Monday, October 26, 2020
Monday, October 12, 2020
Over the course of the last couple of weeks, we have talked about the dreaded ACL (anterior cruciate ligament) injury. One of the keys in preventing these devastating injuries is education about how they occur and how we as clinicians, coaches, parents and athletes can identify what puts an athlete at risk. Over the last 2 weeks, I talked about two ways we can identify those that are at risk. One is having an athlete perform a single leg squat and what we should look for when they are performing that motion. Secondly, we talked about core testing. Not only what types of core testing to do but what things we should look for when the athlete is performing the core testing.
Identifying these flaws in these movements not only help to identify those that are at risk but also give us a clear indication of what to do to prevent. In a single leg squat for example, if the athlete’s knee is going in toward midline during the performance of the test, when we train them, don’t let them do that! Is it really that simple? Yes, it is. If your athlete cannot do 10 reps of a single leg squat without letting the knee go in towards midline, have them do as many as they can with proper form. When they can no longer control the motion and do with proper form, simply stop or better yet, regress the exercise.
The last movement we will discuss on evaluating is the squat. Why the squat? One of the number one reasons is that we know that athletes who improve their performance on the squatting motion will increase their vertical jump and sprint speed. Squatting motion is an excellent movement to improve explosive power. In most athletic situations, this is also a movement that most athletes will be doing as a part of their training throughout their athletic career.
Looking at the athlete from behind, visualize (or better yet have stand in front of) a plumb line that runs through the center of the skull, cervical spine all the way down the sacrum. As the athlete performs the squatting motion, their hips should remain relatively equal distance from the plumb line. If not, then the athlete is shifting his/her weight to one side.
This shifting is a common motion that we first identified back in early 2000s and we call this a lateral shift. In 2012, was the first research paper to describe this was published and the authors termed this a lateral displacement of the pelvis during a squatting motion. As we initially suspected, this lateral shift results in several things:
• Increase in weight distribution to the side you are shifting to
• Increase in EMG (muscle activation) to the side you are shifting to
• Increase in GRF on the side you are shifting to
There is a whole slew of additional things that occur with this shifting motion but the key is the loading is abnormal and you don’t load the way the system was designed to be loaded. With increase force on one side versus the other, this adds to a wearing and tearing on that side which can add to injury. Same time, if the muscles are more active on one side versus the other, then strength will never ever be symmetrical unless this is addressed. In addition, what we see is that if you can see this under body weight conditions, when the athlete goes into the weight room and starts doing this under a weighted bar, this motion gets even worse. This means when squatting #225, the load on the spine, hips and lower limb is greater on one side than it is on the other. For optimal performance AND injury reduction, we must balance this out.
Next week, we conclude this discussion by talking about fatigue state training. What is it and how do we do. I hope you found this information useful and looking forward to sharing more with you.
*Dr. Nessler is a practicing physical therapist with over 23 years sports medicine clinical experience. He is a nationally recognized expert in the area of athletic movement assessment and injury prevention. He is the founder | developer of the ViPerform AMI, ViPerform AMI RTPlay, the ACL Play It Safe Program, Run Safe Program, author of a college textbook on this subject and published researcher. Trent has performed >5000 athletic movement assessments in the US and abroad. He is the President of Rebound Vitality providing injury prevention services for the tactical athlete and movement consultant for numerous colleges and professional teams. Trent also a Brazilian Jiu Jitsu purple belt and complete BJJ/MMA junkie. Follow Dr. Nessler on Instagram @ BJJPT_ACL_GUY or Twitter @ ACL_prevention. www.drtrentnessler.com*
Monday, October 5, 2020
Last week, we started a deep dive into what are some of the positions that the knee gets into that causes the non-contact ACL (dynamic valgus) and how we can assess that. However, non-contact ACL injuries are very complex and there are a lot of things feeding into this. One that is often ignored is the contribution of the core. First of all, when I talk about the core, what I am referring to is the section from the knees to the chest. From an anatomical point of view, this includes the majority of the structures that impact the core. Structures and tissues that attach to or directly influence loading to the core or kinetic energy transfer across the system. Some would argue that anything from the foot to the head would impact core, which I agree, but from a training perspective, we are sticking with my definition.
