Strongman Event EMG Analysis
McGill, SM, McDermott, A, and Fenwick, CMJ.
Comparison of different strongman events: trunk muscle activation and lumbar spine motion, load, and stiffness.
J Strength Cond Res 23(4): 1148–1161, 2009
Strongman events are attracting more interest as training exercises because of their unique demands. Further, strongman competitors sustain specific injuries, particularly to the back. Muscle electromyographic data from various torso and hip muscles, together with kinematic measures, were input to an anatomically detailed model of the torso to estimate back load, low-back stiffness, and hip torque. Events included the farmer’s walk, super yoke, Atlas stone lift, suitcase carry, keg walk, tire flip, and log lift. The results document the unique demands of these whole-body events and, in particular, the demands on the back and torso. For example, the very large moments required at the hip for abduction when performing a yoke walk exceed the strength capability of the hip. Here, muscles such as quadratus lumborum made up for the strength deficit by generating frontal plane torque to support the torso/ pelvis. In this way, the stiffened torso acts as a source of strength to allow joints with insufficient strength to be buttressed, resulting in successful performance. Timing of muscle activation patterns in events such as the Atlas stone lift demonstrated the need to integrate the hip extensors before the back extensors. Even so, because of the awkward shape of the stone, the protective neutral spine posture was impossible to achieve, resulting in substantial loading on the back that is placed in a weakened posture. Unexpectedly, the super yoke carry resulted in the highest loads on the spine. This was attributed to the weight of the yoke coupled with the massive torso muscle co-contraction, which produced torso stiffness to ensure spine stability together with buttressing the abduction strength insufficiency of the hips. Strongman events clearly challenge the strength of the body linkage, together with the stabilizing system, in a different way than traditional approaches. The carrying events challenged different abilities than the lifting events, suggesting that loaded carrying would enhance traditional lifting-based strength programs. This analysis also documented the technique components of successful, joint-sparing, strongman event strategies.
I hope everyone enjoyed the first blog post of the series. I thought it would be a fun to post something different that everyone may not think of as scientific. I will admit that the journal article itself is not well done, however that does not take from the fact that is different.
This is a unique study identifying a variety of factors, which contribute to lifting capabilities that strongmen possess in the events they compete in. At the time (2009) there were currently no other research articles investigating muscle activation patterns with estimates of joint loading. As Everett is well versed in, strongman events include but not limited to; Farmer’s Walk (FW), Suitcase Carry (SC), Super Yolk Walk (YW), Tire Flip (TF), Log lift (LL), Atlas Stone Lift (SL), and Shoulder Keg Walk (KW). These movements are “functional” in the sense that the total body effort far surpasses the body effort required during free weight lifting and training machines. They challenge the whole musculoskeletal system in terms of both strength and physiological demand. The experiment used 3 subjects with an average age of 25 and are all actively competing. One subject is a world-classed ranked strongman. The researchers used an EMG (electromyography), 3 dimensional spine motion and external load recordings, which recorded torso stiffness, compression, and shear loading of the lumbar spine.
The following is the chart summarizing the findings mentioned above;
From the chart I have highlighted the important findings that would interest everyone from the highest to lowest forces. Now I will briefly discuss those lifts and what to keep in mind in terms of injury prevention. The findings that I want you to be aware of is that the Tire Flip causes the most torque through the spine. Some advice from me, this particular movement is when you want to really concentrate on good form (talk to Everett about proper technique). The amount of torque they are showing can destroy a spine and it’s discs if not prepared for the movement, so be careful! The next major finding shows that the Super Yolk causes the greatest amount of compression in both the muscular and joint systems. For those that are already suffering from any type of disc injuries you will want to take extra care here, however for healthy backs this exercise will bullet proof your back to compression type injuries down the road. Those exercises causing the most amount of A/P (anterior to posterior or front to back) force is the Keg Walk (specifically right-sided) with the muscular system and the Farmer’s Walk in the joint system. During these exercises I cannot stress the importance of creating complete core engagement, including but not limited to the abdominals, obliques, lumbar paraspinals, diaphragm and pelvic floor muscles, to avoid shearing injuries in the spine.
Now for a couple interesting charts that examines the execution styles of the world-class strongman vs. amateur during a couple of the events.
This chart is examining the timing of muscle activation during the Log Lift. The column on the left side shows poor performance during the lift, which the amateur strongman activate his back muscles before the glutes. While on the right, the world-class strongman activates both back and glutes musculature at the same time. The hips are the strongest joint in the body and are important to co-contract it along with the back musculature in order to avoid injury and increase power output.
The chart above is showing the Tire Flip. The poorer performance is showing that the amateur strongman started his lift earlier and did not properly brace his abdominals, where the world-class strongman abdominally braced before he started his lift. As with most lifts, creating a strong core before the lift is important in performance and injury prevention.
You can see a general trend now. FOCUS on your body mechanics BEFORE you execute your lift. Depending on what kind of lift you do it is important to understand the biomechanics of it before you start lifting heavy. I will say I am not a strong man competitor, nor will I most likely never be one. If you have specific questions related to lifting techniques, look to Coach Sloan for advice. He is not the head of the Crossfit Strongman seminars for nothing! If you have any questions about biomechanics or any other body related question don’t hesitate to stop me in the gym.
Happy New Year!