Impact of oral contraceptive use and menstrual phases on patellar tendon morphology, biochemical composition, and biomechanical properties in female athletes

2013 ◽  
Vol 114 (8) ◽  
pp. 998-1008 ◽  
Author(s):  
Mette Hansen ◽  
Christian Couppe ◽  
Christina S. E. Hansen ◽  
Dorthe Skovgaard ◽  
Vuokko Kovanen ◽  
...  
Keyword(s):  
Patellar Tendon ◽  
Female Athletes ◽  
Maximum Voluntary Contraction ◽  
Biomechanical Properties ◽  
Cross Sectional Area ◽  
Cross Linking ◽  
Sectional Area ◽  
Cross Sectional ◽  
Collagen Cross Linking

Sex differences exist with regards to ligament and tendon injuries. Lower collagen synthesis has been observed in exercising women vs. men, and in users of oral contraceptives (OC) vs. nonusers, but it is unknown if OC will influence tendon biomechanics of women undergoing regular training. Thirty female athletes (handball players, 18–30 yr) were recruited: 15 long-term users of OC (7.0 ± 0.6 yr) and 15 nonusers (>5 yr). Synchronized values of patellar tendon elongation (obtained by ultrasonography) and tendon force were sampled during ramped isometric knee extensor maximum voluntary contraction to estimate mechanical tendon properties. Furthermore, tendon cross-sectional area and length were measured from MRI images, and tendon biopsies were obtained for analysis of tendon fibril characteristics and collagen cross-linking. Overall, no difference in tendon biomechanical properties, tendon fibril characteristics, or collagen cross-linking was observed between the OC users and nonusers, or between the different phases of the menstrual cycle. In athletes, tendon cross-sectional area in the preferred jumping leg tended to be larger than that in the contralateral leg ( P = 0.09), and a greater absolute ( P = 0.01) and normalized tendon stiffness ( P = 0.02), as well as a lower strain ( P = 0.04), were observed in the jumping leg compared with the contralateral leg. The results indicate that long-term OC use or menstrual phases does not influence structure or mechanical properties of the patellar tendon in female team handball athletes.

Habitual loading results in tendon hypertrophy and increased stiffness of the human patellar tendon

2008 ◽  
Vol 105 (3) ◽  
pp. 805-810 ◽  
Author(s):  
C. Couppé ◽  
M. Kongsgaard ◽  
P. Aagaard ◽  
P. Hansen ◽  
J. Bojsen-Moller ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Patellar Tendon ◽  
Cross Sectional Area ◽  
Isometric Contractions ◽  
Sectional Area ◽  
Cross Sectional ◽  
Strength Difference ◽  
Distal Tendon

The purpose of this study was to examine patellar tendon (PT) size and mechanical properties in subjects with a side-to-side strength difference of ≥15% due to sport-induced loading. Seven elite fencers and badminton players were included. Cross-sectional area (CSA) of the PT obtained from MRI and ultrasonography-based measurement of tibial and patellar movement together with PT force during isometric contractions were used to estimate mechanical properties of the PT bilaterally. We found that distal tendon and PT, but not mid-tendon, CSA were greater on the lead extremity compared with the nonlead extremity (distal: 139 ± 11 vs. 116 ± 7 mm2; mid-tendon: 85 ± 5 vs. 77 ± 3 mm2; proximal: 106 ± 7 vs. 83 ± 4 mm2; P < 0.05). Distal tendon CSA was greater than proximal and mid-tendon CSA on both the lead and nonlead extremity ( P < 0.05). For a given common force, stress was lower on the lead extremity (52.9 ± 4.8 MPa) compared with the nonlead extremity (66.0 ± 8.0 MPa; P < 0.05). PT stiffness was also higher in the lead extremity (4,766 ± 716 N/mm) compared with the nonlead extremity (3,494 ± 446 N/mm) ( P < 0.05), whereas the modulus did not differ (lead 2.27 ± 0.27 GPa vs. nonlead 2.16 ± 0.28 GPa) at a common force. These data show that a habitual loading is associated with a significant increase in PT size and mechanical properties.

scholarly journals Sex Differences in the Morphological and Mechanical Properties of the Achilles Tendon

2021 ◽  
Vol 18 (17) ◽  
pp. 8974
Author(s):  
Xini Zhang ◽  
Liqin Deng ◽  
Songlin Xiao ◽  
Lu Li ◽  
Weijie Fu
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Cross Sectional Area ◽  
Morphological Properties ◽  
Sectional Area ◽  
Cross Sectional ◽  
Force Peak ◽  
Strain Stress

