Why exercising your ‘good arm’ can also help the one in a sling

Ken Nosaka, Edith Cowan University

Injured limbs need rest. They are often kept in a sling or cast to immobilise them as a way to promote healing. But that can mean smaller and weaker muscles several weeks later. It takes a long time to rehabilitate these muscles and muscle strength and function may not be fully restored for some people.

Experts are learning more and more about the “cross-education effect” where training one side of the body results in an increased strength of the opposite side of the body. Our recent study shows it can also stop muscle wasting in the “unused” arm.

So, how can we harness that effect?

How it works

First discovered 100 years ago, the mechanisms underpinning the cross-education effect have not been fully clarified yet. But it is likely associated with neural adaptations in the motor cortex of the brain that controls movement in the body.

Researchers have reviewed almost 100 studies and showed the average cross-body transfer ratio between the strength gain in the trained muscle to non-trained muscle ranged from 48% to 77%. So, if your trained arm strength increased by 20% after training the same muscle of your non-trained arm strength might increase by 10% even though you did nothing with that arm.

Such changes could be due to increased cortical excitability (the brain activity to control movement), reduced cortical inhibition (the signal to stop movements), reduced inter-hemispheric inhibition (the signals that direct movement instructions to one side of the body but not the other), changes in voluntary activation or new brain regions getting switched on.

It appears the type of muscle contraction in the training affects the extent of the cross-education effect.

There are three types of muscle contractions:

  • isometric (static) where the force produced by a muscle is equal to the load to the muscle, such as holding a dumbbell
  • concentric (shortening) in which force is greater than load, such as lifting a dumbbell
  • eccentric (lengthening) in which force is less than load, such as lowering a dumbbell.

Muscles can produce greater force during eccentric than isometric or concentric contractions. And less fatigue is induced during eccentric than other contractions. Resistance exercises – when muscles work against a weight or force – increase muscular strength and endurance using these types of muscle contractions.

Several studies report exercise consisting of eccentric-only muscle contractions (say, lowering a dumbbell but not lifting it) produces greater cross-education effect than exercise consisting of concentric-only (lifting only) or concentric-eccentric contractions (lifting and lowering).

One study showed eccentric exercise training affected brain-spine responses and stopping (inhibition) signals of the untrained limb to a greater extent than concentric training.

woman in gym setting holding dumbbell in one hand
Lowering a dumbbell is an example of an eccentric exercise. Shutterstock

What we studied

In 2021, we compared eccentric and concentric resistance exercise training for cross-education effect in which 18 young people (aged 20–23) performed progressive elbow flexor resistance training with one arm twice a week for five weeks using a dumbbell.

Both eccentric (lengthening) and concentric (shortening) training groups increased muscle strength similarly after the training (by 23 to 26%) for the trained arm. But the non-trained arm showed greater strength increase after eccentric (23%) than concentric training (12%). The cross-body transfer ratio (the correspondence between the strength gain in both sides) was much greater (91%) for eccentric training when participants lowered a dumbbell only compared to concentric training (49%) when they lifted it.

This tallies with our previous study that showed greater strength gains and cross-education effect from eccentric training.

Published in February, our most recent study involved 12 young men and showed how training one arm can prevent weakening of the other. No training saw muscle strength and size of the inactive arm reduced by up to 17%. Concentric training reduced the loss to to 4%. But eccentric training increased the immobilised arm strength by 4% and completely abolished atrophy (muscle wasting).

What to ask your physio

These findings support the recommendation of resistance training using eccentric or lengthening movements of the non-immobilised limb to prevent muscle strength loss and atrophy in real injuries such as ligament sprains and tears or bone fractures and after surgery.

This type of training has not been used extensively in rehabilitation so far. Further investigation into the mechanisms at play is needed but our findings could inform changes to how rehabilitation is implemented.

If you’re injured and or have had surgery and have an arm or leg immobilised, it’s worth discussing with your doctor, surgeon or physio whether exercising the corresponding limb on your good side – especially with lengthening movements against resistance or with a weight – could be worth trying.

