Tuck Jump Assessment: A review of our recent publications and the impact on physical therapy, injury screening, and protocol
In the last few months, some of our research efforts in physical therapy, strength training, and injury screening have been published by the Journal of Strength and Conditioning Research and the International Journal of Sports Physical Therapy along with a commentary in the Journal of Sports Science and Medicine. The publications were focused on jumping test performance and the underlying methods.
These tests are useful in a full rehabilitation program to determine readiness for activity, however even the best tests have limitations that need to be understood. There is no such thing as perfect test but we can use a variety of tests to gain a more complete perspective.
After a publication, it’s fun to look back at the results and figure out how to use it to improve the outcomes at Smith Performance Center, which is the major reason our team is involved this deeply in research.
Here is my attempt to unpack the results of two of these papers, explain how we approach jumping tests differently from this work and how it feeds into our model of long term development. I will highlight the commentary on the Modified Tuck Jump Assessment in another post.
Lininger, M. R., Smith, C. A., Chimera, N. J., Hoog, P. & Warren, M. Tuck Jump Assessment: An Exploratory Factor Analysis in a College Age Population. J Strength Cond Res 31, 653–659 (2017).
A factor analysis just sounds confusing. A factor analysis is a useful tool to evaluate the psychometric properties of a test (kinda like the theory and construct of the test, including the validity and reliability). We used it to investigate the structure of the Tuck Jump Assessment which proposed a single composite score along with 5 categories for the 10 flaws (Figure 1).
First, what is the Tuck Jump Assessment? An athlete is asked to perform a tuck jump continuously for 10 seconds. This is recorded from the front and side. The video is reviewed and the rater uses 10 flaw criteria to create a total score. If you demonstrate the flaw during the 10 seconds, you receive a 1. This is done for every flaw. All of the flaws are then added up so you can have a score ranging from a 0 (the best possible score) to a 10 (which means you are a walking ACL tear). I love this test because it makes you work surprisingly hard for 10 seconds. Everyone in our strength training program performs this test.
The creators of the original Tuck Jump Assessment used their clinical and research experience to compile the list of 10 flaws associated increased risk for knee injury. These 10 flaws were then grouped into 5 categories that described the neuromuscular deficit leading to these flaws. As I write this, it seems confusing so look again at the picture showing the flaws with their matching categorization (Figure 1). After scoring the Tuck Jump Assessment, a look at the total number of flaws or at the category with the most flaws will decide which neuromuscular deficit should be targeted first.
The Dynamic Recursive Model of Long Term Development: A key principle in our strength training and physical therapy methodology
Activity brings benefits and risks. Every step, competition or practice is an exposure that impacts the body. The questions - how do I get better and how do I stay healthy - are part a dynamic and constantly changing system (Figure 1). We can model that system to show how the activity, like running or playing football, impact your next exposure.
Figure 1. The Dynamic Recursive Model of Long Term Development: The integration of physical therapy and strength training to reduce injury while allowing for adequate exposure for improvement. Modified from Meeuwisse, W. H., Tyreman, H., Hagel, B. & Emery, C. A Dynamic Model of Etiology in Sport Injury: The Recursive Nature of Risk and Causation: Clinical Journal of Sport Medicine 17, 215–219 (2007).
If you are a runner, you need to run.
If you want to get stronger, you need to lift.
If you want to be a great triathlete, you need to swim, bike, and run.
If you want to shoot well during a basketball game, you have to shoot over and over.
You get the picture (maybe). There are no prodigies (Ericsson 2004). Reaching your potential requires effort and time. However the very activity you participate in impacts the next time you do it. This process is endless until you stop being active or competing in sport.
I perform running analyses everyday in order to improve performance or get an athlete past an injury. Viewing the changes in muscle action and joint angles of each phase from stance to float to swing phases provides insight into a runner’s performance and problems. The incredible coordination of running is not conscious and lets me get a glimpse of person’s overall nervous and musculoskeletal system. It is a natural process (at least prior to coaching).
But if it is natural, what about it hurts us? Can we analyze your gait in enough depth to figure out why you are hurting?
The truth is that analyzing running gait is not enough. The how and why someone runs with their current pattern or why they may be susceptible to injury cannot be determined by watching them run without checking out other ‘things’. Injury prevention is not as simple as a switch to a midfoot or forefoot (which anecdotally is the most common statement I hear from repeat injury offenders). AND injury prevention is never a clear proposition- it is more of moving probability that you are constantly trying to lower through screening and intervention.
What are these other ‘things’?
We have to dig into the exam, which seems to surprise runners that come to see us because we have a reputation as gait specialists. There have been runners who come in for a running analysis who I do not analyze for running gait because of the glaring problems in the basic exam that must be addressed before we move on to a gait correction. Without a thorough exam, running gait cannot be explained. Sure, I can determine how much pelvic drop is present, but the ‘why’ is missing. And the ‘why’ is critical for injury prevention and overall performance.
Today’s post will give an overview of how to use running analysis within a framework of diagnosis.
At our clinic we dig into 5 general areas:
Neuromuscular fatigue has been implicated as a significant problem for individuals returning to sport following an anterior cruciate ligament (ACL) injury and reconstruction. Due to the high rate of re injury in those that have had an ACL reconstruction, one hypothesis is that neuromuscular fatigue will negatively impact strength performance, postural stability (single leg balance), and biomechanics during jumping and landing. It blows my mind that a female athlete with an ACL tear is 16 times more likely than a healthy female athlete to tear an ACL again.
The interplay between a previous injury, the resulting changes to the input to the brain, modified motor planning, and re injury is an interesting development in research. Today I wanted to dive a little more into fatigue, the impact on biomechanics, and how physical therapy and strength training can start to augment the problem.
Neuromuscular fatigue is a decrease the ability of an athlete to produce voluntary force in a muscle or group of muscles (McLean), which is combination of central and peripheral fatigue. Peripheral fatigue is a related to muscle damage and metabolic factors distal to the connection between the motor neuron and muscle fiber. Central fatigue can occur anywhere prior to the connection between the muscle and motor neuron (Figure 1). On the surface, quantifying or even getting a clear view of central fatigue seems impossible to examine in detail with any moving or jumping test. When I was reading over all the information on fatigue, I kept imagining when I ran a 400 meter race in track (just a horrible experience). The first two hundred meters felt fine but by the final curve, my ability to run and pick my legs up was basically gone. This fatigue was due to the metabolic byproducts produced from all out effort along with bumping against a central governor.
Functional Hop Tests and Tuck Jump Assessment Scores Between Female Division I Collegiate Athletes Participating in High vs. Low ACL Injury Risk Sports
As a clinician and researcher, I am lucky enough to interact with multiple students who positively impact the profession of physical therapy by engaging in research. This past week was the combined section meeting in Anaheim. A student was able to present some of our research and I wanted to give him a post because this is a great accomplishment.
Nice job Philipp Hogg!!!
Functional Hop Tests and Tuck Jump Assessment Scores Between Female Division I
Collegiate Athletes Participating in High vs. Low ACL Injury Risk Sports . Philipp Hoog, Meghan Warren, Craig Smith, Nicole Chimera. Combined Sections Meeting, 2016.