Triceps Surae Muscle-Tendon Properties as Determinants of the Metabolic Cost in Trained Long-Distance Runners

Purpose: This study aimed to determine whether triceps surae’s muscle architecture and Achilles tendon parameters are related to running metabolic cost (C) in trained long-distance runners.Methods: Seventeen trained male recreational long-distance runners (mean age = 34 years) participated in this study. C was measured during submaximal steady-state running (5 min) at 12 and 16 km h–1 on a treadmill. Ultrasound was used to determine the gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and soleus (SO) muscle architecture, including fascicle length (FL) and pennation angle (PA), and the Achilles tendon cross-sectional area (CSA), resting length and elongation as a function of plantar flexion torque during maximal voluntary plantar flexion. Achilles tendon mechanical (force, elongation, and stiffness) and material (stress, strain, and Young’s modulus) properties were determined. Stepwise multiple linear regressions were used to determine the relationship between independent variables (tendon resting length, CSA, force, elongation, stiffness, stress, strain, Young’s modulus, and FL and PA of triceps surae muscles) and C (J kg–1m–1) at 12 and 16 km h–1.Results: SO PA and Achilles tendon CSA were negatively associated with C (r2 = 0.69; p < 0.001) at 12 km h–1, whereas SO PA was negatively and Achilles tendon stress was positively associated with C (r2 = 0.63; p = 0.001) at 16 km h–1, respectively. Our results presented a small power, and the multiple linear regression’s cause-effect relation was limited due to the low sample size.Conclusion: For a given muscle length, greater SO PA, probably related to short muscle fibers and to a large physiological cross-sectional area, may be beneficial to C. Larger Achilles tendon CSA may determine a better force distribution per tendon area, thereby reducing tendon stress and C at submaximal speeds (12 and 16 km h–1). Furthermore, Achilles tendon morphological and mechanical properties (CSA, stress, and Young’s modulus) and triceps surae muscle architecture (GM PA, GM FL, SO PA, and SO FL) presented large correlations with C.

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Reduction in tendon elasticity from unloading is unrelated to its hypertrophy

Journal of Applied Physiology ◽

10.1152/japplphysiol.00384.2010 ◽

2010 ◽

Vol 109 (3) ◽

pp. 870-877 ◽

Cited By ~ 20

Author(s):

Ryuta Kinugasa ◽

John A. Hodgson ◽

V. Reggie Edgerton ◽

David D. Shin ◽

Shantanu Sinha

Keyword(s):

Achilles Tendon ◽

Young’S Modulus ◽

Young's Modulus ◽

Plantar Flexion ◽

Three Dimensional ◽

Strain Curve ◽

Medial Gastrocnemius ◽

Morphological Properties ◽

Cross Sectional ◽

Tendon Stiffness

Tendinous tissues respond to chronic unloading with adaptive changes in mechanical, elastic, and morphological properties. However, little is known about the changes in the detailed structures of the entire tendinous tissue and whether the change in tendon stiffness is related to morphology. We investigated changes in dimensional (volume, cross-sectional area, segmented lengths) and elastic (Young's modulus) properties of the Achilles tendon and distal aponeurosis in response to chronic unilateral lower limb suspension (ULLS) using velocity encoded phase contrast (VE-PC) and three-dimensional morphometric magnetic resonance imaging (MRI). Five healthy subjects underwent ULLS for 4 wk. Axial morphometric MRI was acquired along the entire length from the calcaneous to the medial gastrocnemius insertion. An oblique sagittal VE-PC MRI was also acquired. The Young's modulus could be calculated from this cine dynamic sequence of velocity encoded images from the slope of the stress-strain curve during the submaximal isometric plantar flexion. After 4 wk of ULLS, we found significant (46.7%) decrease in maximum plantar flexion torque. The total volumes of entire tendinous tissue (determined as the sum of the Achilles tendon and distal aponeurosis) increased significantly by 6.4% (11.9 vs. 12.7 ml) after ULLS. In contrast, Young's modulus decreased significantly by 10.4% (211.7 vs. 189.6 MPa) for the Achilles tendon and 29.0% for the distal aponeurosis (158.8 vs. 113.0 MPa) following ULLS. There was no significant correlation between relative change in volume and Young's modulus with 4 wk of ULLS. It is suggested that, although tendon hypertrophy can be expected to adversely affect tendon stiffness, the absence of any significant correlation between the magnitude of tendon hypertrophy and reduced Young's modulus indicates that dimensional factors were not critical to the elastic properties.

