scholarly journals Longer Achilles tendon moment arm results in better running economy

2021 ◽  
Vol 107 (4) ◽  
pp. 527-541
Author(s):  
B. Kovács ◽  
I. Kóbor ◽  
Ö. Sebestyén ◽  
J. Tihanyi
Keyword(s):  
Electrical Activity ◽  
Achilles Tendon ◽  
Body Height ◽  
The Body ◽  
Running Economy ◽  
Medial Gastrocnemius ◽  
Moment Arm ◽  
Marathon Runners ◽  
The Right ◽  
Leg Kinematics

AbstractBased on the current literature, the link between Achilles tendon moment arm length and running economy is not well understood. Therefore, the aim of this study was to further investigate the connection between Achilles tendon moment arm and running economy and the influence of Achilles tendon moment arm on the function of the plantarflexor muscle-tendon unit during running.Ten male competitive marathon runners volunteered for this study. The participants ran on a treadmill at two running speeds: 3 and 3.5 m s−1. During running the oxygen consumption, lower leg kinematics, electrical activity of plantar flexor muscles, and fascicle behavior of the lateral gastrocnemius were measured simultaneously. On the second occasion, an MRI scan of the right leg was taken and used to estimate the Achilles tendon moment arm length.There was a negative correlation between running economy and the body height normalized moment arm length at both selected speeds (r = −0.68, P = 0.014 and r = −0.70, P = 0.01). In addition, Achilles tendon moment arm length correlated with the amplitude of the ankle flexion at both speeds (r = −0.59, P = 0.03 and r = −0.60, P = 0.03) and with the electrical activity of the medial gastrocnemius muscle at 3 m s−1 speed (r = −0.62, P = 0.02). Our finding supports the concept that a longer moment arm could be beneficial for distance runners.

The Effects of Orthotic Heel Lifts on Achilles Tendon Force and Strain During Running

2012 ◽  
Vol 28 (5) ◽  
pp. 511-519 ◽  
Author(s):  
Dominic James Farris ◽  
Erica Buckeridge ◽  
Grant Trewartha ◽  
Miranda Polly McGuigan
Keyword(s):  
Achilles Tendon ◽  
Lower Limb ◽  
Inverse Dynamics ◽  
Force Plate ◽  
Medial Gastrocnemius ◽  
Ultrasound Images ◽  
Moment Arm ◽  
Flexion Extension ◽  
Tendon Force ◽  
The Right

This study assessed the effects of orthotic heel lifts on Achilles tendon (AT) force and strain during running. Ten females ran barefoot over a force plate in three conditions: no heel lifts (NHL), with 12 mm heel lifts (12HL) and with 18 mm heel lifts (18HL). Kinematics for the right lower limb were collected (200 Hz). AT force was calculated from inverse dynamics. AT strain was determined from kinematics and ultrasound images of medial gastrocnemius (50 Hz). Peak AT strain was less for 18HL (5.5 ± 4.4%) than for NHL (7.4 ± 4.2%) (p = .029, effect size [ES] = 0.44) but not for 12HL (5.8 ± 4.8%) versus NHL (ES = 0.35). Peak AT force was significantly (p = .024, ES = 0.42) less for 18HL (2382 ± 717 N) than for NHL (2710 ± 830 N) but not for 12HL (2538 ± 823 N, ES = 0.21). The 18HL reduced ankle dorsiflexion but not flexion-extension ankle moments and increased the AT moment arm compared with NHL. Thus, 18HL reduced force and strain on the AT during running via a reduction in dorsiflexion, which lengthened the AT moment arm. Therefore, heel lifts could be used to reduce AT loading and strain during the rehabilitation of AT injuries.

scholarly journals Ground Reaction Forces during Vertical Hops Are Correlated with the Number of Supervised Physiotherapy Visits after Achilles Tendon Surgery

2021 ◽  
Vol 10 (22) ◽  
pp. 5299
Author(s):  
Łukasz Sikorski ◽  
Andrzej Czamara
Keyword(s):  
Achilles Tendon ◽  
Study Groups ◽  
The Body ◽  
Ground Reaction Forces ◽  
Group I ◽  
Tendon Surgery ◽  
Reaction Forces ◽  
Number Of Visits ◽  
Group Ii ◽  
The Right

