Development and Functional Testing of An Unloading Concept for Knee Osteoarthritis Patients: A Pilot Study

Author(s):  
Jonas Stensgaard Stoltze ◽  
Jari Pallari ◽  
Behrokh Eskandari ◽  
Anderson S. Oliveira ◽  
Cristina I. Pirscoveanu ◽  
...  

Abstract This paper presents a knee brace design that applies an extension moment to unload the muscles in stance phase during gait, and thereby the knee, as alternative to conventional valgus braces for knee osteoarthritis patients. The concept was tested on one healthy subject during normal gait with a prototype, which was designed to activate and deactivate in order to apply the extension moment in the stance phase only and hereby avoid any interference during the swing phase. Electromyography measurements and musculoskeletal models were used to evaluate the brace effects on muscle activation and knee compressive forces respectively. Simulations predicted an ideal reduction of up to 36%, whereas experimental tests revealed a reduction of up to 24% with the current prototype. The prototype brace also reduced the knee joint force impulse up to 9% and EMG peak signal of the vasti muscles with up to 19%. Due to these reductions on a healthy subject, this bracing approach seem promising for reducing knee loads during normal gait. However, further clinical experiments on knee osteoarthritis patients are required to evaluate the effect on both pain and disease progression.

The Knee ◽  
2021 ◽  
Vol 29 ◽  
pp. 500-509
Author(s):  
J.C. Schrijvers ◽  
D. Rutherford ◽  
R. Richards ◽  
J.C. van den Noort ◽  
M. van der Esch ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3422
Author(s):  
Jian-Zhi Lin ◽  
Wen-Yu Chiu ◽  
Wei-Hsun Tai ◽  
Yu-Xiang Hong ◽  
Chung-Yu Chen

This study analysed the landing performance and muscle activity of athletes in forefoot strike (FFS) and rearfoot strike (RFS) patterns. Ten male college participants were asked to perform two foot strikes patterns, each at a running speed of 6 km/h. Three inertial sensors and five EMG sensors as well as one 24 G accelerometer were synchronised to acquire joint kinematics parameters as well as muscle activation, respectively. In both the FFS and RFS patterns, according to the intraclass correlation coefficient, excellent reliability was found for landing performance and muscle activation. Paired t tests indicated significantly higher ankle plantar flexion in the FFS pattern. Moreover, biceps femoris (BF) and gastrocnemius medialis (GM) activation increased in the pre-stance phase of the FFS compared with that of RFS. The FFS pattern had significantly decreased tibialis anterior (TA) muscle activity compared with the RFS pattern during the pre-stance phase. The results demonstrated that the ankle strategy focused on controlling the foot strike pattern. The influence of the FFS pattern on muscle activity likely indicates that an athlete can increase both BF and GM muscles activity. Altered landing strategy in cases of FFS pattern may contribute both to the running efficiency and muscle activation of the lower extremity. Therefore, neuromuscular training and education are required to enable activation in dynamic running tasks.


2021 ◽  
Vol 86 ◽  
pp. 38-44
Author(s):  
Marina Petrella ◽  
Luiz Fernando A. Selistre ◽  
Paula R.M.S. Serrão ◽  
Giovanna C. Lessi ◽  
Glaucia H. Gonçalves ◽  
...  

2014 ◽  
Vol 49 (3) ◽  
pp. 317-321 ◽  
Author(s):  
Yen-Po Huang ◽  
You-Li Chou ◽  
Feng-Chun Chen ◽  
Rong-Tyai Wang ◽  
Ming-Jer Huang ◽  
...  

Context: Bench-press exercises are among the most common form of training exercise for the upper extremity because they yield a notable improvement in both muscle strength and muscle endurance. The literature contains various investigations into the effects of different bench-press positions on the degree of muscle activation. However, the effects of fatigue on the muscular performance and kinetics of the elbow joint are not understood fully. Objective: To investigate the effects of fatigue on the kinetics and myodynamic performance of the elbow joint in bench-press training. Design: Controlled laboratory study. Setting: Motion research laboratory. Patients or Other Participants: A total of 18 physically healthy male students (age = 19.6 ± 0.8 years, height = 168.7 ± 5.5 cm, mass = 69.6 ± 8.6 kg) participated in the investigation. All participants were right-hand dominant, and none had a history of upper extremity injuries or disorders. Intervention(s): Participants performed bench-press training until fatigued. Main Outcome Measure(s): Maximal possible number of repetitions, cycle time, myodynamic decline rate, elbow-joint force, and elbow-joint moment. Results: We observed a difference in cycle time in the initial (2.1 ± 0.42 seconds) and fatigue (2.58 ± 0.46 seconds) stages of the bench-press exercise (P = .04). As the participants fatigued, we observed an increase in the medial-lateral force (P = .03) and internal-external moment (P ≤ .04) acting on the elbow joint. Moreover, a reduction in the elbow muscle strength was observed in the elbow extension-flexion (P ≤ .003) and forearm supination-pronation (P ≤ .001) conditions. Conclusions: The results suggest that performing bench-press exercises to the point of fatigue increases elbow-joint loading and may further increase the risk of injury. Therefore, when clinicians design bench-press exercise regimens for general athletic training, muscle strengthening, or physical rehabilitation, they should control carefully the maximal number of repetitions.


