This is going to be Part 1 in a multi-part series on the feet as a doorway into the nervous system.
We know that having flat feet or collapsed arches has been touted as a risk factor for injury (albeit somewhat inconsistently). And it just doesn't pass the eyeball test... Flat feet just look unathletic. However, the static assessment of having feet flatter than Frodo is just that -- static. A more appropriate assessment of the feet should include a dynamic element that allows for pronation when they're supposed to pronate and supination when they're supposed to supinate. Which illustrates the point here: the foot is a dynamic system of sensory inputs and neuromuscular outputs. One way that we can upregulate and harness this dynamic system is thru maintaining the short foot position during movement. Or, to steal my own thunder, generation of the short foot may be an indicator of neurological readiness and capacity to safely tolerate high volume and load.
Developmentally, the foot has a few fixed points that were crucial when we learned to bear weight and eventually walk; points which we can reclaim as adults and undo our shoe-wearing, flat-footed foolishness. And most babies are not born with flat feet - we develop collapsed arches with our propensity for cushioned, heeled shoes and artificial arch supports robbing the foot of the demand to maintain the perfect balance of mobility and stability.
But I digress...
The three crucial points of the weight-bearing foot:
Essentially, this is the tripod or short foot position. This foot position is absolutely vital for powerful lifts, big jumps, and at the end of stance phase of gait when the foot re-supinates. Short foot puts the 33 joints of the foot on tension, centers the foot, and fires off the high density of proprioceptive nerve endings which are relayed to the brain. This stable position allows for a system-wide increase in force output and motor control. The strength of this stimulus probably improves motor learning due to the positive, feedforward stimuli. A centered foot position tells the brain that the position is a stable one and it is safe to generate a lot more force without risk of destabilization and injury.
It is no coincidence that the external cue to "screw the feet into the ground" helps to foster this short foot position. The system seeks joint centration for max output, so by bearing weight predominantly thru these 3 points the foot is most centered. The other thing you'll notice with this cue is that the foot is not a static, inanimate object! It is a prime source of neurological input and output (more on that with an upcoming post). Maintaining the short foot position can generate an arch and produce a monstrous feed-forward loop that maintains tension and stability throughout the system reinforcing to the brain that force can be safely produced. When the arch collapses the nervous system quickly downregulates in an attempt to avoid excess force thru the entire lower quarter while in an unstable position, yielding decreased output. This is not unlike how head/jaw position influences spine control or how chronically "tight" hamstrings are likely a protective response to prevent neurologic injury when in untenable positions.
Also, check out Charlie Weingroff and Andreo Spina for their take on this topic.
Movement baselines, or the minimum movements necessary for human function and performance, are essential to efficiency and resiliency. The inability to perform basic movements set us up for failure down the road as I believe it lowers the ceiling on performance and movement efficiency. You can buffer large loads and high reps with poor movement for a while, sometimes even a long while, right up until you can't. Taking some time to work on these basic movements can improve system adaptability and ultimately improve performance.
A good starting stance is individual depending on each person's motor control and anatomical alignment.
Bottomline: Take 5 minutes to work on this movement pre-workout (just add it into your warm-up). Many will be surprised at how much of a struggle it is to maintain a neutral spine while flexing at the hips and maintaining vertical shins. Try it prior to a pulling or squat pattern and see if movement quality improves and pain resolves.
In case you missed it, here is the piece I wrote for my buddy Dr. Dan Pope's site FitnessPainFree.com:
Proper squatting forms the basis of any performance system and is essential to meaningful function as an athlete and human - which includes the elderly (might need to scale though, bro). As an athlete and as a practitioner who treats fellow CrossFitters frequently, one of the things I love is the emphasis on the squat pattern. But with high squatting volume in any performance system we need to ensure it’s reproducible.
