So, what attaches to that hip capsule anyway....

I was trying to figure to which muscles attached to the labrum of the hip, as I see many folks where theres has gone south. I had always wondered if the iliopsoas attached, since many people with labral pathology have hip flexor dysfunction, where they use their psoas and iliacus as hip flexion initiators (or sometimes the rectus femoris, TFL and sartorius), instead of the abdominals. It turns out that NO MUSCLES attach to the labrum, but some attach to the capsule. 

Have you noticed that many of the muscles on the list below (not the obturator internus) are internal rotators AND work during the 1st part of stance phase? Remember "glide and roll"? With internal rotation of the hip comes posterior translation of the femoral head. If these are dysfunctional, you may get capsular "pinching". Think about it with the next patient with hip joint pain from initial contact to midstance. 

"An updated knowledge of the intricate relationship of the pericapsular and capsular structures is essential in guiding our treatment of the hip. Following dissection the authors were able to discern that the iliocapsularis, indirect head of the rectus, conjoint tendon (of the psoas and iliacus),  obturator externus and gluteus minimus all have consistent capsular contributions whereas the piriformis did not have a capsular attachment."

Walters BL, Cooper JH, Rodriguez JA New findings in hip capsular anatomy: dimensions of capsular thickness and pericapsular contributions.
Arthroscopy. 2014 Oct;30(10):1235-45. doi: 10.1016/j.arthro.2014.05.012. Epub 2014 Jul 23.

More anterior hip pain dialogue.

On a recent podcast we discussed complex hip problems, particularly hip stability and mobility issues lending themselves to anterior hip pain.
We have often mentioned ankle rocker being important in the discovery of hip pain, insufficient rocker can cause some impairments and abilities to get to ample hip extension function and range.
Here, this slightly older article mirrors a discussion we had on a recent podcast. We discussed the need for balance in the hip. More so, that focusing only on the glutes and hip extension can get one into trouble. One needs to also consider hip flexion skill, endurance and strength. The glutes and the hip flexors are a team to help maintain hip stability, mobility, and centration of the opposing joint surfaces during roll and glide motions. This is some of Shirley Sahrman's work, and others of course. When these component parts are not in harmony, and a loading force potentiates the femoral head towards the anterior labrum, it is the job of the glutes and hip flexors, to name two of the big players, to centrate that femoral head and keep it from impinging, and applying a forward load especially when this occurs during end motion loading into hip flexion and extension. I came across an article a while back that suggested these anterior directed movement risks are greater when the limb is loaded from being externally rotated, such as when making a strong power move or "cut" off the stance leg into the contralateral direction (we are looking for that source).
The bottom line is pretty simple, create sufficient stability to endure the loading challenge, but have enough strength and skill to still enable safe mobility. That being said, it is the diagnostics and the remedy that can be the tricky and challenging part of this game.

Anterior hip joint force increases with hip extension, decreased gluteal force, or decreased iliopsoas force. Lewis CL1, Sahrmann SA, Moran DW. J Biomech. 2007;40(16):3725-31. Epub 2007 Aug 17.

"Abnormal or excessive force on the anterior hip joint may cause anterior hip pain, subtle hip instability and a tear of the acetabular labrum.

We found that decreased force contribution from the gluteal muscles during hip extension and the iliopsoas muscle during hip flexion resulted in an increase in the anterior hip joint force. The anterior hip joint force was greater when the hip was in extension than when the hip was in flexion."

Got Hip Pain ? Attention Runners and Athletes with Hip Pain.

Compensatory joint motions are quite often a source of a person’s pain. Shirley Sahrmann named her hip syndromes for the direction of the movement most consistently associated with pain. In a recent CME presentation we did for www.onlineCE.com we discussed the accessory movements found with the hip.

Lets look at the known normal biomechanical facts:

During hip flexion the accessory motion is posterior glide of the femoral head.

Hip extension: accessory motion is anterior glide of the femoral head.

Hip medial (internal) rotation: accessory motion is posterior glide of the femoral head.

Hip lateral (external) rotation: accessory motion is anterior glide of the femoral head.

Hip abduction: accessory motion is inferior glide of the femoral head.

Hip adduction: accessory motion is superior glide.

Impairment, either from joint/bony deformation (ie. torsions) or from functional muscular asymmetry, can lead to impairment of the accessory motions (compensation) that are necessary for clean joint function.  This can lead to pain. 

For you clinicians out there, knowing your hip torsions and versions will impact the amount/degree of these accessory motions. This is why we harp on knowing your fixed anatomic variants.  (You can find discussions on these in our prior blog posts and on previous recorded www.onlineCE.com teleseminar presentations.) For example, reduced medial rotation at the hip (usually met with increased external rotation) is often seen in people with retrotorsion of the femur. Said another way, when your client has impaired medial or lateral hip rotation you must go beyond looking at the muscles at some point and consider whether they have a form of ante or retro torsion.

Hip extension is a critical part of normal human ambulation, whether you are walking or running.  Normally the hip, when moving into extension during the final propulsive phase of ambulation, allows for the femoral head of the hip to glide anterior in the socket (acetabulum). This reduces labral RIM pinch (RIM Syndromes) and allows for greater safe extension range. If hip extension range is impaired then this accessory motion of anterior glide can be impaired and lead to compensation and pain.

Think about this:

What if the quadriceps are tight ?

What If the Glutes are weak ?

What if rotational muscles are short ?

What if ankle rocker (dorsiflexion) is impaired ?

What if there is neuro-inhibition from joint pain (ie. osteoarthritis or joint mal-centration etc) ?

What if there is imbalance and weaknesses about the hip ?

What if there are other faulty movement patterns ?

What if there is one of the femoral torsions present ?

Much of this is “chicken or the egg”, who came first ?  These “what ifs” are what make practicing medicine difficult and a real challenge. Some of these issues can be found during functional movement assessments, but some of them will be missed if that is all you are doing. These issues may be what separates the good clinician, therapist, coach or trainer from the “not so good”. Knowing if a person has an impaired rolling pattern (see here http://youtu.be/dqnR0EcW2YY) is great to know, but knowing if the lower limb driver is off because the hip cannot internally rotate is even greater. Merely giving the person the homework of practicing and repeating the rolls on the impaired driver side without assessing all of the parts (for example some of the issues above) may cause you to miss the boat, or to engrain a new faulty motor pattern. 

Knowledge is prince, application of knowledge is king.

Next week we will begin a blog post a week on the biomechanics of the hip. We hope you will join us.

Shawn and Ivo

Here are some of our prior blog posts to add and deepen this dialogue:

• http://thegaitguys.tumblr.com/post/7493909435/the-hip-part-1-hip-labral-tears-the-rim-syndromes
• http://thegaitguys.tumblr.com/post/7533986761/ars-acetabular-rim-syndromes-hip-pain-some
• http://thegaitguys.tumblr.com/post/7573791535/the-hip-part-3-more-on-hip-rim-syndromes-and-labral