Kinematic and dynamic aspects of chimpanzee knuckle walking - finger flexors likely do not buffer ground impact forces

2021 ◽  
Author(s):  
Leijnse JN ◽  
Spoor CW ◽  
Pullens P ◽  
Vereecke EE
Keyword(s):  
Flexor Tendon ◽  
Point Of View ◽  
Biomechanical Analysis ◽  
Ground Reaction Forces ◽  
Flexor Muscle ◽  
Load Bearing ◽  
Impact Forces ◽  
Buffering Hypothesis ◽  
Reaction Forces ◽  
Ground Impact

Chimpanzees are knuckle-walkers, with forelimbs contacting the ground by the dorsum of the finger's middle phalanges. As these muscular apes are given to high velocity motions, the question arises how the ground reaction forces are buffered so that no damage ensues in the load bearing fingers. In literature, it was hypothesized that the finger flexors help buffer impacts because in knuckle stance the metacarpophalangeal joints (MCPJ) are strongly hyperextended, which would elongate the finger flexors. This stretching of the finger flexor muscle-tendon units would absorb impact energy. However, EMG studies did not report significant finger flexor activity in knuckle walking. While these data by themselves question the finger flexor impact buffering hypothesis, the present study aimed to critically investigate the hypothesis from a biomechanical point of view. Therefore, various aspects of knuckle walking were modeled and the finger flexor tendon displacements in the load bearing fingers were measured in a chimpanzee cadaver hand, of which also an MRI was taken in knuckle stance. The biomechanics do not support the finger flexor impact buffering hypothesis. In knuckle walking, the finger flexors are not elongated to lengths where passive strain forces would become important. Impact buffering by large flexion moments at the MCP joints from active finger flexors would result in impacts at the knuckles themselves, which is dysfunctional for various biomechanical reasons and does not occur in real knuckle walking. In conclusion, the current biomechanical analysis in accumulation of previous EMG findings suggests finger flexors play no role in impact buffering in knuckle walking.

scholarly journals Heel impact forces during barefoot versus minimally shod walking among Tarahumara subsistence farmers and urban Americans

2018 ◽  
Vol 5 (3) ◽  
pp. 180044 ◽  
Author(s):  
Ian J. Wallace ◽  
Elizabeth Koch ◽  
Nicholas B. Holowka ◽  
Daniel E. Lieberman
Keyword(s):  
Effective Mass ◽  
Ground Reaction Forces ◽  
Musculoskeletal Health ◽  
Subsistence Farmers ◽  
Loading Rates ◽  
Impact Forces ◽  
Recent Interest ◽  
Walking Biomechanics ◽  
Reaction Forces

Despite substantial recent interest in walking barefoot and in minimal footwear, little is known about potential differences in walking biomechanics when unshod versus minimally shod. To test the hypothesis that heel impact forces are similar during barefoot and minimally shod walking, we analysed ground reaction forces recorded in both conditions with a pedography platform among indigenous subsistence farmers, the Tarahumara of Mexico, who habitually wear minimal sandals, as well as among urban Americans wearing commercially available minimal sandals. Among both the Tarahumara ( n  = 35) and Americans ( n  = 30), impact peaks generated in sandals had significantly ( p  < 0.05) higher force magnitudes, slower loading rates and larger vertical impulses than during barefoot walking. These kinetic differences were partly due to individuals' significantly greater effective mass when walking in sandals. Our results indicate that, in general, people tread more lightly when walking barefoot than in minimal footwear. Further research is needed to test if the variations in impact peaks generated by walking barefoot or in minimal shoes have consequences for musculoskeletal health.

scholarly journals Changes in Ground Reaction Forces, Joint Mechanics, and Stiffness during Treadmill Running to Fatigue

2019 ◽  
Vol 9 (24) ◽  
pp. 5493 ◽  
Author(s):  
Zhen Luo ◽  
Xini Zhang ◽  
Junqing Wang ◽  
Yang Yang ◽  
Yongxin Xu ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Treadmill Running ◽  
Ground Reaction Forces ◽  
Joint Mechanics ◽  
Soft Landing ◽  
Ankle Stiffness ◽  
Impact Forces ◽  
Reaction Forces ◽  
The Impact ◽  
Kinematics And Kinetics