Ken Nosaka, Professor of Exercise and Sports Science, Edith Cowan University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

9,361 Comments

  1. I loved you better than you would ever be able to express here. The picture is beautiful, and your wording is elegant; nonetheless, you read it in a short amount of time. I believe that you ought to give it another shot in the near future. If you make sure that this trek is safe, I will most likely try to do that again and again.

  2. Magnificent beat I would like to apprentice while you amend your site how can i subscribe for a blog web site The account helped me a acceptable deal I had been a little bit acquainted of this your broadcast offered bright clear idea

  3. Somebody essentially help to make significantly articles Id state This is the first time I frequented your web page and up to now I surprised with the research you made to make this actual post incredible Fantastic job

  4. Hi Neat post There is a problem along with your website in internet explorer would test this IE still is the market chief and a good section of other folks will pass over your magnificent writing due to this problem

  5. Somebody essentially lend a hand to make significantly articles Id state That is the very first time I frequented your website page and up to now I surprised with the research you made to make this actual submit amazing Wonderful task

  6. of course like your website but you have to check the spelling on several of your posts A number of them are rife with spelling issues and I in finding it very troublesome to inform the reality on the other hand I will certainly come back again

  7. I loved even more than you could possibly be able to accomplish right here. Despite the fact that the language is stylish and the overall appearance is appealing, there is something odd about the manner that you write that makes me think that you ought to be careful about what you say in the future. In the event that you safeguard this hike, I will most certainly return on multiple occasions.

  8. Hey there You have done a fantastic job I will certainly digg it and personally recommend to my friends Im confident theyll be benefited from this site

  9. What I do not understand is how you are not even more well-liked than you currently are. You are exceptionally intelligent and know so much about this subject that it caused me to believe it from a multitude of perspectives. It seems that people are not interested in anything related to Lady Gaga. Your own work is consistently excellent.

  10. Excellent blog here Also your website loads up very fast What web host are you using Can I get your affiliate link to your host I wish my web site loaded up as quickly as yours lol

  11. Somebody essentially help to make significantly articles Id state This is the first time I frequented your web page and up to now I surprised with the research you made to make this actual post incredible Fantastic job

  12. Wow, fantastic weblog structure! How lengthy have you been running
    a blog for? you make blogging look easy. The overall glance of your site is
    wonderful, as well as the content material! You can see similar here sklep internetowy

  13. Wow, marvelous weblog format! How lengthy have you ever been running
    a blog for? you made blogging glance easy. The entire look of your web site is wonderful, as well as the content material!
    You can see similar here sklep online

  14. Wow, marvelous weblog format! How lengthy have you been blogging for?
    you made blogging glance easy. The overall look of your site is
    excellent, as smartly as the content! You can see similar here e-commerce

  15. Generally I don’t learn article on blogs, but I would like to
    say that this write-up very pressured me to take a look at and do
    it! Your writing taste has been surprised me. Thanks, quite great article.
    I saw similar here: E-commerce

  16. Hey! Do you know if they make any plugins to assist with SEO?
    I’m trying to get my blog to rank for some targeted keywords but
    I’m not seeing very good results. If you know of any please share.
    Thank you! You can read similar article here:
    Sklep online

  17. Hey there! Do you know if they make any plugins
    to help with SEO? I’m trying to get my blog to rank for some targeted keywords but I’m not
    seeing very good gains. If you know of any please share.
    Thanks! You can read similar text here: Sklep online

  18. My brother suggested I might like this website He was totally right This post actually made my day You cannt imagine just how much time I had spent for this information Thanks

  19. Hello! Do you know if they make any plugins to assist with
    Search Engine Optimization? I’m trying to get my blog to rank for some targeted keywords
    but I’m not seeing very good success. If you know of any please share.
    Thanks! You can read similar blog here: Najlepszy sklep

  20. Hey! Do you know if they make any plugins to help with Search Engine Optimization? I’m trying to get my blog
    to rank for some targeted keywords but I’m not seeing very good success.
    If you know of any please share. Appreciate it! You can read similar blog here: Dobry sklep

  21. Hi my loved one I wish to say that this post is amazing nice written and include approximately all vital infos Id like to peer more posts like this