Before we get into the core’s impact on ACL injuries, I wanted to give you some interesting facts on the core. The core is a critical part of sports performance and yet it is so often ignored as a part of what we do with our training. In baseball, studies have shown that if you increase core stability (which is a combination of strength and endurance) you can improve pitching performance in MLB pitchers (Chaudhari et al J Strength Con Re 2011). It has also been shown that improving core stability in MLB pitchers results in a 3-fold decreased risk of shoulder and elbow injuries including UCL injuries (Tommy John) and labral injuries in the shoulder (Chaudhari et al Am J Sport Med 2014). Core also plays a key role on overall athletic performance. Improvements in core stability has been shown to increase vertical jump in basketball players (Hoshikawa et al J Strength Con Res 2013) and improve sprint speed in sprinters (Tong et al Phy Ther Sport 2014). Improvements in dynamic postural stability (which comes from the core) have been shown in several studies to reduce the risk for concussion (Johnston et al Am J Sport Med 2019, Garner et al In J Kines Sport Science 2020).
As interesting as those facts are, the core also plays a key role in preventing of ACL injuries. Studies as far back as 2013 (Frank et al Am J Sports med 2013) have shown a strong correlation to poor core stability and an increase in risk for ACL injuries. Some recent studies have even indicated certain test positions we can use for the core which have a higher predictive value for determining ACL risk (DeBlaiser et al Am J Sport Med 2019). So how do we test?
Plank – feet should be all the way together (not depicted), knees straight, hips AND spine neutral, shoulders and elbows at 90 degrees and downward angulated gaze (depicted).
Test – hold for 1-minute period of time. What you are looking for:
1. Can they maintain for 1-minute period of time?
2. Do they hike their hips up or slump in the spine? If they do, at what time point do they do that?
3. Do one of their hips drop?
Biomechanically and physiologically, what happens during this test tells us a lot. For our purposes here, we are going to stick with just recognizing these things and making sure when we train that we don’t let it occur.
Test – hold for 1-minute period of time.
What you are looking for:
1. Can they maintain for 1-minute period of time?
2. Do they hike their hips up or drop? If they do, at what time point do they do that?
3. Do their shoulders roll forward? If they do, at what time point do they do that?
4. Does their shin drop to the ground? If it does, at what time point do they do that?
Again, this gives us a starting point of things to recognize and train. Simply preventing these movements during both the plank test and side plank will dramatically improve core stabilization and mitigate the risk for injury in your athlete. Aside from the prevention of injury, improved performance on these movements mean the athlete will be more equipped to transfer kinetic energy from the hips to the core to the shoulders. What this means improved performance for the overhead athlete (baseball pitch velocity, volleyball serve speed and power). Improved stability of the core also means that the quads, hams and hip musculature is now pulling on a stable base and therefore able to produce more force. This means they are able to sprint faster and jump higher. A win-win.
Next week, we will dig into how squatting impacts injury risk and performance. More importantly, what should we be looking for and how do we address? I hope you found this information useful and looking forward to sharing more with you.
Monday, September 28, 2020
Last time, we started our discussion talking about anterior cruciate ligament (ACL) injuries and the impact that anterior cruciate ligament reconstructions (ACLR) have on future performance. We ended the discussion asking the questions, what is it that leads to these injuries, how can we assess this as parents and coaches and what can we do about it? First, lets look at what leads to these injuries.
Nessler et al Cur Rev Musculo Med 2017) meaning there is not contact with another player or external object. Typically, these occur when an athlete plants their foot and cuts off in another direction. We typically see the knee fall in towards the midline and hear the dreaded “pop”. Sometimes the athlete can keep going and sometimes the fall down immediately with pain. Their knee falling toward midline is called a dynamic valgus position at the knee which has been identified as the main mechanism for injury in professional athletes (Johnston et al Am J Sport Med 2018) as well as recreational and high school athletes (Owusu-Akyaw et al Am J Sport Med 2018, Nessler et al Int J Athl Ther Train 2013). The interesting thing is that you can identify those athletes that this is more likely to occur with. As a basketball or volleyball coach, you see this all the time but may not recognize it for what it is. If you are watching your players shoot or go up to block a shot during practice and as they load to jump up, watch what their knees do. Do they collapse toward midline? What you will see, is that some fall a little and some fall a whole lot. This happens in high school, college, professional and Olympic athletes. Why is that?
