Sport Biomechanics - Science topic

Lees, A., Vanrenterghem, J., & De Clercq, D. (2004). “Understanding how elite athletes jump: A biomechanical analysis of the standing long jump.” Bobbert, M.F., & Van Soest, A.J. (2001). “Why do people jump the way they do?” Kubo, K., Kanehisa, H., & Fukunaga, T. (1999). “Influence of elastic properties of tendon structures on jump performance in humans.”

Thank you for your response, But have to use a translator to understand first.

There are many version of this kind of treadmill is available in market with force platform. Pressure-pad-embedded treadmill (Model Gait analysis FDM-TDSL-3i, Zebris Inc.®, Germany; belt length: 150 cm; belt width: 50 cm; maximum incline: 15%; maximum speed: 24 km/h), which was used to record VGRF at a sampling frequency of 50 Hz. You can use this type of treadmill also. Although you need to mention the exact need of yours. Pls go through the following Article for reference -

Pathak, P.; Ahn, J. A Pressure-Pad-Embedded Treadmill Yields Time-Dependent Errors in Estimating Ground Reaction Force during Walking. Sensors 2021, 21, 5511. https://doi.org/10.3390/ s21165511

Try International Journal of Sports Science & Coaching

Hello! Try to use Kinovea (free soft). Nice program for automatically tracking.

I'm delighted to announce this fantastic line up of speakers for the next couple of months of #SportsBiomLS

(subject to change + more to be added!)

You can watch these and all previous lectures here: https://www.youtube.com/c/StuartMcErlainNaylor

I'll stop spamming your feed with replies now but keep an eye out at the link above.

Take care everyone,

Stuart

I think it is best to use anaerobic capacity tests first and set your own goals based on. I don't think the use of distance alone was used to determine the anaerobic capacity.

Great, thank you. I'll send you a message.

I am sure that my response, in that it makes a point, also inherently carries with it the potential for the reader to choose to take offense. Nothing is shared in the spirit of arrogance or petulance, but with the certainty of one who has smacked my palm to my own forehead over my own ignorance.

1. Newton never said "equal and opposite and identical". The ankle possesses DRL, or divergent reactive leverage. In the direction of gravity, it manifests as a class 2 lever. In the reactive direction known in physics by the term "normal force" it manifests simultaneously as a class 1 lever. Both must be modeled accurately in motion analysis.

Question: are these truths not self-evident? If so, then if any research draws any conclusion based upon modeling that excludes either type of leverage, is not that research merely validated by flawed premises, and thus its soundness cannot be assumed?

2. Pain leads to biomechanical changes. This was proved by Pohl 2015 trying to replicate an earlier gait analysis of lesser glute weakening and inquiring about compensatory trunk lean. While kinematic changes were noted in the earlier study, none were seen in Pohl. He told me that there was tremendous resistance to him publishing due to... well... due to people not knowing everything about everything. You see, the earlier study used painful hypersaline injections to weaken the lesser glutes, but Pohl used a painless nerve block. While the other study showed changes, there was no kinematic change in Pohl's subjects. Now, before everyone gets their collective knickers in a twist, understand that Jacquie Perry got it wrong. There isn't one gait paradigm; there are two. Just like the new Chevy truck with a V8 that can also run as a 4 cylinder depending on terrain, the human body has TDGC, or terrain-dependent gait configurations. Only on level terrain do we fully extend the hip and knee in normal gait. Both gastroc and TFL require full extension to be allowed to participate. Where was Pohl's study? In a gait lab on level ground. Have the subjects walk down a hill and things change drastically.

3. Asymmetry leads to biomechanical asymmetry. Whether LLD or muscle, there will be an impact. Give it long enough and Davis' Law can mess with you and cause pain. Bell 2013 looked at short transfemoral amputees and long transfemoral amputees. Both walked with the same gait efficiency, but the short limbs had more trunk lean. While Bell stuck with "compensatory motions are inefficient", her data proves that the truth is "compensatory motions effectively preserve gait efficiency". But here's the point... at what cost? Does the greater trunk lean of the shorter TF amputee lead to back pain sooner? We don't know because Bell had the wrong assumptions.

Gentlemen, one cannot use a linear process in a situation with reactive elements. And everything with gait reacts. We must engage in abductive reasoning prior to either inductive or deductive reasoning. In the words of Carlo Rovelli, the theoretical physicist, "Before measurements, calculations, and meticulous deductions, science is above all about visions. Science begins with a vision. Scientific thought is fed by the capacity to "see" things differently than they have previously been seen."

What are you gentlemen missing? Perhaps that biomechanics itself is limited in its vision. Page 491 of Neumann's kinesiology textbook tells us that with the hip, regardless of whether it is the pelvis or the femur moving, we see the hip osteokinematics in anatomical position. Perfect! You see the pelvis as a class 1 lever. Except... if you have the capacity for vision, you might turn your head sideways 90 degrees and see the femur as a class 3 lever.

And folks... if you've never done that, you don't know what you're missing. You see, the hip is not the class 1 lever espoused by the AAOS and the ASB. It is a UCL, or a unified compound lever, which is multiple levers that are simultaneously supported by a ball fulcrum. For is not the femoral head a circle? Why must you limit your vision to only vertical when the very model violates Archimedes' Law of the Lever (glutes attach to femur, which is the fulcrum-thus the distance value is zero. The hip is mathematically irrational allowing it to include only vertical forces).

Or perhaps it's that biomechanics only utilizes a single simple machine when there are six from which to choose. For the man whose only tool is a hammer, the whole world is a nail. For the researcher whose only tool is a lever... but there is also a wedge, a pulley, an inclined plane, a wheel and axle, and a screw. If your only tool is a lever, you must protect it, you must limit it, you must isolate it. This is the case with "closed chain" movement. Dennis Shavelson , you will find this JOSPT editorial fascinating Closed chain was only supposed to refer to structures, not movement. By only having levers, we create our own errors. In a sense, closed chain allows us to make energy simply stop, in clear violation of the second law of thermodynamics. When we allow abductive reasoning and the vision of the dreamers, we realize that vastus lateralis acts as a heterogeneous wedge to counter the lateral thrust of the femoral lever at the hip.

