint Torque

Lower-Extremity Isokinetic Strength Profiling in Professional Rugby League and Rugby Union

2014 ◽  
Vol 9 (2) ◽  
pp. 358-361 ◽  
Author(s):  
Scott R. Brown ◽  
Matt Brughelli ◽  
Peter C. Griffiths ◽  
John B. Cronin
Keyword(s):  
Lower Extremity ◽  
Knee Flexion ◽  
Peak Torque ◽  
Rugby League ◽  
Knee Extension ◽  
Rugby Union ◽  
Joint Torque ◽  
Cross Sectional ◽  
Hip Strength ◽  
Hip Extension

Purpose:While several studies have documented isokinetic knee strength in junior and senior rugby league players, investigations of isokinetic knee and hip strength in professional rugby union players are limited. The purpose of this study was to provide lower-extremity strength profiles and compare isokinetic knee and hip strength of professional rugby league and rugby union players.Participants:32 professional rugby league and 25 professional rugby union players.Methods:Cross-sectional analysis. Isokinetic dynamometry was used to evaluate peak torque and strength ratios of the dominant and nondominant legs during seated knee-extension/flexion and supine hip-extension/flexion actions at 60°/s.Results:Forwards from both codes were taller and heavier and had a higher body-mass index than the backs of each code. Rugby union forwards produced significantly (P < .05) greater peak torque during knee flexion in the dominant and nondominant legs (ES = 1.81 and 2.02) compared with rugby league forwards. Rugby league backs produced significantly greater hip-extension peak torque in the dominant and nondominant legs (ES = 0.83 and 0.77) compared with rugby union backs. There were no significant differences in hamstring-to-quadriceps ratios between code, position, or leg. Rugby union forwards and backs produced significantly greater knee-flexion-to-hip-extension ratios in the dominant and nondominant legs (ES = 1.49–2.26) than rugby union players.Conclusions:It seems that the joint torque profiles of players from rugby league and union codes differ, which may be attributed to the different demands of each code.

scholarly journals Do PTK2 gene polymorphisms contribute to the interindividual variability in muscle strength and the response to resistance training? A preliminary report

2012 ◽  
Vol 112 (8) ◽  
pp. 1329-1334 ◽  
Author(s):  
Robert M. Erskine ◽  
Alun G. Williams ◽  
David A. Jones ◽  
Claire E. Stewart ◽  
Hans Degens
Keyword(s):  
Skeletal Muscle ◽  
Resistance Training ◽  
Muscle Strength ◽  
Human Skeletal Muscle ◽  
Interindividual Variability ◽  
Knee Extension ◽  
Joint Torque ◽  
Specific Force ◽  
Tyrosine Kinase 2 ◽  
The Impact

The protein tyrosine kinase-2 (PTK2) gene encodes focal adhesion kinase, a structural protein involved in lateral transmission of muscle fiber force. We investigated whether single-nucleotide polymorphisms (SNPs) of the PTK2 gene were associated with various indexes of human skeletal muscle strength and the interindividual variability in the strength responses to resistance training. We determined unilateral knee extension single repetition maximum (1-RM), maximum isometric voluntary contraction (MVC) knee joint torque, and quadriceps femoris muscle specific force (maximum force per unit physiological cross-sectional area) before and after 9 wk of knee extension resistance training in 51 untrained young men. All participants were genotyped for the PTK2 intronic rs7843014 A/C and 3′-untranslated region (UTR) rs7460 A/T SNPs. There were no genotype associations with baseline measures or posttraining changes in 1-RM or MVC. Although the training-induced increase in specific force was similar for all PTK2 genotypes, baseline specific force was higher in PTK2 rs7843014 AA and rs7460 TT homozygotes than in the respective rs7843014 C- ( P = 0.016) and rs7460 A-allele ( P = 0.009) carriers. These associations between muscle specific force and PTK2 SNPs suggest that interindividual differences exist in the way force is transmitted from the muscle fibers to the tendon. Therefore, our results demonstrate for the first time the impact of genetic variation on the intrinsic strength of human skeletal muscle.

scholarly journals Function of the Distal Part of the Vastus Medialis Muscle as a Generator of Knee Extension Twitch Torque

2020 ◽  
Vol 5 (4) ◽  
pp. 98
Author(s):  
Yoshitsugu Tanino ◽  
Takaki Yoshida ◽  
Wataru Yamazaki ◽  
Yuki Fukumoto ◽  
Tetsuya Nakao ◽  
...  
Keyword(s):  
Knee Joint ◽  
Distal Part ◽  
Knee Extension ◽  
Quadriceps Femoris ◽  
Joint Torque ◽  
Vastus Medialis ◽  
Knee Angle ◽  
Quadriceps Femoris Muscle ◽  
Significant Difference ◽  
Femoris Muscle