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Triceps surae muscle-tendon properties in older endurance- and sprint-trained athletes

Journal of Applied Physiology ◽

10.1152/japplphysiol.00511.2015 ◽

2016 ◽

Vol 120 (1) ◽

pp. 63-69 ◽

Cited By ~ 23

Author(s):

Lauri Stenroth ◽

Neil J. Cronin ◽

Jussi Peltonen ◽

Marko T. Korhonen ◽

Sarianna Sipilä ◽

...

Keyword(s):

Achilles Tendon ◽

Young’S Modulus ◽

Young's Modulus ◽

Muscle Architecture ◽

Triceps Surae ◽

Training Experience ◽

Tendon Stiffness ◽

Triceps Surae Muscle ◽

Age Related ◽

Tendon Properties

Previous studies have shown that aging is associated with alterations in muscle architecture and tendon properties (Morse CI, Thom JM, Birch KM, Narici MV. Acta Physiol Scand 183: 291–298, 2005; Narici MV, Maganaris CN, Reeves ND, Capodaglio P. J Appl Physiol 95: 2229–2234, 2003; Stenroth L, Peltonen J, Cronin NJ, Sipila S, Finni T. J Appl Physiol 113: 1537–1544, 2012). However, the possible influence of different types of regular exercise loading on muscle architecture and tendon properties in older adults is poorly understood. To address this, triceps surae muscle-tendon properties were examined in older male endurance (OE, n = 10, age = 74.0 ± 2.8 yr) and sprint runners (OS, n = 10, age = 74.4 ± 2.8 yr), with an average of 42 yr of regular training experience, and compared with age-matched [older control (OC), n = 33, age = 74.8 ± 3.6 yr] and young untrained controls (YC, n = 18, age = 23.7 ± 2.0 yr). Compared with YC, Achilles tendon cross-sectional area (CSA) was 22% ( P = 0.022), 45% ( P = 0.001), and 71% ( P < 0.001) larger in OC, OE, and OS, respectively. Among older groups, OS had significantly larger tendon CSA compared with OC ( P = 0.033). No significant between-group differences were observed in Achilles tendon stiffness. In older groups, Young's modulus was 31-44%, and maximal tendon stress 44–55% lower, than in YC ( P ≤ 0.001). OE showed shorter soleus fascicle length than both OC ( P < 0.05) and YC ( P < 0.05). These data suggest that long-term running does not counteract the previously reported age-related increase in tendon CSA, but, instead, may have an additive effect. The greatest Achilles tendon CSA was observed in OS followed by OE and OC, suggesting that adaptation to running exercise is loading intensity dependent. Achilles tendon stiffness was maintained in older groups, even though all older groups displayed larger tendon CSA and lower tendon Young's modulus. Shorter soleus muscle fascicles in OE runners may be an adaptation to life-long endurance running.

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Age-related differences in Achilles tendon properties and triceps surae muscle architecture in vivo

Journal of Applied Physiology ◽

10.1152/japplphysiol.00782.2012 ◽

2012 ◽

Vol 113 (10) ◽

pp. 1537-1544 ◽

Cited By ~ 136

Author(s):

Lauri Stenroth ◽

Jussi Peltonen ◽

Neil J. Cronin ◽

Sarianna Sipilä ◽

Taija Finni

Keyword(s):

