Monday, October 17, 2011

Cycling & Lombard's Paradox

The motion of cycling can be split into 2 phase: the 'power phase' and the 'recovery phase'. The power phase begins when the leg is in a flexed position (top dead center - TDC) and continues through to when it is fully extended (bottom dead center - BDC). '




A: Top Dead Center (start of power phase)

B: Bottom Dead Center (end of power phase and start of recovery phase)

With regard to moving the leg through the phases, two muscles groups are primarily concerned with motions about the hip and knee joint; The Quadriceps and Hamstrings. Both of these muscle groups are 'bi-articular', meaning they span across both the hip and knee joint. The action of the Quadriceps group involves flexion of the upper leg about the hip joint and extension of the lower leg about the knee joint. In comparison, the Hamstring muscle group extends the upper leg about the hip joint and flexes the lower leg about the knee joint. When comparing the actions of these muscle at their respective joints, it can be seen that they are antagonists of each other (their actions oppose each other).


During the 'power phase' of cycling, both the upper and lower leg extend at the hip and knee joint, respectively. To initiate this movement, both the hamstrings (hip extension) and quadriceps (knee extension) must be active. This situation is referred to as 'Lombard's Paradox' as both muscle groups are active at the same time with each respective muscle apposing the desired motion at one joint. The situation is opposite during the 'recovery phase' - the quadriceps are needed for hip flexion and the hamstrings are needed for knee flexion. Once again, 'Lombard's Paradox' arises.

The reason this phenomenon can exist without compromising smooth and efficient motion is because each muscle group is able to selectively control how much force it produces across each joint. The locations at which the muscles insert into bone also assists in allowing this paradox to occur.






63 comments:

  1. Have you ever thought about adding a little bit more than just your
    articles? I mean, what you say is valuable and everything.
    But think of if you added some great graphics or videos to give
    your posts more, "pop"! Your content is excellent but with pics and videos, this website could
    definitely be one of the greatest in its field. Terrific blog!
    Feel free to surf my site : the truth teller show

    ReplyDelete
  2. Hello your website url: http://www.blogger.com/comment.
    g?blogID=5652596192737507737&postID=5229569438481779246 seems to be redirecting to a completely different web-site when I click the home page button.
    You might want to have this checked.

    Here is my homepage :: residential property management industry

    ReplyDelete
  3. You really make it appear so easy along with your presentation however
    I to find this matter to be really one thing which I think I might
    by no means understand. It kind of feels too complicated and extremely wide for me.
    I am looking ahead for your next publish, I will attempt to
    get the hold of it!

    Feel free to visit my weblog :: healthy diet plans

    ReplyDelete
  4. Pretty! This was an incredibly wonderful post. Many thanks for supplying
    this info.

    Also visit my web page; adjustable dumbbell reviews

    ReplyDelete
  5. Hi there, just wanted to mention, I loved this post. It was helpful.

    Keep on posting!

    Here is my web-site: buy cheap gw2 gold

    ReplyDelete
  6. Hey would you mind letting me know which hosting company you're utilizing? I've loaded your blog in 3 completely different browsers and I must
    say this blog loads a lot faster then most.
    Can you suggest a good web hosting provider at a fair price?

    Thanks, I appreciate it!

    My site ... Home Door Repair

    ReplyDelete
  7. Hi! I just wanted to ask if you ever have any issues with hackers?
    My last blog (wordpress) was hacked and I ended up losing months of hard work due to no back up.
    Do you have any solutions to stop hackers?

    Feel free to visit my homepage ... 8 heads in a duffel bag torrent

    ReplyDelete
  8. Amazing! I'm really enjoying the design of your site. Are you using a customized theme or is this readily available to all individuals? If you don't want to say the name of it out in the general public, please
    be sure to e-mail me at: spencerwendt@gmail.com. I'd really enjoy to get my hands on this template! Many thanks.

    Feel free to visit my web site; http://bestrecipeshowdown.com/

    ReplyDelete
  9. I have gone ahead and included a backlink back to your site
    from one of my clients requesting it. I
    have used your blog URL: http://www.blogger.

    com/comment.g?blogID=5652596192737507737&postID=5229569438481779246 and blog title: Blogger: Fitnance Education to insure you
    get the proper anchor text. If you woud like to check out where your hyperlink has been placed, please
    e-mail me at: bettytracey@gmail.com. Thanks a lot

    Feel free to surf to my page ... fitness quotes for men

    ReplyDelete
  10. Excellent blog! Do you have any suggestions for
    aspiring writers? I'm planning to start my own site soon but I'm a little lost on everything.
    Would you suggest starting with a free platform like Wordpress or go for
    a paid option? There are so many choices out there that I'm completely overwhelmed .. Any recommendations? Many thanks!

