To Clam, or Not to Clam

As the battle to annihilate the coronavirus continues, everyone is faced with new realities. For me, those realities include chatting with my teenage patients on the phone, transitioning to Telehealth, and only seeing "high priority" kids while covered head to toe in PPE. The patients are still the most important part (and my favorite), but the volume is dramatically reduced so the majority of my time has been spent learning. I've also been working on the Seattle Children's Sports Physical Therapy Journal Club, summarizing papers to share with the department on a monthly basis.  The May topic, coming out tomorrow, is a collective look at these four gluteal muscle electromyography (EMG) papers:

1. DiStefano LJ et al, “Gluteal muscle activation during common therapeutic exercises.”  JOSPT 2009.
2. Boren K et al, “Electromyographic analysis of gluteus medius and gluteus maximus during rehabilitation exercises.” IJSPT 2011.
3. Macadam P et al, “An Examination of the gluteal muscle activity associated with dynamic hip abduction and hip external rotation exercise: A systematic review.” IJSPT 2015.
4. Bishop BN et al, “Electromyographic Analysis of Gluteus Maximus, Gluteus Medius, and Tensor Fascia Latae during therapeutic exercises with and without elastic resistance.” IJSPT 2018.  

Why this topic? I believe it is imperative for clinicians to be lifelong learners and that reading research is one approach to improve your skills as a clinician.  I also think it's really hard to do this, which is why I stared writing this blog - a place where I could store things I've learned and write out my thought processes.  The impetus behind this particular topic of learning boils down to two key points.

Key point number one: The Clamshell Debate.

If you've ever gone to outpatient orthopedic physical therapy, you've likely done the clamshell exercise.  It's very common and frequently patients will say they've done them in the past.  Thanks to Seattle Storm Sports Performance Coach Emily Blurton for her video demonstration:

Early in my PT career, I frequently recommended this exercise.  I had pre-made exercise programs that I used repeatedly for multiple conditions.  Now I make every program for the patient in front of me, often updating them at every session, and this exercise rarely appears. To me, the clamshell doesn't look like anything a person does in daily life or in sports. Maybe it looks like you're lifting your leg to get into a car.  But that's standing up, so maybe not.  Even worse, a lot of patients do them incorrectly and find them boring and too easy.  I don't create exceptionally difficult exercise programs, but it's a lot easier to convince someone to work on something that's challenging than on something that's simple and mundane.  And most of the time I don't really harp on having proper form - but with this exercise, is there any benefit to doing it wrong?  Biomechanically speaking, an "incorrect" squat will still give you some strength gains, but potentially not where you may want to target them.  I don't think shooting for the moon, missing, and landing amongst the stars is actually meaningful in this scenario. 

The circumstances under which I will recommend the clamshell are very specific: the patient needs to 1) have a restricted weight bearing status from the physician due to a surgery or fracture and is therefore unable to do the exercises I prefer but would still benefit from strengthening or 2) have a significant deficit in their active hip external rotation movement with available passive mobility that I want them to purposefully control. (Translation - they're too weak to do any of the other exercises I like better, but I never actually tell patients they're weak!)

I share many of my patients with coworkers who like this exercise, so we've had conversations about clamshells for years.  The biggest discussion came when I had a student who I practically forbade from assigning clams without excessive clinical reasoning of why they were a good choice for that patient. Now that I have some extra time to dig into the research, I'm looking to prove myself wrong.  Does the evidence oppose my clinical bias? And how do you explore the efficacy of an exercise?  

Point Number Two:  What research should I be reading?  

Levels of Evidence - Creative Commons CC BY-NC 3.0

In case you're not familiar with the Levels of Evidence for scientific materials, here's a very basic overview.  Certain types of research can be "trusted" more than others, particularly when you're trying to generalize data to a larger population than was actually studied.  Here's an example: Let's say that tonight at dinner, you ask your child if they likes peas.  If they say no, can you now conclude that this single case of your own observation applies to all the kids of the same age in the USA?  Of course not. But it is your expert opinion that your own kid does not like peas and you understand how that data applies in your household.  Now what if you took a survey of your kid and your two next-door neighbors houses who happen to have seven more kids, asking all of them if they like peas.  You have more information about kids in your neighborhood and their feelings about peas, but still shouldn't make wide-spread assumptions about the whole country based on your small sample.  This would be closer to a small case study moving up the pyramid. If you surveyed your neighbors and then three other researchers did a similar study in different cities, asking fifty kids in second grade and then the same kids again in sixth grade and maybe one researcher also asks about carrots, the number of data points continues to increase and your ability to generalize information across a bigger group improves.  Now you've moved up into more of a cohort study.  

