Matching Participants for Triceps Surae Muscle Strength and Tendon Stiffness Does Not Eliminate Age-Related Differences in Mechanical Power Output During Jumping

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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On the mechanical power output comparisons of cone dielectric elastomer actuators

IEEE/ASME Transactions on Mechatronics ◽

10.1109/tmech.2021.3054460 ◽

2021 ◽

pp. 1-1

Author(s):

Chongjing Cao ◽

Lijin Chen ◽

Wenke Duan ◽

Thomas L. Hill ◽

Bo Li ◽

...

Keyword(s):

Power Output ◽

Dielectric Elastomer ◽

Mechanical Power ◽

Dielectric Elastomer Actuators ◽

Mechanical Power Output

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Effect of Accommodating Elastic Bands on Mechanical Power Output during Back Squats

Sports ◽

10.3390/sports6040151 ◽

2018 ◽

Vol 6 (4) ◽

pp. 151 ◽

Cited By ~ 1

Author(s):

Takafumi Kubo ◽

Kuniaki Hirayama ◽

Nobuhiro Nakamura ◽

Mitsuru Higuchi

Keyword(s):

Power Output ◽

Random Order ◽

Mechanical Power ◽

Muscular Force ◽

Force Output ◽

Elastic Band ◽

Free Weight ◽

Mechanical Power Output ◽

Elastic Bands ◽

Acceleration And Deceleration

The aim of this study was to investigate whether accommodating elastic bands with barbell back squats (BSQ) increase muscular force during the deceleration subphase. Ten healthy men (mean ± standard deviation: Age: 23 ± 2 years; height: 170.5 ± 3.7 cm; mass: 66.7 ± 5.4 kg; and BSQ one repetition maximum (RM): 105 ± 23.1 kg; BSQ 1RM/body mass: 1.6 ± 0.3) were recruited for this study. The subjects performed band-resisted parallel BSQ (accommodating elastic bands each sides of barbell) with five band conditions in random order. The duration of the deceleration subphase, mean mechanical power, and the force and velocity during the acceleration and deceleration subphases were calculated. BSQ with elastic bands elicited greater mechanical power output, velocity, and force during the deceleration subphase, in contrast to that elicited with traditional free weight (p < 0.05). BSQ with elastic bands also elicited greater mechanical power output and velocity during the acceleration subphase. However, the force output during the acceleration subphase using an elastic band was lesser than that using a traditional free weight (p < 0.05). This study suggests that BSQ with elastic band elicit greater power output during the acceleration and deceleration subphases.

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Pinacidil-primed ATP-sensitive potassium channels mediate feedback control of mechanical power output in isolated myocardium of rats and guinea pigs

European Journal of Pharmacology ◽

10.1016/j.ejphar.2009.11.013 ◽

2010 ◽

Vol 628 (1-3) ◽

pp. 116-127 ◽

Cited By ~ 1

Author(s):

Diethart Schmid ◽

Dawid L. Staudacher ◽

Christian A. Plass ◽

Hans G. Loew ◽

Eva Fritz ◽

...

Keyword(s):

Feedback Control ◽

Potassium Channels ◽

Power Output ◽

Guinea Pigs ◽

Mechanical Power ◽

Mechanical Power Output ◽

Isolated Myocardium

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Power output by an asynchronous flight muscle from a beetle

Journal of Experimental Biology ◽

10.1242/jeb.203.17.2667 ◽

2000 ◽

Vol 203 (17) ◽

pp. 2667-2689 ◽

Cited By ~ 7

Author(s):

R.K. Josephson ◽

J.G. Malamud ◽

D.R. Stokes

Keyword(s):