The distal part of the vastus medialis (VM) (VM obliquus: VMO) muscle acts as the medial stabilizer of the patella. However, it has been known to facilitate VMO contraction during training of the quadriceps femoris muscle in knee joint rehabilitation. This study aimed to examine the contribution degree of VMO as a knee joint extension torque generator. Sixteen healthy male volunteers participated in this study. Electrical muscle stimulation (EMS) was performed on VMO at 60° knee angle for 20 min to induce muscle fatigue. Knee extension twitch torques (TT) at 90° and 30° knee angle evoked by femoral nerve stimulation were measured before and after EMS. Although each TT at 90° and 30° knee angle significantly decreased after EMS, the decreased TT rate in both joint angles showed no significant difference. Our results show that VMO might contribute to the generation of the knee joint torque at the same level in the range from flexion to extension. Therefore, it was suggested that the facilitating the neural drive for VMO is important during the quadriceps femoris muscle strengthening exercise.

Uncertainty of knee joint muscle activity during knee joint torque exertion: the significance of controlling adjacent joint torque

2005 ◽  
Vol 99 (3) ◽  
pp. 1093-1103 ◽  
Author(s):  
Daichi Nozaki ◽  
Kimitaka Nakazawa ◽  
Masami Akai
Keyword(s):  
Knee Joint ◽  
Hip Joint ◽  
Muscle Activity ◽  
Internal Variability ◽  
Knee Extension ◽  
Activity Level ◽  
Joint Torque ◽  
Knee Extensors ◽  
Joint Torques ◽  
Custom Made

In the single-joint torque exertion task, which has been widely used to control muscle activity, only the relevant joint torque is specified. However, the neglect of the neighboring joint could make the procedure unreliable, considering our previous result that even monoarticular muscle activity level is indefinite without specifying the adjacent joint torque. Here we examined the amount of hip joint torque generated with knee joint torque and its influence on the activity of the knee joint muscles. Twelve healthy subjects were requested to exert various levels of isometric knee joint torque. The knee and hip joint torques were obtained by using a custom-made device. Because no information about hip joint torque was provided to the subjects, the hip joint torque measured here was a secondary one associated with the task. The amount of hip joint torque varied among subjects, indicating that they adopted various strategies to achieve the task. In some subjects, there was a considerable internal variability in the hip joint torque. Such variability was not negligible, because the knee joint muscle activity level with respect to the knee joint torque, as quantified by surface electromyography (EMG), changed significantly when the subjects were requested to change the strategy. This change occurred in a very systematic manner: in the case of the knee extension, as the hip flexion torque was larger, the activity of mono- and biarticular knee extensors decreased and increased, respectively. These results indicate that the conventional single knee joint torque exertion has the drawback that the intersubject and/or intertrial variability is inevitable in the relative contribution among mono- and biarticular muscles because of the uncertainty of the hip joint torque. We discuss that the viewpoint that both joint torques need to be considered will bring insights into various controversial problems such as the shape of the EMG-force relationship, neural factors that help determine the effect of muscle strength training, and so on.

Sarcomere length and joint kinematics during torque production in frog hindlimb

1988 ◽  
Vol 254 (6) ◽  
pp. C759-C768 ◽  
Author(s):  
R. L. Lieber ◽  
J. L. Boakes
Keyword(s):  
Sarcomere Length ◽  
Muscle Force ◽  
Joint Angle ◽  
Distal Tibia ◽  
Knee Extension ◽  
Joint Kinematics ◽  
Joint Torque ◽  
Semitendinosus Muscle ◽  
Lever Arm ◽  
Knee Joint Kinematics

The relationship between semitendinosus muscle force and knee joint kinematics during isometric torque production was examined in the frog (Rana pipiens) hindlimb. Passive muscle sarcomere length was monitored by laser diffraction during knee rotation, and joint center of rotation was determined later using principles of rigid body kinematics. Contractile force at the distal tibia, resulting from semitendinosus contraction, was also measured, and, using the kinematic data, a torque vs. joint angle curve constructed. Muscle sarcomere length varied from 3.6 micron at full knee extension to 2.0 micron at full knee flexion. Effective lever arm varied almost as a sine function, with optimal lever arm at 90 degrees of flexion. Joint torque increased linearly from 0 to 140 degrees of flexion and then sharply decreased to 160 degrees of flexion. Thus the optimal joint angle occurred at an angle (140 degrees) that was neither the angle at which muscle force was maximum (160 degrees) nor the angle at which the effective lever arm was maximum (90 degrees). These data indicate that knee torque production in the frog results from the interaction between muscular and joint properties and not either property alone.

