This article is a very important read for any individual who works in the strength and conditioning and sport training professions. It is my hope that the terminology described within this article will catch on and appear more often in conversation and literature. Please read this article and decide for yourself which language you will proceed to use when describing movement..
In the sport-specific training profession, it’s very common to hear coaches utilizing planar terminology to discuss movement. You might overhear a strength coach saying something like, “I like this exercise because it’s multiplanar,” or, “this exercise is great because it’s a sagittal plane movement that requires stabilization in the frontal and transverse planes.”
There are three body planes (body planes are sometimes called anatomical planes or cardinal planes), which are imaginary lines that divide the body into two parts:
In case you didn’t know, a Turkish get-up would be considered multiplanar since it combines movement in the transverse, sagittal, and frontal planes. A squat is a sagittal plane movement that requires stabilization in the frontal and transverse planes, since the knees tend to want to cave inward and enter into a valgus position (adduction and internal rotation of the femurs), which requires proper firing of the hip external rotators, mostly in the transverse plane. If you look at the diagram below, you’ll be able to envision how a lateral raise or jumping jack is a frontal plane movement, a pec deck or a baseball swing is a transverse plane movement, and a crunch or a lunge is a sagittal plane movement.
While planar terminology is a great start, I believe that we can do better. Planar terminology is too general, which is why we need force vector terminology. Force vector terminology is more specific to movement. Our profession borrowed planar terminology from anatomy language, but gross anatomy doesn’t consider movement. Force vector terminology is used often in engineering, and a vector contains both magnitude and direction.
What’s the Point in Using Force Vector Terminology?
Although I feel that strength coaches should still use planar terminology depending on the situation, I believe that strength coaches should also be well versed in force vector terminology since there are plenty of situations where force vector terminology is more appropriate and descriptive.
Why is planar terminology insufficient? In planar terminology, jumping, running, and backpedaling are all sagittal plane movements, even though they are completely different. One of these actions has you moving upward, one has you moving forward, and one has you moving backward. Force vector terminology corrects these terminology deficiencies and allows us to better describe movement.We can use force vector terminology as a way to categorize exercises, describe movement, assess strengths and weaknesses, and choose exercises that may transfer ideally to sport.
Force vector training takes into account the line of pull, or the direction of the resistance, as well as the position of the exerciser’s body in space when they are directly opposing the resistance or line of pull. The easiest way to determine a force vector is by using images to show a graphical representation of the direction of resistance (via an arrow) in relation to the human body.
Basic Force Vector Terminology
• Posterior – toward the back (sometimes synonymous with dorsal)
• Lateral – toward the side (away from the midline)
• Medial – toward the middle or midline
• Superior – upper or above
• Inferior – lower or below
• Axial – top to bottom
• Torsion – twisting or rotating
• Anteroposterior – front to back
• Posteroanterior – back to front
• Lateromedial – outside to inside
The Six Primary Force Vectors in Strength Training and Sports
Here are the six primary force vectors I see in the weight room and in sports:
6. Axial/Anteroposterior Blend
Force Vector Terminology: Off to a Good Start, but Still Much Room for Improvement
We could certainly be much more technical if need-be. For example, true axial lifts produce compressive forces and wouldn’t include exercises like chin ups, which produce distraction forces. Now, muscular tension creates compressive forces, so a chin-up will still compressively load the spine, but I digress. Nevertheless, if we wanted to be more accurate, we would need to split axial into superoinferior and inferosuperior, and we’d also need to split lateromedial into lateromedial and mediolateral. However, in my model, I lumped them together for the sake of convenience. Another possibility to “clean up” the axial terminology is to use “axial positive” for compressive exercises such as squats and overhead press and “axial negative” for distraction exercises such as chin ups.
Furthermore, I like to consider all horizontal pressing as anteroposterior force vectors, yet depending on the body position (prone vs. supine), the force vector reverses. For example, a push up is technically posteroanterior, while a bench press is anteroposterior. The same can be said about horizontal pulling; an inverted row is anteroposterior while a prone bench row is posteroanterior. Finally, the same could be said for horizontal hip dominant lifts; a hip thrust is anteroposterior while a reverse hyper is posteroanterior. For the sake of simplicity, I lump all horizontal pressing into the anteroposterior category, since the intent is always to push forward via shoulder flexion/horizontal adduction. I lump all horizontal pulling into the posteroanterior category, since the intent is always to pull rearward via shoulder extension/horizontal abduction/scapular retraction. Finally, I lump all horizontal hip dominant lifts into the anteroposterior category, as the intent is to either push the hips forward or to pull the thigh rearward via hip extension/hip hyperextension.
You might be wondering why there’s an axial/anteroposterior blend. This distinction is necessary because it separates acceleration sprinting from max speed sprinting, as well as certain exercises and plyos that are blends of both vectors. This is important, since optimal training for these types of sport actions might require specific exercises as well as a balanced blend of axial and anteroposterior vector exercises. Of course, we could create more blends to describe different sporting movements, as truly every combination of force vector exists.