  22. Hello! Do you know if they make any plugins to help with SEO?
    I’m trying to get my site to rank for some targeted keywords but
    I’m not seeing very good gains. If you know
    of any please share. Many thanks! I saw similar text here: List of Backlinks

  23. Good day! Do you know if they make any plugins to help with Search Engine Optimization? I’m trying to get
    my blog to rank for some targeted keywords but I’m not
    seeing very good success. If you know of any please share.
    Many thanks! You can read similar text here: List of Backlinks

  24. Nice blog here Also your site loads up fast What host are you using Can I get your affiliate link to your host I wish my web site loaded up as quickly as yours lol

  25. I discovered your blog site on google and check a few of your early posts. Continue to keep up the very good operate. I just additional up your RSS feed to my MSN News Reader. Seeking forward to reading more from you later on!…

  26. A mesothelioma lawyer with experience can assist you in determining the best type of lawsuit to suit your situation. The
    process begins with filing an initial complaint.
    The defendants have a short time frame to respond.

    Feel free to surf to my web site – Vimeo.Com

  27. The majority of asbestos victims, and their families begin the
    process by contacting a qualified lawyer. A competent lawyer
    can help them prepare the lawsuit to get compensation from defendants
    who made asbestos-containing products.

    My website: Vimeo.Com

  28. Are You Responsible For An Uk Online Shoe Shopping
    Websites Budget? Twelve Top Tips To Spend Your Money Portrait Frame 7X17 Inch – Martin,

  29. Lawyers Personal Injury Tools To Streamline Your
    Daily Lifethe One Lawyers Personal Injury Technique Every Person Needs
    To Be Able To lawyers personal injury (http://m.fhku.tnsh.dpgshop.co.kr/member/login.html?noMemberOrder=&returnUrl=http://lovewiki.faith/wiki/8_Tips_To_Enhance_Your_Is_It_Worth_Hiring_A_Personal_Injury_Attorney_Game)

  30. ADHD Treatments Adults Tools To Help You Manage Your Daily Lifethe One ADHD Treatments Adults Trick That Everyone Should Learn adhd treatments adults
    Carley,

  31. This Week’s Most Popular Stories About Upvc Window Repairs Upvc Window Repairs upvc window
    repairs near me (Kim)

  32. Double Glazing Companies Near Me Tips To Relax Your Everyday Lifethe Only Double Glazing Companies
    Near Me Trick That Every Person Should Know double glazing companies near me (Lula)

  33. You Are Responsible For The Double Glazed Window Suppliers Near Me Budget?
    12 Top Ways To Spend Your Money Fit

  34. A Trip Back In Time What People Said About Double Glazing Near Me 20 Years Ago double glazed front door (Ada)

  35. Birth Injury Lawyers Tools To Help You Manage Your Everyday Lifethe Only Birth Injury Lawyers Technique Every Person Needs To Know birth injury lawyers (Tammie)

  36. Here’s A Little Known Fact About Why Are CSGO Skins Going Up In Price.
    Why Are CSGO Skins Going Up In Price cs2 cases; Max,

  37. This Most Common Desk Treadmill Debate Could Be As Black Or White As You Might Think
    UREVO Compact Under Desk Treadmill – Double Shock Absorption; Olga,

  38. Congress has approved several incremental legislation plans despite the fact that
    grand rapids asbestos Lawyer (vimeo.com) is still banned.
    One of them proposals, the Frank R.

  39. Upvc Door Repairs Near Me Tips To Relax Your Daily Life Upvc Door Repairs Near Me Trick
    That Should Be Used By Everyone Know upvc door repairs
    near me (Corina)

  40. Guide To Double Glazed Window Near Me: The Intermediate Guide
    Towards Double Glazed Window Near Me double
    glazed window near me (Archer)

  41. Upvc Door Repairs Near Me Tools To Ease Your Daily Lifethe One
    Upvc Door Repairs Near Me Trick That Everybody Should Learn upvc door repairs near me (Lona)

  42. Auto Accident Lawyers Tools To Ease Your Daily Lifethe One
    Auto Accident Lawyers Technique Every Person Needs To Know auto accident lawyers (Sang)

