scholarly journals Lower limb intersegmental forces for below-knee amputee children during standing

1991 ◽  
Vol 15 (3) ◽  
pp. 185-191 ◽  
Author(s):  
J. R. Engsberg ◽  
K. C. Aldridge ◽  
J. A. Harder
Keyword(s):  
Spatial Data ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Anatomical Structure ◽  
Static Force ◽  
Force Analysis ◽  
Knee Angle ◽  
Prosthetic Knee ◽  
Hip Forces

The purpose of this investigation was to compare intersegmental knee and hip forces for below-knee amputee (BKA) and able-bodied children during standing. Three unilateral BKA children and 10 able-bodied children (7-9 years) were tested on four separate occasions at six month intervals. Three trials of external force and spatial data during standing were collected from each subject for each session. These data were utilised to determine the intersegmental forces at the knees and hips of the children using a static force analysis. Results indicated that in some instances the intersegmental forces for the BKA children were significantly greater than those of the able-bodied children and in other instances significantly lower (p < 0.05). In all cases, however, the values were substantially less than corresponding values for walking and running. The effects of the forces upon spatial orientations indicated significant differences between the two groups of children. The frontal plane prosthetic knee angle, the sagittal plane prosthetic and non-prosthetic knee angles, and the sagittal plane trunk angle were all greater for the BKA children when compared to able-bodied children. These differences may be the result of the anatomical structure of the amputee and/or the construction of the prosthesis.

scholarly journals Biologically Inspired Design and Development of a Variable Stiffness Powered Ankle-Foot Prosthesis

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Alexander Agboola-Dobson ◽  
Guowu Wei ◽  
Lei Ren
Keyword(s):  
Lower Limb ◽  
Degrees Of Freedom ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Variable Stiffness ◽  
Plane Motion ◽  
Biologically Inspired ◽  
Passive Rotation ◽  
Ground Conditions ◽  
Biologically Inspired Design

Recent advancements in powered lower limb prostheses have appeased several difficulties faced by lower limb amputees by using a series-elastic actuator (SEA) to provide powered sagittal plane flexion. Unfortunately, these devices are currently unable to provide both powered sagittal plane flexion and two degrees of freedom (2-DOF) at the ankle, removing the ankle’s capacity to invert/evert, thus severely limiting terrain adaption capabilities and user comfort. The developed 2-DOF ankle system in this paper allows both powered flexion in the sagittal plane and passive rotation in the frontal plane; an SEA emulates the biomechanics of the gastrocnemius and Achilles tendon for flexion while a novel universal-joint system provides the 2-DOF. Several studies were undertaken to thoroughly characterize the capabilities of the device. Under both level- and sloped-ground conditions, ankle torque and kinematic data were obtained by using force-plates and a motion capture system. The device was found to be fully capable of providing powered sagittal plane motion and torque very close to that of a biological ankle while simultaneously being able to adapt to sloped terrain by undergoing frontal plane motion, thus providing 2-DOF at the ankle. These findings demonstrate that the device presented in this paper poses radical improvements to powered prosthetic ankle-foot device (PAFD) design.

Muscle Contributions to Balance Control During Amputee and Nonamputee Stair Ascent

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Nicole G. Harper ◽  
Jason M. Wilken ◽  
Richard R. Neptune
Keyword(s):  
Angular Momentum ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Balance Control ◽  
Dynamic Balance ◽  
Frontal Plane ◽  
Rate Of Change ◽  
Prosthetic Devices ◽  
Stair Ascent

Abstract Dynamic balance is controlled by lower-limb muscles and is more difficult to maintain during stair ascent compared to level walking. As a result, individuals with lower-limb amputations often have difficulty ascending stairs and are more susceptible to falls. The purpose of this study was to identify the biomechanical mechanisms used by individuals with and without amputation to control dynamic balance during stair ascent. Three-dimensional muscle-actuated forward dynamics simulations of amputee and nonamputee stair ascent were developed and contributions of individual muscles, the passive prosthesis, and gravity to the time rate of change of angular momentum were determined. The prosthesis replicated the role of nonamputee plantarflexors in the sagittal plane by contributing to forward angular momentum. The prosthesis largely replicated the role of nonamputee plantarflexors in the transverse plane but resulted in a greater change of angular momentum. In the frontal plane, the prosthesis and nonamputee plantarflexors contributed oppositely during the first half of stance while during the second half of stance, the prosthesis contributed to a much smaller extent. This resulted in altered contributions from the intact leg plantarflexors, vastii and hamstrings, and the intact and residual leg hip abductors. Therefore, prosthetic devices with altered contributions to frontal-plane angular momentum could improve balance control during amputee stair ascent and minimize necessary muscle compensations. In addition, targeted training could improve the force production magnitude and timing of muscles that regulate angular momentum to improve balance control.