I should mention that in sports there is often no external load – often the individual is simply propelling his or her own bodyweight. In this case, you’d want to consider the resultant ground reaction forces. Sometimes it can be confusing when determining vector terminology and considering the potential transfer of training from the weightroom over to sports performance. For example, when an individual is sprinting, he or she is moving his or her body forward, which would be posteroanteriorly. If he or she is leaning forward during acceleration, then there exists more of an axial component (as alluded to earlier). Now, axial forces will exist in sprinting due to gravity and the need to raise the body’s center of mass, however, horizontal forces have been shown to be more correlated to sprinting performance than axial forces. Therefore, if we mimic this vector in the weightroom, we must apply a load in that direction. If we put a bar on the hips and do a supine barbell hip thrust, or if we pull a sled with a fairly upright stance, then the direction of the load is anteroposterior. However, if we use a pendulum (such as getting on all-fours underneath a reverse hyper machine) to perform a loaded quadruped hip extension, or if we hold onto a dumbbell during back extensions, the direction of the load is posteroanterior. To rectify this, I believe it’s okay to oversimplify things and refer to sprints, hip thrusts, pendulum quadruped hip extensions, and back extensions as movements that train the anteroposterior vector.
Axial Force Vectors (Includes Superoinferior and Inferosuperior)
• Squat Variations
• Deadlift and Good Morning Variations
• Olympic Lifts (Clean, Jerk, and Snatch Variations)
• Single Leg Squats: Static Lunges, Bulgarian Split Squats, Step Ups, Pistols
• Vertical Pressing (Military Presses)
• Vertical Pulling (Chins Ups, Pull Ups, Upright Rows, Shrugs)
• Barbell Curls
• Vertical Jumping, Vertical Plyos, and Jump Rope
Anteroposterior Force Vectors
• Single Leg Glute Bridges and Single Leg Hip Thrusts
• Barbell Glute Bridges and Barbell Hip Thrusts
• Pendulum Quadruped Hip Extensions and Cable Pull Throughs
• Back Extensions and Reverse Hypers
• Nordic Ham Curls, Glute Ham Raises, and Slideboard Leg Curls
• Bench Presses, Push Ups, and Standing Cable Presses
• Planks, Ab Wheel Rollouts, Bodysaws, and Hollow Rock Holds
• Max Speed Sprinting and Bounding
Posteroanterior Force Vectors
• Band Resisted or Barbell/Dumbbell Forward Lunge
• Backward Sled Drag
• Seated Rows, Inverted Rows, Hammer Strength Rows, One-Arm Rows, Standing Cable Rows, and Face Pulls
• Backward Hops and Backpedal Sprinting
• Walking Lunges
• 45 Degree Hypers
• Kettlebell Swings
• Pendulum Donkey Kicks, Reverse Leg Presses, Power Runner Machine, and Leg Presses
• Incline Presses, Decline Presses, and Dips
• Bent Over Rows, Corner Rows, and Chest Supported Rows
• Sled Pushes and Pulls (with lean)
• Farmer’s Walks and Yoke Walks (mostly axial, but you’re moving forward)
• Stadium Sprints
• Acceleration Sprinting, Forward Leaping, and Pushing an Opponent Forward
Lateromedial Force Vectors (Includes Lateromedial and Mediolateral)
• Side Lying Abduction, X-Band Walks, Sumo Walks, and Band Standing Abduction
• Lateral Raises
• Side Planks and Suitcase Carries
• Lateral Sled Drags
• Lateral Hops, Lateral Plyos, and Jumping Jacks
• Cutting from Side to Side and Carioca
• Slide Board Lateral Sprints
Torsional Load Vectors
• Pallof Presses and Anti-Rotary Holds
• Cable Chops, Cable Lifts, and Landmines
• Band and Cable Hip Rotations
• Tornado Ball Slams and Rotary Med Ball Throws
• Side Lying Clams and Band Seated Hip Abductions
• Pec Deck, Reverse Pec Deck, Flies, Prone Rear Delt Raises (Especially Unilateral Versions of These Movements)
• Swinging, Kicking, Punching, and Throwing
Force Vector Analysis Can Be Pretty In-Depth With Certain Exercises
Consider most anti-rotational exercises – say the Pallof press, the cable half-kneeling anti-rotation press, and the landmine. These exercises each possess both torsional and also lateromedial force vectors, meaning that they place axial twist loads on the body in addition to lateral bending loads. Therefore, these exercises could be lumped into a special torsional/lateromedial blend category. Consider the 1-legged Romanian deadlift with a dumbbell held in the contralateral hand. At face value, you’re lifting the load upward, so this is an axial movement. However, at the bottom of the lift, the torso will be receiving a posteroanterior load, since it’s bent over. Since the lifter is standing on one leg with the load in the opposite hand, there will be a combination of torsional and lateromedial loads on the spine and hips.