  43. Guide To Marc Jacobs Handbag Crossbody: The Intermediate Guide The Steps To Marc Jacobs Handbag Crossbody marc jacobs handbag crossbody (Nelson)

  44. Are You Responsible For A Electric Mobility Scooters For Sale Budget?
    12 Top Notch Ways To Spend Your Money outdoor mobility scooters for sale; Marisol,

  45. Lost Car Key Replacement Near Me Tools To Improve Your Daily Lifethe One Lost Car
    Key Replacement Near Me Trick Every Individual Should Know near me

  46. Responsible For A Natural Anxiety Treatments Budget?
    10 Very Bad Ways To Invest Your Money performance anxiety treatment; http://salsaboston.com/gallery/Randomimage-txt1.01/random.cgi?js=&directory=/Club_Caribe_2011/Club_Caribe_12.29.11/thumbs&link=https://minecraftcommand.science/profile/balldad1,

  47. 10 Things You’ve Learned In Preschool To Help
    You Get A Handle On Double Glazed Repairs Near Me double
    glazing window handles (Kent)

  48. All six types of White Plains Asbestos Lawsuit (https://Vimeo.Com/) are found naturally in strings of pliable and durable fibres.
    They are resistant to heat, fire as well as chemical and electrical conductivity.
    They have a high tensile strength and wear strength.

  49. Are You Responsible For An Slot Demo Princess Budget?
    10 Unfortunate Ways To Spend Your Money slot demo starlight princess gacor (Zelda)

  50. Upvc Window Repairs Near Me Techniques To Simplify Your Daily Lifethe One Upvc
    Window Repairs Near Me Trick That Every Person Should Be Able To upvc window repairs near me (Abraham)

  51. The Reason Behind Replacement Double Glazed Glass Only Near Me Is The Most Sought-After Topic In 2023
    double glazing replacement units (Alisha)

  52. Are You Tired Of Designer Handbags For Ladies?
    10 Inspirational Resources To Invigorate Your
    Love Adorable Multicoloured Little Me Kids Rolling Suitcase: Designer Handbag (Christiane)

  53. This Week’s Best Stories About Upvc Front Doors Supplied
    And Fitted Near Me Upvc Front Doors Supplied And Fitted Near Me new upvc door, Rudolph,

  54. Denver Birth Injury Attorney Tools To Ease Your
    Everyday Lifethe Only Denver Birth Injury Attorney Trick
    Every Individual Should Learn denver birth injury attorney (Mariano)

  55. Usually I do not read article on blogs however I would like to say that this writeup very compelled me to take a look at and do so Your writing taste has been amazed me Thanks quite nice post

  56. See What Veterans Compensation For Mesothelioma Tricks The Celebs
    Are Using veterans compensation for mesothelioma – Kina

  57. Designer Handbags To Sell Tips To Relax Your Everyday Lifethe Only Designer Handbags To Sell
    Trick That Should Be Used By Everyone Know bag

  58. 12 Stats About Demo Slot Princess 1000 To Make You Think About The Other People slot demo
    starlight princess christmas (Dan)

  59. Upvc Window Repairs Near Me Tools To Improve Your Everyday
    Lifethe Only Upvc Window Repairs Near Me Trick Every Individual Should Be Able To upvc window repairs near me (Hilario)

  60. Usually I do not read article on blogs however I would like to say that this writeup very compelled me to take a look at and do so Your writing taste has been amazed me Thanks quite nice post

  61. I loved as much as you will receive carried out right here The sketch is attractive your authored material stylish nonetheless you command get got an impatience over that you wish be delivering the following unwell unquestionably come more formerly again since exactly the same nearly a lot often inside case you shield this hike

  62. Hey! Do you know if they make any plugins to assist with Search Engine Optimization? I’m trying to get my site to rank for some targeted keywords but I’m not seeing
    very good results. If you know of any please share. Many thanks!
    You can read similar text here: Escape rooms

  63. Wonderful beat I wish to apprentice while you amend your web site how could i subscribe for a blog web site The account aided me a acceptable deal I had been a little bit acquainted of this your broadcast provided bright clear idea

  64. I’ve been browsing on-line more than 3 hours lately, yet I never found any interesting article like yours. It is beautiful price enough for me. In my view, if all web owners and bloggers made just right content as you probably did, the internet will be much more helpful than ever before!

