P Aagaard

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..These findings could be explained by an enhanced neural drive, as evidenced by marked increases in EMG signal amplitude and rate of EMG rise in the early phase of muscle contraction...

..e., increased central motor drive, elevated motoneuron excitability, reduced presynaptic inhibition)...

..A significant potential for muscular knee joint stabilization appeared for the elite sailors despite their high maximal quadriceps strength and partially lower (SF) conventional H/Q ratios...

..The purpose of this study was to investigate the relationship between myosin heavy chain (MHC) composition and maximal contraction strength of the human quadriceps femoris muscle...

..This interaction seems to include the specific adaptation responses evoked by intensive resistance training...

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..To examine if cross-sectional area (CSA) differs along the length of the human patellar tendon (PT), and if there is PT hypertrophy in response to resistance training...

..We examine the accuracy of human patellar tendon elongation, in vivo, and its within-day and between-day reproducibility...

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..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...

..The stiffness and Young's modulus exceeded those previously reported for the tibialis anterior tendon in vivo, but were similar to those obtained for various isolated mammalian and human tendons...

..The purpose was to examine the effects of short-term unilateral immobilization on the structural and mechanical properties of the patellar tendon in older men and younger men, in vivo...

..Collagen concentration was reduced, whereas both enzymatic and nonenzymatic cross-linking of concentration was elevated in OM vs. in YM, which may be a mechanism to maintain the mechanical properties of tendon with aging...

..In addition, old individuals showed an attenuated response to retraining after immobilization compared with young individuals...

..However, LL resistance training was inferior to HL training in evoking adaptive changes in muscle size and contractile strength and was insufficient to induce changes in MHC composition...

..In conclusion, 14 weeks of regular recreational football improved peak jump power, maximal hamstring strength and vBMD in the distal tibia, suggesting a decreased fracture risk due to stronger bones and a reduced risk of falling...

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..Thus, screening procedures should involve functional movements to reveal specific fatigue-induced deficits in ACL-agonist muscle activation during high-risk phases of match play...

..This study aimed to compare electromyography activity, patellar tendon strain and joint angle kinematics during standard and decline eccentric squats...

..The superior RFD and balance in elderly footballers were of such a magnitude that no deficit could be observed when compared with young untrained individuals...

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..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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..81+/-0.35 vs inflexible: 1.22+/-0.52 GPa) were not different between the two groups of subjects. These data suggest that differences in knee joint ROM cannot be explained by the mechanical properties of the patellar tendon...

..These data suggest that passive energy absorption of the human skeletal muscle is insensitive to physiological increases in intramuscular temperature...

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..8% and 38.2 +/- 9.8 MPa in non-runners and 4.1 +/- 0.8% and 26.3 +/- 5.1 MPa in runners. The larger tendon cross-sectional area in trained runners suggests that chronic exposure to repetitive loading has resulted in a tissue adaptation...

..05, and 537+/-27 vs 641+/-30 MPa, P<0.05, respectively), while the strain properties were unaffected. Peak stress was similar between the two groups. There was no difference in fascicle diameter between the two groups...

..The present data demonstrate that no measurable EMG activity was detected in either group during the static stretch maneuver. Therefore, the decline in resistance to static stretch was a viscoelastic stress relaxation response...

..However, a total of 7.5 min (5 x 90 s) of stretching for a single muscle group may be an unrealistic stretching program...

..In vertical jumping it is advantageous to generate extensor moments about the knee and hip joint simultaneously, while in horizontal locomotion this would result in inefficient vertical movements...

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..Conclusively, CORT has good short-term but poor long-term clinical effects, in patellar tendinopathy. HSR has good short- and long-term clinical effects accompanied by pathology improvement and increased collagen turnover...

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..To examine the passive energy absorption of the hamstring muscle-tendon unit in 9 women with benign joint hypermobility syndrome (BJHS) and 9 age and sex matched controls...

..An increase in tenascin C expression in the midbelly of the skeletal muscle in both legs provides further evidence of a potential role for the extracellular matrix in the phenomenon of delayed onset of muscle soreness...