This is a very simplistic demonstration, but sometimes simple demonstrates a major point.  Right now with the Coronavirus Pandemic, small studies are being smeared all over the media without sufficient data and with incorrect descriptions.  It's a good time to point out that you need to be cautious about how you interpret what you read.  Notice at the top of the pyramid sits "systematic review." A systematic review takes multiple research papers into account to accumulate more data points to try to make conclusions.  It is based on a researcher compiling data from other researcher's published works.  Each individual study may not have done the same research, but their data overlaps and new conclusions are drawn from having more data points. I DID NOT USE SCIENTIFIC RIGOR in my collection of resources for this blog post and I have minimal experience in data analysis, so I'm certain there are flaws in what I've found by summarizing these four papers.  However, I basically (unintentionally) created a mini systematic review by reading four different papers (including one which was also a systematic review!). 

I collect articles to read in the future. This collection was one reason behind starting a journal club! I've previously written about the anti-library where you collect resources to learn about the things you know you don't know here. Along with my anti-library, I also have folders of papers I've previously read. I had already read Dr. Lindsay DiStefano's Glute EMG paper (the first in the list) which was probably the nail in the coffin for clamshells for me. Imagine assuming that all kids don't like peas because one kid said they didn't?  I've basically assumed that clamshells are a poor quality exercise based on the findings of one paper that studied 21 participants doing 12 exercises.  Dr. DiStefano was my research advisor in PT School so I almost always read her publications, or have them saved for the future. (Bias Alert!)  So I need more data points! I searched for more recent Glute EMG papers to compare to hers and found three more, intentionally choosing papers that included the clam shell exercise and ultimately including one with a somewhat contrary view.  Now the data I'm considering reflects over 500 participants and many more exercises including multiple variations of the clamshell.

EMG studies are used to understand muscle activity during movement.  Not only are these papers valuable, but they can also influence patient care by helping to better understand what exercises target which muscles.  I've previously hinted at reading EMG studies with regard to the shoulder here, and for sure that knowledge changed my PT practice for post-op shoulder patients. EMG studies aren't perfect, but by looking at a collection of them, you can assume similar risk of error for each study.  Participants in these papers were first assessed for their maximal volitional isometric contraction (MVIC) (aka how strong they were for a specific muscle).  Then, by placing sticky electrode sensors on the skin at certain locations, measurements of muscle activity were taken with each exercises and compared to the maximal strength possible for that person. For an exercise to improve strength, the exercise must elicit at least 40-60 % of maximal strength (MVIC) for gains to occur.  

Here's what the papers found:
DiStefano et al: The top exercises for glute medius based on % MVIC were side-lying hip abduction (81%), single limb squat (64%), lateral band walk (61%) and for the glute maximus were single limb squat (59 %) and single limb deadlift (59%). Clamshell exercises (depending on hip flexion position) were shown to have glute medius activation of: 38-40% MVIC and glute maximus activation of 34-39% MVIC.  (Clamshells don't pass the 40% minimum cut point which has been my rationale to discontinue using them in the clinic). Other exercises were examined in the study, but since they did not cross the 40% MVIC threshold, they are omitted here.

The Boren study used a cut-point of 70% MVIC as the minimum acceptable for strengthening and examined a larger variety of exercises. Glute med exercises with >70% (MVIC) were the side plank with hip abduction (103.11% bottom leg, 88.82% top leg), single leg squat (82.86%), clamshell variation #4 hold top leg in full hip extension while internally rotating (76.88%), and prone plank with hip extension (75.13%).  For the gluteus maximus, plank with hip extension (106.22%), glute squeeze (80.72%), side plank with hip abduction top leg (72.87%), bottom leg (70.96%) single leg squat (70.31%).  This paper suggested that the best exercises to target both glute med and glute max were the prone plank with hip extension, side-planks with hip abduction, and single limb squats.

