Adarq.org

All conclusions of studies will be listed in this original post (TABLE OF SUMMARIES) for quick reference.


Post anything related to tendon / muscle / joint stiffness & performance. This could be anything related to different training methods & their effect on stiffness, and the effect of this training on performance (sprinting/jumping etc).




1. Influence of elastic properties of tendon structures on jump performance in humans

Although the stiffness was not significantly related to absolute jump height in either vertical jump, it was inversely correlated with the difference in jump height between the vertical jumps performed with and without countermovement. The results suggested that the stiffness of tendon structures has a favorable effect on stretch-shortening cycle exercise, possibly due to adequate storage and recoil of elastic energy.

2. Effects of isometric squat training on the tendon stiffness and jump performance

These results suggest that isometric squat training changes the stiffness of human tendon aponeurosis complex in knee extensors to act negatively on the effects of pre-stretch during stretch-shortening cycle exercises.

3. Age-related neuromuscular function during drop jumps

These different activation patterns are in line with the mechanical behavior of GM (medial gastroc) showing significantly less fascicle shortening and relative TT (tendon tissue) stretching in the braking phase in the elderly than in the young subjects. These results suggest that age-specific muscle activation patterns as well as mechanical behaviors exist during DJs.

4. Influence of leg stiffness and its effect on myodynamic jumping performance.

The leg and ankle stiffness values were higher when the contact times were shorter. This means that by influencing contact time through verbal instructions it is possible to control leg stiffness.

5. Leg stiffness primarily depends on ankle stiffness during human hopping

Thus, we conclude that the primary mechanism for leg stiffness adjustment is the adjustment of ankle stiffness.

6. Muscle performance during maximal isometric and dynamic contractions is influenced by the stiffness of the tendinous structures

Power, force, and velocity parameters obtained during the jumps were significantly correlated to tendon stiffness. These data indicate that muscle output in high-force isometric and dynamic muscle actions is positively related to the stiffness of the tendinous structures, possibly by means of a more effective force transmission from the contractile elements to the bone.

7. Effect of landing stiffness on joint kinetics and energetics in the lower extremity.

Overall, the muscular system absorbed 19% more of the body's kinetic energy in the soft landing compared with the stiff landing, reducing the impact stress on other body tissues. The ankle plantarflexors provided the major energy absorption function in both conditions, averaging 44% of the total muscular work done followed by the knee (34%) and hip (22%) extensors.

8. Effects of Plyometric and Weight Training on Muscle-Tendon Complex and Jump Performance.

Conclusion: These results indicate that the jump performance gains after plyometric training are attributed to changes in the mechanical properties of muscle-tendon complex, rather than to the muscle activation strategies.

9. Relationships between three potentiation effects of plyometric training and performance

Conclusions: Plyometric training specifically potentiated the normalized EMG, tendon stiffness and elastic energy utilization in the myotendinous complex of the triceps surae. Although these changes are possibly essential determinants, only increases of tendon stiffness were observed to correlate with performance improvements.

10. Effects of different duration isometric contractions on tendon elasticity in human quadriceps muscles

Stiffness increased significantly for the long-duration protocol, but not for the short-duration protocol.

The present study demonstrates a greater increase in stiffness of human tendon structures following isometric training using longer duration contractions compared to shorter contractions. This suggests that the changes in the elasticity of the tendon structures after resistance training may be affected by the duration of muscle contraction.

11. Effects of isometric training on the elasticity of human tendon structures in vivo

Thus the present results indicate that isometric training increases the stiffness and Young's modulus of human tendon structures as well as muscle strength and size. This change in the tendon structures would be assumed to be an advantage for increasing the rate of torque development and shortening the electromechanical delay.

12. Effect of habitual running on human Achilles tendon load-deformation properties and cross-sectional area

The total running duration was ~43 h, distributed over 34 wk. Tendon-aponeurosis displacement during maximal voluntary contraction was unchanged. Tendon CSA also remained unchanged In conclusion, a total training stimulus of ~9 mo of running in previously untrained subjects was adequate to induce significant cardiovascular improvements, although it did not result in any changes in the mechanical properties of the triceps surea tendon-aponeurosis complex or in the dimensions of Achilles tendon.

13. Optimal muscle fascicle length and tendon stiffness for maximising gastrocnemius efficiency during human walking and running

14. On muscle, tendon and high heels

We conclude that long-term use of high-heeled shoes induces shortening of the GM muscle fascicles and increases AT stiffness, reducing the ankle's active range of motion. Functionally, these two phenomena seem to counteract each other since no significant differences in static or dynamic torques were observed.

Nice site guys. It's good to see RJ's article in here -easy to find. Also, just finished reading Andrew's articles on high frequency training and stim. Very interesting. Wouldn't mind trying it out once 100% healthy again.

hey man!!!

hey.

ok so my new journey began today. my one week deload turned in to a 4 day deload. what can i say, resting is boring...

i figure i'm always talking about the ankles, so it's time to put up or shut up. I will attempt to drastically improve my ankle strength/stiffness. I will do at most 1 squat session a week to maintain my hip strength.

I have no routine as of yet, but I have something in mind... so I won't list what I plan on doing yet, I will just try it and see if it falls into place.

peace

Thanks for the answers.  I'll try incorporating RDL and bench yielding isos into my weights program.

this one kid i was training, russel, made crazy progress on bench in 2 months from the pause benching.

3 sets of max rep, with 5 second pause at the bottom..

i forget exactly what he started at, but it was either 185 for 3 or 4 on regular bench, and ended with 185 x 15 at some football combine in 2 months.. the pause benching was just so effective it was crazy.

all we did was work pause from 165, progress to 185, and then keep grinding away at 185-pause-bench to make big progress..

peace man

I have a question about the isometric strength involved in sprinting.  My coach told me before that isometrics were useless because they only increased strength within about 15 degrees of the joint angles at which they were performed.  If I do yielding isometrics with a pause at the bottom of an RDL then how would it help my isometric strength when my leg touches down during running?

Also, if I do incorporate yielding isometric exercises, are they best done at the beginning or end of my weights session?

rj has the studies, he'll give you a better answer..

it's 15-30 degrees, and that mostly applies to overcoming isometrics if I am not mistaken.. performing yielding isos nearest the weakest joint angle will strengthen the entire ROM. A yielding iso is basically a series of eccentric contractions, so strengthening the muscle in this lengthened position is much different than an overcoming iso..

think about it in terms of deep squatting or bench pressing.. a very effective tool to strengthen squat & bench is pause squats and pause bench. if you can increase the amount of force at the bottom, then the natural joint angle-strength curve will kick in.

i've personally implemented pause bench very successful on the few occasions i've used it... pausing at the bottom for 5 seconds & blasting up..

imagine you could only hold a deep lunge iso with 185 for 7 seconds... now imagine you can hold 285 for 7 seconds... there will be some pretty extreme transfer over to other movements that use that musculature.

well, if you went max effort on the yielding isos, then of course do them as the main section of your workout.. if you are only doing them as assistance, do them towards the end.

peace

hey mang! welcome..

going to read it in a little bit (and will give feedback when i do), but it is completely acceptable to advertise an interview, article, or informative video from any site in this subforum.

i would like this section of the forum to discuss off-site and on-site material.

so don't apologize

peace man