Selective recruitment of the lower fibers of the trapezius muscle Arlotta M, Lovasco G, McLean L. J Electromyogr Kinesiol. 2011 Jun;21(3):403-10. Epub 2010 Dec 8.https://www.ncbi.nlm.nih.gov/pubmed/21144767 The scapula has been shown to play a critical role in shoulder function. The scapular stabilizing muscles work together to provide dynamic stability. Some research has demonstrated that the lower trapezius can develop inhibition and the upper trapezius becomes hyperactive in pathologic shoulders. This demonstrates the need for exercises that maximize lower trapezius activity and minimal upper trapezius activity. Therefore, the authors examined a series of rehabilitation exercises to determine the amount of electromyography (EMG; muscle) activity that is produced in each division of the trapezius muscle (upper, middle, and lower)They evaluated muscle activity in 18 healthy individuals with no prior history of shoulder injury or participation in overhead sports. Bilateral EMG was collected during five difference exercises (Latissimus Pull-down, Prone Row, Prone V-Raise, Posterior Fly, and Modified Prone Cobra). The order of exercises was randomly selected. They examined the peak EMG activity and also calculated EMG isolation which was defined as division of interest divided by EMG UT +EMG MT+ EMG LT. They found that there were differences between sex and therefore the data was analyzed separately for each sex. In males the prone row, posterior fly, and modified prone cobra generated the highest activity for the lower trapezius. For females the modified prone cobra and the prone row generated highest activity compared to the other exercises. For both males and females the modified prone cobra, prone row, and latissimus pull down had the most isolated lower trapezius activity. This study presents very clinically relevant data to help justify an exercise selection for patients with lower trapezius inhibition. In addition to determining exercises that produce maximal lower trapezius activation, the activation of the upper trapezius needs to be considered. This study identifies several exercises that can be performed with a more optimal ratio of lower trapezius to upper trapezius activation. In this study these exercises were performed bilaterally and therefore should be perform in a similar fashion clinically. It would have been interesting if the same results would have been produced if the exercises were only done unilaterally. I believe the same isolation would have been produced, however the activation level would have been reduced. Several studies have demonstrated a neuromuscular cross over effect that improves strength and activation when performing exercises bilaterally. The selected exercises are quite common, at least in my experience (although I call them by different names). What are others experience with these exercises? Have you heard or used them in the past? Have you had success? Written by: Stephen ThomasReviewed by: Jeffrey Driban
Has this test been done in an impaired population?
I have some personal interest in this topic. I try to perform some basic scapular stability exercises to maintain my shoulder health, but I don't feel that I am improving my lower trap activation or decreasing my upper trap hypertonicity.
Andy,
Thanks for the comment. That is a great point. This was performed in healthy control subjects to determine if the exercises efficiently activate the lower trap. Another question would be are the same activation patterns occurring in patients with scapular dyskinesis. It is thought that inhibition of the lower trap occurs in patients with dyskinesis so does this translate into altered activation patterns when performing these exercises. The answer is most likely yes. From my clinical experience these patients have a very hard time at the start of rehab. I commonly use easier exercises and a lot of verbal and visual cues to re-train the activation patterns of the traps. This is very difficult and doesn't happen over night but once it does they progress quickly. Something to keep in mind when rehabbing these patients. Great comment!
This summary has been very influential to read. From working in the clinic and at a high school having people activate their lower trapezius has been key in many of the exercise or rehabilitation regimens. Now seeing which exercises and for each sex that have are the most effective will make my decision on which exercises to implement much easier than just working on scapular retractions and lat pull downs.
Thanks for the comment. Yes, I agree having well performed EMG studies helps us as clinicians use scientific data instead of anecdotal evidence to design rehabilitation programs. This helps patients improve more effectively throughout the course of rehabilitation.
nice post.