Trust me... I know... because during transfemoral amputation, the IT band which holds everything in place is cut. Suddenly, the self-neutralizing horizontal forces acting at the hip manifest. And the answer of the AAOS was to remove the IT band and weaken the hip abductors in the name of "balance". Forever my patients have struggled missing 30% of hip power (Ryser 1988)".

Is there more? Yes... but I think I've said enough for today. With those facepalm epiphanies, I've come to be far more aware of unnecessary patient suffering.

My apologies if this appears disjointed. The flawed assumptions in biomechanics are so numerous that it makes it difficult to only address one. Suffice it to say that if your initial approach includes a fatal flaw, everything thereafter is vulnerable as well. While the actions of biomechanics are organisms... unless you are pushing against someone's foot instead of against the ground... those reactions are mechanisms and very different in nature than the organism. And the reactive nature of mechanisms, while foreign to most in healthcare, is all we know in prosthetics.

He suggested building and standardizing tests to measure the desired variable

MVC is frequently used to normalize the data. you may want to divide your peak muscle activation by the MVC and report that. It is not uncommon to exceed 100%, depending on how Mvc is measured. Normalizing by mvc helps account for inter subject variability as well as sensor placement.

Following

Thanks very much. Very usefull for me

The movement of the horse affects a rider's posture, balance, coordination, strength and sensorimotor systems hence helps in sensory intergration for children with sensory processing disorders. prior assessment of the child is important and also interests.experienced horse ridder assisted with ot must be involved

The anatomic location of excess body fat has an impact on associated cardiometabolic morbidity, and visceral adipose tissue (VAT) is more pathogenic than subcutaneous adipose tissue (SAT). However, VAT or SAT alone provides little information regarding the relative distribution of body fat. We hypothesised that the propensity to store energy in VAT relative to SAT depots may be a correlate of cardiometabolic risk, and tested this hypothesis using the VAT/SAT ratio as a metric of fat distribution.

this may be help you.

best reqards

Lower extremity leg amputation: an advantage in running?

Knut Lechler and Magnus Lilja

This paper is a neat review.

Also,

Counterpoint: Artificial legs do not make artificially fast running speeds possible.

Kram et al

Hope this helps

Hi Viara,

Thanks for your concern but the above uploaded article is about mechanography NOT MECHANOMYOGRAPHY. If you get some good stuff related to data validation from Mechanomyography, please do share.

How can you improove your top speed? What is the most efficient method to be faster?

Please let me know if this citation (and reference below) is useful to you.

“Why joints pop

Like nearly all the joints in your body, the knee joint is covered by a protective membrane containing synovial fluid. This fluid lubricates the joint, allowing it to move smoothly and easily.

Occasionally, tiny gas bubbles build up in this fluid. When the joint moves, the bubbles are released, causing the nearby ligaments to emit a snap or pop sound. The technical term for this phenomenon is crepitus, which also describes all grinding or crackling sounds and sensations in the body.

When to be concerned about joints popping

Most of the time, this popping and creaking of joints is harmless. However, crepitus is also a symptom of the joint degeneration that leads to osteoarthritis.

 You should worry about joint popping if:

•It's occurring frequently in one location

•It's accompanied by pain

•It's accompanied by joint swelling, tenderness, or stiffness

•You're also having pain as a result of prolonged joint movement, such as when walking

If you're experiencing pain when a joint pops or you have any other of the symptoms listed above, talk with your doctor. If your symptoms and test results indicate it, your doctor may diagnose osteoarthritis and start treatment. Treatments for osteoarthritis can ease pain, improve mobility, and slow disease progression—especially if it's caught early.”

Reference:

Dennis

Dennis Mazur

Hi

what do you mean

other than

VO2, VE and respiratory exchange ratio (RER)

The study of muscle fatigue with EMG can be done with the median frequency obtained from the power spectrum. However the EMG signal needs to be very stable and this only happens in an isometric contraction. In other words, the calculation of the median frequency of the EMG signal can not be done based on a dynamic muscle contraction. You can have a dynamic exercise which induces fatigue and two isometric contractions, for instance, before and after. In these two isometric contractions you can calculate the median frequency.

If I didn't have the equipment - I still start HEP of seated heel raises - creating minimal loading but stimulating muscular activity we desire.  they can still shift emphasis to slow lowering or eccentric control.  I do have patients work heel raise in modified plantigrade using a table or high counter support so they can partially unload body weight by leaning trunk weight onto table or counter - still work heel raises but give them some ability to graduate loading.  can progress from slow loading to quicker eccentric shifts partial body weight loading with progression to working more upright and taking greater percentage of body weight to finally full erect posture as well as ability to walk on balls of feet.  not certain if I am drifting off your initial questions?

Additional question about gravity correction in the Cybex Humac norm:

We investigate the shoulder internal/external ration in tetraplegics. We use the "seated mod" setting and use the built in gravity correction/weighing the limb. When we analyze the data should we just report the data in preview or check the button "gravity correction"? When we tick off the box "gravity correction", we would expect the software to subtract the MAXGET from internal rotation (gravity assisted direction) and add to the external rotation (gravity resisted direction) BUT Cybex seems to do the opposite! So we get increased ratios, far off the normative values previously reported. So, to get the correct peak torque, should we just gravity correct after the ROM setting and no further, or do it again in the analysis? Yours sincerely, Claus Bech, University of Southern Denmark

I believe that the time measured in this article began after passing through the photoelectric cell placed at 90% stride distance before the center of the force plate. The time between the onset and the peak of the ground reaction force curve should be much lower, in which case the time addressed in the article seems to be the interval between the passage through the cell and the peak of fx and fz.

hi

you can also use Isokinetic  instruments  like biodex and ..... I sent for you a  article  

You're asking too broad a question Rodolfo. There are too many other factors to consider. For example: Long hold (30 seconds or more) static stretching done immediately before a soccer match can have a detrimental effect on explosive power and speed, so static stretching used this way would decrease performance.

