Learn how I use biomechanics knowledge to improve the performance of myself and my clients.
Interest in biomechanics has grown in the fitness community over the past couple of years. It’s not just for science nerds anymore. Now, the average gym goer uses biomechanical terminology to better understand and explain their workouts.
I love it.
However, as with most complex subjects, there is a lot of misinformation online. You have to be vigilant on social media. While there’s a wealth of valuable knowledge, not everyone making content is genuine. Social media is often more about getting attention and likes than actually helping people.
That said, today’s article is about the practical application of biomechanics. Keep in mind that although I’ve taken multiple college courses in biomechanics, including at the graduate level, it doesn’t make me an expert. This is just to give you the framework for how I use it. Let’s dig in.
What is Biomechanics?
Before we get too far, what is biomechanics? In a basic sense, biomechanics is the study of human movement. It focuses on the mechanisms through which the muscles and skeleton interact to create movement. It’s a mix of physics, physiology, and anatomy.
There are many ways to use biomechanics to enhance training, but the most prominent ones surround improving technique and exercise selection.
Qualitative Biomechanical Analysis
One of the fundamental applications of biomechanics is technique analysis. As a coach, I do a lot of it with clients. I use a system called qualitative biomechanical analysis. It’s just a fancy way to say I break down a movement into its basic elements and then look at these elements from a biomechanical perspective.
A biomechanical technique analysis involves four key steps: description, observation, evaluation, and instruction.
Description
The first step is to define and describe the technique you are looking for. It can be in your head, but you must set expectations for yourself or your client before watching the technique. Remember, there is no one-size-fits-all ‘proper’ technique. It’s individual-specific and goal-oriented. For instance, my definition of an effective squat technique for an elite powerlifter differs from that of a 16-year-old high school football player.
Observation
Next, we have the active step of observation. This is where you watch the performance to see what it actually looks like. As an online coach, this often involves reviewing a video of clients performing a lift. I do this for myself as well. Recording your training is one of the best things you can do to improve your technique. Ideally, I want to see clips from a few different angles. It’s almost impossible to properly judge a lift from one viewpoint. It’s why the three powerlifting judges are stationed at different sides of the platform during a meet.
Video is often more beneficial than seeing a lift in person because you can watch it back multiple times, slow it down, and pause. You can also use video to analyze effort. Hard sets come with reduced bar speeds. Reps are left on the table if a lift doesn’t slow down toward the end.
Again, it’s important to know who you are working with. As the lifter’s skill level increases, the size of the observable errors decreases, as does the variability in performance lift to lift. On the other hand, beginners exhibit easily recognizable errors that are not always repeated from one performance to the next.
Evaluation
Here, you compare the technique you are looking for to the observed performance and identify any errors or problems that need fixing.
When evaluating errors, there is a hierarchy of importance. Errors that could lead to injury should be corrected first. From there, correct significant to minor mistakes in terms of effect on performance. Then, from the earliest to the latest, when they occur in the lift. For example, if you make an error in the setup of a deadlift, errors made after that don’t matter; the setup needs to be fixed first. Lastly, I like to correct easy errors before more difficult ones regarding time and effort. People can often correct a minor error simply by being made aware of it.
Instruction
The last step is instruction. This step is where you provide the feedback needed to correct the errors. High-quality feedback involves clearly communicating the error, what needs to be fixed, and how to fix it. It’s best only to fix one thing at a time.
Injury Prevention
There is some debate in the industry about how much poor form is responsible for injuries. But, like most things, it’s not black and white or a matter of good form versus bad form. A lot of day-to-day movement in life would look like bad form in the weight room, but people survive. It’s more about load distribution and avoiding unnecessary risk.
Most injuries from lifting weights are not traumatic injuries but overuse injuries. They are injuries that develop from repeated stresses over time. It’s rarely one bad rep that causes the damage. It’s not the one lousy deadlift that sends you to Snap City (although that can happen); it’s deadlifting out of position for hundreds of reps.
When I analyze lifts for injury potential, it’s more big-picture stuff. I focus on the joints susceptible to injury, most notably the lower back, shoulders, knees, and elbows. The issues I see a lot are rounded-back deadlifts, elbows flaring on bench presses, poor pelvic positioning on a back squat, and improper bracing, to name a few. None of these things necessarily cause an injury but can lead to injury as load or volume increases.
During a technique analysis, you can identify the instances where rapid joint acceleration and impact occur. For example, in a bench press, the active muscle groups are most stressed at the end of the down phase and the beginning of the up phase. It’s the transition to and off the chest where most injuries occur. This is the part of the lift we want to button up – shoulders and elbows in the right place, good stability, and no jerky movements.
Performance Improvement
In addition to injury prevention, a biomechanical analysis can enhance lifting performance by providing insights into the most effective and efficient technique.
For example, in a powerlifting context, the purpose of the bench press is to lift as much weight as possible for one repetition while staying within the sport’s rules. Biomechanically, this involves maximizing vertical force production while minimizing barbell displacement (distance traveled).
When applying this, a few aspects immediately come to mind: shoulder positioning, grip width, and upper back arch.
Shoulder Positioning
One critical aspect of an effective bench press technique is retracting and depressing the scapula. Doing so provides a stable position to press, offering better force transfer and shoulder safety. Additionally, retracting the shoulders stretches the sternal part of the pectoralis major, allowing it to be in the length range in which the muscle can develop the greatest force. Lastly, retraction slightly shortens the range of motion, helping to reduce the vertical displacement of the barbell.
When analyzing a bench press, the key point is to ensure people maintain the correct shoulder positioning after unracking the barbell. It’s common for lifters to set up with their shoulders retracted and depressed but lose muscle tension during the lift’s unrack portion, thus sacrificing the benefits. Losing tension is easy to see when you break down a lift frame by frame.