Purpose: This study aimed to determine the changes in lower extremity biomechanics during running-induced fatigue intervention. Methods: Fourteen male recreational runners were required to run at 3.33 m/s until they could no longer continue running. Ground reaction forces (GRFs) and marker trajectories were recorded intermittently every 2 min to quantify the impact forces and the lower extremity kinematics and kinetics during the fatiguing run. Blood lactate concentration (BLa) was also collected before and after running. Results: In comparison with the beginning of the run duration, (1) BLa significantly increased immediately after running, 4 min after running, and 9 min after running; (2) no changes were observed in vertical/anterior–posterior GRF and loading rates; (3) the hip joint range of motion (θROM) significantly increased at 33%, 67%, and 100% of the run duration, whereas θROM of the knee joint significantly increased at 67%; (4) no changes were observed in ankle joint kinematics and peak joint moment at the ankle, knee, and hip; and (5) vertical and ankle stiffness decreased at 67% and 100% of the run duration. Conclusion: GRF characteristics did not vary significantly throughout the fatiguing run. However, nonlinear adaptations in lower extremity kinematics and kinetics were observed. In particular, a “soft landing” strategy, achieved by an increased θROM at the hip and knee joints and a decreased vertical and ankle stiffness, was initiated from the mid-stage of a fatiguing run to potentially maintain similar impact forces.

scholarly journals Validation of the wearable sensor system - MoveSole® smart insoles

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Antti Alamäki ◽  
Elina Nevala ◽  
Juha Jalovaara ◽  
John Barton ◽  
Salvatore Tedesco ◽  
...  
Keyword(s):  
Measurement System ◽  
Ground Reaction Force ◽  
Gait Speed ◽  
Pearson Correlation ◽  
Reaction Force ◽  
Reference Method ◽  
Biomechanical Analysis ◽  
Heel Strike ◽  
Ground Reaction Forces ◽  
Reaction Forces

Biomechanical analysis of gait is commonly used in physiotherapy. Ground reaction forces during phases of gait is one element of kinetic analysis. In this article, we analyze if the MoveSole® smart insole is valid and accurate equipment for measuring ground reaction forces in clinical physiotherapy. MoveSole® StepLab is a mobile measurement system for instant underfoot force measurements during gait. Unique electromagnetic film (EMFI) based sensor technology and printed electronics production technology is integrated in the MoveSole® StepLab measurement system. The MoveSole® StepLab measures plantar ground reaction force distribution over the sensors and provides an estimation of the maximum total ground reaction force. We developed a two phase validation process to extract relevant parameters and compared the results to a Kistler force plate using the BioWare® analyzing program as a reference method. Our results show that MoveSole® smart insoles reach the strong level of accuracy needed in clinical work concerning highest ground reaction forces during step (Pearson correlation .822 - .875). The correlation of the time when the maximum ground reaction force occurred was moderate, e.g. during heel strike or toe-off (Pearson correlation natural gait speed .351 - .462, maximum gait speed .430). Our conclusion is that MoveSole® smart insoles are a potential tool for analyzing and monitoring gait ground reaction forces during physiotherapy processes.

Ground Reaction Force Reduction of Biped Robot for Walking Along a Step with Dual Length Linear Inverted Pendulum Method

2013 ◽  
Vol 25 (1) ◽  
pp. 220-231 ◽  
Author(s):  
Fariz Ali ◽  
◽  
Naoki Motoi ◽  
Kirill Van Heerden ◽  
Atsuo Kawamura
Keyword(s):  
Inverted Pendulum ◽  
Reaction Force ◽  
Biped Robot ◽  
Ground Reaction Forces ◽  
Bipedal Robot ◽  
Impact Forces ◽  
Reaction Forces ◽  
Left And Right ◽  
Newton Raphson ◽  
Force Reduction

A bipedal robot should be robust and able to move in various directions on stairs. However, up to date many research studies have been focusing on walking in the up or down direction only. Therefore, a strategy to realize walking along a step is investigated. In conventional methods, CoM is moved up or down during walking in this situation. In this paper, a method named as Dual Length Linear Inverted Pendulum Method (DLLIPM) with Newton-Raphson is proposed for 3-D biped robot walking. The proposed method applies different length of pendulum at left and right legs in order to represent the CoM height. By using the proposed method, maximum impact forces are reduced. From the Ground Reaction Forces (GRF) data obtained in the simulations, the validity of the proposed method is confirmed.