There are a lot of factors that can result in this dynamic valgus position. One thing is large growth spurts. For our 12-14 year old athletes that go through a massive growth spurt you will typically see this start to develop. With the big change in height often comes a decrease in their sense of body awareness (Nessler et al Curr Rev Musculo Med 2017) which often leads to that awkward movement patterns we see in our younger athletes. If this is never addressed, which it is often not, then this remains. In addition, weakness in the quadriceps (Smith et al Am J Sport med 2015, Ho et al J Physio 2015) can lead to increase in dynamic valgus. Considering this, how can we, as non-clinicians and without high tech equipment analyze this? The easiest way to do this is have your athlete do 10 single leg squats. What you want to watch for is:
1. Can they perform the task?
2. Is there symmetry between the right side and left? Do they look the same?
3. Does their knee fall in toward midline (middle)?
4. Do they lose their balance?
If you see an athlete like what is depicted here, we see several things. One is that there is a significant difference between her right leg and her left leg. Her right knee is going in toward midline while her left is not. The fact that there is a difference between both sides and that one knee goes in toward midline will not only impact her risk but also impact her performance. (Melick et al Br J Sport Med 2016) Secondly, what we would most likely see is when performing the single leg squats on her right side, she is more likely to lose her balance than she would on her left side (Markstrom et al Am J Sport Med 2020, Pappas et al Clinic J Sport Med 2011).
Brazen et al Clinic J Sport Med 2010), increase in forces at your knee (Nessler et al Curr Rev Mucolo Med 2017) and a decrease in control of the muscles that control your hip and knee (Weist et al Am J Sport Med 2004). One thing we know, is that when we fatigue our athletes with our standardized protocol, we see a significant impact on the way they move. The protocol we use is called the FAST-FP or functional agility short term fatigue protocol (Quamman et al J Athl Train 2012) which has been show be one of the few protocols to actually draw out this dynamic valgus position we are looking to assess. It is this knowledge that has actually led to our prevention approach which we call fatigue state training. We will talk about this in detail later, but it is one of the key concepts we have implemented that we feel has resulted in such a significant impact on our injury rates as well as athletic performance in our athletes. Although we are using this to prevent the initial injury, studies are also now showing that this is especially critical if an athlete has had an ACLR. After an ACLR, fatigue has a bigger impact on movement and overall risk (Benjaminse et al Sport Health 2019). Considering this, fatigue state training should be a critical part of returning any athlete to sport after an ACLR.
Some additional factors that we can assess that directly impact this dynamic valgus and risk of injury and impact performance are how you squat and core strength. We will discuss this more in depth in our next blog. I hope you found this information useful and looking forward to sharing more with you.
Monday, September 21, 2020
Whether you are a parent, an athlete or a coach, when you think about one of the most dreaded sports injuries for an athlete to have, the ACL or anterior cruciate ligament often rises to the top mind. All of us have either had personal experience with or know someone that has suffered an ACL injury. This topic became a huge passion for me and a part of a higher calling when I had 22 young athletes come into my sports physical therapy practice over a 2-week period with an ACLR (anterior cruciate ligament reconstruction). I knew I had to do something about it. As a master’s degree level PT, I knew I needed to know more so went back to school to do my doctorate to focus on biomechanics and motor learning. That was in the year 2000. I wanted to learn what was leading to these injuries and how could we prevent. I was determined to try to find out as much as I could, to become a part of the solution versus just treating these athletes the same way we always have. To change this trend, I knew we had to do something very different. This is one reason I have spent the last 20 years investigating ways to prevent these injuries in athletes as both a treating clinician and as a researcher. In 2017, we commercially launched a technology to assess movement patterns that we now know put athletes at risk for these injuries. Since then, we have collected data on over 20,000 athletes and have >20M data points related to movement and risk. With this level of mass data, we are learning more than we ever have before and are leading the research by ~3-5 years. In this series, I hope to share with you what we have learned and some really exciting things that are being done on the prevention side that you can implement today to make a difference.