1995 ◽  
Vol 198 (4) ◽  
pp. 975-987 ◽  
Author(s):  
A C Guimaraes ◽  
W Herzog ◽  
T L Allinger ◽  
Y T Zhang

The relationship between force and electromyographic (EMG) signals of the cat soleus muscle was obtained for three animals during locomotion at five different speeds (154 steps), using implanted EMG electrodes and a force transducer. Experimentally obtained force-IEMG (= integrated EMG) relationships were compared with theoretically predicted instantaneous activation levels calculated by dividing the measured force by the predicted maximal force that the muscle could possibly generate as a function of its instantaneous contractile conditions. In addition, muscular forces were estimated from the corresponding EMG records exclusively using an adaptive filtering approach. Mean force-IEMG relationships were highly non-linear but similar in shape for different cats and different speeds of locomotion. The theoretically predicted activation-time plots typically showed two peaks, as did the IEMG-time plots. The first IEMG peak tended to be higher than the second one and it appeared to be associated with the initial priming of the muscle for force production at paw contact and the peak force observed early during the stance phase. The second IEMG peak appeared to be a burst of high muscle activation, which might have compensated for the levels of muscle length and shortening velocity that were suboptimal during the latter part of the stance phase. Although it was difficult to explain the soleus forces on the basis of the theoretically predicted instantaneous activation levels, it was straightforward to approximate these forces accurately from EMG data using an adaptive filtering approach.


2019 ◽  
Vol 27 (7) ◽  
pp. 1033-1042 ◽  
Author(s):  
S.M. Robbins ◽  
M. Morelli ◽  
P.A. Martineau ◽  
N. St-Onge ◽  
M. Boily ◽  
...  

2019 ◽  
Vol 8 (11) ◽  
pp. 509-517 ◽  
Author(s):  
Kyoung-Tak Kang ◽  
Yong-Gon Koh ◽  
Kyoung-Mi Park ◽  
Chong-Hyuck Choi ◽  
Min Jung ◽  
...  

Objectives The aim of this study was to investigate the biomechanical effect of the anterolateral ligament (ALL), anterior cruciate ligament (ACL), or both ALL and ACL on kinematics under dynamic loading conditions using dynamic simulation subject-specific knee models. Methods Five subject-specific musculoskeletal models were validated with computationally predicted muscle activation, electromyography data, and previous experimental data to analyze effects of the ALL and ACL on knee kinematics under gait and squat loading conditions. Results Anterior translation (AT) significantly increased with deficiency of the ACL, ALL, or both structures under gait cycle loading. Internal rotation (IR) significantly increased with deficiency of both the ACL and ALL under gait and squat loading conditions. However, the deficiency of ALL was not significant in the increase of AT, but it was significant in the increase of IR under the squat loading condition. Conclusion The results of this study confirm that the ALL is an important lateral knee structure for knee joint stability. The ALL is a secondary stabilizer relative to the ACL under simulated gait and squat loading conditions. Cite this article: Bone Joint Res 2019;8:509–517.


2020 ◽  
Vol 17 (6) ◽  
pp. 1163-1174
Author(s):  
Ning Li ◽  
Tie Yang ◽  
Yang Yang ◽  
Peng Yu ◽  
Xiujuan Xue ◽  
...  

AbstractExoskeleton robots have demonstrated the potential to rehabilitate stroke dyskinesia. Unfortunately, poor human-machine physiological coupling causes unexpected damage to human of muscles and joints. Moreover, inferior humanoid kinematics control would restrict human natural kinematics. Failing to deal with these problems results in bottlenecks and hinders its application. In this paper, the simplified muscle model and muscle-liked kinematics model were proposed, based on which a soft wrist exoskeleton was established to realize natural human interaction. Firstly, we simplified the redundant muscular system related to the wrist joint from ten muscles to four, so as to realize the human-robot physiological coupling. Then, according to the above human-like musculoskeletal model, the humanoid distributed kinematics control was established to achieve the two DOFs coupling kinematics of the wrist. The results show that the wearer of an exoskeleton could reduce muscle activation and joint force by 43.3% and 35.6%, respectively. Additionally, the humanoid motion trajectories similarity of the robot reached 91.5%. Stroke patients could recover 90.3% of natural motion ability to satisfy for most daily activities. This work provides a fundamental understanding on human-machine physiological coupling and humanoid kinematics control of the exoskeleton robots for reducing the post-stroke complications.


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