Foot Forces Induced Through Tai Chi Push-Hand Exercises

2013 ◽  
Vol 29 (4) ◽  
pp. 395-404 ◽  
Author(s):  
Shiu Hong Wong ◽  
Tianjian Ji ◽  
Youlian Hong ◽  
Siu Lun Fok ◽  
Lin Wang
Keyword(s):  
Body Weight ◽  
Tai Chi ◽  
Balance Training ◽  
The Body ◽  
Ground Reaction Forces ◽  
Impact Forces ◽  
Average Maximum ◽  
Reaction Forces ◽  
Plantar Force ◽  
Hand Exercises

The low impact forces of Tai Chi push-hand exercises may be particularly suited for older people and for those with arthritis; however, the biomechanics of push-hand exercises have not previously been reported. This paper examines the ground reaction forces (GRFs) and plantar force distributions during Tai Chi push-hand exercises in a stationary stance with and without an opponent. Ten male Tai Chi practitioners participated in the study. The GRFs of each foot were measured in three perpendicular directions using two force plates (Kistler). The plantar force distribution of each foot was measured concurrently using an insole sensor system (Novel). The results showed that the average maximum vertical GRF of each foot was not more than 88% ± 6.1% of the body weight and the sum of the vertical forces (103% ± 1.4%) generated by the two feet approximately equals the body weight at any one time. The horizontal GRFs generated by the two feet were in the opposite directions and the measured mean peak values were not more than 12% ± 2.8% and 17% ± 4.3% of the body weight in the medio-lateral and antero-posterior directions respectively. Among the nine plantar areas, the toes sustained the greatest plantar force. This study indicates that push-hand exercises generate lower vertical forces than those induced by walking, bouncing, jumping and Tai Chi gait, and that the greatest plantar force is located in the toe area, which may have an important application in balance training particularly for older adults.

Spade design, lumbar motions, risk of low-back injury and digging posture

1998 ◽  
Vol 1 (3) ◽  
pp. 157-172
Author(s):  
Robert S. Bridger ◽  
Patrick Sparto ◽  
William S. Marras
Keyword(s):  
Risk Group ◽  
High Risk Group ◽  
Point Of View ◽  
Back Injury ◽  
Ground Reaction Forces ◽  
Low Back ◽  
Low Back Injury ◽  
Fundamental Point ◽  
Reaction Forces ◽  
Reported Data

A laboratory investigation of the ergonomics of digging is reported. Data on lumbar motions, ground reaction forces and posture were obtained simultaneously as subjects transferred sand from one container to another while standing on a force platform. Digging with a conventional spade was found to carry a substantial probability of inclusion in a high-risk group for low back injury. A prototype two-handled spade reduced the probability by approximately 8%. used but this was partly offset by an increase in twisting. From a fundamental point of view, the prototype merits further evaluation. Digging is a hazardous task when conventional spades are used and that ergonomic redesign can reduce the risk of back injury.

scholarly journals Biomechanical Analysis of Ankle during the Stance Phase of Gait on Various Surfaces: A Literature Review

2016 ◽  
Vol 17 (3) ◽  
Author(s):  
Athanasios Psarras ◽  
Dimitra Mertyri ◽  
Panagiotis Tsaklis
Keyword(s):  
Muscle Activation ◽  
Stance Phase ◽  
Gait Cycle ◽  
Biomechanical Analysis ◽  
Ground Reaction Forces ◽  
Advantages And Disadvantages ◽  
Sand Surface ◽  
Reaction Forces ◽  
Downhill Walking ◽  
Uphill Walking

