It is widely accepted that decreased hip strength and stability leads to knee valgus. Excessive frontal plane motion and valgus torque increase the risk for non-contact ACL injuries. While we know that hip abductor weakness is more of an issue in females than males, the question remains to what degree other factors are involved.

Claiborne et al (1) noted that only 22% of knee variability could be linked solely to hip muscles surrounding the hip. In light of this we must look at the whole kinetic chain when assessing movement dysfunction and injury risk. In the most recent issue of the IJSPT, researchers sought to discover how activating the core during a single leg squat would impact the kinematics of 14 female college-age women. They excluded participants with current pain or injury to the lower extremities or torso, or if they had a history of any lower extremity injuries or surgeries in the past 12 months.
The participants were assessed for their capacity to recruit core stabilizer muscles using lower abdominal strength assessment as described by Sahrman (2). This testing model has 5 levels of increasing difficulty used to challenge participants to maintain a neutral spine. The draw back of this method is that it is done in supine versus the standing position of this study, but the author acknowledges this limitation. Out of a possible high score of 5, five of the participants scored a 1 or 2, while the other nine scored a zero.
For the study, a six inch step was used to assess 2 reps of a single leg squat. Each participant was asked to perform the test with the dominant leg to standardize conditions. They performed the reps under two conditions:
1. CORE – engaged abdominal muscles as they had been instructed to do so during the Sahrman test
2. NOCORE – no purposeful engagement of abdominal muscles
Results
How do we use this information to affect our practice? Well, in terms of rehab it seems straightforward and many of us may already encourage patients to activate their core during treatment. However, I think the greater contribution may come in injury prevention programs (particularly ACL programs) where we are looking at all facets of neuromuscular control and appropriate muscle activation patterns.
With any prehab or rehab strategy, we as clinicians, trainers and strength coaches are essentially trying to reprogram the brain to summon and execute a better motor pattern or strategy – feedforward training. We know that healthy individuals tend to have better transverse abdominus and multifidus muscle activation, so it only makes sense to consider activation of local stabilizers as we work on global muscles. Improving core and pelvic stability should only help reduce unwanted frontal plane motion.
With that said, the authors of this study readily acknowledge more work needs to be done with larger clinical populations (including EMG work) to more clearly identify what magnitude the core musculature has on lower extremity motion and displacement.
Keep in mind the proper program will always stem from your ability to assess movement impairment and tissue dysfunction. I suggest beginning with a FMS in the athletic population and incorporating parts of that or the SFMA to compliment your evaluation in the clinic. This will generally reveal the priorities for the corrective exercises. For now, we can use this information in this particular study to be more intentional with our patients and clients suffering knee and hip dysfunction by adding this one simple step to our programming.
References
1. Claiborne TL, Armstrong CW, Gandhi V, Princivero DM. Relationship between hip and knee strength and knee valgus during a single leg squat. Journal of applied biomechanics. 2006;22(1):41.
2. Faries MD, Greenwood M. Core training: stabilizing the confusion. Strength & Conditioning Journal. 2007 ;29(2):10.
Dysfunctional movement is common with shoulder pain and impingement. One dysfunction you may encounter is a downwardly rotated scapula. If upward rotation is limited, a client will display excessive shoulder flexion above 90 degrees when the humerus is in maximal internal rotation. Typically, a person will have minimal flexion beyond 90 degrees if the scapula is moving properly.
Upward rotation of the scapula is the result of a force couple between the upper and lower trap along with the serratus anterior. If any of these muscles are weak, rotation can be limited and overpowered by the rhomboids and levator scapulae muscles (both downward rotators). This pattern of muscle dominance is common.
Additionally, tightness in the rhomboids, levator scapulae, pec minor or latissimus can also restrict normal mobility. It is probably safe to assume stretching of the chest and lats would be helpful, but it is critical to encourage the proper muscle firing patterns in the traps and serratus anterior as well.
Below is a video demonstrating wall slide shrugs. The shrug should be done at or above 90 degrees. You can perform reps at multiple angles or move to end range and perform a series there.
Application: The exercise is designed to encourage upward rotation in a more functional manner as opposed to traditional shrugs with the arms at the side. While I am not opposed to traditional shrugs with little or no weight for basic elevation, this position generally tends to activate the rhomboids and levator scapulae which is not desired given their natural dominance pattern.
The wall slide shrugs should not create any pain or discomfort. However, they may feel awkward particularly if the client has a faulty muscle activation pattern. As muscle tightness resolves and strength improves, clients should gain more mobility and optimal shoulder function.