However, short hold (15 seconds or less) static stretch used early in the warm up procedure is a very effective part of a complete warm up, which in turn will help to improve performance. And then there's static stretching for cooling down, improving ROM, etc, etc.

It's more about how and when static stretching is used, rather than making a blanket statement that static stretching is either good or bad.

As far as your project is concerned (Acute effects of static stretching on leg power in soccer players)... I can already tell you what the results will be. In this case, like in my first example above, static stretching immediately before a Wingate test will DECREASE the production of explosive force in any athlete.

These types of studies have been done a hundred times before and it's already well established that doing long hold static stretching immediately before power based activities will have a detrimental effect on explosive power and speed. Maybe try to come up with a variation of this test.

Anyway, good luck with it and if I can help with anything else, just ask.

Regards,

Brad Walker

greetings

the attached file may help you. by the way study this paper: Changes in muscle contractile properties and neural control during human muscular fatigue

good luck

There is plenty of self-adhesive electrodes available for purchase. In case you want to make your own electrodes:

You might want to consider double-sided (foam) tape that you can cut (laser-cut if possible) as you wish. The wholes of the foam tape can then be filled with conductive material, such as conductive gel. The electrode material itself is usually Ag/Cl or Au. References for examples (double-sided tape in HD-EMG applications) and recommendations for EMG set-up (including electrode material):

- Hermens, H. J., Freriks, B., Disselhorst-Klug, C., & Rau, G. (2000). Development of recommendations for SEMG sensors and sensor placement procedures. Journal of Electromyography and Kinesiology, 10(5), 361–374.

- Lapatki, B. G., Van Dijk, J. P., Jonas, I. E., Zwarts, M. J., & Stegeman, D. F. (2004). A thin, flexible multielectrode grid for high-density surface EMG. Journal of Applied Physiology, 96(1), 327–36. 

Hi Steven,

Thank you for your response. Indeed the first barrier when trying to get into this topic is terminology. You can't talk about heel strike (first contact) vs forefoot strike (first contact) without the argument of shod vs barefoot clouding the issue (not made any better by me putting 'barefoot' in my question; but I thought as much of the literature confuses the two things I would put barefoot in the question too). To be clear I am interested in heel first contact vs forefoot first contact, and whether there is any good research to show that there is a reduced incidence of injury when forefoot running, especially if the people were trained to forefoot run having previously been a heel first contact runner.

I am very interested in a few of the argument you made: Have you got any evidence that 'all' distance runners are heel strikers? What are you defining as distance? I have recorded runners forefoot striking an entire 10km time trial, in fact I have done it myself? You only have to look at video of the Olympic 10km runners to see a small percentage forefoot striking. And I know people that have run both half and marathon distance on their forefoot.  

The natural selection argument is an interesting one. It is a key principle that evolution by natural selection does not come up within the 'best solution' to a problem, it comes up with solutions that are more of a survival advantage than the last. Bearing that in mind, it is perfectly reasonable that humans, or sport scientists, designed running shoes that are better for reducing injury than evolution did with barefoot running or they thought they were improving things and didn't. Both are possible that's why we need evidence.

Patrick's answer pretty much sums things up. You could implement what he has detailed with the Opal system (as mentioned by Ebenezer) or try building your own! Sparkfun have all the inertial sensor components you would need. There are lots of tutorials on YouTube also.

For any theory reference, the book by Titterton and Weston: "Strapdown Inertial Navigation Technology", is a good go to guide. But be warned its very mathematical. 

 Dear friend:

To assess the Spatio-temporal variables of gait in field conditions you have 2 main options depends of the aim of your research.

The 2 options are:

1-    Pressure/contact/optical mats.

2-    Inertial movement units (IMUs). (accelerometer + gyroscope).

If your idea is evaluate the subject in a field test, both options are well. But, if you need a system to assess the training of the athletes or that the subject place and training itself and later you collect the data, the  IMUs is better because usually have a internal SD card to record by itself.

About the first option (Pressure/optical sensors), the most popular equipments are:

GaitRITE (pressure mat):   http://www.gaitrite.com

Tekscan (pressure mat): https://www.tekscan.com/products-solutions/systems/walkway-system

ProtoKinetics (pressure mat): http://www.protokinetics.com/zenowalkway.html

iMagiMat (pressure mat): http://www.mub.eps.manchester.ac.uk/imagimat/more-information/

Optogait (optical bar): http://www.optogait.com

About the second option (IMU sensors) you can make your own system (only need buy some IMUs sensors and make your own software with matlab, C++ or similar, there are some manuscripts about the calculi of spatio-temporal parameters with IMU sensors (only search in PubMed or Medline) and you can place only one sensor in the sacrum or in both shanks.

 Or you can buy a commercial solution:

Xsens: http://www.xsens.com/products/

NexGen: http://www.nexgenergo.com/

GaitUP: http://www.gaitup.com/products/

McRoberts: http://www.gaitup.com/products/

 I hope I have helped.

Hi Sarah, I helped with a study that found that these patellar straps decrease the mean localized computational strain in the area of the patellar tendon commonly involved in jumper's knee by increasing the patella-patellar tendon angle.  Michael

The EPTIS database (www.eptis.bam.de) provides information about the organizers of proficiency testing,

In this database you'll find a large share of PT providers, the database contains up to 2888 PT schemes.