Achilles Tendon ◽

Young’S Modulus ◽

Young's Modulus ◽

Cross Sectional Area ◽

Triceps Surae ◽

Sectional Area ◽

Cross Sectional ◽

Tendon Stiffness ◽

Triceps Surae Muscle ◽

Age Related

This study examined the concurrent age-related differences in muscle and tendon structure and properties. Achilles tendon morphology and mechanical properties and triceps surae muscle architecture were measured from 100 subjects [33 young (24 ± 2 yr) and 67 old (75 ± 3 yr)]. Motion analysis-assisted ultrasonography was used to determine tendon stiffness, Young's modulus, and hysteresis during isometric ramp contractions. Ultrasonography was used to measure muscle architectural features and size and tendon cross-sectional area. Older participants had 17% lower ( P < 0.01) Achilles tendon stiffness and 32% lower ( P < 0.001) Young's modulus than young participants. Tendon cross-sectional area was also 16% larger ( P < 0.001) in older participants. Triceps surae muscle size was smaller ( P < 0.05) and gastrocnemius medialis muscle fascicle length shorter ( P < 0.05) in old compared with young. Maximal plantarflexion force was associated with tendon stiffness and Young's modulus ( r = 0.580, P < 0.001 and r = 0.561, P < 0.001, respectively). Comparison between old and young subjects with similar strengths did not reveal a difference in tendon stiffness. The results suggest that regardless of age, Achilles tendon mechanical properties adapt to match the level of muscle performance. Old people may compensate for lower tendon material properties by increasing tendon cross-sectional area. Lower tendon stiffness in older subjects might be beneficial for movement economy in low-intensity locomotion and thus optimized for their daily activities.

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Biomechanics and Exercise

Pediatric Exercise Science ◽

10.1123/pes.2015-0033 ◽

2015 ◽

Vol 27 (1) ◽

pp. 34-38

Author(s):

Thomas D. O’Brien

Keyword(s):

Achilles Tendon ◽

Young’S Modulus ◽

Young's Modulus ◽

Plantar Flexion ◽

Tendon Injury ◽

Time Curve ◽

Tendon Stiffness ◽

Prepubertal Children ◽

Experimental Group ◽

Tendon Properties

Children develop lower levels of muscle force, and at slower rates, than adults. While strength training in children is expected to reduce this differential, a synchronous adaptation in the tendon must be achieved to ensure forces continue to be transmitted to the skeleton with efficiency while minimizing the risk of strainrelated tendon injury. We hypothesized that resistance training (RT) would alter tendon mechanical properties in children concomitantly with changes in force production characteristics. Twenty prepubertal children (8.9 ± 0.3 years) were equally divided into control (nontraining) and experimental (training) groups. The training group completed a 10-week RT intervention consisting of 2-3 sets of 8-15 plantar flexion contractions performed twice weekly on a recumbent calf raise machine. Achilles tendon properties (cross-sectional area, elongation, stress, strain, stiffness and Young’s modulus), electromechanical delay (EMD; time between the onset of muscle activity and force), rate of force development (RFD; slope of the force-time curve) and rate of EMG increase (REI; slope of the EMG-time curve) were measured before and after RT. Tendon stiffness and Young’s modulus increased significantly after RT in the experimental group only (~29% and ~25%, respectively); all other tendon properties were not significantly altered, although there were mean decreases in both peak tendon strain and strain at a given force level (14% and 24%, respectively, n.s) which may have implications for tendon injury risk and muscle fiber mechanics. A ~13% decrease in EMD was found after RT for the experimental group which paralleled the increase in tendon stiffness (r = −0.59), however RFD and REI were unchanged. The present data show that the Achilles tendon adapts to RT in prepubertal children and is paralleled by a change in EMD, although the magnitude of this change did not appear to be sufficient to influence RFD. These findings are of potential importance within the context of the efficiency and execution of movement.