The objective of this study was to assess the effectiveness of, and the correlation between, an average of 42 supervised physiotherapy (SVPh) visits for the vertical ground reaction forces component (vGRF) using ankle hops during two- and one-legged vertical hops (TLH and OLH, respectively), six months after the surgical suturing of the Achilles tendon using the open method (SSATOM) via Keesler’s technique. Hypothesis: Six months of supervised physiotherapy with a higher number of visits (SPHNVs) was positively correlated with higher vGRF values during TLH and OLH. Group I comprised male patients (n = 23) after SSATOM (SVPh x = 42 visits), and Group II comprised males (n = 23) without Achilles tendon injuries. In the study groups, vGRF was measured during TLH and OLH in the landing phase using two force plates. The vGRF was normalized to the body mass. The limb symmetry index (LSI) of vGRF values was calculated. The ranges of motion of the foot and circumferences of the ankle joint and shin were measured. Then, 10 m unassisted walking, the Thompson test, and pain were assessed. A parametric test for dependent and independent samples, ANOVA and Tukey’s test for between-group comparisons, and linear Pearson’s correlation coefficient calculations were performed. Group I revealed significantly lower vGRF values during TLH and OLH for the operated limb and LSI values compared with the right and left legs in Group II (p ≤ 0.001). A larger number of visits correlates with higher vGRF values for the operated limb during TLH (r = 0.503; p = 0.014) and OLH (r = 0.505; p = 0.014). An average of 42 SVPh visits in 6 months was insufficient to obtain similar values of relative vGRF and their LSI during TLH and OLH, but the hypothesis was confirmed that SPHNVs correlate with higher relative vGRF values during TLH and OLH in the landing phase.

scholarly journals The Relationship of Some Kinematic Variables of the Fixed Foot and Body and the Accuracy of Scoring While Performing Penalty by Futsal Players

2019 ◽  
Vol 16 (2) ◽  
Author(s):  
Nihad Ayub Qadr
Keyword(s):  
Mechanical Axis ◽  
Body Height ◽  
The Body ◽  
Leg Length ◽  
Effective Role ◽  
The Right ◽  
The University ◽  
Relationship Of ◽  
The Relationship ◽  
Academic Year

There is a difference in terms of the views of coaches and specialists regarding the fixed foot and position of the body. No study has been noted on futsal in which the variables of the kinematics of the fixed foot and body were analyzed. These variables have a significant importance in terms of the angle of fixed foot and body and their direction and distance. They are important in order to be accurate in scoring and specifically in the fixed balls. The objective of the study was to identify the relationship of some kinematic variables of the fixed foot and body to the accuracy of scoring when performing penalty by futsal players. The research participants were the team of the University of Koya for the academic year 2016-2017. The researcher chose the sample by deliberate method and reached 13 players. Each player has played for at least four years, and all players use the right foot, while the the average age of sample  is 23.4 years, body mass 67.37 kg, body height 171 cm, and leg length 93.76 cm. The conclusions of the researcher are that the fixed foot as other parts of the body have an effective role during the scoring of a fixed ball in the game of futsal. The direction angle of the fixed foot has an impact on the mechanical axis of the body and is reflected on the accuracy of the scoring in fixed balls in futsal.

scholarly journals Biofotogrametric and electromyographic analysis in different position in women with temporomandibular disorder.