Power Output ◽

Flight Muscle ◽

Muscle Length ◽

Mechanical Power ◽

Effect Of Temperature ◽

Muscle Temperature ◽

Work Output ◽

Stroke Frequency ◽

Mechanical Power Output ◽

Wing Stroke

The basalar muscle of the beetle Cotinus mutabilis is a large, fibrillar flight muscle composed of approximately 90 fibers. The paired basalars together make up approximately one-third of the mass of the power muscles of flight. Changes in twitch force with changing stimulus intensity indicated that a basalar muscle is innervated by at least five excitatory axons and at least one inhibitory axon. The muscle is an asynchronous muscle; during normal oscillatory operation there is not a 1:1 relationship between muscle action potentials and contractions. During tethered flight, the wing-stroke frequency was approximately 80 Hz, and the action potential frequency in individual motor units was approximately 20 Hz. As in other asynchronous muscles that have been examined, the basalar is characterized by high passive tension, low tetanic force and long twitch duration. Mechanical power output from the basalar muscle during imposed, sinusoidal strain was measured by the work-loop technique. Work output varied with strain amplitude, strain frequency, the muscle length upon which the strain was superimposed, muscle temperature and stimulation frequency. When other variables were at optimal values, the optimal strain for work per cycle was approximately 5%, the optimal frequency for work per cycle approximately 50 Hz and the optimal frequency for mechanical power output 60–80 Hz. Optimal strain decreased with increasing cycle frequency and increased with muscle temperature. The curve relating work output and strain was narrow. At frequencies approximating those of flight, the width of the work versus strain curve, measured at half-maximal work, was 5% of the resting muscle length. The optimal muscle length for work output was shorter than that at which twitch and tetanic tension were maximal. Optimal muscle length decreased with increasing strain. The curve relating work output and muscle length, like that for work versus strain, was narrow, with a half-width of approximately 3 % at the normal flight frequency. Increasing the frequency with which the muscle was stimulated increased power output up to a plateau, reached at approximately 100 Hz stimulation frequency (at 35 degrees C). The low lift generated by animals during tethered flight is consistent with the low frequency of muscle action potentials in motor units of the wing muscles. The optimal oscillatory frequency for work per cycle increased with muscle temperature over the temperature range tested (25–40 degrees C). When cycle frequency was held constant, the work per cycle rose to an optimum with increasing temperature and then declined. We propose that there is a temperature optimum for work output because increasing temperature increases the shortening velocity of the muscle, which increases the rate of positive work output during shortening, but also decreases the durations of the stretch activation and shortening deactivation that underlie positive work output, the effect of temperature on shortening velocity being dominant at lower temperatures and the effect of temperature on the time course of activation and deactivation being dominant at higher temperatures. The average wing-stroke frequency during free flight was 94 Hz, and the thoracic temperature was 35 degrees C. The mechanical power output at the measured values of wing-stroke frequency and thoracic temperature during flight, and at optimal muscle length and strain, averaged 127 W kg(−1)muscle, with a maximum value of 200 W kg(−1). The power output from this asynchronous flight muscle was approximately twice that measured with similar techniques from synchronous flight muscle of insects, supporting the hypothesis that asynchronous operation has been favored by evolution in flight systems of different insect groups because it allows greater power output at the high contraction frequencies of flight.

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The effect of medial arch support over the plantar pressure and triceps surae muscle strength after prolonged standing

Medical Journal of Indonesia ◽

10.13181/mji.v24i3.1198 ◽

2015 ◽

Vol 24 (3) ◽

pp. 146-9 ◽

Cited By ~ 1

Author(s):

Hindun Saadah ◽

Deswaty Furqonita ◽

Angela Tulaar

Keyword(s):

Muscle Strength ◽

Contact Area ◽

Plantar Pressure ◽

Peak Pressure ◽

Standing Position ◽

Triceps Surae ◽

Prolonged Standing ◽

Triceps Surae Muscle ◽

Before And After ◽

Arch Support

Background: The activity with prolonged standing position is one of the causes of abnormalities in the lower leg and foot. The aim of this study is to discover the effect of medial arch support over the distribution of plantar pressure when standing and walking.Methods: This was an experimental study with pre- and post-design the strength of triceps surae muscle after prolonged standing, was also evaluated in an experimental study with pre- and post-design. Variables of plantar pressure measurement are the contact area and pressure peak were measured by using the Mat-scan tool. The measurement of the triceps surae muscle strength was done with a hand-held dynamometer, before and after using the medial arch support. Measurement was performed before and after working with prolonged standing position which took place about seven hours using the medial arch support inserted in the shoes. Data was analyzed using paired T-test.Results: There was a significant difference of peak pressure between standing (p = 0.041) and walking (p = 0.001). Whereas the contact area showed a significant decrease in the width of the contact area when standing (104.12 ± 12.42 vs 99.08 ± 10.21 p = 0.023). Whereas, the triceps surae muscle strength pre- and post-standing prolonged did not indicate a significant difference.Conclusion: There was decrease in peak pressure when standing and walking and decrease in contact area when standing on plantar after used of the medial arch support after prolonged standing.

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