scholarly journals An Investigation into the Relation between the Technique of Movement and Overload in Step Aerobics

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Alicja Rutkowska-Kucharska ◽  
Katarzyna Wysocka ◽  
Sławomir Winiarski ◽  
Agnieszka Szpala ◽  
Małgorzata Sobera
Keyword(s):  
Knee Joint ◽  
Joint Angle ◽  
Sagittal Plane ◽  
Flexion Angle ◽  
Trunk Flexion ◽  
Smart System ◽  
Video Cameras ◽  
Reaction Forces ◽  
Joint Flexion ◽  
Dorsal Flexion

The aim of this research was to determine the features of a step workout technique which may be related to motor system overloading in step aerobics. Subjects participating in the research were instructors (n=15) and students (n=15) without any prior experience in step aerobics. Kinematic and kinetic data was collected with the use of the BTS SMART system comprised of 6 calibrated video cameras and two Kistler force plates. The subjects’ task was to perform basic steps. The following variables were analyzed: vertical, anteroposterior, and mediolateral ground reaction forces; foot flexion and abduction and adduction angles; knee joint flexion angle; and trunk flexion angle in the sagittal plane. The angle of a foot adduction recorded for the instructors was significantly smaller than that of the students. The knee joint angle while stepping up was significantly higher for the instructors compared to that for the students. Our research confirmed that foot dorsal flexion and adduction performed while stepping up increased load on the ankle joint. Both small and large angles of knee flexion while stepping up and down resulted in knee joint injuries. A small trunk flexion angle in the entire cycle of step workout shut down dorsal muscles, which stopped suppressing the load put on the spine.

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.

Continuous Estimation Prediction of Knee Joint Angles Using Fusion of Electromyographic and Inertial Sensors for Active Transfemoral Leg Prostheses

2018 ◽  
Vol 10 (02) ◽  
pp. 1840008
Author(s):  
Alberto López-Delis ◽  
Cristiano J. Miosso ◽  
João L. A. Carvalho ◽  
Adson F. da Rocha ◽  
Geovany A. Borges
Keyword(s):  
Knee Joint ◽  
Joint Angle ◽  
Inertial Sensors ◽  
Sagittal Plane ◽  
Joint Angles ◽  
Knee Joint Angle ◽  
Improved Performance ◽  
Continuous Estimation ◽  
Movement Intention ◽  
Semg Signals

Information extracted from the surface electromyographic (sEMG) signals can allow for the detection of movement intention in transfemoral prostheses. The sEMG can help estimate the angle between the femur and the tibia in the sagittal plane. However, algorithms based exclusively on sEMG information can lead to inaccurate results. Data captured by inertial-sensors can improve this estimate. We propose three myoelectric algorithms that extract data from sEMG and inertial sensors using Kalman-filters. The proposed fusion-based algorithms showed improved performance compared to methods based exclusively on sEMG data, generating improvements in the accuracy of knee joint angle estimation and reducing estimation artifacts.

scholarly journals The Reversed Dynamic Patellar Apprehension Test (ReDPAT) mimics anatomical complexity in lateral patellar instability

2019 ◽  
Vol 7 (6_suppl4) ◽  
pp. 2325967119S0022
Author(s):  
Felix Zimmermann ◽  
Peter Balcarek
Keyword(s):  
Risk Factors ◽  
Knee Joint ◽  
Knee Flexion ◽  
Patellar Instability ◽  
Trochlear Dysplasia ◽  
Valgus Deformity ◽  
Tibial Tuberosity ◽  
Flexion Angle ◽  
Knee Flexion Angle ◽  
Joint Flexion

Aims and Objectives: To develop a dynamic physical examination test that functionally simulates actual patellar instability events and that mimics the range of patellar stabilizer insufficiency in an individual patient. Materials and Methods: Seventy-four consecutive patients (male/female 33/41; mean age 22±7 years) with recurrent lateral patellar instability and thirty controls (male/female 16/14; mean age 31±14 years) were prospectively evaluated using the reversed dynamic patellar apprehension test (ReDPAT). The examination starts with the knee flexed at 120°. The knee is then extended while the patella is translated laterally. The maneuver is stopped at first onset of a subjective apprehensive reaction, and the ReDPAT result is considered positive according to this knee joint flexion angle. Anatomical predisposition was assessed according to Dejour’s classification of trochlear dysplasia, tibial tuberosity-trochlear groove distance, tibial tuberosity-posterior cruciate ligament distance, patellar height, and varus/valgus malalignment. Results: The study group had an average of 3.4 ± 1.0 (1-6) anatomical risk factors for lateral patellar dislocation. Severe trochlear dysplasia (84%) and patella alta (49%) were the most common. Test sensitivity, specificity, and accuracy reached 97.3%, 90%, and 95.2%, respectively, and test-retest reliability was good (Pearson’s r 0.84; p<0.0001). The ReDPAT results became positive at a mean knee flexion angle of 58°±17° (20°-90°). Knee flexion angle correlated significantly with the severity of trochlear dysplasia (p=0.018), valgus deformity (p=0.011), and the total number of anatomical risk factors (p=0.02). Conclusion: This study introduced the reversed dynamic patellar apprehension test as a reliable clinical examination tool in the assessment of lateral patellar instability. The results of this study indicate that the degree of knee joint flexion at which the provocative sense of apprehension becomes positive correlates with severity of trochlear dysplasia, valgus deformity and the total number of anatomical risk factors for patellar instability.