I hope you can find there what you need.

I tend to agree with Md. Saidul Islam. But surely there are other factors that influence Bolt's success. The RR polymorphism of the ACTN3 gene is over represented in Jamaica due to human selection performed by slavers. Jamaica was one of the main hubs for the slave trade and it is assumed that the fastest and strongest slaves managed to flee from slavers and hide in places that were difficult to access. Bolt comes from a region of Jamaica that has evolved from these slave villages. 

In a biomechanical point of view, his long legs also help with sprinting. 

There is also a social influence, of course. Sprinting is popular and very competitive in Jamaica. To a point that is glamour is as great as that of any other competitive sport. I guess in other countries Bolt could have joined Football, basketball or other competitive sports teams that are not only popular, but also lucrative. 

If you are interested in reading about this kind of issue, I would recommend a book written by David Epstein called "The Sports Gene". It explains not only the success of jamaican sprinters, but also the dominance of Kenya and Ethiopia in endurance events and many other biological and sociological features of competitive sports.

Regards

Hi Ashr,

If you still interesting the following papers maybe help you.

1.       Andrade, R. J., Nordez, A., Hug, F., Ates, F., Coppieters, M. W., Pezarat-Correia, P., & Freitas, S. R. (2015). Non-invasive assessment of sciatic nerve stiffness during human ankle motion using ultrasound shear wave elastography. Journal of Biomechanics. doi: http://dx.doi.org/10.1016/j.jbiomech.2015.12.017

2.       Dal Pupo, J., Dias, J. A., Gheller, R. G., Detanico, D., & dos Santos, S. G. (2013). Stiffness, intralimb coordination, and joint modulation during a continuous vertical jump test. Sports Biomech, 12(3), 259-271. doi: 10.1080/14763141.2013.769619

3.       de Gooijer-van de Groep, K. L., de Vlugt, E., van der Krogt, H. J., Helgadóttir, Á., Arendzen, J. H., Meskers, C. G. M., & de Groot, J. H. (2016). Estimation of tissue stiffness, reflex activity, optimal muscle length and slack length in stroke patients using an electromyography driven antagonistic wrist model. Clin Biomech (Bristol, Avon). doi: 10.1016/j.clinbiomech.2016.03.012

4.       Ditroilo, M., Watsford, M., Murphy, A., & De Vito, G. (2013). Sources of variability in musculo-articular stiffness measurement. PLoS One, 8(5), e63719. doi: 10.1371/journal.pone.0063719

5.       Fábrica, G., & López, F. (2016). Mechanical stiffness: a global parameter associated to elite sprinters performance. Revista Brasileira de Ciências do Esporte. doi: 10.1016/j.rbce.2016.02.004

6.       Foure, A., Cornu, C., McNair, P. J., & Nordez, A. (2012). Gender differences in both active and passive parts of the plantar flexors series elastic component stiffness and geometrical parameters of the muscle-tendon complex. J Orthop Res, 30(5), 707-712. doi: 10.1002/jor.21584

7.       Gustafson, J. A., Gorman, S., Fitzgerald, G. K., & Farrokhi, S. (2015). Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability. Gait Posture. doi: 10.1016/j.gaitpost.2015.09.025

8.       Han, H., Jo, S., & Kim, J. (2015). Comparative study of a muscle stiffness sensor and electromyography and mechanomyography under fatigue conditions. Med Biol Eng Comput, 53(7), 577-588. doi: 10.1007/s11517-015-1271-1

9.       Hannah, R., & Folland, J. P. (2015). Muscle-tendon unit stiffness does not independently affect voluntary explosive force production or muscle intrinsic contractile properties. Appl Physiol Nutr Metab, 40(1), 87-95. doi: 10.1139/apnm-2014-0343

10.   Huang, Y., & Wang, Q. (2016). Torque-Stiffness-Controlled Dynamic Walking: Analysis of the Behaviors of Bipeds with Both Adaptable Joint Torque and Joint Stiffness. IEEE Robotics & Automation Magazine, 23(1), 71-82. doi: 10.1109/MRA.2015.2510753

11.   Inouye, J. M., & Valero-Cuevas, F. J. (2016). Muscle Synergies Heavily Influence the Neural Control of Arm Endpoint Stiffness and Energy Consumption. PLoS Comput Biol, 12(2), e1004737. doi: 10.1371/journal.pcbi.1004737

12.   Kerkum, Y., Harlaar, J., van den Noort, J., Becher, J., Buizer, A., & Brehm, M. A. (2015). The effects of different degrees of ankle foot orthosis stiffness on gait biomechanics and walking energy cost. Gait Posture, 42, S89-S90. doi: 10.1016/j.gaitpost.2015.06.163

13.   Kubo, K., Miyazaki, D., Ikebukuro, T., Yata, H., Okada, M., & Tsunoda, N. (2016). Active muscle and tendon stiffness of plantar flexors in sprinters. J Sports Sci, 1-7. doi: 10.1080/02640414.2016.1186814

14.   Leong, H. T., Hug, F., & Fu, S. N. (2016). Increased Upper Trapezius Muscle Stiffness in Overhead Athletes with Rotator Cuff Tendinopathy. PLoS One, 11(5), e0155187. doi: 10.1371/journal.pone.0155187

15.   Maloney, S. J., Richards, J., Nixon, D. G., Harvey, L. J., & Fletcher, I. M. (2016). Vertical stiffness asymmetries during drop jumping are related to ankle stiffness asymmetries. Scand J Med Sci Sports. doi: 10.1111/sms.12682

16.   McGowan, C. P., Grabowski, A. M., McDermott, W. J., Herr, H. M., & Kram, R. (2012). Leg stiffness of sprinters using running-specific prostheses. J R Soc Interface, 9(73), 1975-1982. doi: 10.1098/rsif.2011.0877

17.   Ovesy, M., Nazari, M. A., & Mahdavian, M. (2016). Equivalent linear damping characterization in linear and nonlinear force-stiffness muscle models. Biol Cybern, 110(1), 73-80. doi: 10.1007/s00422-016-0680-z

18.   Pruyn, E. C., Watsford, M. L., & Murphy, A. J. (2015). Validity and reliability of three methods of stiffness assessment. Journal of Sport and Health Science, 1-8. doi: 10.1016/j.jshs.2015.12.001

19.   Sanchis-Sales, E., Sancho-Bru, J. L., Roda-Sales, A., & Pascual-Huerta, J. (2016). Dynamic Flexion Stiffness of Foot Joints During Walking. Journal of the American Podiatric Medical Association, 106(1), 37-46.

