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1

Classification of mild and severe adolescent idiopathic scoliosis (AIS) from healthy subjects via a supervised learning model based on electromyogram and ground reaction force data during gait

Sikidar Arnab, Vidyasagar Koyyana Eshwar Chandra, Gupta Manish, Garg Bhavuk, Kalyanasundaram Dinesh

Biocybernetics and Biomedical Engineering

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2022

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Vol. 42, no. 3

870--887

EN

At early stages, adolescent idiopathic scoliosis (AIS) is quite hard to be distinguished from healthy (HC) subjects by the naked eye. AIS demands multiple corrective surgeries when detected later, thereby causing significant physical and psychological trauma as no mathematical models exist for the classification of mild AIS (MS) (20° < Cobb’s angle < 40°) from HC, we propose a k-nearest neighbour (kNN) method based model. In this work, we collected both the EMG and GRF data from nine severe AIS (SS), three MS and four female HC during gait. Delayed muscle activation in Erector spinatus Iliocostalis, Gluteus Medius and Gastrocnemius lateralis was observed in SS compared to HC. However, no such distinction was noticed between MS and HC motivating for a mathematical model. Eighteen time-domain and nine frequency-domain features were computed from the EMG data of 14 lower extremity muscles, while five time-domain features were calculated from GRF data during gait. Out of all the features computed for each subject, the principal component analysis (PCA) yielded 15 principal components that coupled both time and frequency domains (TFD). Further, the kNN model classified SS, MS and HC from each other by these 15 TFD features. The model was trained and validated using 32 and 21 EMG and GRF data datasets during gait, respectively. The classification and validation accuracy of 90.6% and 85.7% were obtained among SS, MS and HC. The proposed model is capable of early detection of AIS and can be used by medical professionals to plan treatments and corrective measures.

2

Effects of age and gender on spatiotemporal and kinematic gait parameters in older adults

Tanaka Ryo, Jung Hungu, Yamashina Shunsuke, Inoue Yu, Nakamura Rinna, Toda Haruki, Imura Takeshi, Tamura Hiroyuki

Acta of Bioengineering and Biomechanics

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2022

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Vol. 24, no. 4

13--19

EN

Gait changes are more prominently observed in older adults than in young adults, especially in kinematics of lower extremities and trunk. These changes can result in incidental falls during gait, possibly leading to inability to perform activities of daily living independently. This study aimed to investigate the effect of gender and age on gait changes, such as spatiotemporal parameters and peak joint angles in lower extremities and trunk during gait. Methods: A total of 387 participants (223 women) were included. The Microsoft Kinect V2 sensor was used to obtain the coordinate data of lower extremities and trunk during gait. The coordinate data obtained were processed using the software. Walking speed, stride length, stride time and cadence were calculated as spatiotemporal variables of walking. Forward trunk tilt angle (FTT), hip flexion and extension, and knee flexion and extension were measured as peak angles during one-gait cycle. Participants were categorized into five groups according to age by five years. Multivariate analysis of variance was performed to compare the spatiotemporal and kinematical data among groups. Results: Significant differences among age groups were noted in terms of the walking speed and stride length. Significant differences were also observed in the FTT and hip extension angle. Conclusions: Increased gait changes, increased peak FTT and decreased peak hip extension angle were observed with an increase of age. These altered symptoms may contribute to the screening of older adults at risk of declined physical function at an early stage.

3

Reliability and validity of a novel Isokinetic Knee Dynamometer System

Riemann Bryan M., Watson Matthew D., Davies George J.

Acta of Bioengineering and Biomechanics

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2021

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Vol. 23, no. 4

107--116

EN

Purpose: The aim of this work was to determine the intersession reliability and validity of a recently developed prototype Isokinetic Knee Dynamometer to assess isokinetic knee extension and flexion peak moments compared to a Biodex System 4 dynamometer. Methods: Thirty--five healthy participants performed two sessions (48-h separation) of bilateral concentric isokinetic knee extension and flexion on both isokinetic devices at 60 °/s (6 repetitions), 180 °/s (10 repetitions) and 240 °/s (15 repetitions). Dynamometer and limb order were randomized among participants while peak moment of each set was used for data analysis. Results: The Isokinetic Knee Dynamometer had excellent relative reliability, comparable to the System 4, and both systems displayed acceptable absolute reliability. Proportional biases were observed favoring the System 4 during knee extension of both limbs at 60 °/s and the dominant limb at 180 °/s, and fixed biases favoring the Isokinetic Knee Dynamometer in seven conditions. Relative agreement between systems was good across all test conditions with the majority demonstrating excellent agreement. Conclusions: These data support the Isokinetic Knee Dynamometer as a reliable and valid knee isokinetic testing system. Due to its reduced system complexity, space requirements, and production cost, the Isokinetic Knee Dynamometer may increase the clinical utilization of isokinetic knee assessments. Finally, these data fill an existing isokinetics literature void with the results supporting similar and acceptable measurement properties jointly for dominant and non-dominant limbs and at the higher testing velocities considered.