2020 ◽  
pp. 1-7
Author(s):  
Muriel Priebe e Silva ◽  
Jovana de Moura Milanesi ◽  
Fernanda Pasinato ◽  
Helenize Veron ◽  
Ana Gabrieli Ferreira Antunes ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Masticatory Muscles ◽  
The Body ◽  
Sitting Position ◽  
Temporal Muscle ◽  
Horizontal Alignment ◽  
Cervical Muscles ◽  
Upper Trapezius ◽  
Seventh Cervical Vertebra ◽  
The Right

Introduction: The relationship established between TMJ (Temporomandibular Joint), cranium and cervical spine requires the synchrony of these structures for the proper performance of stomatognathic functions and muscle balance in this region. Objective: Evaluate the craniocervical posture and the electrical activity of masticatory and cervical muscles in sitting and standing positions in patients with TMD, correlating these variables. Method: The participants were 21 women, with mean age 28 ± 5.33 years and severe TMD. The participants were evaluated by electromyography of the masseter, anterior temporal and sternocleidomastoid (SCM) and upper trapezius muscles, bilaterally, in standing and sitting position. The body posture was evaluated by biophotogrammetry, with analysis of the Head Horizontal Alignment (HHA) and Acromion Horizontal Alignment (AHA) in frontal view and the Head Vertical Alignment (HVA) and Head Horizontal Alignment related to seventh cervical vertebra (HHAc7) in lateral view. Results: The electrical activity of masticatory muscles during resting did not differ between the different evaluated positions. During maximum intercuspation, the electrical activity was significantly lower in the left masseter (p=0.016), higher in the left anterior temporal muscle (p=0.046) and higher in the right (p=0.005) and left (p=0.015) upper trapezius muscles, in standing position when compared to sitting position. The photogrammetric values found were within the normal range. There was a significant and moderate negative correlation between the left SCM muscle and the right (r=0.386) and left (r=0.428) HHAc7 angle. Conclusions: Muscular electrical activity was modified with the change between sitting and standing positions, with an increase in cervical muscle recruitment and asynchrony of the masticatory muscles. Thus, it can be inferred that there is a postural destabilization with possible head anteriorization during maximum intercuspation, reinforcing the relation of synergy between the masticatory and cervical muscles.

scholarly journals Distribution of feet pressure on ground and maintaining body balance among 8–10-year-old children with and without external load application

2020 ◽  
Vol 22 (4) ◽  
Author(s):  
Jarosław Jaszczur-Nowicki ◽  
Joanna M. Bukowska ◽  
Dariusz Kruczkowski ◽  
Magdalena Pieniążek ◽  
Grzegorz Mańko ◽  
...  
Keyword(s):  
Body Mass ◽  
Research Group ◽  
External Load ◽  
Body Height ◽  
The Body ◽  
Body Balance ◽  
Balance Testing ◽  
Foot Force ◽  
The Right ◽  
The Impact

Purpose: The aim of this study was to analyse the impact of applying an external load on the distribution of pressure on the plantar side of the foot and maintaining body balance, using the podobarographic platform. Methods: The study was conducted on 130 school children aged 8–10: girls (n = 68, body mass = 22.8 ± 6.0 kg, body height = 129.3 ± 7.5 cm) and boys (n = 62, body mass = 31.1 ± 6.5 kg, body height 134.4 ± 7.3 cm). The study involved 2 trials. At first, children stood on the platform assuming a natural position. Then, they put on a 5-kg backpack and stood on the platform once more. Results: The results indicate that after backpack loading, for the total research group of girls and boys, statistically significant differences were found in the distribution of foot force on the ground in the left forefoot (p = 0.008), metatarsus (p = 0.000) and heel areas (p = 0.002). While in the right foot, these differences were noted for the forefoot (p = 0.024) and metatarsus (p = 0.000). The results of balance testing were also statistically significant. They concerned measurements of the body barycentre area (cop-bars p = 0.003), the barycentre area of the left foot (l-bars p = 0.034) and the parameter comparing distance to surface ratio (cop-lsf p = 0.000). Conclusions: It may be concluded that prolonged overloading with backpacks affects movement patterns, which may further lead to the acquisition and consolidation of postural defects.

Does Foot Anthropometry Predict Metabolic Cost During Running?

