The inner muscles of the thigh are like the child star cliché: famous in the Eighties but then chronically overlooked, and out of favour.
From Jane Fonda fame and Suzanne Sommer's mastery, these inner thigh muscles fell into disgrace in the more recent decade of thigh gap.
Well, thigh gap is for flamingos.
Healthy adductor muscles will power your golf swing, and save the discs in your lower back. They might even stop you from peeing your pants.
Beneath a saggy lower back and hips tipped forward, shortened adductors may be found.
When inner arches of the feet are inwardly tipped, looking rather "fallen", the adductor above may be tight, and opposed only weakly by it's cohorts: the hip aBductors.(1) This is the scene of a miserable misalignment loop.
This old moniker was long ago given to a long strappy portion of the adductor group. It's vulnerable to postural injuries from sewing marathons, or when one is leg crossed over for extended periods, work balanced on top.
Adductors are vulnerable to power injuries when there's hip flexion under load, with the knees turned out. Soccer, hockey, skate-skiing, tennis, running down mountains: these activities all pass repetitive hip flexor loading into the groin.
Groin pain can accompany shear forces on the pubic symphysis. This torsion occurs when there's an imbalance of the quads and hams, and it can even cause just a one sided forward tilt of the hemi-pelvis, (8) One or two-sided pelvic tilt can be held by short, tight uninjured adductors, mind you.
Osteoarthritis in the Knee
Every step you take cumulatively loads the muscles on the inner side of the knee. An osteoarthritic knee, over a single day, endures almost twice the normal load as a healthy knee. (2) That's extra adductor firing, and joint wear once muscles are fatigued.
A tight aDductor and a it's weakly opposing hip aBductor contribute to a vicious partnership of misalignment. The resulting change in surface angle where the thigh bone now meets the knee, contributes to further osteoarthritic wear.
Joint Position Sensing
When healthy people stretch their adductors, the accuracy of joint position censor cells in their legs improve - especially at 45 degrees of knee flexion.(5) So in everyday functions, when your knee is bent to 45 degrees, do you want your Joint Position Sensing to be as optimal as possible? If you're going down stairs, or moving over uneven ground, heck yeah.
Gams on the Greens
The mechanics of the trunk and shoulders are often measured in golfers, to help perfect their swing. But, there are also essential sequences of firing patterns required of the hip and knee during swing, especially in earlier phases.
In the leading leg, hamstrings have the job of keeping a stable flexed knee so the pelvis can rotate properly. In the trailing leg, healthy adductor magnus, the hip extensors and hip abductors would need to have already initiated this pelvic rotation. (4)
"If either or both adductors are too tight,
this can mess up early optimal sequencing.
And then upper body becomes compromised
in the later portion of your golf swing."
If your knees cave inward during a double-legged squat, don't drop blame only on tight calves. Tight adductor muscles are playing a role, too. (7) “Medial knee displacement during squatting tasks appears to be associated with increased hip-adductor activation...” (10).
To recruit maximal firing in order to boost building the inner thigh, squat exercises are often done with the hips rotated out 30 degrees, and the squat down to a minimum of 90 degrees flexion.
But, if the adductors are already hyper-toned, strengthening in this range could worsen hip and low back problems, when tight adductors pull forward on the hemipelvis. (9)
"The result is torsion on the public joint
between the two pelvis bones
resulting in groin pain.
A chain of torsion up into the lower spine
can aggravate the lower back."
Two Feet to Stand On
When you stand still for at least one minute your brain and nervous system controls your posture. The aDductor and the aBductor muscles steady that side-to-side stability of the hips. Faulty dynamics between the two will affect the other muscles above: iliacus, tensor fascia latae. abdominal obliques, lats, intercostals - the muscles between the ribs. (6)
But, in people who have a type of scoliosis that originiated in childhood, this motor control is constrained at the hip level. When their hips are destabilized - literally, shoved - these neurological controls brace the posture from swaying front to back. But will posture brace the swaying due to side-to-side forces in these people with scoliosis? Not so much.