I understand and share the pride that comes with the ability to squat deep while lifting some serious weight. However, many athletes are unable to squat deep with load due to hip or low back pain. Femoral-acetabular impingement is often the culprit here, where the neck of the femur is literally jamming into the acetabulum of the pelvis. Dan goes into much greater detail in one of his prior posts on FAI. These same biomechanics also cause butt winking where there is a reversal of the lumbar spine causing a loss of segmental control. This spinal shear under load is dangerous and never okay - a butt wink is an immediate fault and nobody gets a pass. Altering squat width is a strong start to fixing these train wrecks.
So how do we determine best squat width for depth and performance (and to help prevent hip pain and butt winking)? “Shoulder width” is often used however that differs for each individual. Many times we just start with a random width and that becomes the default. However, factors such as motor control of the entire system (particularly the over-extended spine), hip and ankle mobility, and individual structural differences in acetabulum and femur alignment all influence squat width and depth.
The sooner the femur runs into the pelvis, the less depth you’ll achieve and squat numbers will plateau. But you don’t need an x-ray to determine how you should squat. Rather, we need to find the best squat width that allows the most depth while maintaining movement integrity (such as a neutral spine). The best position yields the best performance and the fewest injuries. The test below helps find where these limitations are least restrictive and determines the best starting squat width.
I like this test (originally from Dr. Stu McGill, spine biomechanist) as a screen for new lifters, those who are having hip or low back pain, and athletes whose squat numbers are plateauing.
Things to consider with this test:
1) Performing this test on your hands and knees allows you to assess the hip and core without bringing other structures into the equation. You’re also performing this in an unloaded position (i.e. not standing) which helps eliminate movement inefficiencies you might find while standing.
2) Demonstrates lumbopelvic motor control. If a strong contraction of the anterior core allows greater depth prior to butt winking or decreases pinching in the front of the hip, motor control deficits are present. This is not an anatomical variation, you need to improve trunk stiffness as the lumbar spine is over-extended causing the pelvis and femur to meet prematurely. In so many cases, we can prevent butt winking and un-impinge the hip with appropriate movement patterns and control rather than rushing to surgery to correct bony deformities. Improve motor control first and foremost regardless of structure.
3) Once you’ve found the width that allows the most depth without impinging or butt winking, this is where you should start when squatting. Can use this screen for those new to squatting as a way to determine the most effective width to start while you work on motor control and mobility to allow for a variable squat program.
4) Those who show poor motor control in this test and have hip or low back pain will most likely need to correct this for successful rehabilitation and return to squatting.
So ultimately, what is the best squat width? The one that allows the best depth while preserving a neutral spine. Regardless of starting squat width or structural variation, this does NOT change the essential movement principles of the squat. Feet should be straight, knees tracking over the foot, shins vertical as possible for as long as possible, hips externally-rotated. You MUST prioritize and control the lumbar spine and pelvis, above all else. In my opinion, the ability to control the spine and pelvis is a prime determinant in the performance ceiling of athletics and human function so don’t lower that ceiling with improper movement patterns. Squat depth and width do not matter if these principles are not upheld.
Acknowledge what we can’t change (structural alignment), optimize the many variables we can change including squat width, and then vary it for an effective motor program.
As a physio, I see a lot of running-related injury, dysfunction, and performance loss. Depending on who you read, injury incidence among runners can be as high as 85% many of which are due to training errors and poor mechanics. In that vein, this week's post is from Jeff Ford, a CrossFit Endurance and USA Triathlon Certified Coach, Owner and Founder of Fire Coaching Consulting, and excellent endurance athlete. Great dancer. Drives a nice car.
Foot-strike: Time and time again, I watch runners on the street and I just want to pull over. A large majority of the endurance athletes I get on tape are landing out-front and breaking themselves while landing on their heels as they chronically over-stride (increasing peak forces on the body). Your heel was not meant to land first guys. Trust me. Take your shoes off and have someone video-tape you running. Your body physically will not let you heel strike. It wasn’t meant to. When you strike heel first, you land primarily on bone and lose the ability to harness muscle elasticity in your foot/ankle complex. What that means in KISS (Keep It Simple Stupid) terms is that you’ve lost the ability to absorb your weight as you land. You’ve shut down your muscles ability to stretch and contract when force is applied. Not good at all, especially as the distance gets greater. So fall from your ankles, don't smash thru them. Seth and I recommend a consult prior to switching strike patterns as this is a daunting task on your own.