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Tendinopathy alters mechanical and material properties of the Achilles tendon

Journal of Applied Physiology ◽

10.1152/japplphysiol.00259.2009 ◽

2010 ◽

Vol 108 (3) ◽

pp. 670-675 ◽

Cited By ~ 185

Author(s):

Shruti Arya ◽

Kornelia Kulig

Keyword(s):

Achilles Tendon ◽

Young’S Modulus ◽

Material Properties ◽

Young's Modulus ◽

Treatment Strategies ◽

Achilles Tendinopathy ◽

Cross Sectional ◽

Tendon Stiffness ◽

And Gender

The purpose of this study was to investigate the in vivo material and mechanical properties of the human Achilles tendon in the presence of tendinopathy. Real-time ultrasound imaging and dynamometry were used to assess Achilles tendon stiffness, Young's modulus, stress, strain, and cross-sectional area (CSA) in 12 individuals with Achilles tendinopathy and 12 age- and gender-matched controls. The results of this study suggest that tendinopathy weakens the mechanical and material properties of the tendon. Tendinopathic tendons had greater CSA, lower tendon stiffness, and lower Young's modulus. These alterations in mechanical characteristics may put the Achilles tendon at a higher risk to sustain further injury and prolong the time to recovery. Results from this study may be used to design treatment strategies that specifically target these deficits, leading to faster and permanent recovery from tendinopathy.

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Ultrasonic evaluations of Achilles tendon mechanical properties poststroke

Journal of Applied Physiology ◽

10.1152/japplphysiol.91212.2008 ◽

2009 ◽

Vol 106 (3) ◽

pp. 843-849 ◽

Cited By ~ 70

Author(s):

Heng Zhao ◽

Yupeng Ren ◽

Yi-Ning Wu ◽

Shu Q. Liu ◽

Li-Qun Zhang

Keyword(s):

Achilles Tendon ◽

Young’S Modulus ◽

Young's Modulus ◽

Biomechanical Properties ◽

Block Matching ◽

Cross Sectional ◽

Mechanical Hysteresis ◽

Biomechanical Changes ◽

Hemiparetic Stroke

Spasticity, contracture, and muscle weakness are commonly observed poststroke in muscles crossing the ankle. However, it is not clear how biomechanical properties of the Achilles tendon change poststroke, which may affect functions of the impaired muscles directly. Biomechanical properties of the Achilles tendon, including the length and cross-sectional area, in the impaired and unimpaired sides of 10 hemiparetic stroke survivors were evaluated using ultrasonography. Elongation of the Achilles tendon during controlled isometric ramp-and-hold and ramping up then down contractions was determined using a block-matching method. Biomechanical changes in stiffness, Young's modulus, and hysteresis of the Achilles tendon poststroke were investigated by comparing the impaired and unimpaired sides of the 10 patients. The impaired side showed increased tendon length (6%; P = 0.04), decreased stiffness (43%; P < 0.001), decreased Young's modulus (38%; P = 0.005), and increased mechanical hysteresis (1.9 times higher; P < 0.001) compared with the unimpaired side, suggesting Achilles tendon adaptations to muscle spasticity, contracture, and/or disuse poststroke. In vivo quantitative characterizations of the tendon biomechanical properties may help us better understand changes of the calf muscle-tendon unit as a whole and facilitate development of more effective treatments.

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Structural Achilles tendon properties in athletes subjected to different exercise modes and in Achilles tendon rupture patients

Journal of Applied Physiology ◽

10.1152/japplphysiol.00384.2005 ◽

2005 ◽

Vol 99 (5) ◽

pp. 1965-1971 ◽

Cited By ~ 140

Author(s):

M. Kongsgaard ◽

P. Aagaard ◽

M. Kjaer ◽

S. P. Magnusson

Keyword(s):

