Human Locomotion Strategies Under Changed Bodyweight Support

2021 ◽  
Vol 92 (1) ◽  
pp. 4-10
Author(s):  
Alexey Vasilievich Shpakov ◽  
Anton Anatolievich Artamonov ◽  
Andrey Vladimirivich Voronov ◽  
Evgeni V. Plotnikov ◽  
Alina Alexandrovna Puchkova ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Knee Joint ◽  
Musculoskeletal System ◽  
Small Variation ◽  
Human Locomotion ◽  
Loading Conditions ◽  
Joint Angles ◽  
Phase Trajectories ◽  
Flexion And Extension ◽  
Weight Loading

INTRODUCTION: The aim of this study was the analysis of human musculoskeletal system energy costs of normal walking and walking under reduced weight loading.METHODS: There were 15 subjects who participated in the study. We analyzed the biomechanical parameters of walking under different musculoskeletal system loads. The subjects walked on a treadmill at a pace of 90 steps/min under various loading conditions: 1) 100% bodyweight loading, corresponding to the terrestrial surface; 2) 38% bodyweight loading, corresponding to the surface of Mars; and 3) 17% bodyweight loading, corresponding to the surface of the Moon. Joint angles and angular velocities were recorded from the hip, knee, and ankle.RESULTS: We analyzed changes in joint phase trajectories and the ratio of kinetic extension energy to kinetic flexion energy in the joints. We observed changes in kinetic energy parameters associated with both flexion and extension motions in the joints of the feet while walking under various loads. In terrestrial conditions (walking under 100% bodyweight), flexion kinetic energy in the hip joint prevailed over extension kinetic energy by 90%, with a small variation equal to 22%. If weight loading decreased up to 17% (lunar conditions), the difference between flexion and extension kinetic energies diminished, and eventually reached only 9%. The ratio of flexion energy and extension energy in the ankle joint equalized under lower loading conditions. Thus, 38% bodyweight loading was sufficient for approximation of flexion and extension energy values.DISCUSSION: Our results revealed that phase trajectories shifted toward smaller joint angles and a decreased ratio between extension kinetic energy and flexion kinetic energy in the knee joint of all subjects. However, significant differences in the ratio of flexion and extension kinetic energy in the knee joint under bodyweight support were not found. The methods used for musculoskeletal system assessments that were proposed in our work can be used in clinical practice to evaluate the effectiveness of rehabilitation measures in a patients musculoskeletal system disorders.Shpakov AV, Artamonov AA, Voronov AV, Plotnikov EV, Puchkova AA, Orlov DO. Human locomotion strategies under changed bodyweight support. Aerosp Med Hum Perform. 2021; 92(1):410.

Modeling the resistance mechanism of passive knee joint flexion and extension for use in rehabilitation equipment

2021 ◽  
pp. 095441192199013
Author(s):  
Mansoor Amiri ◽  
Farhad Tabatabai Ghomsheh ◽  
Farshad Ghazalian
Keyword(s):  
Knee Joint ◽  
Sagittal Plane ◽  
Resistance Mechanism ◽  
Time Dependent ◽  
Coefficient Of Determination ◽  
Joint Movement ◽  
Elastic Coefficient ◽  
Knee Movement ◽  
Joint Flexion ◽  
Flexion And Extension

The purpose of this study was to model the resistance mechanism of Passive Knee Joint Flexion and Extension to create a similar torque mechanism in rehabilitation equipment. In order to better model the behavior of passive knee tissues, it is necessary to exactly calculate the two coefficients of elasticity of time-independent and time-dependent parts. Ten healthy male volunteers (mean height 176.4+/−4.59 cm) participated in this study. Passive knee joint flexion and extension occurred at velocities of 15, 45, and 120 (degree/s), and in five consecutive cycles and within the range of 0 to 100° of knee movement on the sagittal plane on Cybex isokinetic dynamometer. To ensure that the muscles were relaxed, the electrical activity of knee muscles was recorded. The elastic coefficient, (KS) increased with elevating the passive velocity in flexion and extension. The elastic coefficient, (KP) was observed to grow with the passive velocity increase. While, the viscous coefficient (C) diminished with passive velocity rise in extension and flexion. The heightened passive velocity of the motion resulted in increased hysteresis (at a rate of 42%). The desired of passive velocity is lower so that there is less energy lost and the viscoelastic resistance of the tissue in the movement decreases. The Coefficient of Determination, R2 between the model-responses and experimental curves in the extension was 0.96 < R2 < 0.99 and in flexion was 0.95 < R2 < 0.99. This modeling is capable of predicting the true performance of the components of passive knee movement and we can create a resistance mechanism in the rehabilitation equipment to perform knee joint movement. Quantitative measurements of two elastic coefficients of Time-independent and Time-dependent parts passive knee joint coefficients should be used for better accurate simulation the behavior of passive tissues in the knee which is not seen in other studies.