This week's post is a public service announcement to get everyone to cease and desist leaning on one leg (i.e. hanging on one hip) when standing. Many of us do it without even thinking, shifting our body weight over onto one leg and just hanging out there. But in the effort to use less effort, we are reinforcing awful movement patterns and putting the entire kinetic chain in a damaging position. If you or your athletes have medial knee pain, hip or back dysfunction a good place to start may be how they're standing. We also definitely see this in our athletic new mother's too, who hold the baby on their hip while leaning on one leg (hello pelvic floor dysfunction).
Here's the deal:
Our musculoskeletal system is set-up to distribute the weight of our body plus gravity in an optimal way. However, when leaning onto one leg that weight is redistributed such that the pelvis drops toward that leg (see image below). The result is ugly:
But the real problem is that we are reinforcing this faulty pattern daily and even hourly often out of habit. This contralateral pelvic drop is a pathognomic we look for often as physios, yet our athletes are reinforcing it even between reps while training! How much will you benefit from motor control or strength training - often directly targeted at this hip/pelvic control issue - if you lean on one hip while drinking water between sets? Yet this happens all the time. In order for our training and performance gains to stick there has to be carryover to everyday movements. You move how you move. Chances are if you are standing with this pattern you will walk and run with this same pattern.
Here's the fix (it's an easy one): stop leaning on one leg! You should have active glutes while standing (you need to be squeezing them and your abs while upright). No more passive leaning, hanging on your hip joint. If necessary, stand with a wider base of support, march in place, or put one foot on stool for a bit to unload your spine during prolonged standing. Penalize yourself or your athletes with 10 burpees for every minute of leaning on one leg.
Here ends this Public Service Announcement.
Part 1 of Improving the Overhead Squat - Cueing and Maintaining an Upright Torso - can (must?) be read here.
As we discussed last week, the overhead squat is nearly unmatched in its demands on stability, motor control, and power. One of the main faults in performance of the movement, dumping the torso forward, was effectively crushed last week. However, as with all squat variations (back, front, and overhead), another common fault is the knees tracking forward and inward with the athlete unable to achieve full depth without falling forward or backward. Is this you? Right the ship.
Here's the problem: Improper cueing and loading of the glutes and hamstrings (posterior chain) causes quad dominance in which the knees track forward during the squat. This causes tons of compressive forces thru the patella but also prevents adequate depth and control during the squat. This is what the coach or physio will see with athletes attempting the overhead squat (or any squat for that matter):
1) They will avoid loading their hamstrings and glutes (won't sit back in the squat) and the knees are erroneously loaded first
2) The torso or shoulders may start to come forward
3) The knees cave in and the arch of the foot collapses
3) Near the bottom of the squat, they will stop short and are unable to go further down because something (self-preservation?) tells them if they go any further down, they'll fall over (not good)
4) They are unable to efficiently complete the up phase of the squat, will say "gee, I must not be very strong" and you will cringe.
So, here's the real question: is the athlete (or you) weak?
Anytime the athlete feels as though they will fall backwards during squats, motor control is always at the forefront of diagnosing the movement. *Mobility and tissue extensibility are also possible differential causes - though not the focus of this post*
Here's the solution: Oftentimes, the athlete is not necessarily weak (though it is certainly a possibility) it's just that they do not know how to fire muscles appropriately in the context of that particular movement. For instance, if I manually resist an athlete's glutes or hamstrings they may be quite strong yet they are unwilling or unable to activate that same posterior chain musculature during a squat, deadlift, jump landing, etc. Comparing isolated strength to dynamic, functional movements is like revving the engine on a parked Ferrari versus taking it out on the Pacific Coast Highway - what tells you more about how that car runs? Same muscles, very different motor program - it's a system of systems.