AbstractThe purpose of this article is to review the literature that deals with the biomechanical analysis of the ankle during gait stance phase on slopes, on uneven and rock surfaces, on sand, and on grass surfaces, as well as to present the observed differences. Methods. The literature was searched in the databases of PubMed and Google Scholar, for the years of 2005–2015. The keywords were: biomechanics, gait analysis, ankle joint, stance phase, uphill walking, downhill walking, sand surface, uneven surface, grass surface, and ballast. Results. The kinetic and kinematic gait behaviour is directly influenced by the surface on which it is being performed. The uphill or downhill surfaces, the surfaces of stone, sand, grass, and uneven surfaces have a direct impact on the biomechanics on joints of the lower limb, changing the energy cost, muscle activation, the resulting mechanical work, ground reaction forces and balance, and the parameters of the gait cycle. All these changes are raising many questions about the safety and comfort of these surfaces. In the structures of the foot, ankle and lower leg high compressive and rotational forces are transmitted resulting in injuries in these regions. Conclusions. Each surface has its own advantages and disadvantages, changing the biomechanics of the lower extremity and particularly the ankle. According to the purpose that one wants to achieve they can choose a suitable surface. To prevent injuries and falls, we must choose shoes that fit well, are comfortable with cushioning, and have a feeling neither too hard nor too soft, with laces and low collar.

Finite Element Analysis for the Estimation of the Ground Reaction Force and Pressure Beneath the Foot Prosthesis during the Gait of Transfemoral Patients

2017 ◽  
Vol 33 ◽  
pp. 1-11 ◽  
Author(s):  
Le Van Tuan ◽  
Kengo Ohnishi ◽  
Hiroshi Otsuka ◽  
Yukio Agarie ◽  
Shinichiro Yamamoto ◽  
...  
Keyword(s):  
Finite Element ◽  
Experimental Method ◽  
Reaction Force ◽  
Biomechanical Analysis ◽  
Ground Reaction Forces ◽  
Similar Data ◽  
Fe Method ◽  
Element Analysis ◽  
Reaction Forces ◽  
Dynamics Method

Ground reaction forces (GRF) and pressure beneath the foot prosthesis are the main parameters used in biomechanical analysis to estimate the joint load and evaluate the quality of the prosthesis, especially with transfemoral patient who have amputation that occurs through the femur. The information of ground reaction forces and beneath pressure of foot prosthesis is conventionally achieved using dynamics method or the experimental method. However, these methods have some limitation for a prosthetist and designers to choose the best prosthesis solution for transfemoral patient. In the dynamics method, the deformation of the foot prosthesis and the variation in the shape of the residual limb in the socket is neglected and the center of gravity of the prosthesis component is estimated; thus, the method is less accurate because the prosthesis consists of several parts with different materials and shapes. The experimental method involves time and cost in setting-up the device. Data can be acquired only after the patient wears the prosthesis. In this study, the authors were implemented a finite element (FE) method for computing the GRF, and the pressure beneath the foot prosthesis and its distribution. The finite element model of all components of transfemoral of the prosthesis was created. The ground reaction forces, beneath pressure of foot prosthesis and other parameters were disclosed after solving by explicit solver of LS-Dyna software. The results of the vertical ground reaction forces exhibit consistently similar data between the simulation and the measurement. A correlation coefficient of 0.91 between them denotes their correspondence. The reaction force at knee joint, distribution of beneath pressure of foot prosthesis were included in results and discussion. These results can be used for prosthesis design and optimization; they can assist the prosthetist in selecting a comfortable prosthesis for the patient and in improving the rehabilitation training.

Preliminary investigation of maximal fetlock extension during jump landing phase on two arena surfaces; two dimensional motion analysis

2006 ◽  
Vol 35 ◽  
pp. 243-246
Author(s):  
G. Openshaw ◽  
A. J. Northrop ◽  
C. Brigden ◽  
J. H. Martin
Keyword(s):  
Preliminary Investigation ◽  
Field Studies ◽  
High Impact ◽  
Ground Reaction Forces ◽  
Surface Type ◽  
Surface Conditions ◽  
Jump Landing ◽  
Impact Forces ◽  
Reaction Forces ◽  
Show Jumping

Surface type has a recognised effect on the biomechanics of a horse, yet suitability of surfaces to discipline has not been fully substantiated. Ideal exercise surface conditions should be a balance of energy absorption to minimise concussion and energy return to aid performance (Barrey et al., 1999) and these conditions vary according to type of work. Greater force on a particular limb will increase the probability of injury, especially in sports that are repetitive in nature, such as show jumping. It is well known that high impact forces occur during the landing phase of jumping (Meershoek et al., 2001); investigation of this phase is therefore integral to understanding the effect that surface has on horses that jump. Maximal fetlock extension may be useful as an indicator of magnitude of ground reaction forces (Clayton, 1997). This means that in-field studies can be used to measure maximal fetlock extension as a guide to forces placed on the limb.

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