scholarly journals Accelerometer-Based Navigation in Total Knee Arthroplasty for the Management of Extra-Articular Deformity and Retained Femoral Hardware: Analysis of Component Alignment

Joints ◽  
2019 ◽  
Vol 07 (01) ◽  
pp. 001-007 ◽  
Author(s):  
Andrea Cozzi Lepri ◽  
Matteo Innocenti ◽  
Fabrizio Matassi ◽  
Marco Villano ◽  
Roberto Civinini ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Navigation System ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Control Group ◽  
Navigation Systems ◽  
Level Of Evidence ◽  
Total Knee

Abstract Purpose Recent advances in total knee arthroplasty (TKA) include an accelerometer portable system designed to improve component position and alignment. The purpose of this study is to evaluate whether accelerometer navigation system can be a valuable option in complex TKAs for extra-articular deformity of the lower limb or in case of retained femoral hardware. Methods A group of 13 patients underwent TKA with an accelerometer navigation system. Three patients had a tibial extra-articular deformity, six had a femoral extra-articular deformity, and four had an intramedullary nail in the femur. Preoperative and postoperative mechanical axes were measured from full-length lower extremity radiographs to evaluate alignment. The alignment of prosthetic components in the frontal and sagittal planes was determined by postoperative radiographs. Results At 30-days postoperative radiographic check, the hip knee ankle angle was within 2.0° (0 ± 1) of the neutral mechanical axis. The alignment of the tibial component on the frontal plane was 90.0° (range 89–91) and on the sagittal plane 5.0° (range 3–7). The alignment of the femoral component on the frontal plane was 90.0° (range 89–91) and on the sagittal plane 3.0° (range 0–5). Conclusion The alignment of the prosthetic components has been accurate and comparable to other navigation systems in literature without any increase in surgical times. The accelerometer-based navigation system is therefore a useful technique that can be used to optimize TKA alignment in patients with extra-articular deformity or with lower limb hardware, where the intramedullary guides cannot be applied. Level of Evidence This is an observational study without a control group, Level III.

Sensitivity of the Toe Height to Multijoint Angular Changes in the Lower Limbs During Unobstructed and Obstructed Gait

2020 ◽  
pp. 1-9
Author(s):  
Chuyi Cui ◽  
Brittney Muir ◽  
Shirley Rietdyk ◽  
Jeffrey Haddad ◽  
Richard van Emmerik ◽  
...  
Keyword(s):  
Young Adults ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Singular Value ◽  
Lower Limbs ◽  
Joint Angles ◽  
Adult Lifespan ◽  
Main Contributor ◽  
Bilateral Lower Limb

Tripping while walking is a main contributor to falls across the adult lifespan. Trip risk is proportional to variability in toe clearance. To determine the sources of this variability, the authors computed for 10 young adults the sensitivity of toe clearance to 10 bilateral lower limb joint angles during unobstructed and obstructed walking when the lead and the trail limb crossed the obstacle. The authors computed a novel measure—singular value of the appropriate Jacobian—as the combined toe clearance sensitivity to 4 groups of angles: all sagittal and all frontal plane angles and all swing and all stance limb angles. Toe clearance was most sensitive to the stance hip ab/adduction for unobstructed gait. For obstructed gait, sensitivity to other joints increased and matched the sensitivity to stance hip ab/adduction. Combined sensitivities revealed critical information that was not evident in the sensitivities to individual angles. The combined sensitivity to stance limb angles was 84% higher than swing limb angles. The combined sensitivity to the sagittal plane angles was lower than the sensitivity to the frontal plane angles during unobstructed gait, and this relation was reversed during obstacle crossing. The results highlight the importance of the stance limb joints and indicate that frontal plane angles should not be ignored.

scholarly journals The shape of disposable diaper affects spontaneous movements of lower limbs in young infants

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hirotaka Gima ◽  
Midori Teshima ◽  
Etsuko Tagami ◽  
Toshihiro Sato ◽  
Hidenobu Ohta
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Type A ◽  
Lower Limbs ◽  
Type B ◽  
Limb Movements ◽  
Young Infants ◽  
Knee Movement ◽  
Spontaneous Movements