If you ask most surgeons how many of their athletes return to sport following an ACLR, most will tell you 85-95%. That is awesome, but what does that mean? Does that may mean the athlete goes back and sits on the sidelines or plays half their regular time? It couldn’t mean that right? Most of us assume return to sport means back at the same level they were before and at 100% previous level of performance. But sadly, that simply is not the case. Looking at the research, you would think professional athletes would fair much better than most. When looking at NFL football players who have had an ACLR, what we see is that their athletic performance is decreased (decreased sprint speed, percentage of tackles is down, etc) for up to two years following return to sport after an ACLR (Mia et al Am J Sport Med 2017). Keep in mind, the mean time for return to play in professional football players is 10.4 months (Logstaffee et al Am J Sport med 2020). If you include the time it takes for them to get back to play plus their decreased performance once returned, this is a three year impact! Coaches, think what this does for your overall team’s performance if this is one of your key players! What the studies also show is that their professional career is decreased by 2 years (Mia et al Am J Sport Med 2017). This is professional athletes. Folks who have 24 hour access to some of the best health care and some of the latest technology and advances in sports science available. Folks who have rehab 2 times per day and an athletic trainer at their beckon and call. Knowing all this, it just further stresses the fact that we have to prevent the initial injury from occurring. Can we really prevent these injuries? The quick answer is, we can prevent a large percentage of these. Up to 80%. But first, we have to know what put them at risk and how do we as athletes, parents, coaches and sports medicine professionals address.
Next blog, we will start that discussion. What is it that leads to these injuries, how can we assess this as parents and coaches and what can we do about it. Hope you found this information useful and looking forward to helping you keep your athletes in the game.
Monday, September 14, 2020
COVID-19 has impacted all our lives in ways we may not full realize yet. One thing that happened across the US, was that there were 10s of thousands of athletes who had ACL reconstructions (ACLR) who were no longer able to continue with their one on one physical therapy. Most had access to their therapists via telehealth. As good as that may be, it is never as good as one on one physical therapy. For some athletes, this was only a minor inconvenience lasting only a couple of weeks. However, for 1000s of our athletes, this meant months of no one on one therapy. These athletes had to rely on what their PT could see over the computer, instruct over the computer and the hope that the athlete continued with their individualized program correctly. One of the things we do prior to returning an athlete to sport is we run them through a series of tests (ViPerform AMI). This test measures how stable the athlete is through a series of sport related movements. This gives us a good indication on whether or not the athlete is physically ready for the rigorous demands of sports and stable enough to not stress their reconstructed ACL.
For definition purposes, I am going to refer post-COVID. What I mean is athletes who have been undergoing rehab via telehealth and not had traditional regular pre-COVID PT. This DOES not refer to athletes who have had COVID. Having defined that, if we compare our athletes who have been tested at 6 months, 9 months and 12 months post ACLR pre-COVID to those who we testing now post COVID, we see an alarming drastic difference. Those athletes who we are testing post COVID have much greater quadriceps deficit, much less control of dynamic valgus in single limb performance, much greater speeds of valgus in single limb testing and less pelvic and core control. These athletes, on the average, are 3-4 months behind what we see in pre-COVID test results. This is extremely alarming since these athletes think they are at 6 or 9 months post ACL when in reality, they are functionally where they are typically at when at the 3 to 6 months post op mark.
I don't say this to discourage athletics this season. I say this to encourage us to think through what this should look like on an athlete by athlete basis. I, as well as many of the leading experts in sports medicine, have a great fear of the injuries we will see this year. We think we are about to see an unprecedented number of ACL injuries and concussion. That is why I am devoting the next two series to The Dreaded ACL Injury and Concussion. I will put screenings you can do with your athlete as well as some exercises to improve performance. For those looking to get their athlete assessed, there are over 400 providers across the US using the Viperform AMI. Feel free to DM on instagram @bjjpt_ACL_guy or twitter @ ACL_prevention. I hope you enjoy this series, God Bless and keep safe.