Tuesday, April 22, 2014

Core training

It's been a couple of weeks since posting so I thought I should return to writing with a big topic. Let's talk about "core" training. What is the core, what does it do and how do we train it? And just as importantly, how should we not be training it?

I like to think [1] of the core as 2 systems that work together to stabilize the body. The two systems are as follows:

Outer unit:
The role of the outer unit is to generate movement and stabilize the spine during excursions of the upper and lower body. Additionally the outer unit allows for efficient full body movement by keeping the spine in proper alignment. Think of a volleyball player leaping and then spiking the ball. The core muscles generate rotation in the torso to increase the velocity on the spike and they maintain stability at the spine and prevent overextension, which allows the force from the jump and the torso rotation to transfer effectively to the shoulder and eventually to the ball.

Muscles involved:
Glutes (yes the lats and glutes are core muscles. They directly influence pelvic position, which directly influences lower back position. If we are going to agree that part of the role of the core is spinal stability then we have to include these muscles as part of the core)
Rectus Abdominus (the abz)
Erector Spinae
External obliques

Inner unit
The inner unit is sort of like a box in the middle of your torso. The role of that box is to expand to create pressure within the abdomen. This pressure stabilizes the spine and allows for lifting of greater loads and transfer of force through the kinetic chain. The diaphragm in particular has a huge role in proper breathing mechanics and therefore spinal alignment.

Muscles involved:
Transverse abdominus
Internal Obliques
Pelvic Floor

Given what we now know about anatomy and function the natural next question is how best to train this area of the body for optimal performance, either in sporting activity, weightlifting or just daily life.

As previously mentioned one of the primary roles of the trunk musculature is to aid in transfer of force between upper and lower extremity. If every joint is an opportunity to lose force the spine is the area that has the greatest potential for loss. However, with a well trained inner unit and outer unit, force is transferred effectively from hips to shoulders or vice versa. In many people the inner unit is underactive and the outer unit over active from a stability standpoint and this can compromise force transfer and spinal stability, as well as lead to a higher likelihood of injury. This often occurs by overtraining the outer unit muscles (particularly the lats and rectus abdominus). These type of athletes typically appear to have strong core muscles but are challenged to perform even one repetition of a true stability task.

All show, No go

We can categorize our core training movements as follows

Lateral Flexion
Anti-lateral flexion

Let's look closely at each of the areas and see what sort of value they have and how to implement them in training.

Flexion - Spinal flexion exercises used to be all the rage in the fitness industry and the predominant method of training the abs; in the common gym going public they still are. Go to any gym and look on the mat area and you're likely to find a few people stretching and a group of people doing all sorts of crunches in pursuit of the elusive six pack. [2]

However, in recent years the crunch and situp have lost favor particularly due to the research of Dr. Stuart McGill who has repeatedly shown the stress that high repetition and/or loaded flexion can have on the lumbar spine. If you haven't read into any of his work I highly suggest that you do so. I agree that loaded flexion is a major no-no and that people who sit all day aren't doing themselves any favors either. This part is important so I will re-state it.

No loaded flexion and no high repetition flexion. That means tighten up your weightlifting technique and toss out that 1000 crunches per day plan.

With that said the spine should have the ability to bend and flex. We can train it through simple cat/camel positions to start and eventually progress to advanced tumbling techniques. These type of movements are actually a great dynamic warmup for people with no history of disk problems and a moderate level of coordination

One last note on the issue of spinal flexion: after a long restful night sleep when the spine has been horizontal for hours the hydration status of the disks is very high. This increased hydration status can cause higher likelihood of herniation or other disk injury. For this reason I avoid all tumbling and flexion based movements with my 6 and 7 am clients

Lateral Flexion - 

Loaded lateral flexion has been shown to cause a lot of disk problems and this isn't a movement I recommend training with clients. If you want to include unloaded lateral flexion in your dynamic warmup I see no reason why you can't although I don't know that it would be the best use of your training time. Additionally this movement will hypertrophy the quadratus lumborum, a thick muscle running from your pelvis to your lumbar spine. In other words the muscle under your love handles. If that is an area that you want to make bigger while simultaneously doing long term damage to your disks then this exercise is for you!