Abstract This study examined the characteristics of young infants’ lower limb spontaneous movements based on differences in shape of diapers. Twenty-seven healthy infants (103 ± 16.3 days old) were enrolled in this study. We measured the spontaneous movements of their lower limbs in four conditions (Naked, wearing Normal type diapers, wearing Type A diapers, and wearing Type B diapers). The Normal diaper has a wider waist belt than the Type A diaper, and the Type B diaper has a narrower crotch area than the Type A diaper. We observed them in seven indices (the velocity of lower limb movements, the trajectory area of knee movement in the sagittal plane and the frontal plane, the distance between both knees and between side of abdomen and knee, and correlation of velocities between side of abdomen and knee and between left and right ankles). The results showed that the velocity of the lower limb movements in the Naked condition was higher than when wearing Normal diapers. The value for the trajectory area of knee movement in sagittal plane, which reflects the range of lower leg lifting movements and closeness of such movements to the trunk, for the Type B diaper condition was higher than that for the Normal diaper condition. This result indicates that the shape of the diaper affects the spontaneous movements of the lower limbs of young infants.

scholarly journals A Comparison of Static and Dynamic Measures of Lower Limb Joint Angles in Cycling: Application to Bicycle Fitting

2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Rodrigo Rico Bini ◽  
Patria Hume
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Digital Camera ◽  
Gear Ratio ◽  
Knee Angle ◽  
Joint Angles ◽  
Ankle Angle ◽  
Dynamic Measures ◽  
Potential Use ◽  
Dynamic Cycling

AbstractPurpose. Configuration of bicycle components to the cyclist (bicycle fitting) commonly uses static poses of the cyclist on the bicycle at the 6 o’clock crank position to represent dynamic cycling positions. However, the validity of this approach and the potential use of the different crank position (e.g. 3 o’clock) have not been fully explored. Therefore, this study compared lower limb joint angles of cyclists in static poses (3 and 6 o’clock) compared to dynamic cycling. Methods. Using a digital camera, right sagittal plane images were taken of thirty cyclists seated on their own bicycles mounted on a stationary trainer with the crank at 3 o’clock and 6 o’clock positions. Video was then recorded during pedalling at a self-selected gear ratio and pedalling cadence. Sagittal plane hip, knee and ankle angles were digitised. Results. Differences between static and dynamic angles were large at the 6 o’clock crank position with greater mean hip angle (4.9 ± 3°), smaller knee angle (8.2 ± 5°) and smaller ankle angle (8.2 ± 5.3°) for static angles. Differences between static and dynamic angles (< 1.4°) were trivial to small for the 3 o’clock crank position. Conclusions. To perform bicycle fitting, joint angles should be measured dynamically or with the cyclist in a static pose at the 3 o’clock crank position.

Pelvifemoral Kinematics while Ascending Single Steps of Different Heights

2010 ◽  
Vol 26 (3) ◽  
pp. 290-294 ◽  
Author(s):  
Richard W. Bohannon ◽  
Jason Smutnick
Keyword(s):  
Motion Capture ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Step Height ◽  
Motion Capture System ◽  
Pelvic Rotation ◽  
Hip Flexion

Motion of the femur and pelvis during hip flexion has been examined previously, but principally in the sagittal plane and during nonfunctional activities. In this study we examined femoral elevation in the sagittal plane and pelvic rotation in the sagittal and frontal planes while subjects flexed their hips to ascend single steps. Fourteen subjects ascended single steps of 4 different heights leading with each lower limb. Motion of the lead femur and pelvis during the flexion phase of step ascent was tracked using an infrared motion capture system. Depending on step height and lead limb, step ascent involved elevation of the femur (mean 47.2° to 89.6°) and rotation of the pelvis in both the sagittal plane (tilting: mean 2.6° to 9.7°) and frontal plane (listing: mean 4.2° to 11.9°). Along with maximum femoral elevation, maximum pelvic rotation increased significantly (p< .001) with step height. Femoral elevation and pelvic rotation during the flexion phase of step ascent were synergistic (r= .852–.999). Practitioners should consider pelvic rotation in addition to femoral motion when observing individuals’ ascent of steps.