Histological Features of Osteoarthritis in a State of Decompensation

2021 ◽  
Vol 53 ◽  
pp. 51-58
Author(s):  
Timur B. Minasov ◽  
Ekaterina R. Yakupova ◽  
Dilmurod Ruziboev ◽  
Ruslan M. Vakhitov-Kovalevich ◽  
Ruslan F. Khairutdinov ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Knee Joint ◽  
Blood Vessels ◽  
Subchondral Bone ◽  
Musculoskeletal System ◽  
Hyaline Cartilage ◽  
Material Selection ◽  
Central Zone ◽  
Cartilage Tissue ◽  
Social Significance

Degenerative pathology of the musculoskeletal system is one of the main reasons for decreased mobility in patients of the older age group. Increasing the life expectancy leads to predominance non-epidemic pathology in all developed countries. Therefore, degenerative diseases of musculoskeletal system have not only medical significance but also social significance. Objective is studying the morphological features of synovial environment of the decompensated osteoarthritic (OA) knee joint. Structural features of subchondral bone, hyaline cartilage of the femur and tibia, the articular capsule, menisci and ligamentous apparatus of the knee joint were studied in 64 patients who underwent total knee arthroplasty at the Department of Traumatology and Orthopedics Bashkirian State Medical University in the period from 2015 to 2020. Material selection, preparation of histological samples, staining with hematoxylin-eosin, microscopy was performed. Adaptive signs of articular cartilage of the femoral condyles manifest in the form of cartilage tissue rearrangement, which are most pronounced in the central zone of the cartilage. At the same time, the phenomena of decompensation and significant areas of destruction are noted. Also, the subchondral bone was replaced with connective tissue with subsequent sclerosis. This sclerosis subsequently led to the decompensation of structures of the hyaline cartilage in the deep and middle zones. Destructive and dystrophic processes were noted in the knee joint menisci. Articular cartilage was replaced with granulation tissue with subsequent invasion of blood vessels. Cruciate ligaments in patients with OA show signs of adaptation due to expansion of endothenonium layers between bundles of collagen fibers and an increase in the diameter of blood vessels.

Assessment of Muscle Activity and Joint Angles in Small-Handed Pianists: A Pilot Study on the 7/8-Sized Keyboard versus the Full-Sized Keyboard

2006 ◽  
Vol 21 (1) ◽  
pp. 3-9
Author(s):  
B G Wristen ◽  
M C Jung ◽  
A K G Wismer ◽  
M S Hallbeck
Keyword(s):  
Pilot Study ◽  
Research Question ◽  
Wrist Flexion ◽  
Joint Angles ◽  
Ulnar Deviation ◽  
Surface Electrodes ◽  
Musical Excerpt ◽  
Muscle Loading ◽  
Maximal Angle ◽  
Flexion And Extension

This pilot study examined whether the use of a 7/8 keyboard contributed to the physical ease of small-handed pianists as compared with the conventional piano keyboard. A secondary research question focused on the progression of physical ease in pianists making the transition from one keyboard to the other. For the purposes of this study, a hand span of 8 inches or less was used to define a “small-handed” pianist. The goal was to measure muscle loading and hand span during performance of a specified musical excerpt. For data collection, each of the two participants was connected to an 8-channel electromyography system via surface electrodes, which were attached to the upper back/shoulder, parts of the hand and arm, and masseter muscle of the jaw. Subjects also were fitted with electrogoniometers to capture how the span from the first metacarpophalangeal (MCP) joint to the fifth MCP joint moves according to performance demands, as well as wrist flexion and extension and radial and ulnar deviation. We found that small-handed pianists preferred the smaller keyboard and were able to transition between it and the conventional keyboard. The maximal angle of hand span while playing a difficult piece was about 5º smaller radially and 10º smaller ulnarly for the 7/8 keyboard, leading to perceived ease and better performance as rated by the pianists.

Contrasting roles of inertial and muscle moments at knee and ankle during paw-shake response

1985 ◽  
Vol 54 (5) ◽  
pp. 1282-1294 ◽  
Author(s):  
M. G. Hoy ◽  
R. F. Zernicke ◽  
J. L. Smith
Keyword(s):  
Steady State ◽  
Knee Joint ◽  
Ankle Joint ◽  
Muscle Activity ◽  
Angular Acceleration ◽  
Average Maximum ◽  
Muscle Moments ◽  
Knee Muscle ◽  
State Cycles ◽  
Flexion And Extension