Extension - 

There is a common misconception in the fitness community that a sore or painful lower back is caused by a weak lower back. In many cases that couldn't be further from the truth. Many low back pain sufferers are in their current predicament because they lack anterior core strength to keep the spine in a neutral position. This forces the lower back to work harder than necessary and put excessive extension based strain on the lumbar spine. Using a proper assessment protocol can help you see what the problem really is

Not a weak back, but maybe a painful one

Back extension is best trained isometrically and in conjunction with hip extension. Deadlift and squat variations are simple exercise staples that when performed for appropriate volume and with good technique provide sufficient back extension training. Someone with very specific training goals (like squatting 3x their body weight, may be well served to add in additional back extension training). As with many spinal movements, extension in an unloaded environment is also of significant value for restoring or maintaining proper mobility. 

Rotation - If you haven't read about Mike Boyle's joint by joint theory I highly suggest you REVIEW IT. In it he discusses that the lumbar spine is intended to be a stable joint and the thoracic spine operates as a mobile joint, or series of joints in this case. With that in mind we can form a multiplanar approach to core training. Rotation exercises of the spine are excellent for developing range of motion, power and athletic ability, so long as the rotation is occurring through the thoracic spine and not in the presence of flexion.

Anti-flexion - These are the isometric back extension exercises I referenced earlier. Any exercise in which the load pulls you into a flexed (or round back) position and you must resist is an anti flexion exercise. Think squats, deadlifts, kettlebell swings, even some lunge variations

Anti-extension - This is the bulk of the "abs" training that I do with my own clients. The goal is to place the client in a position where resisting extension forces is the goal. Many clients will attempt to complete these movements by activating the hip flexors so keep an eye on anterior pelvic tilt to ensure proper technique. These type of exercises train the glutes and abdominal muscles to work in unison to allow force transfer across the spine. Some personal favorite exercises include barbell rollouts, Pushups, TRX fallouts and OH pressing

Anti-rotation - Developing rotation and power in multiple planes is great and is the foundation for success in a lot of sports (golf, tennis, lacrosse, hockey, etc) but an inability to control throughout a full range of motion can lead to wasted energy and poor performance. That is why anti-rotation drills are a staple in almost every sports program I design and a part of most general population programs as well. Usually I will focus the first couple of weeks of training on anti-rotation stability and training rotation range of motion and then transition to more powerful active rotation drills for the trunk

Anti-lateral flexion - Lateral flexion under load causes disk problems for a lot of people by putting excessive strain on the lateral components of the vertebrae. However, we can still strengthen those muscles isometrically and in a manner that has greater carryover to real life. Options here are endless. Anything in which you load one side of the body will cause the body to want to shift it's weight to easily accommodate the load. Single arm squats, single arms lunges, single arms presses etc.

So what would a daily routine look like for a client with the goal of "improved core strength" ?[3] This will vary depending on a persons posture and injury history or the sport they participate in but lets keep this plan well rounded just to be thorough

Dynamic warmup
Yoga flow and tumbling 10minutes (not first thing in the morning)

Deadlift (training anti-extension) 
ss/ hip flexor mobility (not necessarily core training but restoring proper length to the hip flexor will keep the pelvis/lower back in good positions)
Overhead Press (training anti-extension)
TRX single arm row (anti-rotation)
ss/ pushup march (anti-extension and anti-rotation)
lateral lunge (not directly core training but anterior loading will cause some anterior core contribution)
ss/ pallof press (anti-rotation)

Interval circuit
Sledgehammer swings (rotation)
farmers walk (anti-flexion and extension)
rowing ergometer (anti flexion)

A good full body routine with sufficient multiplanar challenge for the trunk all without doing a single crunch or side bend. This method of categorizing your core training will allow you to build a strong and stable core and keep a happy and healthy lower back. Now get to work!

[1] Obviously I am not the only person or the first person to categorize the core this way. If I could remember who I learned this concept from I would gladly give them credit. I want to say Paul Chek
[2] your six pack is not missing due to a lack of crunches, but rather a lack of disciplined eating and likely sleeping
[3] A vague goal but one that every personal trainer has heard at least a dozen times

Tuesday, April 1, 2014

The front of my hip hurts. What should I do?

