Longer Achilles tendon moment arm results in better running economy (original) (raw)
Related papers
Tendon Length and Joint Flexibility Are Related to Running Economy
Medicine & Science in Sports & Exercise, 2011
Purpose: The purpose of study was to determine whether quadriceps/patella and Achilles tendon length and flexibility of the knee extensors and plantar flexors are related to walking and running economy. Methods: Twenty-one male distance runners were subjects. Quadriceps/patella and Achilles tendon length were measured by magnetic resonance imaging; body composition was measured DXA; oxygen uptake at rest while seated, walking (3 mph), and mrming (6 and 7 mph) were measured by indirect calorimetry; knee and ankle joint flexibility were measured by goniometry; and leg lengths were measured by anthropometry while seated. Correlations were used to identify relationships between variables of interest. Results: Net VO2 (exercise VO2-rest VO2) for walking (NVOWK) and running at 6 and 7 mph (NV06 and NV07, respectively) was significantly related to Achilles tendon length {r varying from-0.40 to-0.51, P all < 0.04). Achilles tendon cross section was not related to walking or running economy. Quadriceps/ patella tendon length was significantly related to NV07 (r =-0.43, P = 0.03) and approached significance"for NV06 (r =-0.36, P = 0.06). Flexibility of the plantar flexors was related to NV07 (-K).38, P = 0.05). Multiple regression showed that Achilles tendon length was independently related to NV06 and NV07 (partial r varying fi-om-0.53 to-0.64, all P < 0.02) independent of lower leg length, upper leg length, quadriceps/patella tendon length, knee extension flexibility, or plantarflexion flexibility. Conclusions: These data support the premise that longer lower limb tendons (especially Achilles tendon) and less flexible lower limb joints are associated with improved running economy.
Lower leg muscle–tendon unit characteristics are related to marathon running performance
Scientific Reports, 2020
The human ankle joint and plantar flexor muscle–tendon unit play an important role in endurance running. It has been assumed that muscle and tendon interactions and their biomechanical behaviours depend on their morphological and architectural characteristics. We aimed to study how plantar flexor muscle characteristics influence marathon running performance and to determine whether there is any difference in the role of the soleus and gastrocnemii. The right lower leg of ten male distance runners was scanned with magnetic resonance imagining. The cross-sectional areas of the Achilles tendon, soleus, and lateral and medial gastrocnemius were measured, and the muscle volumes were calculated. Additional ultrasound scanning was used to estimate the fascicle length of each muscle to calculate the physiological cross-sectional area. Correlations were found between marathon running performance and soleus volume (r = 0.55, p = 0.048), soleus cross-sectional area (r = 0.57, p = 0.04), soleus...
Influence of the muscle-tendon unit's mechanical and morphological properties on running economy
Journal of Experimental Biology, 2006
SUMMARYThe purpose of this study was to test the hypothesis that runners having different running economies show differences in the mechanical and morphological properties of their muscle-tendon units (MTU) in the lower extremities. Twenty eight long-distance runners (body mass: 76.8±6.7 kg, height: 182±6 cm, age: 28.1±4.5 years) participated in the study. The subjects ran on a treadmill at three velocities (3.0, 3.5 and 4.0 m s-1) for 15 min each. The \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\dot{V}}_{\mathrm{O}_{2}}\) \end{document}consumption was measured by spirometry. At all three examined velocities the kinematics of the left leg were captured whilst running on the treadmill using a high-speed digital video camera operating at 250 Hz. Furthermore the runners performed isometric maximal voluntary plantarflexion and knee extension contractions at eleven differen...
