Tag Archives: muscle imbalance

The Glute vs TFL Muscle Battle: Proper Exercise Selection to Correct Muscle Imbalance

Selkowitz, DM, Beneck, GJ, and Powers CM. Which Exercises Target the Gluteal Muscles While Minimizing Activation of the Tensor Fascia Lata? Electromyographic Assessment Using Fine-Wire Electrodes. J Orthop Sports Phys Ther. 2013; 43(2):54-64.

Overview and Introduction:
JandaSyndromesVladamir Janda revolutionized human movement dysfunction and rehabilitation when he described three compensatory movement patterns as a result of pattern overload and static posturing. Most musculoskeletal injuries are multifactorial, but more often than Janda’s described three compensation patterns – upper crossed syndrome, lower crossed syndrome and pronation distortion syndrome – are the key contributor to our pain complaints.

Since Janda introduced this topic research has continued to answer what and why questions surrounding these compensatory patterns. We have learned hypertonic / hypotonic muscles and the delicate interplay they have on integrated functional movement. Studies continue to show how these dysfunctional patterns lead to our most common injuries – PFPS, ITBS, Achilles tendinopathy, plantar fasciitis, epicondylopathy, biceps tendinosis, impingement syndromes, MTSS, etc.

As research evolves we continue to fine-tune our clinical decision making. For several years now rehabilitation journals have published articles linking a myriad of injuries to lower-crossed syndrome, gluteal inhibition, and over-activation of the tensor fasciae latae (TFL). We have learned that these should be a focal point in our rehabilitation techniques to resolve lower extremity overuse injuries. The article by Selkowitz, et al., in the Feb 2103 edition of JOSPT is unique and what I believe to be one of the most clinically relevant studies to be published in the last few months. I liked it so much I had to blog it.

Statement of the Problem:
A common descriptor associated with lower-crossed syndrome is femoral internal rotation and hip adduction. From a rehabilitation perspective we must enhance neuromuscular firing of hip abduction and external rotation. In addition we must inhibit over activity of hip adductors and hip internal rotators.

As a health care practitioner we understand the delicate interplay of functional anatomy. The problem is how do we inhibit a chronically hypertonic TFL while activating the hypotonic gluteal group if they both produce similar movements? It is a fine balance we must be cognizant of when designing rehabilitation programs.

This study examined which exercises elicit the greatest gluteal (medius / maximus) activation while minimizing activation of the TFL. This is exactly what we need to know when designing a rehabilitation program to target lower crossed compensatory patterns.

Study Methodology:
Electromyographic data of the gluteus medius and superior gluteus maximus was collected utilizing fine-wire electrodes on 20 healthy participants during the execution of 11 exercises.

Seven of the 11 exercises -bilateral bridge, unilateral bridge, side step, clam, squat and two quadruped variations – demonstrated statistically significant greater muscle activation in the gluteus medius and gluteus maximus when compared to the TFL. Side-lying hip abduction, hip hike, the lunge, and the step-up were either not significant or demonstrated higher TFL values compared to the gluteal group.

The authors ranked the exercises in order of highest gluteal to TFL ratios. Clam, side step, and unilateral bridge had the highest ratios, while lunge, hip hike, and squat had the lowest ratios.

Clinical Application of Data:
Altered arthrokinematics and muscle imbalances are a common cause of overuse injuries. Lower-crossed syndrome is a common compensatory pattern that is associated with hypertonicity of the hip flexors complex, which elicits altered reciprocal inhibition of the gluteal group. Targeting this dysfunctional pattern using proper exercise selection indicated here can prevent injuries, improve patient outcomes, and restore optimal function. When designing your program be sure to reference the material here to determine a proper rehabilitation program.

Studies are equivocal on reliability of surface EMG vs intramuscular. However, the authors cite using the method by Delagi and Perotto, which appears reliable. Still one has to question specificity and sensitivity to a minimal degree.

The participants were instructed on proper exercise technique. However, substitutions patterns are common in patients exhibiting muscle imbalance. Any slight deviation from proper technique can skew the data. I am curious how closely exercise technique was monitored and what occurred when deviation did occur.

Like I said from the top, rarely do we have a published data with such clinical relevance. Studies that show how deep ultrasound penetrates a rats muscle are great, but clinically have little clinical utility. Data revealed here will guide decision making on proper exercise selection and ensure they are applying the proper strengthening exercise to specifically target the underactive glutes while avoiding the over active TFL. Kudos to the authors.

