Mechanical and morphological properties of different muscle-tendon units in the lower extremity and running mechanics: effect of aging and physical activity (original) (raw)
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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...
The role of muscle strength on tendon adaptability in old age
European Journal of Applied Physiology, 2018
Purpose The purpose of the study was to determine: (1) the relationship between ankle plantarflexor muscle strength and Achilles tendon (AT) biomechanical properties in older female adults, and (2) whether muscle strength asymmetries between the individually dominant and non-dominant legs in the above subject group were accompanied by inter-limb AT size differences. Methods The maximal generated AT force, AT stiffness, AT Young's modulus, and AT cross-sectional area (CSA) along its length were determined for both legs in 30 women (65 ± 7 years) using dynamometry, ultrasonography, and magnetic resonance imaging. Results No between-leg differences in triceps surae muscle strength were identified between dominant (2798 ± 566 N) and non-dominant limb (2667 ± 512 N). The AT CSA increased gradually in the proximo-distal direction, with no differences between the legs. There was a significant correlation (P < 0.05) of maximal AT force with AT stiffness (r = 0.500) and Young's modulus (r = 0.414), but only a tendency with the mean AT CSA. However, region-specific analysis revealed a significant relationship between maximal AT force and the proximal part of the AT, indicating that this region is more likely to display morphological adaptations following an increase in muscle strength in older adults. Conclusions These findings demonstrate that maximal force-generation capabilities play a more important role in the variation of AT stiffness and material properties than in tendon CSA, suggesting that exercise-induced increases in muscle strength in older adults may lead to changes in tendon stiffness foremost due to alterations in material rather than in its size.
Scandinavian Journal of Medicine & Science in Sports, 2007
We examined whether long-term habitual training (a) was associated with differences in structural and mechanical properties in tendon in women and (b) yielded different tendon properties in men and women. Ten male runners, 10 female runners and 10 female non-runners were tested. Tendon cross-sectional area (CSA) and length of the patellar and Achilles tendon were determined with MRI. Ultrasonography-based measurement of tendon elongation and force during isometric contractions provided mechanical properties. Distal patellar and Achilles tendon CSAs were greater than the proximal part in all three groups (Po0.05). Weight-normalized Achilles tendon CSA were similar in trained (2.78 AE 0.17 mm 2 /kg 3/4) and untrained women (2.60 AE 0.13 mm 2 /kg 3/4), while that in trained men (3.77 AE 0.27 mm 2 /kg 3/4) was greater compared with trained women (Po0.01). Patellar tendon CSA were comparable in trained and untrained women, while that in trained men was greater compared with trained women (Po0.01). Patellar tendon stiffness was greater in male runners (3528 AE 773 N/mm) compared with female runners (2069 AE 666 N/mm) and non-runners (2477 AE 381 N/mm), (Po0.01), but patellar tendon deformation, stress, strain and modulus were similar. These data indirectly suggest that the ability of Achilles and patellar tendons to adapt in response to habitual loading such as running is attenuated in women.
Triceps surae muscle-tendon properties in older endurance- and sprint-trained athletes
Journal of applied physiology (Bethesda, Md. : 1985), 2015
Previous studies have shown that aging is associated with alterations in muscle architecture and tendon properties. 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) and sprint runners (OS, n=10, age=74.4±2.8) with an average of 42 years of regular training experience, and compared to age-matched (OC, n=33, age=74.8±3.6) and young untrained controls (YC, n=18, age=23.7±2.0). Compared to 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 to 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 tendo...
Scand J Med Sci Sports, 2007
We examined whether long-term habitual training (a) was associated with differences in structural and mechanical properties in tendon in women and (b) yielded different tendon properties in men and women. Ten male runners, 10 female runners and 10 female non-runners were tested. Tendon cross-sectional area (CSA) and length of the patellar and Achilles tendon were determined with MRI. Ultrasonography-based measurement of tendon elongation and force during isometric contractions provided mechanical properties. Distal patellar and Achilles tendon CSAs were greater than the proximal part in all three groups (Po0.05). Weight-normalized Achilles tendon CSA were similar in trained (2.78 AE 0.17 mm 2 /kg 3/4) and untrained women (2.60 AE 0.13 mm 2 /kg 3/4), while that in trained men (3.77 AE 0.27 mm 2 /kg 3/4) was greater compared with trained women (Po0.01). Patellar tendon CSA were comparable in trained and untrained women, while that in trained men was greater compared with trained women (Po0.01). Patellar tendon stiffness was greater in male runners (3528 AE 773 N/mm) compared with female runners (2069 AE 666 N/mm) and non-runners (2477 AE 381 N/mm), (Po0.01), but patellar tendon deformation, stress, strain and modulus were similar. These data indirectly suggest that the ability of Achilles and patellar tendons to adapt in response to habitual loading such as running is attenuated in women.