Other functional forms of scoliosis that just come with postural compensations in adulthood may compromise posture control as well.
People with wonky trunk or pelvis posture have consistently weird muscle activation patterns when standing on one leg. (3) These folks are predisposed to hip and thigh muscle injuries.
Groin injuries occur while standing on one leg, and when there are changes of trunk position from side-to-side forces, and/or changes to pelvic position from front-or-back forces. Forces from these angles have the greatest effect on adductor activation.
"The function of muscles isn't always just limited to movement.
There's a link between tight adductors and the urinary frequency associated with an irritated or a compromised bladder."
So, unless you're a gymnast, an advanced yogini, or a ballerina, chances are pretty good that your adductors are short and tight. Stretching lengthens short, tight muscles.
Keep adductors in a healthy tone - and in a healthy length - before you take a hit while standing, or a slip while on one leg. And, if you golf, play hockey, tennis, squash, soccer or baseball, you'll want healthy firing sequences, and forgiving, elastic adductors.
© Lana Brown 2017. Major shout-out to all the researchers linked below.
(1) Correlations Between Hip Strength and Statis Foot and Knee Posture. Hollman, John H. et al. Journal of Sport Rehabilitation. Feb 2006 Vol. 15 Issue 1. p12 11p. ISSN 10566716
(2) Cumulative knee adductor load distinguishes between healthy and osteoarthritic knees - A proof of principal study. Maly, Monica R (email@example.com) Gait & Posture. Mar2013. Vol 37 Issue 3. p397 5p. ISSN 09666362
3) The influence of changes in trunk and pelvis posture during single leg standing on hip and thigh muscle activation in pain free population. Prior S (firstname.lastname@example.org) et al. BMC Sports Science, Medicine And Rehabiiitation, 2014 Mar27; Vol 6(1), pp 13. Date electronic publication: 2014 Mar 27. PubMed not medline. DOI 10.1186/2052-1847-6-13
(4) Electromyographic analysis of the hip and knee during the golf swing. Bechler JR et al. Clinical Journal of Sport Medicine (Canadian Academy of Sport Medicine) 1995 Jul; Vol 5 (3) pp 162-6 PMID: 7670971
(5) Effect of static stretching of muscles surrounding the knee on knee joint position sense. Ghaffarinejad, F et al, British Journal of Sports Medicine, Oct2007; 41 (10): 684-687 (4p). ISSN 0306-3674. PMID 20151204
(6) Postural control in idiopathic scoliosis: comparison between healthy and scoliotic subjects. Silferi V et al. Revue De Chirurgie Orthopédic Et Réparatrice De L’appareil Moteur. 2004 May; Vol 90(3) pp 215-25
(7) Muscle Activity and Flexibility in Individuals With Medial Knee Displacement During the Overhead Squat, Bell David R, et al. Athletic Training & Sports Health: The Journal for the Practicing Clinician. May/Jun2012, Vol 4 Issue 3, p117 9p. ISSN 19425864
(8) Groin Pain and Muscular Imbalance of Quadriceps and Hamstrings in an Elite Soccer Player - A Case Study. Sportverietzung Sportschaden: Organ Der Gesellschaft Fur Orthopadisch - Traumatologische Sportmedizin. 2016 Aug; Vol 30(3), pp 163-7/ epub: 2016 Aug 4. PMID 27490356.
(9) Influence of hip external rotatation on hip adductor and recuts femoris myoelectric activity during a dynamic parallel squat. Pereira GR et al. Journal of Strength & Conditioning Research. Oct 2010; 24
(10): 2749-2754 (6p). ISSN 1064-8011
(10) Neuromuscular characteristics of individuals displaying excessive medial knee displacement. Padua DA et al, Journal of Athletic Training, 2012 Sep-Oct, Vol 47 (5), pp 525-36. PMID 23068550