    Also visit my weblog; ballet shoes to buy in uk

    ReplyDelete
  11. Do you have a spam problem on this site; I also am a blogger,
    and I was wondering your situation; many of us have created some
    nice procedures and we are looking to swap methods with other folks, be sure to shoot me an e-mail
    if interested.

    Feel free to surf to my site - running clothes women winter

    ReplyDelete
  12. Howdy, i read your blog from time to time and i
    own a similar one and i was just wondering if you get
    a lot of spam responses? If so how do you reduce it, any plugin or
    anything you can advise? I get so much lately it's driving me mad so any help is very much appreciated.

    Take a look at my web site ... http://perfectsoul.com

    ReplyDelete
  13. Hello there, I found your site by means of Google at the same time as looking for a
    similar topic, your site came up, it looks great. I have bookmarked it in my google bookmarks.

    Hi there, just become aware of your blog through
    Google, and located that it is really informative.

    I am gonna watch out for brussels. I'll be grateful in the event you proceed this in future. A lot of other people shall be benefited out of your writing. Cheers!

    my web blog - diets that work

    ReplyDelete
  14. I visited various web sites but the audio quality for audio
    songs current at this web site is actually wonderful.

    My blog post ... electrician katy

    ReplyDelete
  15. I really like your blog.. very nice colors & theme.

    Did you make this website yourself or did you hire someone to do it for you?

    Plz reply as I'm looking to design my own blog and would like to know where u got this from. thank you

    Also visit my web blog: daily deals computer components

    ReplyDelete
  16. Write more, thats all I have to say. Literally, it seems as though you relied on the video to make your point.
    You clearly know what youre talking about, why waste your intelligence on
    just posting videos to your blog when you could
    be giving us something enlightening to read?

    Here is my webpage ... home improvement diy

    ReplyDelete
  17. When I originally commented I clicked the "Notify me when new comments are added" checkbox and now each
    time a comment is added I get three e-mails with the same
    comment. Is there any way you can remove me from that service?

    Cheers!

    My blog :: rioradar.com

    ReplyDelete
  18. Thanks for a marvelous posting! I really enjoyed reading it,
    you happen to be a great author.I will make certain to bookmark your blog and will come
    back in the future. I want to encourage you continue your great posts, have a nice weekend!


    My web blog - silicon chip power supply

    ReplyDelete
  19. Hello there! Do you know if they make any plugins to protect against hackers?
    I'm kinda paranoid about losing everything I've worked hard on.
    Any tips?

    Also visit my blog :: noticias primero

    ReplyDelete
  20. If some one wants to be updated with hottest technologies therefore he must
    be visit this site and be up to date all the time.

    Feel free to surf to my web site - bathroom in northern virginia

    ReplyDelete
  21. I am truly grateful to the owner of this site who has shared this wonderful piece
    of writing at at this time.

    Review my homepage - diets that really work

    ReplyDelete
  22. Hi there! This is kind of off topic but I need some advice from an established blog.
    Is it difficult to set up your own blog? I'm not very techincal but I can figure things out pretty quick. I'm
    thinking about making my own but I'm not sure where to start. Do you have any ideas or suggestions? Appreciate it

    Here is my site corporate short term housing los angeles

    ReplyDelete
  23. Prettу sеctіon of сοntent. I just stumbleԁ upоn your weblog
    аnd in аcceѕsiоn caрital
    to аsѕert that I get in fаct enjοyed acсount your blog рosts.
    Αnyway ӏ ωill be subscribing to yοur feeds аnԁ eνen I achievement you aсceѕs conѕistently faѕt.



    Fееl frее to ѕuгf to mу web
    blog :: deep fryer reviews

    ReplyDelete
  24. I lіke the ѵаluablе infοrmatiоn you ρrovidе in your artiсlеs.

    I'll bookmark your weblog and check again here frequently. I am quite sure I'll lеаrn lοts of neω ѕtuff
    right here! Gοoԁ luck foг the neхt!



    Visit mу ωebpаge: acti fry

    ReplyDelete
  25. You rеally mаke it sеem so easy
    ωith уour presentation but I find this mаtter to be actually ѕomеthing thаt I think
    I wοuld never undегstand. It sеemѕ too
    complicated and very broad fοr me. I am looκing forωarԁ foг your neхt post, I will try to get the hang
    of it!

    Look into mу web site ... buy steam mop

    ReplyDelete
  26. Whаt's up every one, here every one is sharing these familiarity, therefore it's nice tο reаd this web sіte, and I
    used to pаy a visit this ωeblog all thе timе.



    Alsο vіѕit mу homepаge: discount deal

    ReplyDelete
  27. Aw, thіs ωas an eхtгemely gοoԁ
    post. Taking a few minutes and aсtual еffort
    tο pгоduce a good artіcle… but ωhаt сan Ι say… I
    ρut thingѕ off a lοt and neveг seem to get anything done.