20.   Silder, A., Besier, T., & Delp, S. L. (2015). Running with a load increases leg stiffness. J Biomech, 48(6), 1003-1008. doi: 10.1016/j.jbiomech.2015.01.051

21.   Skidmore, J., & Artemiadis, P. (2016). On the effect of walking surface stiffness on inter-limb coordination in human walking: toward bilaterally informed robotic gait rehabilitation. J Neuroeng Rehabil, 13(1), 32. doi: 10.1186/s12984-016-0140-y

22.   Struzik, A., & Zawadzki, J. (2013). Leg stiffness during phases of countermovement and take-off in vertical jump. Acta of bioengineering and biomechanics / Wroclaw University of Technology, 15(2), 113-118.

23.   Struzik, A., Zawadzki, J., & Rokita, A. (2016). Leg stiffness and potential energy in the countermovement phase and the CMJ jump height. Biomedical Human Kinetics, 8, 39–44. doi: 10.1515/bhk-2016-0006

24.   Takahashi, K. Z., Gross, M. T., van Werkhoven, H., Piazza, S. J., & Sawicki, G. S. (2016). Adding Stiffness to the Foot Modulates Soleus Force-Velocity Behaviour during Human Walking. Sci Rep, 6, 29870. doi: 10.1038/srep29870

25.   Yasuda, T., Fukumura, K., Iida, H., & Nakajima, T. (2015). Effects of detraining after blood flow-restricted low-load elastic band training on muscle size and arterial stiffness in older women. SpringerPlus, 4, 348. doi: 10.1186/s40064-015-1132-2

Regards,

I understand now.This topic is important intraop during TKA and when you explore a patient in the office ( TKA stability).I will try to read the articles above.Thank you!

A simple solution as suggested by Abdel-Rahman works in theory but is complicated by signal drift and noise. Errors will exponentially increase when double-integrating the acceleration signal. As a result, the calculated displacement will be highly unreliable. Luckily, more sophisticated methods exist. One approach that has shown to work particularly well involves periodically applying a zero-velocity update in the integration process. However, this requires knowledge about an instance during which the sensor will be stationary. If your question is related to walking or running, I suggest reading up on Pedestrian Dead Reckoning and ZUPT algorithms. Here are some helpful resources:

Angermann, Michael, et al. "A high precision reference data set for pedestrian navigation using foot-mounted inertial sensors." Indoor Positioning and Indoor Navigation (IPIN), 2010 International Conference on. IEEE, 2010.

Fischer, Carl; Talkad Sukumar, Poorna; Hazas, Mike "Tutorial: Implementing a Pedestrian Tracker Using Inertial Sensors", Pervasive Computing, IEEE, On page(s): 17 - 27 Volume: 12, Issue: 2, April-June 2013

Dear Masoumeh

I am working on QE training, you can go to My lab and visit it.

Maybe in book by Kari, Bo et al 2015 Evidence based physiotherapy for pelvic floor muscles. Although I don't  see the connection because in horseback riding important muscle groups are thigh adductors, gluteals, guadriceps, core muscles...just my oppinion.

It depends where the marker is located and if it's a cyclic movement: if the marker is part of a (more or less) rigid body, for example the shank, and you have other markers on that rigid body that are still visible, you can generate a virtual marker based on the markers that you can still see (because you know the position of the missing marker with respect to the visible one). If it's a cyclic movement, e.g. walking, you can extrapolate from previous cycles. If it's neither of the two, you could extrapolate for example in Matlab after exporting the marker data, but of course you wouldn't know if this extrapolation is correct.

Yes , refer to tutorial given at webpage of act-r.

Great, glad to offer some help.

Just another pointer,  to remember  that during maximal kicking not all forces which act to accelerate the lower leg and foot are supplied directly by the muscles but from 'motion-dependent' or 'interactive' forces as well, which you would have to take into account if performing dynamometry!

Thanks

Simon

some axons may be neurapraixic and if it humans you can try ETOIMS to aid recovery of neurapraxia

I'm using quaternions, but it does not help in answering your question. So, please, let me intriduce you with Dr. Chris Kirtley who asked the very same question than yours 15 years ago (http://biomch-l.isbweb.org/threads/11415-Summary-Quaternions-vs-Euler-angles). He said : "I guess it's time I summarized the great quaternion debate. To remind you, I asked why quaternions (otherwise known as Euler parameters) seem to be used as the standard method for representaing motion in computer animation and video games, but are not so often used in biomechanics. It seems that, whilst quaternions have advantages in terms of lack of gymbal lock, and insensitivity to round-off errors, they suffer from problems of interpretation in terms of meaningfully clinical or anatomical angles. As Joe Sommer and Bruce MacWilliams suggest, the best compromise is perhaps to use quaternions for intermediate calculations, then convert to Euler angles at the end." I do share their advice; using quaternions for math, and convert to Euler at the end to help our 3D-limited brain.

Dear my  colleague Hamdy,

I hope the following papers help you.

