Anatomy Lesson: Hip/Pelvis

Up next in our series of Anatomy Lessons is the Hip and Pelvis.  Let's first set the story straight by saying these two areas are about as complicated as they come.  The hips and pelvis essentially connect the lower body and the upper body.  There is a whole mess of things going on in this area, and it's pretty dang easy to get lost.  It's like those super highway interchanges in huge cities, on and off ramps going in every which direction. 

Basically The Hip and Pelvis
(photo: myclipta.blogspot.com)

But we're gonna try and take you through some of the basics of the hip and pelvis, and hopefully leave you with a better understanding of this area.  Don't get discouraged, this is tough stuff, and even the best out there often times need a quick reminder of these things.  So let's start this crazy adventure!

Bones

• Femur - Your big thigh bone.  At the superior (top) end of the bone is the head of the femur which fits into the acetabulum of the pelvis.

       - The femur has aspects that are also very important in the anatomy and function of the hip.  One of these includes the greater trochanter, which acts as a very important place for muscle attachments. 

• Pelvis - Comprised of the ilium, pubis, and ischium.  These bones are separate from birth until puberty when they are fused together to form the pelvis.  The pubis consists of the medial aspects, the ilium consists of the upper/superior aspects, and the ischium consists of the lower, lateral aspects.  The pelvis actually consists of two haves that connect together.

• Sacrum - This isn't really part of the hip or pelvis (technically part of the spine), but it connects the two halves of the pelvis together.  It sits on the posterior side of the pelvis fitting right between the two pelvic halves.

• Coccyx - Your tailbone, bottom portion of sacrum

• Pubic Symphysis - Not a bone, but cartilaginous joint that connects the two halves of the pelvis together

(photo: thankyourbody.com)

Muscles - The hip and pelvis are crossed by a ton of muscles.  The hip/pelvis basically connects the lower body to the upper body, so many muscles from both the lower and upper bodies play significant roles in the function of this area. So without getting way to in-depth we are going to just touch upon a few of these major muscles.

• Glutes - This includes the glute maximus, medius, and minimus.  This group is responsible for hip extension, abduction, and external rotation; as well as playing a key stabilization role.  The glutes for simplicity sake connect from different parts of the illium to different parts of the femur - this connection may not be direct, but through connective tissues or other muscles.

• Illiopsoas - The group consists of the illiacus and psoas (major and minor).  This group is grouped together because they attach the anterior part of the femur to the pelvis, with the exception of the psoas which connects to the first 5 lumbar spine.  They mainly act to flex and externally rotate the hip, but also act as pelvic stabilizers and pelvic alignment.

• Outer Abdomen - There are numerous abdomen muscles that interplay with the pelvis.  The rectus abdominus, oblique complex, erector spinae, and QL all play a role in the pelvis

• Inner Abdominal Group - This consists of the transverse abdominus (TVA), pelvic floor, diaphragm, and multifidus.  They form a cylinder shape structure with the TVA providing anterior support, the pelvic floor supporting from the bottom, the multifidus acting posteriorly, and the diaphragm supporting from the top.  These boys are instrumental in respiration function as well as pelvic/spinal stabilization and control. 

• Piriformis - The piriformis runs laterally from the sacrum to the femur.  The piriformis laterally rotates the femur with hip extension and abducts the femur with hip flexion  

• Latissimus Dorsi - The lats also connect to the iliac crest.  This connection is often through thoracolumbar fascia, but it' role on the pelvis is often under-stated.  

• Quads/Hammies - As you know from Anatomy Lesson of the Knee - These muscles groups also greatly effect the hip.  Simply the quads on the anterior side of the femur act to flex the the hip, while the hamstrings act to extend the hip.  They also act as stabilizers and help control flexion and extension eccentrically at different times.   

• Adductor Group - These are the muscles on the inside portion of your leg, better known as your groin complex.  This group mainly acts to adduct the leg. 

• Reproductive Organs - Our respective reproductive organs also play a role in pelvic structure, and provide support to the bottom aspects of the pelvis

(photo: crossfitforglory.com)

(photo: www2.ma.psu.edu)

(photo: physiodetective.com)

Movements/Alignments

• Flexion - Bringing knee towards the chest or vise versa
• Extension - Straightening leg or pulling chest away from the lower body
• Adduction - Bringing the leg towards the midline or crossing over the midline
• Abduction - Pulling the leg away from the midline
• External Rotation - Rotating the femur head away from the midline.  Can also be done by keeping a fixed leg and rotating pelvis inward
• Internal Rotation - Rotating the femur head towards the midline.  Can also be done by keeping a fixed leg and rotating the pelvis outward
• Anterior Pelvic Tilt - When the top of the pelvis tilts forward.  Think about pushing your butt out to give that Baby Got Back look
• Posterior Pelvic Tilt - Top of the pelvis tilts backwards.  Think about tucking your butt under, giving you the ever dreaded flat butt syndrome.
• Lateral Pelvic Tilt - The pelvis also has the ability to tilt or rotate laterally

(photo: joegambina.wordpress.com)

Problems

• Mobility - Going by the joint-by-joint theory, the hip favors mobility, and this is true.  The hip is a very mobile joint with the ability to move in many different planes and directions.  Problems occur when we lose ROM in our hips.  It differs in everyone, but there is a good chance you are missing mobility in some movement or another. Here are some common ROM standards you should be able to achieve

• Extension - 15-20 degrees
• Flexion - 120-130 degrees
• Adduction - 30+ degrees
• Abduction - 45+ degrees
• Internal Rotation - 45+ degrees
• External Rotation - 45-50 degrees

These are normal ranges of motion, and a loss of ability to reach these ranges could lead to increased chances of injury, dysfunction, or sub-optimal performance.  But on the same token, too much ROM, could mean some joint laxity and lack of stability, which is also not optimal.  It's the whole, more is NOT necessarily better.