The clamshell exercise had four variations in the Boren paper. Of these variations, #4 described above was the only option to reach their defined threshold of >70%.  If you use the criteria of 40-60% outlined in the DiStefano paper, all the clamshell variations would meet that target as sufficient for strenghtening for the glute med, but only the standard clamshell works for the glute max at 53.10% with other variations all below 30% MVIC.

The Systematic Review by Macadam et al reviews multiple papers and breaks down exercises by body position.  The cross-over step up and lateral step up had the highest average glute max and glute med % MVIC.  Pelvic drop, sidestepping with hip internally rotated and band at the ankle, standing hip abduction variations, rotational single leg squat and transverse lunges all had glute med % MVIC over 40%.  Standing hip abduction, rotational single leg squats and transverse lunges also had % MVIC over 40% for glute max. 

In sidelying, side planks with hip abduction had the highest average glute max and glute med % MVIC. (That exercise is really hard, though, and wouldn't actually be appropriate for the majority of my patients.)  The paper examined 13 clamshell variations including the standard hip external rotation and others.  In one study, three clam variations (not the standard hip external rotation) had average glute med % MVIC over 60% but other studies had clamshell averages in the 30% range.  From this paper, I can start to ease up on my thoughts that patients do the clamshell incorrectly - and more that they're just creating their own variation.

And finally, Bishop et al compared glute med and glute max EMG to tensor fascia latae (TFL) EMG creating a "Glute to TFL Index."  The TFL and gluteus maximus both insert on to the iliotibial band and contribute to hip abduction.  The TFL is sometimes considered to be a contributor to low back and lower extremity pains and/or injuries and may increase in tone or "tightness" to compensate for gluteal deficits.  Bishops "Glute to TFL Index" findings were that the clamshell with resistance was 99.54 and the clamshell without resistance was 87.89 meaning that the gluteal muscles were selectively used for these exercises much more than the TFL.  The clamshell exercises far surpassed all the other tested exercises in this study with the next best exercise being the bridge with resistance at 48.86 and prone hip extension with 48.57, both about half of the clamshell values.  Thus, this paper recommends use of the clamshell exercise as a glute-targeting exercise that does not incorporate the TFL.  To these findings, I'll add another dose of bias. Does this really matter?  Does the Glute to TFL Index have clinical meaning?  I'm not sure because I don't know if I really want to "turn off" the TFL. I'll let the clams have this one. 

Free photo 5470017 © Pavel Losevsky - Dreamstime.com

In the end, I haven't been convinced.  A healthy dose of confirmation bias potentially sprinkled with some self-serving bias may contribute to that decision, but to me, the evidence seems clear. Maybe I'll be nicer to those who know that the clamshell has the higher glute to TFL index, but without that rationale, these papers suggest many other glute strengthening exercises.  For sure, I'm open to hearing alternative opinions. Are you team clamshell?  Or team ANYTHING ELSE!  I use prone glute squeezes more often than I use clamshells.  And I'm incredibly grateful for my coworkers who challenge me to think about these topics. 

(Again - this is an abbreviated summary of the results sections of the papers.  More information looking at the discussions and limitations and other aspects of the research is available if you'd like more!  For the full written summary for Seattle Children's Journal Club, go ahead and email abby.gordon@seattlechildrens.org and I can send it any time). 

New WNBA Injury Data Published!

Alert! Hot off the Presses! Physical Therapists working in Sports... Athletic Trainers... Strength and Conditioning Coaches... High School Basketball Coaches... Female Athlete Parents... Orthopedic Surgeons... WNBA Colleagues... Basketball Fans... Any one else who is interested in learning something today... Check this one out.

Presenting at Seattle Children's Sports Symposium

A new paper was published (April 16, 2020) in Arthroscopy, Sports Medicine, and Rehabilitation entitled "Injury in the WNBA from 2015-2019."  You can find the paper here. I jumped for joy to see this new release when it was in my inbox this morning.  Gotta love alerts that know what I'm interested in.  In case you don't know, women's basketball player injuries was the topic of my PT School Thesis paper, "College and Professional Women's Basketball Players' Lower Extremity Injuries: A Survey of Career Incidence" which you can read here.  In November 2019, I
had the opportunity to present on this topic to the Sports Medicine Department at Seattle Children's Hospital, updating my findings and making it more applicable to our department's work in pediatric sports medicine.  This topic is on my mind constantly, and since WNBA Physicals were supposed to be this week, now postponed until the coronavirus battle is under control, I'm thrilled to have basketball on my mind.  A new publication five years after my own with some similar findings from an entirely different approach was both gratifying and validating and this paper could not have come at a better time.