Buller, P. F., & McEvoy, G. M. (2012). Strategy, human resource management and performance: Sharpening line of sight. Human Resource Management Review. http://doi.org/10.1016/j.hrmr.2011.11.002

Cholewicki, J., & McGill, S. M. (1996). Mechanical stability of the in vivo lumbar spine: Implications for injury and chronic low back pain. Clinical Biomechanics, 11(1), 1–15. http://doi.org/10.1016/0268-0033(95)00035-6

Colloca, C. J., Keller, T. S., Harrison, D. E., Moore, R. J., Gunzburg, R., & Harrison, D. D. (2006). Spinal manipulation force and duration affect vertebral movement and neuromuscular responses. Clinical Biomechanics, 21(3), 254–262. http://doi.org/10.1016/j.clinbiomech.2005.10.006

Danion, F., & Sarlegna, F. R. (2007). Can the human brain predict the consequences of arm movement corrections when transporting an object? Hints from grip force adjustments. The Journal of Neuroscience : The Official Journal of the Society for Neuroscience, 27(47), 12839–12843. http://doi.org/10.1523/JNEUROSCI.3110-07.2007

Dulhunty, J. (2002). A simplified conceptual model of the human cervical spine for evaluating force transmission in upright static posture. Journal of Manipulative and Physiological Therapeutics, 25(5), 306–317. http://doi.org/10.1067/mmt.2002.124421

Flanagan, J. R., & Wing, a M. (1997). The role of internal models in motion planning and control: evidence from grip force adjustments during movements of hand-held loads. The Journal of Neuroscience : The Official Journal of the Society for Neuroscience, 17(4),

Han, J. S., Goel, V. K., & Kumar, S. (1991). A nonlinear optimization force model of the human lumbar spine. International Journal of Industrial Ergonomics, 8(3), 289–301. http://doi.org/10.1016/0169-8141(91)90039-O

Hansen, L., de Zee, M., Rasmussen, J., Andersen, T. B., Wong, C., & Simonsen, E. B. (2006). Anatomy and biomechanics of the back muscles in the lumbar spine with reference to biomechanical modeling. Spine, 31(17), 1888–99.

Keenan, K. G., Santos, V. J., Venkadesan, M., & Valero-Cuevas, F. J. (2009). Maximal voluntary fingertip force production is not limited by movement speed in combined motion and force tasks. The Journal of Neuroscience : The Official Journal of the Society for Neuroscience, 29(27), 8784–8789. http://doi.org/10.1523/JNEUROSCI.0853-09.2009

Lackner, J. R., & Dizio, P. (1994). Rapid adaptation to Coriolis force perturbations of arm trajectory. J Neurophysiol, 72(1), 299–313. http://doi.org/citeulike-article-id:450102

Ledet, E. H., Tymeson, M. P., DiRisio, D. J., Cohen, B., & Uhl, R. L. (2005). Direct real-time measurement of in vivo forces in the lumbar spine. Spine Journal, 5(1), 85–94. http://doi.org/10.1016/j.spinee.2004.06.017

Luinge, H. J., & Veltink, P. H. (2004). Inclination measurement of human movement using a 3-D accelerometer with autocalibration. IEEE Transactions on Neural Systems and Rehabilitation Engineering : A Publication of the IEEE Engineering in Medicine and Biology Society, 12(1), 112–121. http://doi.org/10.1109/TNSRE.2003.822759

Shirazi-Adl, A., & Parnianpour, M. (1993). Nonlinear response analysis of the human ligamentous lumbar spine in compression. On mechanisms affecting the postural stability. Spine, 18(1), 147–58. http://doi.org/10.1097/00007632-199301000-00021

Shirazi-Adl, A., Sadouk, S., Parnianpour, M., Pop, D., & El-Rich, M. (2002). Muscle force evaluation and the role of posture in human lumbar spine under compression. European Spine Journal, 11(6), 519–526. http://doi.org/10.1007/s00586-002-0397-7

Shum, G. L. K., Crosbie, J., & Lee, R. Y. W. (2005). Symptomatic and asymptomatic movement coordination of the lumbar spine and hip during an everyday activity. Spine, 30(23), E697–702. http://doi.org/10.1097/01.brs.0000188255.10759.7a

Teo, E. C., & Ng, H. W. (2001). Evaluation of the role of ligaments, facets and disc nucleus in lower cervical spine under compression and sagittal moments using finite element method. Medical Engineering and Physics, 23(3), 155–164. http://doi.org/10.1016/S1350-4533(01)00036-4

Vaz, G., Roussouly, P., Berthonnaud, E., & Dimnet, J. (2002). Sagittal morphology and equilibrium of pelvis and spine. European Spine Journal, 11(1), 80–87. http://doi.org/10.1007/s005860000224

Wada, O., Tateuchi, H., & Ichihashi, N. (2014). The correlation between movement of the center of mass and the kinematics of the spine, pelvis, and hip joints during body rotation. Gait and Posture, 39(1), 60–64. http://doi.org/10.1016/j.gaitpost.2013.05.030

Wu, B., Wang, C., Krug, R., Kelley, D. A., Xu, D., Pang, Y., … Zhang, X. (2010). 7T human spine imaging arrays with adjustable inductive decoupling. IEEE Transactions on Bio-Medical Engineering, 57(2), 397–403. http://doi.org/10.1109/TBME.2009.2030170

Regards, 

Abdel-Rahman

Hi,

  I hope you will find the answer and more in the attached document. They include research in motion analysis using 3D simi motion.

Kind regards.

-

Hi Timothy. I am familiar with FOTO, good product and there are thousands of users. However, we have not used in our research ( I know Len Matheson has in the past). I am not aware of what is clinically meaningful change with FOTO. This is a difficult questions with many outcome tools. I assume you asked FOTO or performed a publication search ? Another way you can look at this is by comparing other standard gold outcome tools clinical significant changes and see if FOTO data are similar . We did this when we compared our tool to VAS, Roland Morris , etc. We also determined sensitivity with change over time. Makes sense  ?  Good luck, Joe Verna

 So, are externally movements a part of circuits of caudate nucleus?