Muscle Fiber Type, Achilles Tendon Length, Potentiation, and Running Economy
Journal of strength and conditioning research / National Strength & Conditioning Association, 2015
The purpose of this investigation is to develop a potential model for how muscle fiber type, Achilles tendon length, stretch shortening cycle potentiation (SSCP), and leg strength interact with running economy. Twenty trained male distance runners 24-40 years of age served as subjects. Running economy (net oxygen uptake) was measured while running on a treadmill. Leg press SSCP and SSCP were determined by measuring the difference in velocity between a static leg press throw and a counter-movement leg press throw. Vertical jump SSCP was determined by measuring the difference in jump height between a static jump and a drop jump from a 20.3 cm bench. Tendon length was measured by magnetic resonance imaging, and muscle fiber type was made from a vastus lateralis muscle biopsy. Type IIx muscle fiber percent (r = 0.70, p < 0.001) and leg strength (r = 0.95, p…
Revista Brasileira de Medicina do Esporte, 2020
Introduction: This study aimed to measure thickness and cross-sectional area of the Achilles tendon (AT), and the range of motion of the ankle joint in dorsiflexion of amateur marathon runners compared to non-active people. Objectives: To analyze the relationship between cross-sectional area and thickness of the Achilles tendon in marathon runners and age, anthropometric characteristics (height and body mass), training habits, running experience, marathon performance, and range of motion in the ankle joint. Methods: Achilles tendon thickness and cross-sectional area were measured using ultrasound images of the left leg in 97 male amateur marathon runners (age 42.0 ± 9.6 years; height 175 ± 6 cm; and body mass 73.7 ± 8.6 kg), and 47 controls (39.9 ± 11.6 years; 176 ± 7 cm; 79.6 ± 16.1 kg). Results: Achilles tendon thickness (4.81 ± 0.77 vs. 4.60 ± 0.66 mm; p = 0.01) and cross-sectional area (60.41 ± 14.36 vs. 53.62 ± 9.90 mm2; p < 0.01) were greater in the marathon runners than in...
2015
Whether the cross-sectional area (CSA) and mechanical properties of the human Achilles tendon change in response to habitual exercise remains largely unexplored. The present study evaluated the CSA and contraction-induced displacement of the aponeurosis-tendon complex of the triceps surae in 11 untrained subjects before (tests 1 and 2) and after (test 3) ϳ9 mo of regular running (ϳ78 training sessions). Displacement of the tendon-aponeurosis complex obtained by ultrasonography; electromyography of the gastrocnemius, soleus, and dorsiflexor muscles; and joint angular rotation were recorded during graded isometric plantarflexion ramps. Tendon CSA and moment arm were measured by using MRI, and tendon force was calculated from joint moments and tendon moment arm. A treadmill test was used to determine submaximal oxygen consumption (V O2) at a given speed and maximal V O2. The total running duration was ϳ43 h, distributed over 34 wk. Maximal V O2 increased 8.6% (P Ͻ 0.01), and submaximal V O2 decreased 6.2% (P Ͻ 0.05). Tendon-aponeurosis displacement during maximal voluntary contraction was unchanged (tests 1-3, 5.2 Ϯ 0.6, 5.2 Ϯ 0.5, and 5.3 Ϯ 0.4 mm, respectively) and yielded a structural stiffness of 365 Ϯ 50, 358 Ϯ 40, and 384 Ϯ 52 N/mm for tests 1-3, respectively (P Ͼ 0.05). Tendon CSA also remained unchanged (tests 1-3, 34.2 Ϯ 2.2, 33.9 Ϯ 2.2, and 33.8 Ϯ 2.1 mm 2 , respectively). In conclusion, a total training stimulus of ϳ9 mo of running in previously untrained subjects was adequate to induce significant cardiovascular improvements, although it did not result in any changes in the mechanical properties of the triceps surea tendon-aponeurosis complex or in the dimensions of Achilles tendon.