• Stability - While the joint-by-joint suggests the hips favor mobility, you can easily argue it needs just as much stability.  Poor control and stability at the hip will often lead to pain or increased chance of injury elsewhere.  The hips are the power house of the body, and they need to provide strength and power.  Lack of adequate strength and stability will lead to energy leaks everywhere, and will sprinkle up and down the chain and increase chance of knee and back pain/injury

• Sacroiliac (SI) Joint - The SI joint is the joint between the sacrum and the ilium.  Remember that the sacrum is sandwiched between the two halves of the pelvis, and this means there is an SIJ on each side of the sacrum.  As you can imagine, this area requires a lot of mobility and stability, as it really connects the posterior lower body to the posterior upper body.  So despite the SIJ being joined by really strong ligaments, it can often be "pulled" by so many different demands and forces that go through the joint.  The SIJ needs a great ability to move while at other times it needs to create stability.  The SIJ can be effected by the erectors spinae, glute max, thoracolumbar fascia, TVA, lats, pelvic floor, piriformis, and biceps femoris.  So as you can see, many different muscles can affect the tension and forces on the SIJ.

• Femoral Acetabular Impingement (FAI) -  FAI is an impingement of the femur with the acetabulum, caused by irregular bone formation resulting in abnormal rub or movement in the joint.  FAI results in a limitation of hip flexion, usually limiting flexion to around 90 degrees before pain or restriction occurs.  There are 3 types of FAI (compliments of Kevin Neeld and learn more here)

1. CAM impingement - Excess bone formation around the ball of the femur. Hip flexion is limited by the bony overgrowth butting up against the top of the acetabulum.
2. Pincer impingement - An over extension or growth of the acetabular hood. The femoral neck contacts the overgrowth at a lower degree of hip flexion.
3. Mixed impingement - A combination of the CAM and pincer structural deviations.

Fixes

• Mobility - A good place to start any hip program should be to work on improving ROM in all directions.  Hip mobility is absolutely vital when it comes to knee and low back health, as well as proper function of the hips. If your hips can't move properly, then your low back and knee may compensate. Everybody is different and there is a great variance in loss of ROM from individual to individual.  Have someone qualified test to see how you fair in each range of motion so you can find out which movements may be restricted.  

I've mentioned it here before, but Kelly Starrett and his MobilityWod's are one of the best      resources around.  Doing soft tissue work, to really get in and straighten some of those tissues out also works great.  Areas like the glute max and med, piriformis, psoas, and QL/thoracolumbar fascia often respond very well to dedicated soft tissue work.  Also check out articles under the Mobility Movement Tab for ideas.  Also check out these links for some other of our favorites

Quads
Extension and Internal Rotation
Adductors

• Strength - To go along with mobility, we need to be sure to add strength and stability on top of it.  No good hip program can exist without strength work of some form.  The hip and pelvis is the connection point for the upper and lower bodies, and it oftens needs great control in order for movements to move smoothly and efficiently.  As we touched upon last time in Anatomy Lesson of the Knee, the knee follows the path set by the hip.  If the hip has poor control and sets a poor path, the knee will follow and be put at an increase risk of injury.

A good start is to add "activation" or strength exercises during warm-ups or between sets, such as naughty dogs, bird-dogs, glute bridges, band walks, prone hip extension, clams, variations of farmers walks/carries, variations of chops/lifts, and animal walks.  From there your exercise program should include a good dosage of compound lifts, such as squats, deadlifts, hip thrusts, Olympic variations, single leg variations (BSS, squat, RDL).  These exercises target the strong and powerful hip musculature from different angles or vectors, this will strengthen the hips in all areas and movements.

• Core Stability - Core stability goes hand in hand with hip and pelvis stability.  Like it's been shown above, many "core" muscle interact at the pelvis and hip.  These muscles will often assist in pelvic and hip control, and keep pelvic tilt in a good position.  The preferred method of strengthening these muscles is through forms of anti-movement instead of repetitive lengthening and shortening ie crunches/sit-ups.  So things like bird-dogs, farmer walks/carries, chop/lift variations, planks, stir the pot, landmines, turkish get-ups are all great options.  Check out articles under the Core Collection Tab to get a few ideas.

• Breathing - Like most things, breathing patterns can affect the hip and pelvis.  We talked about the inner "abs" playing a key role in pelvic stability and orientation.  The diaphragm and pelvic floor (heck it's got pelvic in it's name) are respiratory muscles and often highly dysfunctional.  To go along with the above mentioned core work, which will help strengthen the other 2 inner core muscles - TVA and multifidus, direct breathing exercises can go along way in helping function at the hip and pelvis.  Remember we take 20,000+ breaths each day, that's a huge opportunity to make giant positive changes, but on the other hand, if kept unchecked, you're just putting yourself further and further behind the 8-ball.  Good overview by Paul Ingraham here

Conclusion

Whew!  There you have it, a brief overview of the hip and pelvis.  Believe us when we say we don't fully grasp everything going on at the hip and pelvis.  There are PT's and Dr's who specifically specialize in this area, and they could tell you just how complex it is.  But we gave you the basics here today, and this info should set you straight with about 80% of the stuff happening at the Hip and Pelvis. 

If you missed the first two in this series, check them out here - Foot/Ankle and Knee
Also be sure to sign-up for BBA updates on our home page and like our Building Better Athletes Facebook page so you can stay up to date with everything going on here at BBA.  So until next time Go Get 'Em!