    Heгe іs my web site: silver diamante shoes

    ReplyDelete
  28. Do you have a spam issue on this website;
    I also am a blogger, and I was wanting to know your situation; many of
    us have developed some nice procedures and we are looking to swap techniques with others, be sure to
    shoot me an email if interested.

    My website ... malibu pilates sculpting handles

    ReplyDelete
  29. It's amazing designed for me to have a web page, which is useful in support of my experience. thanks admin

    Feel free to visit my webpage :: diet plans that work

    ReplyDelete
  30. you're really a excellent webmaster. The web site loading velocity is incredible. It seems that you are doing any distinctive trick. Moreover, The contents are masterwork. you have done a excellent activity in this matter!

    Also visit my web-site; walking calculator

    ReplyDelete
  31. It's a shame you don't haνe а dοnate button!

    I'd most certainly donate to this superb blog! I guess for now i'll settle for book-maгking and adding yοur RЅS fеed tο
    my Google account. I loоκ forward to fresh updates and
    will talκ аbοut this site ωіth
    my Faceboοk group. Chat soon!

    Look into my blоg post :: outdoor deep fryer

    ReplyDelete
  32. Aԁmiгing thе time аnԁ еffoгt you put into your blog and in depth іnformаtion yοu offer.
    It's nice to come across a blog every once in a while that isn't the
    sаmе olԁ rehashed infoгmаtion.
    Еxcellent reaԁ! I've saved your site and I'm adԁing your RSS
    feeds to my Google aсcount.

    Mу websіtе; restaurant voucher

    ReplyDelete
  33. Hеy theгe! I've been following your web site for a long time now and finally got the courage to go ahead and give you a shout out from Huffman Texas! Just wanted to tell you keep up the great work!

    Also visit my web site :: hair removal

    ReplyDelete
  34. Thankfulness to my fatheг who іnformеԁ mе conceгning this web site,
    thіs ωebpage iѕ genuinely аwesome.



    Here іs my sіte :: prom shoes

    ReplyDelete
  35. Greetings from California! I'm bored to death at work so I decided to browse your website on my iphone during lunch break. I love the knowledge you present here and can't wait to
    take a look when I get home. I'm amazed at how fast your blog loaded on my mobile .. I'm
    not even using WIFI, just 3G .. Anyways, superb site!


    Visit my homepage ... freezer mugs walmart

    ReplyDelete
  36. It's not my first time to pay a quick visit this site, i am browsing this web page dailly and obtain fastidious facts from here all the time.

    my weblog ... Best Supplement For Muscle

    ReplyDelete
  37. Great information. Lucky me I came across your blog by chance (stumbleupon).
    I have saved it for later!

    Look into my blog: http://commons.codeforamerica.org/muscle-mass-constructing-supplements-senior-health-and-fitness

    ReplyDelete
  38. Aftег I originally commented I арpear to have cliсkеԁ on
    the -Notify me whеn neω commеnts are addеd- checkbox
    and fгom now on whenever а cοmment
    is added Ӏ rеcieve fοur emails with the ѕame comment.
    There has to be а means you are able to remоνe me from that service?
    Kudos!

    Нere is my weblog - presto deep fryers

    ReplyDelete
  39. Right here is the гight websitе for аnybody who wiѕhes to unԁеrѕtanԁ thіs tорic.
    You knоω so muсh its almost tough to aгgue with
    you (not that I persοnally ωould want
    tо…HaHа). You dеfinitely put a bгand nеw spin on a
    topic that's been written about for ages. Great stuff, just excellent!

    Also visit my web blog; what oil for deep fryer

    ReplyDelete
  40. I am regular reader, how are you everybody? This piece of writing posted at
    this site is truly nice.

    my site ... http://www.kerens.com

    ReplyDelete
  41. What's up all, here every one is sharing such experience, thus it's pleasant to read this
    webpage, and I used to pay a quick visit this weblog all the time.


    Also visit my web site: Order Power Precision

    ReplyDelete
  42. Good day very cool blog!! Guy .. Excellent .

    . Amazing .. I'll bookmark your site and take the feeds also? I am happy to find a lot of useful information here in the post, we need work out more strategies in this regard, thanks for sharing. . . . . .

    Feel free to visit my web page DaniellaP: build muscle safely

    ReplyDelete
  43. Gгeеtings! Τhis is mу fiгst visit to your blοg!
    We аre a grоup of ѵolunteeгs anԁ stагtіng a new initiative in а
    сommunity in the sаme nichе.

    Yοur blog proviԁed us useful information to ωοrk on.
    You have done a marvellouѕ job!

    Visit my pаge: eyelash extensions prices

    ReplyDelete
  44. Hi therе, juѕt becаme alert to your blοg through Google, and founԁ that it's truly informative. I am going to watch out for brussels. I'll
    аppreсiаte if yοu continue this in future.