Achilles Tendon ◽

Elite Athletes ◽

Plantar Flexion ◽

Achilles Tendon Rupture ◽

Triceps Surae ◽

Control Group ◽

Endurance Running ◽

Cross Sectional ◽

Tendon Adaptation ◽

Flexion Force

The prevalence of Achilles tendon (AT) injury is high in various sports, and AT rupture patients have been reported to have a 200-fold risk of sustaining a contralateral rupture. Tendon adaptation to different exercise modes is not fully understood. The present study investigated the structural properties of the AT in male elite athletes that subject their AT to different exercise modes as well as in Achilles rupture patients. Magnetic resonance imaging of the foot and leg, anthropometric measurements, and maximal isometric plantar flexion force were obtained in 6 male AT rupture patients and 25 male elite athletes (kayak/control group n = 9, volleyball n = 8 and endurance running n = 8). AT cross-sectional area (CSA) was normalized to body mass. Runners had a larger normalized AT CSA along the entire length of the tendon compared with the control group ( P < 0.05). The volleyball subjects had a larger normalized CSA compared with the control group ( P < 0.05) in the area of thinnest tendon CSA. No structural differences of the AT were found in the rupture subjects compared with the control group. Rupture subjects did not subject their AT to greater force or stress during a maximal voluntary isometric plantar flexion than the other groups. The CSA of the triceps surae musculature was the strongest predictor of AT CSA ( rs = 0.569, P < 0.001). This study is the first to show larger CSA in tendons that are subjected to intermittent high loads. AT rupture patients did not display differences in structural or loading properties of the tendons.

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Lower leg muscle structure and function are altered in long-distance runners with medial tibial stress syndrome: a case control study

Journal of Foot and Ankle Research ◽

10.1186/s13047-021-00485-5 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Joshua Mattock ◽

Julie R. Steele ◽

Karen J. Mickle

Keyword(s):

Lower Leg ◽

Structure And Function ◽

Flexor Hallucis Longus ◽

Plantar Flexor ◽

Distance Runners ◽

Long Distance ◽

Cross Sectional ◽

Muscle Structure ◽

Leg Muscle ◽

And Function

Abstract Background Medial tibial stress syndrome (MTSS) is a common lower leg injury experienced by runners. Although numerous risk factors are reported in the literature, many are non-modifiable and management of the injury remains difficult. Lower leg muscle structure and function are modifiable characteristics that influence tibial loading during foot-ground contact. Therefore, this study aimed to determine whether long-distance runners with MTSS displayed differences in in vivo lower leg muscle structure and function than matched asymptomatic runners. Methods Lower leg structure was assessed using ultrasound and a measure of lower leg circumference to quantify muscle cross-sectional area, thickness and lean lower leg girth. Lower leg function was assessed using a hand-held dynamometer to quantify maximal voluntary isometric contraction strength and a single leg heel raise protocol was used to measure ankle plantar flexor endurance. Outcome variables were compared between the limbs of long-distance runners suffering MTSS (n = 20) and matched asymptomatic controls (n = 20). Means, standard deviations, 95 % confidence intervals, mean differences and Cohen’s d values were calculated for each variable for the MTSS symptomatic and control limbs. Results MTSS symptomatic limbs displayed a significantly smaller flexor hallucis longus cross-sectional area, a smaller soleus thickness but a larger lateral gastrocnemius thickness than the control limbs. However, there was no statistical difference in lean lower leg girth. Compared to the matched control limbs, MTSS symptomatic limbs displayed deficits in maximal voluntary isometric contraction strength of the flexor hallucis longus, soleus, tibialis anterior and peroneal muscles, and reduced ankle plantar flexor endurance capacity. Conclusions Differences in lower leg muscle structure and function likely render MTSS symptomatic individuals less able to withstand the negative tibial bending moment generated during midstance, potentially contributing to the development of MTSS. The clinical implications of these findings suggest that rehabilitation protocols for MTSS symptomatic individuals should aim to improve strength of the flexor hallucis longus, soleus, tibialis anterior and peroneal muscles along with ankle plantar flexor endurance. However, the cross-sectional study design prevents us determining whether between group differences were a cause or effect of MTSS. Therefore, future prospective studies are required to substantiate the study findings.

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Supplement intake in half-marathon, (ultra-)marathon and 10-km runners – results from the NURMI study (Step 2)

Journal of the International Society of Sports Nutrition ◽

10.1186/s12970-021-00460-2 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Wirnitzer Katharina ◽

Motevalli Mohamad ◽

Tanous Derrick ◽

Gregori Martina ◽

Wirnitzer Gerold ◽

...