4

Projekt kończyny dolnej bipeda napędzanego siłownikami z dołączonymi szeregowo elementami podatnymi

Mianowski K., Schuetz S., Nejadfard A., Berns K.

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2018

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z. 196

231--240

PL

W artykule przedstawiono stan projektu kończyny CARL (Compliant Robotnic Leg) dla robota-bipeda opracowywanego w okresie ostatnich kilku lat na uniwersytecie technicznym w Kaiserslautern (Niemcy) w zespole prof. K. Bernsa. Projektowany robot ma być przeznaczony do badań chodu dynamicznego. W celu zwiększenia uniwersalności i zmniejszenia kosztów ogólnych opracowano rozwiązanie przystosowane do pracy zarówno jako prawa jak i lewa kończyna z dołączonymi jako stopy typowymi dynamicznymi protezami kompozytowymi firmy Otto-Bock. W konstrukcji kończyn zastosowano ogólnie dostępne na rynku gotowe podzespoły oraz zastosowano powszechne metody obróbki materiału. W rozwiązaniach układów napędowych zastosowano nowoczesne wysokomomentowe silniki elektryczne "do wbudowania", wysokosprawne przekładnie śrubowe toczne o dużym skoku śruby i wysokiej sprawności oraz sprężyny spiralne specjalne o prostokątnym przekroju zwojów.

EN

Mechanical design of the lower extremity for biped driven using linear serial-elastic actuators with springs is presented in the paper. Designed leg has 6 degrees of freedom, three DOF's are for motion of the hip joint, one for knee joint and two for ankle joint. The advantage of the solution is that the leg can be used even for left and right lower extremity of the robot.

5

Symmetry of electromechanical delay, peak torque and rate of force development in knee flexors and extensors in female and male subjects

Szpala A., Rutkowska-Kucharska A., Stawiany M.

Acta of Bioengineering and Biomechanics

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2015

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Vol. 17, no. 1

61--68

EN

Purpose: The aim of the study was to evaluate electromechanical delay (EMD), peak torque (PT) and rate of force development (RFD) in selected muscles of right and left lower extremities in groups of female and male subjects. Methods: The study evaluated 9 volunteer female subjects (mean ± SD: age: 21.67 ± 0.87 years; height: 168 ± 7 cm; body mass: 59.44 ± 4.8 kg) and 10 male university students (mean ± SD: age 22 ± 1.25 years; height: 179 ± 6 cm; body mass: 74.3 ± 5.1 kg) from the Faculty of Physical Education. Muscle torques and electromyographic activity were measured for knee flexors and extensors in static conditions, separately for the right and the left lower extremities. During the measurements, the subjects generated the maximum torque as fast as possible. Surface electrodes were placed on the right and left lower extremities on the following muscles: rectus femoris, vastus lateralis (m.VL), vastus medialis and biceps femoris. Results: Symmetry of EMD, RFD and “flexors-extensors” ratio was found in the muscles of the right and left lower extremities (with an exception of m.VL) in the group of male and female subjects. Statistical analysis demonstrated the presence of asymmetry in PT (297.66 vs. 272.05 N⋅m) and relative force in knee extensors in the group of men (3.90 vs. 3.54 N⋅m⋅kg–1). Conclusions: Symmetry of EMD and asymmetry of PT might suggest that the cause of asymmetry of the muscular force is mainly morphological characteristics of the muscle rather than the process of controlling its activity.

6

Wyznaczanie sił mięśniowych i obciążeń w stawach kończyn dolnych podczas trójskoku

Mazur Z., Dziewiecki K., Blajer W.

Modelowanie Inżynierskie

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2012

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T. 14, nr 45

99--107

PL

Trójskok polega na wykonywaniu trzech kolejnych skoków: skoku (odbicie i lądowanie na tę samą kończynę dolną), kroku (lądowanie na kończynę przeciwną) oraz zeskoku (lądowanie obunóż na piasku). Jest to konkurencja lekkoatletyczna, w której zawodnik poddawany jest bardzo dużym obciążeniom w stawach, szczególnie w czasie kontaktu zawodnika z bieżnią. Prezentowany jest model symulacyjny dla analizy dynamicznej odwrotnej trójskoku, pozwalający na szacowanie obciążeń wewnętrznych w kończynach dolnych skaczącego (sił mięśniowych i reakcji w stawach) oraz reakcji od podłoża. Rozważania są zilustrowane wybranymi wynikami symulacji numerycznej.