Nerd Alert - In order to improve motor control of complex movements, research on patients (including those with neurologic injury as well as running injuries) indicates that task-oriented training (or practicing and training the movement of interest in its entirety) is the best method to improve movement skill. This makes sense, right? If the movement is the problem, training the movement at its point of restriction is the most viable option. Gray Cook and his Functional Movement crew refer to this as pattern assist because you are performing the faulty pattern with assistance to appropriately fire the correct muscles and strengthen within that movement.
So, short answer: put the athlete in the squat position but reduce the demands so they learn to fire the appropriate muscles without fear of falling over. Check it out:
1) Again, load ordering the squat appropriately is key. Read this.
2) Place the Jump Stretch (or elastic tubing, bike tire inner-tube, whatever works) just below the buttocks and have the athlete perform the picture-perfect squat with assistance from the band. Important, do not hang on the band! It should be only enough tension to assist the motion, not allowing the athlete to rely on it. You can and should reduce the amount of assistance as the movement skill improves.
3) Dosage: enough to make change - this may take a few minutes or a few sessions depending on the individual. How do you know if it's working? Test and re-test the squat - if it's a cueing problem they may improve in a few minutes. Which is so much better than doing quad sets or straight-leg raises for 3 weeks hoping it improves the squat, right? This is why I also like to use this as a warm-up prior to activities requiring lots of posterior chain work - squats, deadlifts, jump landing. You SHOULD see improved depth and stability at the bottom of the squat following this exercise - if not, your dosage may be too low or mobility impairments may be contributing.
4) Variations - try putting a board under the heels or the exercises from last week to also help cue the athlete to fire the appropriate motor program.
Bottomline: As discussed last week, in order to improve complex movements such as the overhead squat, we have to improve the athlete's understanding of stability and control over the entire range of movement. Providing neuromuscular cueing and assistance to the movement teaches the athlete to load their hamstrings and glutes thru performing the movement we aim to improve! Want to improve a movement? Practice that exact movement, while reducing external demands! Sometimes, it is as simple as that.
The overhead squat is nearly peerless in developing proximal stabilization and control over a huge range of motion. It drives an athlete's balance and proprioception (sense of the body's position in space) and demands/develops functional flexibility. It is a staple of the Functional Movement Screen (FMS) and the challenges of an external load with the arms fully-elevated allow physios, coaches, etc. to diagnose/observe athletes' faulty movements otherwise unseen in the back and front squats. Poor overhead squat technique prevents an athlete from transferring power from the large engines (hips and shoulders) to the smaller joints (knees, ankles, elbows) - a MUST for athletic performance. But, man, if it's not done properly it is just plain ugly and dangerous.
Here's the problem: Many beginning athletes are poorly (like REALLY poorly) instructed on appropriate overhead squat technique. Couple that with many athletes being progressed to this movement without having mastered the back squat and front squat (excellent form on the back squat followed by the front squat is a prerequisite for training the overhead squat in my practice) and it's a recipe for some nasty pain and gross form. There are many issues that arise when evaluating one's overhead squat - including mobility, position, and motor control. The focus of this post is to improve motor control of the forward trunk lean - the bane of the overhead squat.
From a motor control standpoint - the ability to maintain an upright torso is absolutely essential to perform this movement otherwise you're dumping the weight and/or subjecting the shoulders and low back to dangerous forces. Additionally, it prevents the athlete from getting to full depth as the pelvis runs into the femur causing a pelvic fault and lots of anterior translation and shear forces to the knees and shoulders. This leaves the athlete unable to generate adequate force in the primary engines (hips and shoulders) and robs athletic performance. Many times the athlete (particularly the beginner) has a difficult time understanding how to organize the movement and pitches the trunk forward to unload the glutes and shoulders. An inability to set the shoulders and create torque early in the movement also unlocks the shoulders allowing the chest to drift forward
Here's the solution: Often, athletes just need some simple neuromuscular cueing to clean up the motor control problems.