Grip width
Grip width in the bench press is about finding a balance between a grip that maximizes muscle force while shortening the range of motion. Research shows that a moderate or wide grip is best when the goal is to lift as much as possible during a 1-RM bench press (Larsen et al., 2021). In powerlifting, a specified maximum grip width is allowed, which limits how wide you can grab the bar. Finding the best grip width takes some trial and error.
Back Arch
The bench press arch is a hotly debated topic in powerlifting. It goes hand in hand with shoulder retraction, but the idea is to create an upper back arch and drive the sternum toward the bar. The most significant advantage this has is shortening the range of motion. In powerlifting, only the head, upper back/traps, and butt need to be in contact with the bench. These rules allow the middle back to be off the bench. A recent study showed that using an arch allows you to lift, on average, 9 pounds more than benching with a flat back (Bartolomei et al., 2022).
For more information on how to maximize your bench press, check out this article: https://kylehuntfitness.com/six-tips-to-increase-your-bench-press/
Using Biomechanics For Exercise Selection
Using biomechanics for exercise selection currently receives the most attention, and for good reason. Analyzing exercises through a biomechanical lens can help match them to the goal, which is what we are going for.
Understanding sources of resistance can help you eliminate specific exercises or techniques right off the bat. For one, gravitational force always points down. This is important when using free weights. I know this is crazy stuff. Try to keep up.
Free-weight exercises that don’t adhere to the force of gravity are problematic. Think of standing dumbbell internal and external rotations. Or doing side raises and then moving the dumbbells horizontally to a front raise position.
The same principle applies to dumbbell rows pulled toward the hip in a front-to-back swinging motion. Just pull the dumbbell straight up, keeping the direction of force in line with the forearm and elbow. It doesn’t have to be more complicated than that.
Cables and machines are different. We can manipulate the line of force to be anywhere we want. This is one of the reasons cable exercises are seeing a resurgence in popularity right now. However, the key with cables is to make sure the exercise is stable enough to allow for appropriate overload.
Foot Placement on a Leg Press
Another way to use biomechanics is to help you manipulate exercise techniques to shift the stress to where you want it—for example, the difference between foot placement on a leg press or hack squat. To increase quad tension, put your feet low on the footplate. This stance allows more forward knee travel and demands more input from the quads. On the other hand, to increase glute and hamstring tension, put your feet high on the footplate. With your feet high on the footplate, the lift becomes more hip extensor dominant.
You can also use heel elevation to increase quad focus. How far forward your knee travels relative to your midfoot during a squat movement pattern is what makes the exercise more quad-biased. So, if you want to shift more tension to the quads in goblet squats or split squats, heel wedges or a slant board can help you do that.
Is Your Incline Press Really an Incline Press?
It’s common knowledge that an incline bench press hits the upper chest. However, it’s not about the angle of the bench but the relationship between the upper arm and the pec. When performing an incline dumbbell or barbell press, you want to take the shape of the bench.
I’m a big fan of using an arch when flat bench pressing to maximize performance. However, I don’t want to use an arch on an incline bench when trying to train the upper pecs. If you arch your back and allow your butt to scoot down the bench, the effectiveness of the lift changes. Yes, you are still laying on an incline bench, but the muscle angle is more similar to a flat press than an incline.
Muscle Lengths
When choosing exercises, you want to look at where the lift is biased in the range of motion. Training muscles in their lengthened position is popular right now, but I’m not ready to give up on exercises targeting short muscle lengths. You should incorporate both.
For example, pick both lengthened and shortened bias exercises when creating a biceps workout. A free-weight preacher curl will target the lengthened bias, whereas a dumbbell spider curl lying facedown on an incline bench is a shortened bias movement. Think about where these exercises are the hardest. A free-weight preacher curl is hardest at the bottom when the biceps are stretched. A spider curl will be hardest at the top when the biceps are shortened.
A low pulley cable curl is unique in that you can face away from the cable stack to bias the lengthened position and face toward the cable to bias the shortened position. When you face away from the cable, it is relatively heaviest at the bottom, and when facing the cable, it is relatively heaviest at the top.
Triceps are another example of this. A well-constructed triceps workout should consist of exercises that stress the muscle at different points in the range of motion. For example, an overhead cable triceps extension will stress the muscle more in the stretched position, while a traditional cable triceps pressdown will stress the muscle more in a contracted position.
Keep it Simple
A common critique of science is it overcomplicates lifting. While this can be true, it doesn’t have to be. Everything I discussed in this article is simple stuff to make your training more effective. That said, nothing trumps progressive mechanical tension over time. That is the primary driver of progress. But, once you have that piece down, understanding the tension and function of the muscle group you are trying to train can help you optimize technique and exercise selection. Hopefully, you found this article useful. If you have any questions, feel free to reach out!
Author: Kyle Hunt
Email: KyleHuntFitness@gmail.com
Hire Kyle as your coach: http://www.kylehuntfitness.com/services/
References:
Bartolomei, S., Caroli, E., Coloretti, V., Rosaci, G., Cortesi, M., & Coratella, G. (2024). Flat-Back vs. Arched-Back Bench Press: Examining the Different Techniques Performed by Power Athletes. Journal of strength and conditioning research, 10.1519/JSC.0000000000004778. Advance online publication. https://doi.org/10.1519/JSC.0000000000004778
Larsen, S., & Gomo, O. (2021). A Biomechanical Analysis of Wide, Medium, and Narrow Grip Width Effects on Kinematics, Horizontal Kinetics, and Muscle Activity on the Sticking Region in Recreationally Trained Males During 1-RM Bench Pressing. Frontiers in Sports and Active Living, 2, 637066. https://doi.org/10.3389/fspor.2020.637066