  65. Hello! Do you know if they make any plugins to help with Search Engine Optimization? I’m trying to get my site to rank for some
    targeted keywords but I’m not seeing very good success.
    If you know of any please share. Thank you!
    You can read similar text here

  66. The Most Underrated Companies To Keep An Eye On In The Shopping Online Uk Clothes Industry Silicone Plug For Bathtub; Dora,

  67. Guide To Uk Online Shopping Sites Like Amazon:
    The Intermediate Guide For Uk Online Shopping Sites Like Amazon uk online shopping sites like amazon (Abdul)

  68. Fantastic beat I would like to apprentice while you amend your web site how could i subscribe for a blog site The account helped me a acceptable deal I had been a little bit acquainted of this your broadcast offered bright clear concept

  69. Its like you read my mind You appear to know so much about this like you wrote the book in it or something I think that you can do with a few pics to drive the message home a little bit but other than that this is fantastic blog A great read Ill certainly be back

  70. 5 Killer Quora Answers On Replacement Double Glazing Units Near Me
    replacement double glazing units near me (Sue)

  71. Somebody essentially help to make significantly articles Id state This is the first time I frequented your web page and up to now I surprised with the research you made to make this actual post incredible Fantastic job

  72. Asbestos victims seek compensation from companies responsible for
    asbestos (image.google.co.bw) exposure.
    Personal injury and wrongful-death claims are used to accomplish this.
    A lawyer with experience can assist victims and their families navigate the process.

  73. Responsible For The Upvc Window Repairs Budget?
    10 Amazing Ways To Spend Your Money upvc window repairs near me
    Mari

  74. Guide To Double Glazing Repairs Near Me:
    The Intermediate Guide For Double Glazing Repairs Near Me double glazing
    repairs near me (Antje)

  75. An asbestos lawyer
    can help victims file a suit against their employers when they are exposed to the harmful mineral.
    A lawsuit could be used to seek compensation for medical expenses, lost wages, and past pain and discomfort.

  76. You’ll Never Be Able To Figure Out This Amazon Online Grocery Shopping Uk’s Tricks amazon online grocery shopping uk,
    Kasey,

  77. Great beat ! I would like to apprentice at the
    same time as you amend your web site, how can i subscribe for a blog site?
    The account helped me a applicable deal. I were tiny bit familiar of this your broadcast offered shiny clear concept

  78. An Asbestos case
    attorney can help victims file a lawsuit against their employers for exposure to the toxic
    mineral. A lawsuit can be used to secure compensation for medical expenses, lost wages, and
    for past discomfort and pain.

  79. The EPA bans the manufacture or importation, processing or distribution of most asbestos-containing products.
    However, asbestos-related
    lawsuits are still appearing on court dockets.

  80. Best Online Shopping Sites For Clothes Techniques To Simplify Your Daily Lifethe One Best Online Shopping Sites For Clothes
    Trick That Every Person Should Learn best online shopping sites for clothes; Jacki,

  81. Door Repairs Near Me Tips To Relax Your Everyday Lifethe Only Door Repairs Near Me Trick
    That Everyone Should Be Able To upvc door repairs near
    me (Cody)

  82. 13 Things You Should Know About Upvc Window Repairs That You Might Not Know
    upvc window repairs near me – Jay

  83. Wonderful web site Lots of useful info here Im sending it to a few friends ans additionally sharing in delicious And obviously thanks to your effort

  84. Just wish to say your article is as surprising The clearness in your post is just cool and i could assume youre an expert on this subject Fine with your permission allow me to grab your RSS feed to keep updated with forthcoming post Thanks a million and please keep up the enjoyable work

  85. Begin By Meeting You The Steve Jobs Of The Double Glazed Window
    Repairs Industry double glazed window repairs near me (Dick)