1) Clean up any load ordering faults in the movement
2) Using elastic tubing (can be Theraband, thin Jump Stretch band, etc) have the athlete perform an overhead squat while maintaining a posterior pull on the band. This engages the back musculature (including the lats and erector spinae which invest into and tighten the thoracolumbar fascia - shared by the glutes, weird right?) allowing the athlete to generate torque and stabilize the movement. The key here is that the resistance from the band is high enough to provide assistance and cueing to the athlete but NOT high enough that they can passively lean on it. This exercise allows the athlete to perform the full movement with proper activation but without the danger of trying to teach this exercise under load. You can attach the band to a wall, pull-up bar, friend's arm, whatever. Check it out:
3) The next exercise is a progression from #2, in which now the athlete has stabilized the torso but is still struggling with locking and stabilizing the shoulders. Using elastic tubing, have the athlete pull the band apart while external rotating at the shoulder and prioritizing an upright torso. This allows the athlete to optimally stabilize the shoulder and thoracic spine allowing for a legit-looking upright torso, not to mention an improved ability to handle an external load overhead once the skill is learned.
4) Load the hamstrings and posterior chain to set the hips and lumbar spine: stay tuned next week for more on this one!
The above exercises are great for a pre-workout neuromuscular primer in order to teach or prep the athlete for the overhead squat. They are also definitely appropriate for overhead athletes to teach midline and proximal stability, balance, and control.
Bottomline: In order to improve complex movements such as the overhead squat, we have to improve the athlete's understanding of stability and control over the entire range of movement. Providing neuromuscular cueing prior to loading up the movement is a must for those learning or struggling with improving their technique - EVEN for those already adept. There is always more potential to be had!
Any time you perform squats, pick up something from the floor, walk up the stairs, or even jump and land your body is making a compromise depending on how you initiate this movement. The result may leave you with you anterior knee pain (think Patellofemoral Pain Syndrome), glute inhibition, and poor force production. And that leaves you landing from a jump like a 6 year old, which is super lame.
So here's the problem: The tissue or joint loaded first in a movement is the tissue or joint loaded the most. Too often we see athletes and patients (even "strong" ones) initiating squats with the knees coming forward - loading their quads instead of their high posterior chain (glute/hamstring complex). This quad dominance sets off a cascade in which the quads continue their powerful force and literally crush the patella against the knee as the athletes descends into the squat, jump land, etc. There is good evidence out there to suggest that the greater the knee flexion angle, the greater the compression forces on the patellofemoral joint - in a nearly linear fashion - and we're not really into crushing our own joints. Once the tissue/joint is loaded, it is virtually impossible to unload it during the middle of the movement - especially with an external load (think a heavy back squat).
You'll see how the athlete load orders their squat in the first few inches of the descent. Knees coming forward first in the descent is an immediate fault. By loading the knees first, the athlete is essentially rendering their glutes and hamstrings incompetent and preventing their substantial ability to not only protect the knee from gnarly compressive and valgus forces, but also greatly limiting power production and stability as you are unable to generate sufficient hip extension force (think jumping). The glutes control the hip and knee in all 3 planes of motion, rather than the quads which control the knee in the sagittal plane only, limiting their ability to stabilize and protect the knee. Quad dominance is seen often in athletes (particularly females - no wonder they are 4-6 times more likely to tear their ACL) and is a faulty movement
Try this yourself: Perform an air squat in front of the mirror. Your initial movement should come from the hip/trunk complex, not the knees coming forward. If you're knees are the first thing to come forward... epic fail. Think about those landing from a jump or descending into a squat while coming forward onto their toes - it's an unstable, weak position. Going into the squat in a poor position makes the finish even uglier: dropping vertical jump height, weakening triple extension, and killing power. Why? Because once a movement is loaded, poor muscle activation and poor position cannot be overcome! Trying to come out of the loaded knee forward position by shooting the hips back will only overextend the athlete and exponentially increase shearing forces.