2017 ◽  
Vol 33 (5) ◽  
pp. 317-322 ◽  
Author(s):  
Herman van Werkhoven ◽  
Stephen J. Piazza
Keyword(s):  
Oxygen Consumption ◽  
Achilles Tendon ◽  
Body Height ◽  
Force Plate ◽  
Metabolic Cost ◽  
Running Economy ◽  
Metabolic Energy ◽  
Flexor Muscle ◽  
Reaction Forces ◽  
Tendon Force

Several recent investigations have linked running economy to heel length, with shorter heels being associated with less metabolic energy consumption. It has been hypothesized that shorter heels require larger plantar flexor muscle forces, thus increasing tendon energy storage and reducing metabolic cost. The goal of this study was to investigate this possible mechanism for metabolic cost reduction. Fifteen male subjects ran at 16 km⋅h−1 on a treadmill and subsequently on a force-plate instrumented runway. Measurements of oxygen consumption, kinematics, and ground reaction forces were collected. Correlational analyses were performed between oxygen consumption and anthropometric and kinetic variables associated with the ankle and foot. Correlations were also computed between kinetic variables (peak joint moment and peak tendon force) and heel length. Estimated peak Achilles tendon force normalized to body weight was found to be strongly correlated with heel length normalized to body height (r = −.751, p = .003). Neither heel length nor any other measured or calculated variable were correlated with oxygen consumption, however. Subjects with shorter heels experienced larger Achilles tendon forces, but these forces were not associated with reduced metabolic cost. No other anthropometric and kinetic variables considered explained the variance in metabolic cost across individuals.

scholarly journals Shorter heels are linked with greater elastic energy storage in the Achilles tendon

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. D. Foster ◽  
B. Block ◽  
F. Capobianco ◽  
J. T. Peabody ◽  
N. A. Puleo ◽  
...  
Keyword(s):  
Energy Storage ◽  
Achilles Tendon ◽  
Elastic Energy ◽  
Mechanical Energy ◽  
Running Economy ◽  
Triceps Surae ◽  
Morphological Data ◽  
Energetic Cost ◽  
Moment Arm ◽  
Moment Arms

AbstractPrevious research suggests that the moment arm of the m. triceps surae tendon (i.e., Achilles tendon), is positively correlated with the energetic cost of running. This relationship is derived from a model which predicts that shorter ankle moment arms place larger loads on the Achilles tendon, which should result in a greater amount of elastic energy storage and return. However, previous research has not empirically tested this assumed relationship. We test this hypothesis using an inverse dynamics approach in human subjects (n = 24) at speeds ranging from walking to sprinting. The spring function of the Achilles tendon was evaluated using specific net work, a metric of mechanical energy production versus absorption at a limb joint. We also combined kinematic and morphological data to directly estimate tendon stress and elastic energy storage. We find that moment arm length significantly determines the spring-like behavior of the Achilles tendon, as well as estimates of mass-specific tendon stress and elastic energy storage at running and sprinting speeds. Our results provide support for the relationship between short Achilles tendon moment arms and increased elastic energy storage, providing an empirical mechanical rationale for previous studies demonstrating a relationship between calcaneal length and running economy. We also demonstrate that speed and kinematics moderate tendon performance, suggesting a complex relationship between lower limb geometry and foot strike pattern.

scholarly journals The Effect of Three Foot Types on the Achilles Tendon Lever Arm

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0020
Author(s):  
Manja Deforth ◽  
Lukas Zwicky ◽  
Tamara Horn Lang ◽  
Beat Hintermann
Keyword(s):  
Achilles Tendon ◽  
The Body ◽  
Triceps Surae ◽  
Horizontal Line ◽  
Neutral Position ◽  
Moment Arm ◽  
Pes Cavus ◽  
Pes Planus ◽  
Lever Arm ◽  
The Moment