European Journal of Applied Physiology, 2014
shortening amplitudes (p < 0.01) of the tendinous tissue of medial gastrocnemius (MG), but greater tendon contribution to the muscle-tendon unit shortening (p < 0.05). The MG fascicles of the Kenyans were shorter not only at the resting standing position, but also during the contact phase at both running speeds (p < 0.01). The EMG profiles of the Kenyans showed lower braking/preactivation ratio in both MG and tibialis anterior (p < 0.05) muscles. They were also characterized by negative relationships between the Achilles tendon moment arm and the MG fascicle shortening during contact (r = −0.54, p < 0.01). In contrast, the Japanese presented the classical stretch-shortening cycle muscle activation profile of relatively high MG EMG activity during the braking phase. Conclusion These findings provide new suggestions that the Kenyans have unique structural characteristics which can result in the reduction of muscle and tendinous stretchshortening loading together with smaller muscle activation during contact at submaximal running speed.
Running a Marathon—Its Influence on Achilles Tendon Structure
Journal of Athletic Training, 2020
Context: Several studies have been conducted to better understand the effect of load on the Achilles tendon structure. However, the effect of a high cumulative load consisting of repetitive cyclic movements, such as those that occur during the running of a marathon, on Achilles tendon structure is not yet clear. Clinicians, coaches, and athletes will benefit from knowledge about the effects of a marathon on the structure of the Achilles tendon. Objective: To investigate the short-term response of the Achilles tendon structure to running a marathon. Design: Case series (prospective). Setting: Sports medicine centers. Patients or Other Participants: Ten male nonelite runners who ran in a marathon. Main Outcomes Measure(s): Tendon structure was assessed before and 2 and 7 days after a marathon using ultrasound tissue characterization (UTC), an imaging tool that quantifies tendon organization in 4 echo types (I-IV). Echo type I represents the most stable echo pattern, and echo type IV, the least stable. Results: At 7 days postmarathon, both the insertional and midportion structure changed significantly. At both sites, the percentage of echo type II increased (insertion P , .01; midportion P ¼ .02) and the percentages of echo types III and IV decreased (type III: insertion P ¼ .01; midportion P ¼ .02; type IV: insertion P ¼ .01; midportion P , .01). Additionally, at the insertion, the percentage of echo type I decreased (P , .01). Conclusions: We observed the effects of running a marathon on the Achilles tendon structure 7 days after the event. Running the marathon combined with the activity performed shortly thereafter might have caused the changes in tendon structure. This result emphasizes the importance of sufficient recovery time after running a marathon to prevent overuse injuries.
Factors related to intra-tendinous morphology of Achilles tendon in runners
PLOS ONE, 2019
The purpose of this study was to determine and explore factors (age, sex, anthropometry, running and injury/pain history, tendon gross morphology, neovascularization, ankle range of motion, and ankle plantarflexor muscle endurance) related to intra-tendinous morphological alterations of the Achilles tendon in runners. An intra-tendinous morphological change was defined as collagen fiber disorganization detected by a low peak spatial frequency radius (PSFR) obtained from spatial frequency analysis (SFA) techniques in sonography. Ninety-one runners (53 males and 38 females; 37.9 ± 11.6 years) with 8.8 ± 7.3 years of running experience participated. Height, weight, and waist and hip circumferences were recorded. Participants completed a survey about running and injury/pain history and the Victorian Institute of Sport Assessment-Achilles (VISA-A) survey. Heel raise endurance and knee-to-wall composite dorsiflexion were assessed. Brightness-mode (B-mode) sonographic images were captured longitudinally and transversely on the Achilles tendon bilaterally. Sonographic images were analyzed for gross morphology (i.e., cross-sectional area [CSA]), neovascularization, and intra-tendinous morphology (i.e., PSFR) for each participant. The factors associated with altered intra-tendinous morphology of the Achilles tendon were analyzed using a generalized linear mixed model. Multivariate analyses revealed that male sex was significantly associated with a decreased PSFR. Additionally, male sex and the presence of current Achilles tendon pain were found to be significantly related to decreased PSFR using a univariate analysis. Our findings suggested that male sex and presence of current Achilles tendon pain were related to intra-tendinous morphological alterations in the Achilles tendon of runners.