Kettlebells are very popular training tools these days. I find them useful in many ways – improving grip strength, core activation, asymmetrical loading, etc. With that said, I also feel with movement flaws and/or improper technique, they carry an inherent injury risk.
It is interesting to note that some people find swings to be very therapeutic and good for their back, while others who are capable of lifting very high loads with traditional lifts find them to be irritating to the spine. So why is this?
If you are like me, knowing the “why” or “cause and effect” behind exercise is very important. I am not one to blindly use an exercise without knowing its intended purpose and then quantifying risk vs. reward and results. So, it was with great interest I read Stuart McGill and Leigh Marshall’s recent article on kettlebell swings, snatches and bottoms-up carries in the NSCA Journal of Strength & Conditioning Research (Jan 2012).
While the sample size is small, I think the article provides some gems in regard to training given no one has really looked at spine loading during various swings and carries. The authors used surface EMG to record muscle activation of the back, hip and core muscles throughout the various exercises – swing, swing with Kime (abdominal pulse at top of the swing), swing to snatch, racked carry and bottoms-up carry.
Without going into all the tiny details, I wanted to share what I consider to be some key takeaways for rehab and training:
So, in my mind kettlebell training (like any other form of training) requires proper form, movement assessment and an intimate knowledge of the client’s medical and training history. In addition to that, we must carefully scrutinize execution of the exercise and deliver appropriate feedback and analysis.
While maximal shear occurs at the bottom, I cannot help but wonder about the potential impact of tight iliopsoas muscles given their unique relationship to the lumbar spine and reverse muscle action. It would be interesting to know if those with a greater anterior tilt and tightness are more likely to experience higher shear forces or potential back soreness over time.
This brings the discussion back to quality of movement and movement assessment. In my mind, adequately assessing the hips (flexibility, strength and stability) is also a key variable in determining how best to approach integrating the swings. As Gray would say, the lumbar spine needs stability while the hips require mobility.
A lack of hip mobility is definitely a relative precaution for swings in my mind. On top of that, fundamental hip strength/stability and core strength should be evident. Perhaps even regressing to rudimentary hip thrusts and bridges may be the best place to start for those needing a primer on form and proper movement before moving to a basic swing.
Nonetheless, a big thanks to Stuart McGill and Leigh Marshall for this work and giving us some practical food for thought. I hope this information helps you as much as it did me. May your training be safe and effective!
Seldom do I use my blog as a platform to rant, boast or anything in between. I generally like to share evidenced based information that helps improve your health and performance. But, every once in a while I feel the need to share my opinions on things I feel strongly about. Today, I want to offer you my suggestions and theory on professional excellence within the fields of health and fitness.

Let me preface this post by simply saying I would never think of writing this or publishing it online for the whole world to read without having several years (15 now) of professional experience under my belt and a proven track record of getting RESULTS for my clients. In my mind, the very reasons for my success include: being blessed with above average intelligence, a strong work ethic, a desire to help and serve others, unquenchable PASSION to be the very best I can be in my field, and an uncanny knack for seeing things others do not and using that information to make impactful exercise and treatment decisions for my patients and clients.
Where am I going with this? Well, unfortunately, not all trainers, coaches and physical therapists share this same passion or possess this knack that I speak of. Some are content after college (or certification) to be good enough and may not read literature, go above and beyond with continuing education, surround themselves with the best in the business or strive to be better each day. Others may simply not have an innate ability to problem solve and synthesize given data to construct the right plan for the client. Often trainers and clinicians default to what is easy or “what they know” as opposed to viewing each client in a different light. In other words, they lack artistry. They will never be revered like Picasso (pictured below).

I thought a fitting way to kick off the new year would be to share the top 10 things I learned or embraced that have most shpaed and impacted my training and rehab this past year. In no particular order I will rattle these things off. I hope at least one of these little pearls has a positive impact on your training and/or rehab as well.