The new paper, written by Orthopedic Surgeons at the University of Chicago summarized injuries in the WNBA between 2015 and 2019 which were compiled from publicly accessible websites.  Interestingly, the findings were similar to my research with regard to ankle sprains being the most common injury and both papers explore ACL Injuries.  My study only looked at lower body injuries so it did not examine concussions, but this recent paper did and I've previously written about the WNBA Concussion Protocol here.

Here's why this paper is important, in my opinion.

PubMed is a search engine for research papers, kind of like Google, only your search will bring scientific information. A PubMed Search conducted today, April 20th, for "WNBA AND Basketball" will give you EIGHT results.  In comparison, A PubMed Search for "NBA AND Basketball" will give you 120.  This new paper doesn't appear in that search.  Neither does mine.  I'm not sure what you need to do for PubMed to determine you're worthy, but it's apparent that the topic isn't a common one found in this search engine.  PubMed is where I go first when I want to find research on a specific topic that impacts my patients. 

So how about a different search engine like Google Scholar.  There "WNBA and Basketball" has 5,120 (94 results since 2020), including this new paper and my own, and "NBA and Basketball has 55,000 (1140 since 2020).  Obviously I did not screen every title to see if they actually refer to basketball and the NBA which is why I wrote the search this way, but it's SO EASY to see the discrepancy.  In my opinion, a new publication looking at the WNBA is a HUGE win for the WNBA. 

The papers that are found on the Google Scholar search are on all sorts of topics.  There are publications about injuries, like the ones I'm talking about and, as a physical therapist, which I find most interesting.  But there are papers about basketball, about female athletes, about gender differences from various perspectives including pay and spectator attitudes, differences between draft selection and playing times, sexuality, fan experiences, race, television time, and the list goes on. 

The battle to improve opportunities for women in sports continues.  The battle for pay equity, though improved with the new WNBA Players Association negotiations for their collective bargaining agreement, continues.  The battle for sports media to increase awareness of women's competitions and to increase support of elite female athletes continues.  And this week, the battle for increased awareness of injury data - which ultimately can help contribute to injury prevention strategies, continues, but with a step forward.  I tip my hat to you, University of Chicago Orthopedics. 

Life in the Time of Quarantine

Hi Everyone -

Hope you're all hanging in there, enjoying being at home as much as you can, staying safe, washing your hands and faces.  Is your mental health ok?  Have you gotten any fresh air?  I know that might be hard for some people.  It has been over a month since my last blog post, but that was certainly not for lack of trying.  I've started to write several times in the past few weeks but the Coronavirus Pandemic has actually left me speechless. (Shocking, I know.)  I can't go to my usual coffee shop where I like to write and life has been turned upside-down, just like I'm sure it has been for anyone reading this.  I'm not a scientist and won't pretend to know anything about the virus itself.  I've never been more aware of how much I touch my own face - and even still I probably don't notice it more than half of the time. I'm not on the front lines fighting this, so don't let the masked image later in this post fool you.  I'm spending most of my time in isolation at home when I'm not in the clinic with occasional stops at the grocery store as needed.  Writing a blog post hasn't been on my priority list because I couldn't decide what to write about in the shadow of a global pandemic. As a writer friend recently told me, sometimes you just need to sit and write, let it flow, and see what happens.

Writing is an outlet for me.  I use it to help organize my thoughts and relieve stresses.  It offers an opportunity to be creative, use different areas of my brain, share ideas, highlight things I'm learning, and to show support for causes that matter to me.  At a time when I'm also not seeing my usual collection of mental health providers and also not going to the gym, the sudden and total removal of so many outlets has been a big deal. It helps to know that everyone else is in the same boat.  Nobody else is going to the gym.  We're all working out in our laundry rooms with whatever we have at home or going for walks in the neighborhood.  I've heard of people doing lots of different crafts, trying out meditation apps, yoga in the home, new types of exercise, and some people are buying pets in order to find novel coping methods. You're not alone...we're in this together!