The Dreaded Hamstring Strain

How many times are we going to see an athlete suffer from recurrent hamstring strains? How many times are we going to see delayed recovery from a mild hamstring pull? Unfortunately, it’s going to continue, because some health and wellness specialists (ATCs, PTs, and Strength coaches) are looking in the wrong area. Sometime ago I had a disagreement with the parent of an athlete (the parent also happened to be a chiropractor).

The parent was upset that I was not fixing the hamstring in rehabilitation. He said, ‘She needs flexibility and strengthening of the hamstring! You are not doing that!’ The concerned parent actually complained to my athletic director. Now I have my boss challenging me on my treatment.  Ugh, such is the life of an Athletic Trainer. Thankfully, after conversation, he backed me up.

Now, before I swarmed by an angry mobs of chiropractors trying to beat me with sticks, this is not about chiropractors – this is just one example of the trap that many health care practitioners – Athletic Trainers, PTs, OTs, RKTs, DC, MD, LMTs, etc – fall in to.  Many practitioners are too concerned with ‘the what‘ rather than ‘the how‘ and ‘the why‘.

This particular parent was upset and did not understand why I was not addressing the what. In my defense, I was dedicating some time to fixing the what – using ultrasound, massage, PROM, etc – to facilitate proper tissue healing. However, I knew this would not fix the problem. In this particular instance (and most hamstring injuries) I needed to correct human movement dysfunction (poor neuromuscular recruitment, suboptimal arthrokinematics, and altered length-tension relationships). This will fix the problem and go a long way in prevention of re-injury. Flexibility and strengthening of the hamstring is not needed.

Don’t get me wrong, flexibility is a good thing, but hamstring flexibility is way overrated. Take yoga as an example, yoga is  known for improving flexibility (among other things). In fact, I’ve prescribed yoga to many of my clients. Unfortunately, many yoga poses place the already lengthened hamstrings under further stretch. Hamstring strains are very common in Yoga enthusiasts, especially amateurs. It is so common, it was given a name – Yoga Butt. Yoga butt is essentially a tear of the proximal hamstrings, subsequent to repetitive lengthening of the hamstrings.   There is a reason for this.

Secondary, to pattern overload or prolonged static posturing many individuals suffer from chronic hypertonicity and mechanical shortening of the psoas.  A chronically tight psoas will cause altered reciprocal inhibition of its functional antagonist, the gluteus maximus. With this muscle imbalance an abnormal force coupling occurs yielding poor arthrokinematics in the form of an anterior pelvic tilt. Because of the hamstring’s proximal attachment to the ischial tuberosity an anterior pelvic tilt will cause the hamstring to migrate superiorly and posteriorly, essentially lengthening the muscle. If you recall from your applied kinesiology course, muscles have optimal length tension relationships – a zone where maximal muscle force can be produced. The longer or shorter a muscle is, the less the muscular force can be applied or tolerated.

In addition to this, with the glute inactivity caused by altered reciprocal inhibition. So now a synergistic muscle must help with glutes ability to perform hip extension. Which muscle is going to this? You guessed it – the hamstring.  This is called synergistic dominance – the hamstring (synergist) must dominate the movement of hip extension.

If you recall from above, the hamstrings are working in a lengthened and suboptimal position. Coupled with this it is being asked to do more work. So, when we are applying the greatest amount of muscular tension – eccentric contraction near end ROM (such as sprinting) – the hamstring fails. Commonly it fails near the proximal attachment secondary to a line of pull change.

Why do we see so many hamstring injuries? Because health and wellness professionals are not identifying or intervening to correct human movement dysfunctional patterns.

Why do we see so many recurrent hamstring injuries? Because we are not fixing what needs to be fixed and allowing the hamstring to work inefficiently.

Why are we seeing delayed recovery? Because we are using antiquated rehabilitation techniques. We are focusing on the hamstring when the problem exists elsewhere.

Correcting movement dysfunction and optimizing function will fix the problem. This is so much easier in the long run. Recently there has been a slew of research published discussing the effectiveness of high-intensity eccentric hamstring strengthening on the prevention and rehabilitation of hamstring injuries. Yes, eccentric hamstring exercises work, but why? They work because you are making the hamstring more tolerable and able to function with poor mechanics. Again, this is not fixing the problem. To fix the problem you must address glute weakness and hip flexor tonicity.