..This study aimed to: 1) examine the mechanical properties of the free human Achilles tendon in vivo by the use of ultrasonography and 2) assess the between-day reproducibility of these measurements...

..In contrast, the collagen metabolism in healthy control tendons seems not to be affected by eccentric training. These findings could indicate a relation between collagen metabolism and recovery from injury in human tendons...

..Taken together, recreational football appears to effectively stimulate musculoskeletal, metabolic and cardiovascular adaptations of importance for health and thereby reduces the risk of developing life-style diseases...

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..Moreover, the lack of symptoms prior to the rupture suggests that clinical tendinopathy is not an etiological factor in complete tendon ruptures...

..Furthermore, the data indicate that neuromuscular activation and contractile RFD are more affected by long-term disuse than maximal muscle strength, which may increase the future risk for falls...

..Therefore, we investigated how chronic training responses are affected by glucose ingestion...

..Future studies should identify intervention strategies to counter-act the observed impairments...

..However, severe tissue damaging effects exist with anabolic steroids, some of which are irreversible...

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..Moreover, football training induced consistent cardiac adaptations, which may have implications for long-term cardiovascular health...

..Thus, physical activity should be continued by patients with SIS, if possible, to avoid the loss in neural and muscle functions associated with inactivity...

..The present findings suggest that heavy resistance training induces long-lasting strength gains and neural adaptations during maximal eccentric muscle contraction in previously untrained subjects...

..DISCUSSION AND CONCLUSION: The results indicate that heavy resistance exercises should be included in rehabilitation programs to induce sufficient levels of neuromuscular activation to stimulate muscle growth and strength...

..However, the present results may have relevance for individuals who are particularly interested in gaining muscle size...

..The improvement in both muscle mass and neural function is likely to have important functional implications for elderly individuals...

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..A phenotypic shift toward faster muscle MHC isoforms (I --> IIA --> IIX) and faster electrically evoked muscle contractile properties in response to detraining may explain the present results...

..The greater tendon size combines to lower the stress on the tendon markedly, which may reduce the risk of injury to the tendon...

..Thus, only subjects with a lesser ability to rapidly attain their maximum force before training improved RFD with slow-speed resistance exercise...

..This may have important practical implications when designing resistance training programs for specific sports...

..Alternatively, in subjects with a suppressed H reflex in the swing phase the knee joint extensors seem to form the primary protection around heel strike...

..These data indicate that tendons in women have a lower rate of new connective tissue formation, respond less to mechanical loading, and have a lower mechanical strength, which may leave the tissue more susceptible to injury...

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..A possible explanation may be that, even though the adopted experimental pain-paradigm may reflect the SIS in terms of the painful structures, it might not reflect the adaptations in the central nervous system seen with chronic pain...

..05). In conclusion, long-term training counteracted the age-related decline in muscle power and functional performance observed in the control subjects, while substantial gains in muscular performance were observed in the trained elderly...

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..To better understand how immobilization and surgery affect muscle size and function in the elderly and to identify effective training regimes...

..The present data emphasize the importance of resistance training in future rehabilitation programs for elderly individuals...

..Remobilization increased muscle size and strength and tendon synthesis and degradation decreased to baseline levels. These dynamic changes in tendon connective tissue turnover were not associated with macroscopic changes in tendon size...

..Maximal muscle contraction force and muscle mass are both reduced during the natural aging process. Long-term training may be used to attenuate this age-related loss in muscle function and muscle size...

..04 g cm(-2) (median 1.41 g cm(-2), range 1.27-1.57 g cm(-2)) (P=0.028). The present results suggest that low bone mineral density may be a potential risk factor for the development of exercise-induced rib stress fractures in elite rowers...

..To ensure optimal knee joint stabilization during sailing and other training activities, it is suggested that hikers should counter this strength imbalance by performing additional strength training for the hamstrings muscle group...

..CLINICAL RELEVANCE: Corticosteroids may weaken specific regions of the injected tendon and leave it more prone to rupture. This weakening effect is manifested in the individual collagen fascicles that constitute the tendon...

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