So I'm writing today.  Without having any planned direction or goals.  I've seen a post going around on Facebook that people want to remember what was happening because this is going to be a historical event.  My parents remember when JFK was assassinated and my friends and I all remember where we were on 9-11.  This will be another memorable event for so many people... and nobody will forget where they were because we've all been on our couches for three weeks already!  So this is not my usual blog-writing approach. Welcome to my stream of consciousness.  My apologies for being scatterbrained.

At the beginning, I thought this was challenging because I felt trapped with nowhere to go.  My family is far away.  I was still seeing patients early on and didn't want to risk getting anyone sick. The first week I saw friends who had already started working from home, but then it seemed wrong for me to be around them.  Once I got into a rhythm, particularly with regular afternoon FaceTime gatherings, things started to improve.  The hardest moments have been worrying about my friends who work on the front lines, concerns about my parents and not being able to help them, and realizing that the Final Four was not going to occur.  This weekend should have been the Women's Basketball National Championship - often referred to as my favorite holiday.  Several of my friends here in Seattle have been connived into outings at random bars around the city to watch games with me.  I'm more than happy to treat my friends to some nachos if it means company to watch the Huskies. The NCAA College Basketball Season was so suddenly aborted after the best year of competition EVER. I don't think it quite hit me until all the replays from previous championships started popping up on social media and I realized how much sports can bring people together, how many years of my life I've spent watching basketball games, and how serious this pandemic really is.  You'd think being told to wear goggles, masks, and gloves to treat my few remaining patients would have been sufficient. If you've never worn them - those things are hot, sticky, and make your glasses fog up! 

So now that I've rambled on, I guess I should find some sort of purpose for taking your time.  All I can come up with is gratitude. On Wednesday, March 18th, I went into my clinic to call my patients and cancel their scheduled appointments. That was sad, but a few days later, I started to really miss what I do. I have fortunately had a few days in the office to treat high priority patients and each time I've seen a patient, I've felt life being restored to my body, air returning back to my lungs, energy surging, and the return of my dimply smile.  Endless gratitude reflecting on how my career has unfolded to this point where I have the world's best coworkers all collectively waiting to restore our previous routines.

I'm grateful for the small businesses in my local community who have been able to transition their usual operations to help support everyone at this time.  I've enjoyed some really good take-out meals in the past 18 days at home and highly recommend supporting your small local businesses that are trying to survive.  I'm grateful for all the people on the front lines - healthcare workers, front desk workers, environmental services cleaning crews, demand flow services, and leadership - in my office and throughout the country and the world who are taking care of so many sick people.  I'm grateful for books, the fact that I had too many out from the library when this all started that I'm slowly working my way through, and also audiobook downloads available from the library, and Netflix and Amazon having rentals to watch movies.

I'm grateful for all the different electronic user interfaces that have made it possible for me to have face-to-face conversations with so many people.  Between FaceTime, Facebook Messenger, Skype, WebEx, Zoom, Google Hangouts, and HouseParty - it really isn't hard to connect, but those virtual gatherings don't quite feel the same. There were a few days last week where I bounced from call to call catching up with old friends, seeing how family members are doing, and trying to find that missing sense of connection.  Today my extended family gathered on Zoom in preparation for Passover to begin on Wednesday.  Check that out! People in 20 different homes in at least 10 different states ranging between Washington, Connecticut, Florida, Ohio, Oklahoma, California, and Washington, D.C.

I'm worried for my friends who are working to save lives.  They have families and kids of their own and are at extremely high risk. I wish I could do more to help them, to help sick people, I guess just to help anybody. The most any of us can really do right now is to stay at home and prevent further spread of the virus. I'm very hopeful that when this all ends, there will be improvements made to how we operate as a country and as a healthcare system.  Let's hope this wraps up in time for everyone to enjoy summer.  Let's hope this doesn't destroy families financially, or in any other ways.  Let's hope we can resume travel soon.  Let's hope everyone stays healthy and safe.  And let's hope we can have a massive celebration together on the other side. Let me know if there's anything I can do to help you out.  We're all in this together.