Optimal Knee Extension Timing in Springboard and Platform Dives from the Reverse Group

2004 ◽  
Vol 20 (3) ◽  
pp. 275-290 ◽  
Author(s):  
Eric J. Sprigings ◽  
Doris I. Miller
Keyword(s):  
Angular Displacement ◽  
Movement Pattern ◽  
Knee Extension ◽  
Lower Limbs ◽  
Joint Torque ◽  
Optimization Process ◽  
Peak Knee ◽  
Mechanical Factors ◽  
The Times ◽  
Insight Into

Optimized computer simulation, using a mathematical model of a diver, was employed to gain insight into the primary mechanical factors responsible for producing height and rotation in dives from the reverse group. The performance variable optimized was the total angular displacement of the diver as measured from last contact to the point where the diver's mass center passed the level of the springboard or platform. The times of onset, and lengths of activation for the joint torque actuators, were used as the control variables for the optimization process. The results of the platform simulation indicated that the magnitude of the hip torque was approximately twice that generated by the knee joint during the early extension phase of the takeoff. Most of the knee extension for the simulation model coincided with the period of reduced hip torque during the later phase of takeoff, suggesting that the knee torque served mainly to stabilize the lower limbs so that the force from the powerful hip extension could be delivered through to the platform. Maintaining a forward tilt of the lower legs (~50° from the horizontal) during hip and knee extension appeared to be paramount for successful reverse somersaults. Although the movement pattern exhibited by the springboard model was limited by the torque activation strategy employed, the results provided insight into the timing of knee extension. Peak knee extension torque was generated just prior to maximum springboard depression, allowing the diver's muscular efforts to be exerted against a stiffer board. It was also apparent that the diver must maintain an anatomically strong knee position (~140°) at maximum depression to resist the large upward force being exerted by the springboard against the diver's feet. The optimization process suggested that, as the number of reverse somersaults increases, both the angle of the lower legs with respect to the springboard and the angle of knee extension at completion of takeoff should decrease.

Pneumatically powered robotic exercise device to induce a specific force profile in target lower extremity muscles

Robotica ◽  
2014 ◽  
Vol 32 (8) ◽  
pp. 1281-1299 ◽  
Author(s):  
Gregory C. Henderson ◽  
Jun Ueda
Keyword(s):  
Muscle Force ◽  
Force Feedback ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Joint Torque ◽  
Moment Arms ◽  
Highly Nonlinear ◽  
Planning Algorithm ◽  
Isotonic Contractions ◽  
Force Profiles

SUMMARYThe goal of this research is to establish a methodology to actively control a pneumatically driven robotic device that can induce specific muscle force patterns in target muscles during a subject's voluntary movement. In this paper, the generation of constant forces in the rectus femoris muscle throughout the knee extension, i.e., isotonic contractions, was studied. Due to a highly nonlinear nature of mapping the joint torque to muscle force, a simple application of constant torques to the knee joint would not realize isotonic contractions. The proposed robotic exercise accounted for nonlinear moment arms of muscles as functions of joint angles and nonlinear coordination of multiple muscles in the neuromuscular system to accomplish individual muscle control. A pneumatically powered one degree-of-freedom device that can impose active force feedback control has been designed and built. An exercise-planning algorithm has been developed that involved a musculoskeletal model of the lower body, and the dynamics of a pneumatic actuator. Five constant force profiles were tested for 20 healthy volunteers and electromyographic signals were collected while the device was applying calculated force profiles.

Model Predictive Control-Based Dynamic Control Allocation in a Hybrid Neuroprosthesis

2014 ◽  
Author(s):  
Nicholas A. Kirsch ◽  
Naji A. Alibeji ◽  
Nitin Sharma
Keyword(s):  
Model Predictive Control ◽  
Muscle Fatigue ◽  
Predictive Control ◽  
Electric Motor ◽  
Dynamic Control ◽  
Rapid Onset ◽  
Knee Extension ◽  
Joint Torque ◽  
Lower Limb Muscles ◽  
Hybrid Neuroprosthesis

To date, a functional electrical stimulation (FES)-based walking technology is incapable of enabling a paraplegic user to walk more than a few hundred meters. This is primarily due to the rapid onset of muscle fatigue, which causes limited torque generation capability of the lower-limb muscles. A hybrid walking neuroprosthesis that combines FES with an electric motor can overcome this challenge, since an electric motor can be used to compensate for any reduction in force generation due to the muscle fatigue. However, the hybrid actuation structure creates an actuator redundancy control problem; i.e., a closed-loop controller must optimally distribute torque between FES and an electric motor. Further, the control inputs to FES and an electric motor must adapt as a skeletal muscle fatigues. We consider these issues as open research control problems. In this paper, we propose that a model predictive control (MPC)-based control design can be used to optimally distribute joint torque, and can adapt as the muscle fatigue sets in. Particularly, a customized quadratic programming solver (generated using CVXGEN) was used to simulate MPC-based control of the hybrid neuroprosthesis that elicits knee extension via FES and an electric actuator.

Sign in / Sign up

Export Citation Format

Share Document