Age-related differences in Achilles tendon properties and triceps surae muscle architecture in vivo
Journal of Applied Physiology, 2012
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 ...
Age-related differences in gastrocnemii muscles and Achilles tendon mechanical properties in vivo
Journal of Biomechanics, 2020
Ageing is associated with alterations in the structure and function of the contractile and elastic tissues that enable movement, posture, and balance. Alterations in structure and mechanical properties of the ankle plantarflexors and Achilles tendon are of particular interest due to their important 'catapultlike' function during efficient and healthy human locomotion. In this study, we examined age-related differences in the in vivo mechanical properties of both muscle and tendon in the human ankle plantarflexors in healthy younger (21 ± 3.25 years) and older (69 ± 2.86 years) adults. All participants were physically active, to represent healthy ageing. B-mode ultrasound coupled with force measurements was used to determine in vivo Achilles tendon stiffness and shear-wave elastography was used to measure shear modulus, an index of muscle stiffness, in the medial and lateral gastrocnemii. We found that older adults displayed 43% lower (p=0.004) Achilles tendon stiffness, 59% lower (p<0.001) Achilles tendon Young's modulus, and 34% greater (p=0.002) Achilles tendon cross-sectional area compared to younger participants. We found no difference in the shear modulus of the medial or lateral gastrocnemii between the younger and older individuals. The reduction in Achilles tendon stiffness coupled with similar gastrocnemii muscle shear modulus likely influences the integrated neuromechanical function of the ankle plantarflexor muscle-tendon units during locomotor tasks. Further investigations into the relationship between altered mechanical properties and in vivo muscle-tendon dynamics will provide greater insights into the age-related declines in mobility and locomotor function.
Effect of aging on muscle and tendon properties in highly functioning elderly people
Scandinavian Journal of Medicine & Science in Sports
Funding information Netzwerk Winter This study analyzes long-term changes in muscle strength, muscle architecture, and patellar tendon mechanical properties in a specific sample of physically active elderly people. Twenty-two participants were reexamined from a former 12-week-long skiing intervention study: 11 from the intervention group (IG: 7 ♀, 4 ♂; 67 ± 3 years) and 11 from the control group (CG: 6 ♀, 5 ♂; 66 ± 4 years). Muscle architecture, strength endurance, maximum torque, and tendon properties were analyzed three times within 6 months, and again 6 years later in a follow-up test. No changes in either group could be observed between June 2009 and April 2015 in any parameter. This can be interpreted positively because no age-related decreases were found. Although our participants were physically active from the very beginning (>150 min/wk), it must be noted that the intensity of the physical activity was too low to provoke physiological improvements in leg strength or muscle/tendon morphology.
PLOS ONE, 2016
The present study aimed to determine whether distinct sets of tendon properties are seen in athletes engaged in sports with contrasting requirements for tendon function and structural integrity. Patellar and Achilles tendon morphology and force-deformation relation were measured by combining ultrasonography, electromyography and dynamometry in elite ski jumpers, distance runners, water polo players and sedentary individuals. Tendon crosssectional area normalized to body mass 2/3 was smaller in water polo players than in other athletes (patellar and Achilles tendon;-28 to-24%) or controls (patellar tendon only;-9%). In contrast, the normalized cross-sectional area was larger in runners (patellar tendon only; +26%) and ski jumpers (patellar and Achilles tendon; +21% and +13%, respectively) than in controls. Tendon stiffness normalized to body mass 2/3 only differed in ski jumpers, compared to controls (patellar and Achilles tendon; +11% and +27%, respectively) and to water polo players (Achilles tendon only; +23%). Tendon size appears as an adjusting variable to changes in loading volume and/or intensity, possibly to preserve ultimate strength or fatigue resistance. However, uncoupled morphological and mechanical properties indicate that functional requirements may also influence tendon adaptations.