EN

The triple jump is a demanding athletics event divided into the hop, step, and jump phases, and during each of the landings/take-offs a jumper must tolerate extremely high impact/impulsive forces. The developed (planar) model of the jumper is valid for all the movement phases. Its actuation involves muscle forces in the lower limbs, and the resultant muscle torques in the joints. The dynamic equations are derived in a compact form, and a discussion is provided on computational aspects related to the inverse dynamics analysis, focused on effective assessment of muscle forces and joint reaction forces in the lower limbs and external reactions during the contact phases. Some numerical results of the inverse dynamics simulation are reported.

7

Właściwości dynamiczne mięśni prostujących i zginających w stawie kolanowym przed i po okresie przygotowawczym u zawodowych piłkarzy nożnych

Korbolewska O., Plenzler M., Popieluch M., Wychowański M.

Aktualne Problemy Biomechaniki

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2012

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z. 6

65--74

8

The effect of various types of power training on muscle torques and power levels of lower extremity

Ostrowska E., Mastalerz A., Urbanik C., Staniszewski M., Iwańska D., Madej A., Pędzich W.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2006

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z. 26

275-280

EN

The aim of this study was to determine the effects of two various types of power training on the muscle torques and power levels of lower extremities. During four weeks (five days a week) 27 students participated in this study. The training device consisted of an incline plane and a sliding seat. The varied types of power training were achieved by utilizing intermissions between the series of take offs. 4 series of 10 takes-offs with rest periods among series were carried out in A group (120s in length). Whereas the group B carried out the same number of take offs (40 take-offs) continuously. The interval training (group A) resulted in more effective dynamic values of the lower extremities than the continuous training adhered to by group B.

9

Identyfikacja i modelowanie dystrybucji momentów sił mięśniowych w trakcie izokinetycznej pracy mięśni

Czaplicki A., Jaszczuk J.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2003

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z. 20

86-92

PL

Niniejsza praca składa się z dwóch zasadniczych części. W pierwszej zaprezentowano wyniki identyfikacji momentów sił mięśniowych w warunkach izokinetycznych uzyskane za pomocą urządzenia BIODEX SYSTEM 3. Analizie poddano wybrane stawy człowieka. Pomiary przeprowadzono dla różnych prędkości kątowych i dla różnych zakresów ruchu w stawach. W drugiej części pracy przedstawiono trójwymiarowy model kończyny dolnej. Główny nacisk w procesie modelowania położono na wyznaczanie dystrybucji sił mięśniowych na poszczególne mięśnie obsługujące badany staw. Wykorzystano w tym celu metodę "pseudoodwrócenia" macierzy dystrybucji tych momentów.

EN

The paper is divided into two basic parts. The results of identification of net artificial torques have been presented in the first part of the paper. Isometric testing was done with the use of the BIODEX SYSTEM 3 equipment. The selected joints of human being were examined. The angular velocities and the joint's range of motion were successively changed while testing. The second part of the paper deals with 3D modelling of the lower extremity of a human being. The main goal of the modelling process was focused on distributing the net artificial torques for individual muscles. In order to achieve it, the authors used the pseudoinverse method.

10

Symulacja numeryczna ruchu kończyn dolnych człowieka

Świtoński E., Tejszerska D., Gzik M., Michnik R.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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1998

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z. 8

81-86

PL

Symulacja numeryczna ruchu człowieka stanowi ważną metodę badań przy określaniu obciążeń stawów, postaci funkcji opisujących sterowanie mięśni, a także cech konstrukcyjnych protez mechanicznych. W pracy sformułowano model ruchu płaskiego kończyn dolnych wraz z korpusem traktowanych jako człony sztywne połączone obrotowo stawami. W modelu uwzględniono siły ciężkości i bezwładności, sprężyste i cierne warunki kontaktu nóg z podłożem, opory ruchu i sprężyste ograniczenia obrotu w stawach oraz rozmieszczenie i kierunki skurczowego oddziaływania poszczególnych mięśni. Przedstawiono wstępną fazę symulacji ruchu przy założonym przebiegu sił mięśniowych.

EN

Numerical simulation of human motion is a very important method for estimation of loads of joints, form of function describing muscles control and design features of mobile prostheses. A model of plane motion of lower limbs with a trunk is presented in the paper. The model consists of rigid bodies conected by revolute joints. The model considers gravity and inertial forces, flexible and frictional contact between legs and ground, motion resistance, flexible constraints of revolution in joints as well as placement and direction of particular muscles shrinkage reactions. The preliminary phase of motion simulation for assumed muscles forces is presented.