Background: Patients with Achilles tendon (AT) injuries are often engaged in sedentary work because of decreasing tendon vascularisation. Furthermore, men are more likely to be exposed to AT tendinosis or ruptures. These conditions are related to the morphological and mechanical properties of AT, but the mechanism remains unclear. This study aimed to investigate the effects of sex on the morphological and mechanical properties of the AT in inactive individuals. Methods: In total, 30 inactive healthy participants (15 male participants and 15 female participants) were recruited. The AT morphological properties (cross-sectional area, thickness, and length) were captured by using an ultrasound device. The AT force–elongation characteristics were determined during isometric plantarflexion with the ultrasonic videos. The AT stiffness was determined at 50%–100% maximum voluntary contraction force. The AT strain, stress, and hysteresis were calculated. Results: Male participants had 15% longer AT length, 31% larger AT cross-sectional area and 21% thicker AT than female participants (p < 0.05). The plantarflexion torque, peak AT force, peak AT stress, and AT stiffness were significantly greater in male participants than in female participants (p < 0.05). However, no significant sex-specific differences were observed in peak AT strain and hysteresis (p > 0.05). Conclusions: In physically inactive adults, the morphological properties of AT were superior in men but were exposed to higher stress conditions. Moreover, no significant sex-specific differences were observed in peak AT strain and hysteresis, indicating that the AT of males did not store and return elastic energy more efficiently than that of females. Thus, the mechanical properties of the AT should be maintained and/or improved through physical exercise.

Free autografting of entire limb muscles in the cat: histochemistry and biochemistry

1978 ◽  
Vol 44 (3) ◽  
pp. 431-437 ◽  
Author(s):  
L. C. Maxwell ◽  
J. A. Faulkner ◽  
S. A. Mufti ◽  
A. M. Turowski
Keyword(s):  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Muscle Fibers ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Succinate Dehydrogenase Activity ◽  
Cross Sectional ◽  
The Mean ◽  
Fast Twitch

Fifty extensor digitorium longus muscles of 25 cats were autografted, 33 with and 17 without prior denervation. After 50 days, no significant differences were observed between predenervated and nonpredenervated autografts. Autografted muscles weighed 48% of the weight of control muscles. Few original muscle fibers survived and within 2 wk autografts contained regenerating muscle fibers. The mean cross-sectional area of muscle fibers in the autografts reached 125% of the value for control nontransplanted muscles. The mean percentage of fibers classified high oxidative in autografted muscles was 67% of values for control muscles. SDH activity of autografted muscle homogenates reached 55% of control values. Up to 60 days after surgery autografts had only fast-twitch fibers. At 170 days autografts remained 95% fast twitch in composition. Revascularization began within 4 days, but the capillary to fiber ratio of long term autografts reached only 60% of control values. Although fiber hypertrophy suggests that cats use autografted muscles, lower than control succinate dehydrogenase activity may result from altered recruitment.

Effects of disuse on growing and adult chick skeletal muscle

1981 ◽  
Vol 48 (1) ◽  
pp. 35-54
Author(s):  
C.R. Shear
Keyword(s):  
Skeletal Muscle ◽  
Postnatal Development ◽  
Latissimus Dorsi ◽  
Plaster Cast ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Motor Endplates ◽  
And Control

The effects of long-term muscle inactivity, throughout post-hatching development, have been examined. Continuous immobilization of the chicken posterior latissimus dorsi (PLD) muscle from the first hour after hatching for varying periods up to 330 days, resulted in a significantly greater decrease in myofibre size (40-64% less than control) than occurred when adult muscles were immobilized for similar periods (20-40% less than control). The myofibre atrophy resulting from long-term immobilization of adult muscle is reversible, after removal of the plaster cast. In contrast, the myofibres immobilized immediately after hatching, for similar periods of time, were unable to recover one the casts were removed. On the basis of myofibre cross-sectional area, 2 populations of cells were seen in muscles immobilized during postnatal development: small myofibres of 0.5-200 micron 2 and larger myofibres of 500–800 micron 2. The distribution of fibre cross-sectional area within immobilized adult muscles was similar to controls, suggesting a uniform response (i.e. atrophy) by all of the myofibres within the muscle. Immobilization in both newly hatched and adult PLD muscles did not appear to alter the pattern of motor endplate distribution within the muscle. Small, multiple motor endplates were observed associated with immobilized and control myofibres near their terminal ends. This finding suggests that the embryonic pattern of myofibre innervation is not entirely lost from all the fibres during postnatal development.