Quadriceps Inhibition Induced by an Experimental Knee Joint Effusion Affects Knee Joint Mechanics during a Single-Legged Drop Landing

2007 ◽  
Vol 35 (8) ◽  
pp. 1269-1275 ◽  
Author(s):  
Riann M. Palmieri-Smith ◽  
Jennifer Kreinbrink ◽  
James A. Ashton-Miller ◽  
Edward M. Wojtys
Keyword(s):  
Knee Joint ◽  
Sagittal Plane ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Joint Effusion ◽  
Ground Reaction Forces ◽  
Joint Mechanics ◽  
Drop Landing ◽  
Muscle Inhibition ◽  
Reaction Forces

Background Arthrogenic quadriceps muscle inhibition accompanies knee joint effusion and impedes rehabilitation after knee joint injury. Hypothesis We hypothesized that an experimentally induced knee joint effusion would cause arthrogenic quadriceps muscle inhibition and lead to increased ground reaction forces, as well as sagittal plane knee angles and moments, during a single-legged drop landing. Study Design Controlled laboratory study. Methods Nine subjects (4 women and 5 men) underwent 4 conditions (no effusion, lidocaine injection, “low” effusion [30 mL], and “high” effusion [60 mL]) and then performed a single-legged drop landing. Lower extremity muscle activity, peak sagittal plane knee flexion angles, net sagittal plane knee moments, and peak ground reaction forces were measured. Results Vastus medialis and lateralis activity were decreased during the low and high effusion conditions (P < .05). However, increases in peak ground reaction forces and decreases in peak knee flexion angle and net knee extension moments occurred only during the high effusion condition (P < .05). Conclusions Knee joint effusion induced quadriceps inhibition and altered knee joint mechanics during a landing task. Subjects landed with larger ground reaction forces and in greater knee extension, thereby suggesting that more force will be transferred to the knee joint and its passive restraints when quadriceps inhibition is present. Clinical Relevance Knee joint effusion results in arthrogenic quadriceps muscle inhibition, increasing loading about the knee that may potentially increase the risk of future knee joint trauma or degeneration.

scholarly journals Hip-Extensor Strength, Trunk Posture, and Use of the Knee-Extensor Muscles During Running

2016 ◽  
Vol 51 (7) ◽  
pp. 519-524 ◽  
Author(s):  
Hsiang-Ling Teng ◽  
Christopher M. Powers
Keyword(s):  
Muscle Strength ◽  
Sagittal Plane ◽  
Knee Injuries ◽  
Knee Extensor ◽  
Extensor Muscle ◽  
Muscle Performance ◽  
Flexion Angle ◽  
Knee Extensors ◽  
Trunk Flexion ◽  
Trunk Posture

Context: Diminished hip-muscle performance has been proposed to contribute to various knee injuries. Objective: To determine the association between hip-extensor muscle strength and sagittal-plane trunk posture and the relationships among hip-extensor muscle strength and hip- and knee-extensor work during running. Design: Descriptive laboratory study. Setting: Musculoskeletal biomechanical laboratory. Patients or Other Participants: A total of 40 asymptomatic recreational runners, 20 men (age = 27.1 ± 7.0 years, height = 1.74 ± 0.69 m, mass = 71.1 ± 8.2 kg) and 20 women (age = 26.2 ± 5.8 years, height = 1.65 ± 0.74 m, mass = 60.6 ± 6.6 kg), participated. Main Outcome Measure(s): Maximum isometric strength of the hip extensors was assessed using a dynamometer. Sagittal-plane trunk posture (calculated relative to the global vertical axis) and hip- and knee-extensor work (sum of energy absorption and generation) during the stance phase of running were quantified while participants ran over ground at a controlled speed of 3.4 m/s. We used Pearson product moment correlations to examine the relationships among hip-extensor strength, mean sagittal-plane trunk-flexion angle, hip-extensor work, and knee-extensor work. Results: Hip-extensor strength was correlated positively with trunk-flexion angle (r = 0.55, P &lt; .001) and hip-extensor work (r = 0.46, P = .003). It was correlated inversely with knee-extensor work (r = −0.39, P = .01). All the correlations remained after adjusting for sex. Conclusions: Our findings suggest that runners with hip-extensor weakness used a more upright trunk posture. This strategy led to an overreliance on the knee extensors and may contribute to overuse running injuries at the knee.

scholarly journals Characteristics of Knee Joint Flexion Angle and Foot Pressure according Slope Climbing

2010 ◽  
Vol 10 (2) ◽  
pp. 268-276
Author(s):  
Tae-Young Oh ◽  
Hyeon-Ju Song ◽  
Seul-Gi Lee ◽  
Ye-Ji Jung ◽  
Jong-Su Lim
Keyword(s):  
Knee Joint ◽  
Flexion Angle ◽  
Foot Pressure ◽  
Joint Flexion
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