Thank you for your answers.

Many thanks for your help. Your comments have helped me a lot as I could not find that information anywhere.

Hi Marcelo. We are trying something new out in this area. You might want to take a look at http://academic.udayton.edu/murray/DIMLAB/pubs/conference/2015/T2OC-3.pdf. Unfortunately, this isn't our most recent work which streamlines the process significantly compared to the work presented in that paper. That publication is currently under preparation, but you can find most of it in an upcoming dissertation. I can supply a draft if interested.

I'm especially interested in the M. Gastrocnemius and the M. Soleus (and thereby also the Achilles tendon). 

Studies have allready proven that changing from an initial rearfoot strike pattern to an initial front foot strike pattern (in running) lower the knee loading, but the plantarflexors (as mentioned above) will be more activated. 

My question is: if you change from a initial rearfoot strike pattern to an initial front foot strike pattern, how many of the subjects (%) will keep this changed pattern (because by more activating the plantarflexors, injuries as achilles tendinopathies can occur, and it is often difficult to run with a changed pattern). 

Dear All,

Finally I could remove a specific part of body in a video display.  It is possible and it is simple.

My investigations of body posture have revealed that posture is highly variable and dependent upon person, activity and constraints in that activity.  More important is the capacity within the environment for anyone to change posture.  There are many techniques for measuring body posture but the ultimate question concerns the posture associated with the activity and can the posture change.  For example, short drivers use an erect posture to raise their eye height for driving while tall drivers use a slumped posture to fit in the car.  The question is whether drivers can sit in these postures in the same car and is there capacity within the car seating package to allow a change of posture.  We have learned that repetitive motions are dangerous and fixed, "good" postures are dangerous.  Thus, I would recommend a question concerning how to measure the range of postures available within an activity rather than one that assumes there is a "good posture" for everyone in the investigation.

Hi Mansour 

I was wondering if you have to come to a conclusion regarding what organisation is best for sports biomechanics labs? We are currently investigating the same.

Thanks

Shane

Speed and Distance are related to accuracy as well as if the skill is a Simple to Complex skill and if it is in an Open or Closed Enviorment also weather effects and shoe surface interaction effects also play and effect as well as the skill of the opponent and/or teammate.  Thus, if one starts practicing the skill in a slow, smaller distance, closed environment with min. to no distractions, then moves into a faster greater distance and involve a more complex scenario and practice, practice in a blocked and random practice manner, the skill of passing and cutting should improve. I hope this helps.

Clinical gait is usually associated with data collected for patients that underwent a THA or TKA or have certain pathological problems that might affect their gait where we need to follow their progression before and after treatment. It also might require clinical observation by an orthopedic surgeon during gait data collection. Clinical gait is performed in clinical setting and is usually an extension of a clinic. Clinical data is usually to evaluate patients gaits for the purpose of identifying a musculus-skeletal   problem and monitor the gait after a hip or knee surgery. General gait is used to estimate the working muscles forces and torques at the joints, analysis of stability, and other work-energy related functions.

One suitable approach could be a metal or wood (thick) square under the platform. The size should be larger than the size of platform. This should be solve the problem of irregularity of packed dirt surface. However, the surface density should be considered in order to avoid dissipation of forces. If possible, the under base should be thicker than 10 cm.

You can use Morin's formula (Morin et al., 2005) and you only have to measure when running velocity, fly time and contact time. You also have to measure lower limb lenght and body mass of each athlete. Using an Opto Jump and a radar you can easily find muscle stiffness of the lower limb. 

Hi Zach. You can add force plates etc. in the "system" panel within Nexus. When looking at the system panel (over on the left-hand side of the screen) there will be an option for "add devices" towards the bottom. In here you can select force plates and Nexus already has the different types of force plates for Bertec, AMTI, Kistler loaded in. All you have to do is select the appropriate version from the drop-down list and then input the specific data for each of the channels associated with the force plate as well as the dimensions (this information will be located in the manual that came with the force plate). So long as Nexus can see the analog signal associated with the force plates (which it will of your AD box is working), the installation is pretty straight forward (so much so that I was able to do ours at ESU). Good luck.

Dear Simon,

maybe you can use the following Information…

Mänty M, Kuh D, Cooper R. Associations of Midlife to Late Life Fatigue With Physical Performance and Strength in Early Old Age: Results From a British Prospective Cohort Study. Psychosom Med. 2015;77(7):823-32. http://journals.lww.com/psychosomaticmedicine/Abstract/2015/09000/Associations_of_Midlife_to_Late_Life_Fatigue_With.13.aspx

Boter H, Mänty M, Hansen AM, Hortobágyi T, Avlund K. Self-reported fatigue and physical function in late mid-life. J Rehabil Med. 2014 Jul;46(7):684-90. https://www.rug.nl/research/portal/files/16333749/1915.pdf

Tanaka M, Ishii A, Watanabe Y. Neural effect of mental fatigue on physical fatigue: a magnetoencephalography study. Brain Res. 2014;1542:49-55. https://www.researchgate.net/publication/259504008_Neural_effect_of_mental_fatigue_on_physical_fatigue_A_magnetoencephalography_study

Tanaka M, Ishii A, Watanabe Y. Neural mechanism of facilitation system during physical fatigue. PLoS One. 2013;8(11):e80731. http://www.plosone.org/article/fetchObject.action?uri=info:doi/10.1371/journal.pone.0080731&representation=PDF

Singh T, Zatsiorsky VM, Latash ML. Contrasting effects of fatigue on multifinger coordination in young and older adults. J Appl Physiol (1985). 2013;115(4):456-67. http://jap.physiology.org/content/jap/115/4/456.full.pdf

Martin H. Determinants of isometric grip strength and fatigue in human subjects. Geneva College, Department of Biology: https://pressfolios-production.s3.amazonaws.com/uploads/story/story_pdf/70289/702891394910126.pdf

Best wishes from Germany

Martin

Hi Robin.