Ultrasound does not provide reliable results for the measurement of the patellar tendon cross sectional area

2013 ◽  
Vol 23 (6) ◽  
pp. 1278-1282 ◽  
Author(s):  
Antonis Ekizos ◽  
Fyllis Papatzika ◽  
Georgios Charcharis ◽  
Sebastian Bohm ◽  
Falk Mersmann ◽  
...  
Keyword(s):  
Patellar Tendon ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional

Effects of long-term continuous respiratory resistive loading on rat diaphragm function and structure

1993 ◽  
Vol 74 (3) ◽  
pp. 1212-1219 ◽  
Author(s):  
D. J. Prezant ◽  
T. K. Aldrich ◽  
B. Richner ◽  
E. I. Gentry ◽  
D. E. Valentine ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Cross Sectional Area ◽  
Male Rats ◽  
Internal Diameter ◽  
Type I ◽  
Fiber Types ◽  
Sectional Area ◽  
Cross Sectional ◽  
Resistive Loading

The effects of long-term (24- to 28-wk) continuous respiratory resistive loading on diaphragm mass, contractility, fatigue, and fiber types were studied in male rats. Increased respiratory resistance was produced by extratracheal banding, and results were compared with sham-operated pair-fed controls. At the time the animals were killed, banded tracheal segment internal diameter was reduced by 57% of control values. Diaphragm surface area and muscle mass (normalized for body mass) increased by 19% of control values. Isometric diaphragm contractility and fatigue resistance indexes were measured using an in vitro diaphragm costal strip preparation at 37 degrees C. Twitch and tetanic stimulations were evoked using direct stimulation. Compared with controls, baseline tensions (normalized for diaphragm cross-sectional area) were significantly decreased at low frequencies. Fatigue resistance (endurance) indexes were significantly increased at all frequencies. These findings were consistent with observed increases in number and cross-sectional area of type I (low-tension high-endurance) fibers. We conclude that the diaphragm adapts to chronic long-term resistive loads by sacrificing peak tensions for an increase in endurance capacity.

scholarly journals CNTF 1357 G → A polymorphism and the muscle strength response to resistance training

2009 ◽  
Vol 107 (4) ◽  
pp. 1235-1240 ◽  
Author(s):  
Sean Walsh ◽  
Bethany K. Kelsey ◽  
Theodore J. Angelopoulos ◽  
Priscilla M. Clarkson ◽  
Paul M. Gordon ◽  
...  
Keyword(s):  
Resistance Training ◽  
Muscle Strength ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Cross Sectional Area ◽  
Isometric Strength ◽  
Sectional Area ◽  
Cross Sectional ◽  
Caucasian Men ◽  
Before And After

The present study examined associations between the ciliary neurotrophic factor (CNTF) 1357 G → A polymorphism and the muscle strength response to a unilateral, upper arm resistance-training (RT) program among healthy, young adults. Subjects were 754 Caucasian men (40%) and women (60%) who were genotyped and performed a training program of the nondominant (trained) arm with the dominant (untrained) arm as a comparison. Peak elbow flexor strength was measured with one repetition maximum, isometric strength with maximum voluntary contraction, and bicep cross-sectional area with MRI in the trained and untrained arms before and after training. Women with the CNTF GG genotype gained more absolute isometric strength, as measured by MVC (6.5 ± 0.3 vs. 5.2 ± 0.5 kg), than carriers of the CNTF A1357 allele in the trained arm pre- to posttraining ( P < 0.05). No significant associations were seen in men. Women with the CNTF GG genotype gained more absolute dynamic (1.0 ± 0.1 vs. 0.6 ± 0.1 kg) and allometric (0.022 ± 0.0 vs. 0.015 ± 0.0 kg/kg−0.67) strength, as measured by 1 RM, than carriers of the CNTF A1357 allele in the untrained arm pre- to posttraining ( P < 0.05). No significant associations were seen in men. No significant associations, as measured by cross-sectional area, were seen in men or women. The CNTF 1357 G → A polymorphism explains only a small portion of the variability in the muscle strength response to training in women.

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