Intralimb kinetics of the paw-shake response (PSR) were studied in four spinal, adult cats. Using rigid body equations of motion to determine the dynamic interactions between limb segments, knee and ankle joint kinetics were calculated for the steady-state cycles as defined in the preceding paper. Hindlimb motion was filmed (200 frames/s) to obtain knee and ankle kinematics. Responses of flexors and extensors at both joints were recorded synchronously with cinefilm. Ankle and knee joint kinematics were determined from 51 steady-state cycles of 16 PSRs. Average maximum displacements, velocities, and accelerations were substantially greater for the ankle than for the knee joint. Knee and ankle motions were out of phase in the first part of the cycle; knee extension occurred simultaneously with ankle flexion. In the second part of the cycle, motions at the two joints were sequential; rapid knee flexion, accompanied by negligible ankle displacement, preceded rapid ankle extension with minimal knee displacement. At the ankle joint, peak net moments tending to cause flexion and extension were similar in magnitude and determined primarily by muscle moments. Moments due to leg angular acceleration contributed significantly to an extensor peak in the net moment near the end of the cycle. Other inertial and gravitational moments were small. At the knee joint, net moments tending to cause flexion and extension were also similar, but smaller than those at the ankle. The knee muscle moments, however, were large and counteracted large inertial moments due to paw angular acceleration. Also, moments due to leg angular acceleration and knee linear acceleration were substantial and opposite in effect. Other inertial and the gravitational moments were negligible. Muscle moments slowed and reversed joint motions, and active muscle force components of muscle moments were derived from lengthening of active musculotendinous units. Segmental interactions, in which proximal segment motion augmented distal segment velocity, increased the effectiveness of PSR steady-state cycles by facilitating the generation of extremely large paw linear accelerations. Limb oscillations during PSR steady-state result from interactions between muscle synergies and motion-dependent limb dynamics. At the ankle, muscle activity functioned to control paw acceleration, whereas at the knee, muscle activity functioned to control leg and paw inertial interactions.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Neuromuscular Control of the Knee during a Resisted Single-Limb Squat Exercise

2005 ◽  
Vol 33 (10) ◽  
pp. 1520-1526 ◽  
Author(s):  
Richard K. Shields ◽  
Sangeetha Madhavan ◽  
Emy Gregg ◽  
Jennifer Leitch ◽  
Ben Petersen ◽  
...  
Keyword(s):  
Body Weight ◽  
Knee Joint ◽  
Knee Flexion ◽  
Neuromuscular Control ◽  
Biceps Femoris ◽  
Medial Gastrocnemius ◽  
Isometric Contractions ◽  
Low Resistance ◽  
Squat Exercise ◽  
Flexion And Extension

Background Closed kinetic chain exercises such as single-limb squats are preferred for knee rehabilitation. A complete understanding of the neuromuscular control of the knee during the single-limb squat is essential to increase the efficiency of rehabilitation programs. Hypothesis Performing a controlled single-limb squat with resistance to knee flexion and extension will increase the coactivation of the hamstring muscle group, thus reducing the quadriceps/hamstrings ratio. Study Design Descriptive laboratory study. Methods A total of 15 healthy human subjects (7 women, 8 men) performed controlled single-limb squats in a custom mechanical device that provided resistance to both flexion and extension. Subjects performed the task at 3 levels of resistance, set as a percentage of body weight. Surface electromyographic recordings from 7 muscles (gluteus medius, rectus femoris, vastus medialis oblique, vastus lateralis, biceps femoris, semitendinosus, and medial gastrocnemius) were collected during the task. Results Biceps femoris activity during knee flexion increased from approximately 12% maximum voluntary isometric contractions during low resistance (0% body weight) to approximately 27% maximum voluntary isometric contractions during high resistance (8% body weight). Although the quadriceps had greater activity than the hamstrings at all levels of resistance, the quadriceps/hamstrings ratio declined significantly with resistance (F2,27 = 29.05; P=. 012) from 3.0 at low resistance to 2.32 at the highest resistance. Conclusions Performing controlled resisted single-limb squats may help to simultaneously strengthen the quadriceps and facilitate coactivation of the hamstrings, thus reducing anterior tibial shear forces. The coactivation may also increase the dynamic control of the knee joint. Clinical Relevance The typical single-limb squat exercise performed in the clinic does not usually control for bidirectional resistance and knee joint excursion. As seen in this study, controlled single-limb squats at increased levels of resistance help to increase the coactivation of the hamstring muscles, which is essential to optimize neuromuscular control of the knee.

Assessment of Comfort During NMES-induced Quadriceps Contractions at Two Knee Joint Angles

2015 ◽  
Vol 7 (5) ◽  
pp. 181-189 ◽  
Author(s):  
Cody B. Bremner ◽  
William R. Holcomb ◽  
Christopher D. Brown ◽  
Michael G. Miller
Keyword(s):  
Knee Joint ◽  
Joint Angles

scholarly journals The anterolateral ligament is a secondary stabilizer in the knee joint

2019 ◽  
Vol 8 (11) ◽  
pp. 509-517 ◽  
Author(s):  
Kyoung-Tak Kang ◽  
Yong-Gon Koh ◽  
Kyoung-Mi Park ◽  
Chong-Hyuck Choi ◽  
Min Jung ◽  
...  
Keyword(s):  
Knee Joint ◽  
Muscle Activation ◽  
Cruciate Ligament ◽  
Knee Kinematics ◽  
Anterolateral Ligament ◽  
Loading Conditions ◽  
Joint Stability ◽  
Musculoskeletal Models ◽  
Subject Specific ◽  
Cycle Loading

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.

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