Keyword(s):

Personal Characteristics ◽

Sport Nutrition ◽

Intake Rate ◽

Vitamin Supplements ◽

Distance Runners ◽

Long Distance ◽

Cross Sectional ◽

Protein Supplements ◽

Cross Sectional Design ◽

Supplement Intake

AbstractThe primary nutritional challenge facing endurance runners is meeting the nutrient requirements necessary to optimize the performance and recovery of prolonged training sessions. Supplement intake is a commonly used strategy by elite and recreational distance runners to meet nutritional recommendations. This study was conducted to investigate the patterns of supplement intake among different groups of distance runners and the potential association between supplement intake and sex, age, running and racing experiences.In a cross-sectional design, from a total of 317 runners participating in this survey, 119 distance runners were involved in the final sample after data clearance, assigned into three groups of 10-km runners (n = 24), half-marathoners (n = 44), and (ultra-)marathoners (n = 51). Personal characteristics, training and racing experiences, as well as patterns of supplement intake, including type, frequency, and dosage, were evaluated by questionnaire. Food Frequency Questionnaire was implemented to assess macronutrient intake. ANOVA and logistic regression were used for statistical analysis.While 50 % of total distance runners reported consuming supplements regularly, no differences between distance groups in consumption of carbohydrate/protein, mineral, or vitamin supplements were observed (p > 0.05). In addition, age, sex, running and racing experience showed no significant association with supplement intake (p > 0.05). Vitamin supplements had the highest intake rate in runners by 43 % compared to minerals (34 %) and carbohydrate/protein supplements (19 %).The present findings provide a window into the targeted approaches of long-distance runners as well as their coaches and sport nutrition specialists when applying and suggesting sustainable nutritional strategies for training and competition.Trial registration: ISRCTN73074080. Retrospectively registered 12th June 2015.

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Effects of cross-sessional area and aspect ratio coupled with orientation on mechanical properties and deformation behavior of Cu nanowires

Nanotechnology ◽

10.1088/1361-6528/ac3e32 ◽

2021 ◽

Author(s):

Hui Cao ◽

Wenke Chen ◽

Zhiyuan Rui ◽

Changfeng Yan

Keyword(s):

Mechanical Properties ◽

Aspect Ratio ◽

Yield Stress ◽

Young’S Modulus ◽

Young's Modulus ◽

Cross Sectional Area ◽

Sectional Area ◽

Cross Sectional ◽

Cu Nanowires ◽

The Cross

Abstract Metal nanomaterials exhibit excellent mechanical properties compared with corresponding bulk materials and have potential applications in various areas. Despite a number of studies of the size effect on Cu nanowires mechanical properties with square cross-sectional, investigations of them in rectangular cross-sectional with various sizes at constant volume are rare, and lack of multifactor coupling effect on mechanical properties and quantitative investigation. In this work, the dependence of mechanical properties and deformation mechanisms of Cu nanowires/nanoplates under tension on cross-sessional area, aspect ratio of cross-sectional coupled with orientation were investigated using molecular dynamics simulations and the semi-empirical expressions related to mechanical properties were proposed. The simulation results show that the Young’s modulus and the yield stress sharply increase with the aspect ratio except for the <110>{110}{001} Cu nanowires/nanoplates at the same cross-sectional area. And the Young’s modulus increases while the yield stress decreases with the cross-sectional area of Cu nanowires. However, both of them increase with the cross-sectional area of Cu nanoplates. Besides, the Young’s modulus increases with the cross-sectional area at all the orientations. The yield stress shows a mildly downward trend except for the <111> Cu nanowires with increased cross-sectional area. For the Cu nanowires with a small cross-sectional area, the surface force increases with the aspect ratio. In contrast, it decreases with the aspect ratio increase at a large cross-sectional area. At the cross-sectional area of 13.068 nm2, the surface force decreases with the aspect ratio of the <110> Cu nanowires while it increases at other orientations. The surface force is a linearly decreasing function of the cross-sectional area at different orientations. Quantitative studies show that Young’s modulus and yield stress to the aspect ratio of the Cu nanowires satisfy exponent relationship. In addition, the main deformation mechanism of Cu nanowires is the nucleation and propagation of partial dislocations while it is the twinning-dominated reorientation for Cu nanoplates.

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