Biomechanical Performance of Habitually Barefoot and Shod Runners during Barefoot Jogging and Running

2018 ◽  
Vol 38 ◽  
pp. 1-10 ◽  
Author(s):  
Suo Di Xu ◽  
Zhi Qiang Liang ◽  
Yu Wei Liu ◽  
Gusztáv Fekete
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Three Dimensional ◽  
Frontal Plane ◽  
Influential Factor ◽  
Hip Abduction ◽  
Foot Strike ◽  
Limb Kinematics

The purpose of this study was to evaluate the biomechanical performances, running stability of habitually barefoot (BR) and shod runners (SR) during barefoot jogging and running. Ten healthy male subjects, 5 habitually shod runners and 5 habitually barefoot runners, from two different ethnics participated in this study. Subjects performed jogging (2m/s) and running (4m/s) along a 10-m runway. Three-dimensional lower-limb kinematics, ground reaction force, center of pressure (COP) and contact time (CT), were collected during testing. During jogging and running, all participants adopted rear-foot strike pattern, SR had larger VALR. SR showed significantly larger lower-limb range of motion (ROM) in sagittal plane, significantly larger hip abduction and opposite knee ROM in frontal plane, as well as significantly larger ankle internal rotation in horizontal plane. All participants’ CT showed decreased trend with running speed up; and SR was significantly longer than BR; BR and SR in COP showed different trajectories, especially forefoot and rearfoot areas. Habitually barefoot and shod runner from different ethnics still exist significant differences in lower-extremity ROM; and different foot morphological of participants is an important influential factor for these variations.

scholarly journals The mechanisms and mechanical energy of human gait initiation from the lower-limb joint level perspective

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guoping Zhao ◽  
Martin Grimmer ◽  
Andre Seyfarth
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Mechanical Energy ◽  
Body Movement ◽  
Frontal Plane ◽  
Energy Output ◽  
Human Gait ◽  
Gait Initiation ◽  
Related Data ◽  
Flexion Extension

AbstractThis study aims to improve our understanding of gait initiation mechanisms and the lower-limb joint mechanical energy contributions. Healthy subjects were instructed to initiate gait on an instrumented track to reach three self-selected target velocities: slow, normal and fast. Lower-limb joint kinematics and kinetics of the first five strides were analyzed. The results show that the initial lateral weight shift is achieved by hip abduction torque on the lifting leg (leading limb). Before the take-off of the leading limb, the forward body movement is initiated by decreasing ankle plantarflexion torque, which results in an inverted pendulum-like passive forward fall. The hip flexion/extension joint has the greatest positive mechanical energy output in the first stride of the leading limb, while the ankle joint contributes the most positive mechanical energy in the first stride of the trailing limb (stance leg). Our results indicate a strong correlation between control of the frontal plane and the sagittal plane joints during gait initiation. The identified mechanisms and the related data can be used as a guideline for improving gait initiation with wearable robots such as exoskeletons and prostheses.

scholarly journals Lower Limb Kinematics Using Inertial Sensors during Locomotion: Accuracy and Reproducibility of Joint Angle Calculations with Different Sensor-to-Segment Calibrations

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 715 ◽  
Author(s):  
Julien Lebleu ◽  
Thierry Gosseye ◽  
Christine Detrembleur ◽  
Philippe Mahaudens ◽  
Olivier Cartiaux ◽  
...  
Keyword(s):  
Lower Limb ◽  
Inertial Sensors ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Human Movement ◽  
Absolute Difference ◽  
Measurement Unit ◽  
Joint Angles ◽  
3D Tracking ◽  
Limb Kinematics

Inertial measurement unit (IMU) records of human movement can be converted into joint angles using a sensor-to-segment calibration, also called functional calibration. This study aims to compare the accuracy and reproducibility of four functional calibration procedures for the 3D tracking of the lower limb joint angles of young healthy individuals in gait. Three methods based on segment rotations and one on segment accelerations were used to compare IMU records with an optical system for their accuracy and reproducibility. The squat functional calibration movement, offering a low range of motion of the shank, provided the least accurate measurements. A comparable accuracy was obtained in other methods with a root mean square error below 3.6° and an absolute difference in amplitude below 3.4°. The reproducibility was excellent in the sagittal plane (intra-class correlation coefficient (ICC) > 0.91, standard error of measurement (SEM) < 1.1°), good to excellent in the transverse plane (ICC > 0.87, SEM < 1.1°), and good in the frontal plane (ICC > 0.63, SEM < 1.2°). The better accuracy for proximal joints in calibration movements using segment rotations was traded to distal joints in calibration movements using segment accelerations. These results encourage further applications of IMU systems in unconstrained rehabilitative contexts.

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