I just returned from leading a personal training workshop in California. I do these workshops fairly often. It's a really fun opportunity for me to get to teach, which is really what being a coach or a trainer is all about. This weekend a girl asked me about a pain she was having in the anterior portion of her hip. I heard a similar complaint from a man in a workshop two weeks ago. It's not the first time I have heard these complaints. Someone in the Crossfit I coach at has had similar problems. While every injury is slightly different in it's causes and solutions I can hypothesize that many of these anterior hip pains are coming from the same root cause. The pain they are feeling is what would be classified as femoral anterior glide syndrome. This is something I learned about by reading Dr. Shirley Sahrman's fantastic book Diagnosis and Treatment of Movement Impairment Syndromes. [1]

To fully understand this injury you have to have a basic understanding of the anatomy of the hips.

The Glutes (or gluteus maximus to be more specific) attach on the pelvis and the femur, making it a one joint muscle and our primary hip extensor

The hamstrings run from attachment sites on the pelvis to down below the knee, making them two joint muscles. That's why hamstrings can be trained through either hip extension exercises like Romanian Deadlifts, or knee flexion exercises like leg curls.

These muscles (the hamstrings and gluteus) are intended to work in unison with each one contributing force during certain parts of a movement depending on joint angle. This applies to squatting, deadlifting, lunging and even simple walking and running patterns. When the hamstrings are overly active it can pull the femur forward in the hip socket, causing an irritation in the front of the hips. This is due to the attachment site on the tibia. The distance between origin and insertion causes a gross movement pattern, lacking in stability near the joint. This over activity can also be the cause of hamstring and groin strains and many cases of lower back pain as well.

When the glutes are appropriately strong they maintain stability at the hips and keep the femur secure within the socket where it should be. The glutes are able to do this more effectively than the hamstring because of their shorter length and attachment near the head of the femur.

Imagine trying to pick up a big pipe shaped like the letter L. Picking it up by the bottom of the letter is like just using your hamstrings. It's likely to tip over while you carry it (or in the case of the femur, bang up against the anterior capsule). Picking it up by the top is like using the glutes, because of the attachment site near the head of the femur. It is a much more stable position but when moving something heavy it's still not optimal. You want to grab that pipe with two hands to be as strong and as stable as possible. That's the effect of getting a go co-contraction of the hamstring and glute muscles.

At this point you probably just want to know how to make the pain go away so you can get back to your normal routine. The key is figuring out what caused it in the first place and then eliminating the bad things and adding in a few things to correct any imbalances [2] Here are some ideas:

1. Stop cranking on your hip flexors. I know the pain feels like it's a tight hip flexor but it probably is not. Repeatedly leaning hard into that tender area is going to put greater amounts of pressure on the already inflamed zone.

Don't do this

2. If anything makes it hurt then stop doing that movement. I know it's hard to give up your favorite big lift but if something is causing pain that is your body giving you a message to stop. Replace the lift with something less painful for 2-4 weeks and then see how it feels before returning to your previous patterns.

3. Finish all of your hip extension lifts with a strong glute contraction. Not only will that prevent anterior hip pain but it also will strengthen the glutes to a greater degree, allowing for better overall performance.

This would be a perfect example of deadlift technique that would promote injury to the anterior structures of the hip. Notice the hard arch at the top and lack of glute involvement.

How to not complete your squat. Poor lockout leads to anterior glide of the femoral head. [3]

Whether you are squatting, deadlifting or even lunging it's very important that you complete the ROM with each repetition. Complete hip extension will help prevent the hamstrings from dominating the glutes while also protecting the lower back and improving strength in general

3. Strengthen your glutes. This is a cure (or at least part of the cure) for atleast 75% of the problems that I see in my gym. Stronger glutes have a myriad of benefits but specific to this issue they will maintain stability of the femoral head in the acetabulum, preventing the anterior shift and associated pain. Start with simple ground based exercises like bridges and progress into single leg work and then eventually back to basic barbell training.

Strengthening the psoas and stretching the TFL would also be on my correction to do list but after correcting these more obvious problems. Hopefully this helps at least one person fix a nagging injury and get back to their normal training routine.

[1] Actually still in the process of reading it. That thing is a monster.
[2] in some cases no corrective exercise needs to be added at all and it is a simple case of addition by subtraction
[3] The videos above are of Lee Boyce and Eric Cressey. Both are great trainers and are doing the lifts incorrectly as a teaching tool