1) Prioritize motor control and emphasize loading the glutes and hamstrings first. Tilt forward at the torso to tension the posterior chain and stabilize pelvic position. Following the load-ordering concept, at the bottom of the squat the posterior chain tissues are now under high amounts of tension having been loaded first. This allows for some highly modulated force production (i.e. a lot of oomph) and reducing forces on the patella.
A common error is to have the athlete stick their butt back first and keep the chest up during the squat descent. This faulty movement instruction can compromise spinal position resulting in overextension of the lumbar spine. A wide-open chest and overextended spine is commonly coached but woefully incorrect - causing the athlete to complain of low back pain (big surprise) during/after squats.
The first 6-8 inches of the squat is crucial to appropriately load the movement
2) Have the athlete shove their knees out laterally while keeping feet forward to pre-activate the glutes and create torque to take up tension in the system (glutes, hip capsule, hip adductors all control the pelvis) rather than finding tension with the knees tracking forward - this unloads the knee . Think about pulling yourself into the bottom position rather than dropping into it.
3) The shins should stay vertical as long as possible during the squat, tracking forward only at maximum depth (and that's butt to heel - limiting squats to 90 deg in perpetuity is NOT normal nor natural for humans). Tilting the torso forward at the hips while maintaining a stable, neutral spine is key and will assist in loading the posterior chain first in squatting.
4) Box squats are a great way to teach and improve control of the squat as you can vary the height of the box while teaching midline spinal stability. Box squats also help to cue driving back with the hamstrings as targets are useful in motor planning and control. Just don't reach with the butt causing overextension - instead coach tilting forward at the hips and shoving the knees out to stabilize the pelvis.
Elite and non-elite athletes alike need to be able to squat correctly and avoid this "quad dominance" seen so often in athletes - otherwise you're putting dangerous forces through your knee complex and gutting athletic potential. Appropriate load ordering is critically important in both human movement and mobility exercises and can/should be applied to all movements.
If you or your athlete cannot get the knee to full extension (straight) it's a problem - seriously. It can cause numerous performance deficits - both acute and chronic - a big problem if you want to produce maximal force in the lower extremities and avoid injury. Check out the video and discussion below:
It's clear in the video that sprint coach Jared Krout of KroutPerformance.com, is lacking full (terminal) knee extension. Normal knees are able to extend past neutral into hyperextension approximately 5 degrees. Restoring terminal knee extension is one of the first tasks your PT will take on post-surgically and it's one of the first things I look for in my athletes. You may have seen or even done the above exercise for quad-strengthening albeit with less resistance. However, the advantage of the way I've done it is to provide both an anterior glide to the tibia parallel to the joint surface in the Maitland/Kaltenborn method of joint mobilization and cue the quads to contract in a closed-chain function allowing what is essentially a two-for-one: mobilizing the joint into the position of restriction and activating the quads (which have an anterior joint glide moment in terminal extension) at this end range against some considerable resistance. Do NOT do this if you are early post-op ACL, patellar/quad tendon repair, or have some funky unstable knee (listen to your MD and PT - don't be a bozo). You can find these bands here.
So why is terminal knee extension so important?
1. If your joint does not have full range of motion in all directions, it is not normal/healthy. Now, an athlete can manage this restriction in terminal knee extension for some time, until they can't and they come to me with pain - in the knee or elsewhere. Without this critical range of motion they are predisposing the joint to high loads at a mechanical disadvantage.
2. If your knee is unable to get straight and then we stack some loading on top of it, think deadlift or jumping/landing, the joint is unable to fully disperse this load across the joint surface. A fully extended knee is considered the close-packed position of the knee because it is the position in which the articular surfaces are most congruent and the ligaments are the most taut. If you cannot obtain full extension, the load is poorly dispersed and cartilage does not do well with repetitive loading to a localized area. Here is some great evidence on the correlation of knee motion and early arthritic changes. Don't wear a hole in your knee!