Category: Hindfoot Introduction/Purpose: During locomotion, propulsion of the body is created by the force of the triceps surae complex as it is transmitted to the metatarsal heads. The amount and pattern of the resulting propulsion force highly depends on the moment arm of the Achilles tendon. To our knowledge, no data exists on how and to which extent position and morphology of the foot affects the moment arm of the Achilles tendon. The aim of this study was 1) to develop a method to determine the Achilles tendon moment arm, and 2) to calculate the Achilles tendon moment arm with the foot in different degrees of dorsi- and plantarflexion for 3 foot types (normal arched foot, pes planus, and pes cavus). Methods: 99 study participants with a healthy ankle joint (males, 40; females, 59; mean age 49 [range, 14 – 78] years) were included. Participants’ foot type was classified as a normal arched foot (n = 33), as pes planus (n = 33), or as pes cavus (n = 33) based on the calcaneal inclination angle (CI) (Figure 1). Besides the foot type, the foot length (FL), the calcaneal insertion of the Achilles tendon (ATI), the angle (a) between the line (L) connecting ATI with the center of rotation of the ankle (COR) and the horizontal line (L’) were measured on the lateral radiographs. The interrater reliabilities of measuring a on radiographs and on MRIs were compared. The lever arm of the Achilles tendon (L’calculated) was calculated as following (foot and tibia were regarded as two rigid segments; the influences of other muscles were neglected): L’calculated = cos(a - plantarflexion)*L Results: The interrater reliability of a was higher on radiographs (ICC = 0.84, [0.73 – 0.91]) than on MRIs (ICC = 0.61, [0.27 – 0.81]). The ICC comparing a measured on MRIs and radiographs was 0.63 [0.50-0.74]. There was no difference in FL between the three foot types (p = 0.199). However, the average a was significantly different (normal arched foot 31°, pes planus 24°, pes cavus 36°, p = 0.021), resulting in a statistically significant shorter Achilles tendon lever arm for pes cavus than for pes planus (p < 0.0001) and normal arched feet (p = 0.006) in neutral position. The maximum lever arm for the three different foot types was reached at different degrees of plantarflexion (Figure 2). Conclusion: The assessment of the Achilles tendon lever arm using radiographs is reliable. The foot configuration determines the lever arm of the Achilles tendon for a given flexion position of the foot. It also determines the plantarflexion position where the Achilles tendon reaches the maximum of its lever arm. This has to be taken into consideration when planning surgeries that change a or L, as they may also result in changes of plantarflexion power.

scholarly journals Relative length of human kidney as more precise measuring of normal kidney

2010 ◽  
Vol 63 (11-12) ◽  
pp. 784-787 ◽  
Author(s):  
Slobodan Vlajkovic ◽  
Rade Cukuranovic ◽  
Marija Dakovic-Bjelakovic ◽  
Goran Ilic ◽  
Tijana Jaksic ◽  
...  
Keyword(s):  
Kidney Development ◽  
Left Kidney ◽  
Body Height ◽  
Relative Length ◽  
The Body ◽  
Kidney Length ◽  
Significant Difference ◽  
The Absolute ◽  
The Right ◽  
Renal Length

Introduction. Malformations in kidney development and kidney diseases are accompanied with changes in their size. For kidney evaluation in clinical practice, the kidney length is the most widely used measurement, since it provides the most precise results and it is easy to perform. Recently, the measurement of relative renal length has become more preferable as it takes into account the body height. The aim of this study was to measure both the absolute and relative length of normal cadaveric kidneys according to the body height, sex and age. Material and methods. In this study, we examined 95 adult cadaveric kidneys, without renal and vascular impairment, their age ranging from 23-87 years. To determine the period of the most abundant changes in kidney length, we separated them into a 10-year range. The relative renal length was calculated using the kidney length anybody height ratio (kidney/body ratio). Results. The absolute and relative length of left kidney in males was longer than the right one, with a statistically significant correlation. In females, the left kidney length was also longer than the right one, however, without a statistical significance. In contrast to the absolute length, the relative length of both kidneys did not show a significant difference between sexes, and did not manifest a significant decrease with age. There was a significant correlation between the kidney length and the subject?s height. Conclusion. The relative renal length represents kidney size better than the absolute renal length because it eliminates sex and height differences until the age of 59 year. From the seventh decade of life, there is a significant decrease in both the absolute and relative renal length.

The Role of Computer Modeling in Electrocardiography

1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom
Keyword(s):  
Electrical Activity ◽  
Computer Modeling ◽  
Body Surface ◽  
Electrical Current ◽  
The Body ◽  
Volume Conductor ◽  
Current Generator ◽  
Cardiac Electrical Activity ◽  
Source Models

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.

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