Try;

Laurentino, G., Ugrinowitsch, C., Aihara, A.V., Femandes, A.R., Parceli, A.C., Ricard, M., Tricoli, V. ''Effects of Strength Training and Vascular Occlusion.' (2008) International Journal of Sports Merdicine, 29(8), pp.664-667

There were no adverse events from using BfR with higher training loads (around 60-80% 1RM) but it brought nothing extra to the gains seen in 1RM values and quadriceps cross-section area. (These occured at similar levels in both the BfR and control groups). As Steve says, training at that intensity level without BfR would occlude blood-flow during muscular loading anyway.

Best,

Phil

I hope that this answer help you

hay dr.

gauge= what is mean please look your question please

Hello Bhaskar

Of course you can use copper, as every conducting material, to record surface EMG. To my experience copper has many disadvantages for that purpose. It will fast be covered by a patina (not only at the soldering points as mentioned by Joachim). This oxide (hydroxide) is caused by contact with salt water, sweat, soldering flux, conducting gel, or other agents which react with copper. The patina alters the electrode-skin impedance in an erratic fashion and this might influence the signals intended to record. That is why most electrodes are built (or at least covered) of precious metals or stainless steel. Using the latter for special purpose electrodes was always without problems in our applications. As Joachim already mentioned a kind of conducting gel or would be needed too. Please keep in mind, that pairing copper with other conducting materials might result in a bias voltage (cause by the electro-chemical voltage) which might drive your amplifier in saturation if you use a DC amplifier.

Try to use standard material first (e.g. your mentioned electrode, or a stainless steel plate of one dime in diameter) with your recording apparatus to be sure it is the copper material problem which let your records fail. What kind of recording system, which type of recording amplifier (differential, single ended, AC) are you using? In your description the purpose or practical reason why you persist to use copper is unclear. Maybe some explanations are possible without uncovering the secret application ;-).

Microelectrodes (I guess you are talking about electrodes of sizes < 1mm) will cause additional problems, of which the dramatically reduced recording area - i.e. the distance in space within any active muscle fibers must be situated to substantially contribute to the recorded EMG Amplitude – is the most influential. In short: small electrodes monitor only few muscle fibers, and those might eventually not be representative for the activity of the whole muscle.

Regards Thomas

Hi Ashley,

May I suggest you to use Scilab (http://www.scilab.org/), which is a FREE computation software initially  developed by the French Research Institute on Artificial Intelligence (INRIA) and which is quite as powerful as Matlab ?

Best regards,

Philippe.

Hi Esmaeel,

First, could you explain why you want to know the instant of ball release? Are you trying to compare with previous research? Or are you trying to answer a specific research question? How accurate do you have to be?

Second, could you elaborate on what data you have measured?

Frankly, I don't think you can reliably detect the instant of ball release if you only have joint angle data. Sure, you can estimate it happens at for example the the peak velocity of the wrist angle, but you will never be entirely accurate due to (functional) variability. Ultimately, you would have to validate your assumption that instant of release and some variable of joint angles are related.

Good luck,

Rens

Hi Hannes, 

There are two great papers about EMG normalization during cycling: 

In addition to those, there is a very good review (Nick Ball and Joanna Scurr, Journal of applied biomechanics, 2013) about EMG normalization during high-velocity muscle actions.

The normalization method that you choose in the end, will depend on your research question... But is important to have in mind that this method should be both repeatable (reliable) and sensitive. Both issues are very well discussed in the Albertus-Kajee paper, so maybe you would like to use that article as a reference. 

In my opinion, in case that you are analyzing high-velocity cycling, sub-maximal dynamic reference contractions are better for normalization in comparison to an isometric MVC.

Hope that this helped and good Luck with your work,

Kind Regards,

Eduardo 

The Sorenson test is standardized with normative values for trunk extension endurance (Demoulin, C, 2006). For those with access to a Biodex unit, there is a back attachment that quantifies isometric and is kinetic strength of trunk flexion and extension (Grabiner MD, 1990). Finally Timed Loaded Standing is a standardized measure of combined trunk and arm endurance suitable for people with vertebral osteoporosis. (Shipp, KM, 2000).

Hello Peter,

I would say that it depends on the level of accuracy you want to get and the general purpose of computing these variables (for discriminating different phases of a particular movement, f.ex.). If these are simple kinematic quantities (angular motion of joint angles or limb accelerations...) ,  I think you can either use the upper limb models you mentioned. The variations in the limb/joints during movement execution would follow a pattern close to real, I assume. Otherwise, I would recommend to create your own model (for throwing) by yourself in Nexus.

I would be curious to see the distortions between such a model and the ISB standards.

Halim

We are doing some research on prevalence of injuries among players Chhattisgarh, India.

 A good starting point is that it is linear. However, this is only when the muscle is activated isometrically at the same length across different intensities. In reality, a true linear relationship is not really recorded due to, but not limited to:

These are only a select few reasons why on the global side (i.e. in vivo) of the muscular force-activation relationship, we report a curvilinear relationship between activation (surface EMG) and muscle force. Further, if you are measuring force on a force platform, then you have many muscles crossing many joints that you are then trying to sum (and/or weight accordingly) to develop a relationship.

My thesis can be found here (https://www.researchgate.net/publication/273759936_Mechanical_factors_affecting_the_estimation_of_tibialis_anterior_force_using_an_EMG-driven_modelling_approach), which focuses on this question in detail, so instead of putting a lot of references here for your further research, there are a lot at the back of the thesis.