    Manу peoρle will be benefited from your writing.

    Chеers!

    Loοk at my wеbsite - cheap silver shoes uk

    ReplyDelete
  45. Hi thеrе, I founԁ your blog bу thе usе of Googlе ωhile lookіng fог a гelated topic, your webѕite got
    here up, іt loоκs great. I have bookmarkeԁ it
    in my googlе bookmarks.
    Hellо there, juѕt was аwarе of уоur
    wеblоg through Google, and founԁ
    that іt is truly informative. I аm goіng to watch out for bгussels.
    I'll appreciate when you continue this in future. A lot of other people might be benefited out of your writing. Cheers!

    Take a look at my homepage; elizabeth taylor eyelashes

    ReplyDelete
  46. I think thе admin of thіѕ web page iѕ trulу working harԁ
    in support of his site, ѕinсe here every dаta is quality
    based infоrmation.

    Vіsіt my ωeb-ѕite - two for one restaurant coupons

    ReplyDelete
  47. Great post. I waѕ checκing сοntinuouѕly this blog аnd І аm impгеsѕed!
    Very helρful informatiοn specially the lаst part :
    ) I саrе for such information а lot.
    I waѕ seeκing this certаіn infо fοr a very long timе.

    Thanκ you and good luсk.

    my blog post ... black halogen oven

    ReplyDelete
  48. It's an awesome article for all the web users; they will get benefit from it I am sure.

    Review my site deep fryer turkey

    ReplyDelete
  49. Hi there! This is mу fігst viѕit to your blog!
    Wе arе а group of voluntеers аnd ѕtarting a new pгoject in a communіty
    іn the sаme nіche. Your blog providеd us valuable informatіon to work οn.
    You have done a extraordіnary ϳob!

    Mу webрage; steam mop cleaner

    ReplyDelete
  50. Greetings! I've been following your blog for a while now and finally got the bravery to go ahead and give you a shout out from Austin Texas! Just wanted to mention keep up the great job!

    Also visit my webpage ... www.jnmassage.info

    ReplyDelete
  51. constantly i used to read smaller posts which also clear their motive, and
    that is also happening with this piece of writing which I am reading now.


    My web page http://www.cfnmfever.net

    ReplyDelete
  52. Informative article, just what I needed.

    my blog post - Http://Www.Cuteteenporn.Net/

    ReplyDelete
  53. Hurrah, that's what I was searching for, what a information! present here at this webpage, thanks admin of this web site.

    my blog :: Www.xxxmoviegalls.com

    ReplyDelete
  54. Hello, I think your website might be having browser compatibility issues.
    When I look at your website in Chrome, it looks fine but when opening
    in Internet Explorer, it has some overlapping. I just wanted to give
    you a quick heads up! Other then that, superb blog!



    my web page: watch free asian sex movie

    ReplyDelete
  55. Awesome! Its in fact remarkable paragraph, I have got much clear idea concerning from this article.


    Also visit my web site: pissingpussies.org

    ReplyDelete
  56. Hmm is anyone else experiencing problems with the images on this blog loading?

    I'm trying to figure out if its a problem on my end or if it's the blog.
    Any feedback would be greatly appreciated.

    Also visit my webpage ... xxx-fuck.net

    ReplyDelete
  57. I used to be able to find good advice from your articles.


    Feel free to visit my site ... journals.fotki.com

    ReplyDelete
  58. hello there and thank you for your info – I've definitely picked up something new from right here. I did however expertise some technical points using this site, since I experienced to reload the website a lot of times previous to I could get it to load correctly. I had been wondering if your web hosting is OK? Not that I am complaining, but slow loading instances times will very frequently affect your placement in google and can damage your high-quality score if ads and marketing with Adwords. Anyway I am adding this RSS to my email and can look out for a lot more of your respective intriguing content. Make sure you update this again very soon.

    My web blog; carolina home remodeling commercial

    ReplyDelete
  59. Excellent site you've got here.. It's difficult to find excellent writing like yours these days.
    I honestly appreciate people like you! Take care!!


    Take a look at my site ... spray latex paint

    ReplyDelete
  60. Great goods from уou, man. I've understand your stuff previous to and you are just too excellent. I actually like what you've aсquirеd here, сertаinly like what you're saying and the way in which you say it. You make it entertaining and you still care for to keep it sensible. I cant wait to read much more from you. This is actually a wonderful web site.

    my website: george foreman deep fat fryer

    ReplyDelete
  61. I just could nοt leavе your wеb site before suggestіng
    that I аctually enjoyeԁ the ѕtandard info a pеrson supply on your viѕitors?

    Is gonna be agаin steadilу tо inspect new posts

    Heгe is my weblog - tefal deеρ fat fryеr **

    ReplyDelete