3. In addition to the cartilage loading, lack of terminal knee extension means that you are unable to lock out the knee and the angle of pull on the patella and patellar tendon is altered, causing increased compression of the patella against the knee. This may lead to Patellofemoral Pain Syndrome and possibly patellar tendinitis due to the increased off-axis pull on the patella.
4. Perhaps most importantly, you need full knee extension to generate optimal quad force production. We will typically see poor quad function toward knee extension in those who are restricted in this motion. I don't need to tell you how important force development is for your quads. Any loss in quad function can destabilize the knee and increase joint loading.
Here's the kicker, loss of terminal knee extension will likely cause deficits up and down the kinetic chain. If you're unable to get your knee straight during triple extension (ankle plantarflexion, knee and hip extension) which is needed in basically all athletics, the hip cannot get into neutral extension causing you to overextend at the lumbar spine in order to keep you upright. Blow through some reps like that with hip flexors that are now super tight and it's hello spondy, plus it just looks like weak sauce. You may also have difficulty with appropriate foot strike during running, but that's a whole other topic.
Bottomline: Athletes must have full knee extension for optimal performance of the entire kinetic chain. If you are walking around and can't get your knee straight, get it together! Try the video above as a starting point (I realize that the screw-home rotational component may still need addressed for full extension, though not discussed here).
If your golf swing is weak and feels upper body-driven, poor lower extremity mobility may be stealing your power and leaving you as the guy no one wants to play with on a scramble. Or does your athlete look rigid on his lead leg while pitching (or rear leg while swinging)? Check this out:
When analyzing an athlete's movement, it's important to realize that human movement is a system of systems. While that may sound complicated, what we find is that oftentimes clearing up a dysfunctional pattern can resolve poor position and position = power.
Check out the the video above. In the video of super-stud Jared Krout (speed coach extraordinaire - he'll be featured on this site in future posts), you can see that as he rotates he's essentially running out of room in his hip and any further rotation comes from his spine. This is a sweet example of Regional Interdependence, in which dysfunction in one region causes dysfunction in another. It doesn't take much to figure that his rotation has to come from somewhere and once runs out of internal rotation and jams his femur into his pelvis, the rest of the motion will come from the lumbar spine, potentially causing some back pain down the road.
Obviously I have oversimplified the analysis of this (motor control is always an issue with athletes in addition to mobility - more on this in later posts), but look at how much his rotation improves! In my practice, we will typically go after this with several correlate movements (conjugate training/mobility) in addition to the one Jared is doing, followed by actually practicing the affected movement (golf swing in this case) to motor program the movement and maintain his new range of motion.
Poor hip rotation is a huge problem in rotational athletes including throwers. We see an increase in upper extremity injuries in those with poor hip internal rotation as they essentially make up for the loss of hip rotation through the shoulder and elbow (also potentially through the lumbar spine). Lacking hip internal rotation may also be correlated to hip impingement (FAI - femoroacetabular impingement) and possibly cause poor positioning of the knee and ankle (knee valgus). Mobility and control of the body over a fixed leg is huge folks and we're going to come after this like an angry caddie in future posts.
In this video, you can see how poor hip mobility can negatively your swing (and this dude could use some more hip mobility himself).
Check out these articles on the correlation of hip range and injuries (Nerd Alert):
Associations Among Hip and Shoulder Range of Motion and Shoulder Injury in Professional Baseball Players
Hip rotation in golfers may determine pathology
Basically, by putting the athlete into positions of restriction and improving that position we can optimize their movement at these limited end-ranges of movement. Why should you care? Because your performance will improve and your back won't feel like a wet rag after 18 holes. And your church league softball swing may have a little more oomph in it. After all, performance improvements are what we really care about. Try the method above - one of many ways to improve hip internal rotation - and let me know what you think.