As you can see:
1. Often multiple force vectors exist within a single exercise
2. Force vectors can fluctuate throughout an exercise, and
3. Force vectors can vary according to different regions of the body during a single exercise and technically there’s at least a slightly different force vector acting on every single joint in the body during an exercise
Application to Sport-Specific Training
Force Vector Training (FVT) is not a specific type of routine that you can follow. It’s simply a model that you should keep in mind during programming to make sure you’re training the appropriate vectors and keeping balanced strength between different directional demands. Although force vectors are important considerations for all types of fitness endeavors, FVT has the most application to sport-specific training. Below are some bullet-points to consider.
• Let the sporting actions dictate the best way to train in the weightroom. See the pictures below. What do these pictures tell you? Consider the exact lines of decelerative and propulsive force for each activity. Then analyze which strength and power exercises follow similar patterns of force vectors.
• An athlete is always moving in one direction while stabilizing in the other directions.
• FVT blends together Physics and Functional Anatomy and the direction of force influences the torque-angle curves that are inherent to sporting and weightroom movements.
• Strength and power training according to the proper force vectors activates muscles in a similar manner (though often not at the same speeds) in which they activate during sporting movement. This is important.
• There is certainly appreciable overlap between the development of strength in various vectors. For example, performing heavy squats will likely transfer to every single vector. However, for maximal total vector strength, more specific means are likely necessary.
• Use all the tools available; bodyweight, dumbbells, barbells, specialty bars, kettlebells, resistance bands, chains, body leverage systems, cable columns, suspension systems, machines, sleds, battle ropes, medballs, Indian clubs, and landmine units.
Start looking critically at various exercises. Although most movements are beneficial and provide a training effect, start asking yourself questions like these:
• How would a static lunge have an axial vector whereas a walking lunge would have an anteroposterior/axial blend vector? At what range of hip motion does hip extension torque “shut down” with each movement?
• What is the difference between a good morning, a 45 degree hyper, and a back extension? Do they possess unique hip extension torque-angle curves? Which exercises loads the stretch position best, which exercise maximizes mean torque, and which exercise loads the end-range position best? Do they complement each other?
• How do force vectors impact accentuated regions of force development and positions of maximum muscular contraction? For example, in what position is the most difficult part for the glutes in a squat (axial loaded) – at the bottom of the movement (hips flexed) or at the top of the movement (hips neutral)? In what position is the most difficult part for the glutes in a hip thrust (anteroposterior loaded) – at the bottom of the movement (hips flexed) or at the top of the movement (hips neutral)? Would these exercises not complement each other to produce hip extension strength and power through a full spectrum of motion?
• Which implements are best suited for training specific rotary power; a landmine unit, resistance bands, dumbbells, cables, a barbell, a kettlebell, or a suspension system?
• During a side lunge, is the emphasis on pushing upward or laterally? Would a slideboard be better at training lateral power? Which requires more hip abduction and hip external rotation torque?
• Would a resistance band or a dumbbell be more useful for training punching power in terms of a jab? What about an uppercut?
• What implement would be better suited for training for rotary power for chop and lift patterns – a medball or a cable column?
• For forward deceleration and backpedaling power, would a forward lunge not better-replicate the demands on the knee joint than a reverse lunge?
• For vertical power production, could one not substitute barbell jump squats with dumbbell or trap bar jump squats? Could heavy kettlebell swings be a suitable replacement for power cleans and snatches depending on the situation?
• For sprinting speed and acceleration, should you use a weighted vest to provide more axial loading, or a sled to provide more anteroposterior loading?
Application to Bodybuilding/Physique Enhancement Training
• Let the muscle fiber directions dictate the best way to train a muscle part, muscle, or muscle group. See the pictures below. What do these fiber directions tell you?
• Hit the muscles from different angles, and perform some movements that target the stretch position, some that target the mid-range position, and some that target the contracted position.
Application to Powerlifting
• The force vectors for the big three lifts are: squat – axial, bench press – anteroposterior, deadlift – axial.
• Therefore, you’ll want to perform axial lower body lifts for specificity, such as good mornings and additional squat and deadlift variations, and you’ll want to consider including anteroposterior lower body lifts for additional posterior chain activation, such as hip thrusts, back extensions, 45 degree hypers, reverse hypers, and glute ham raises.
• You’ll want to perform anteroposterior upper body lifts for specificity, such as board presses, chain suspended push-ups, and chest supported rows, and you’ll want to consider including axial upper body lifts for additional delt and lat activation, such as military press and chins.
Application to Core Stability Training
To improve core stability, the spine, pelvis, and hips need to be hit from multiple vectors, since different muscles are used to stabilize the body depending on the direction of force. Consider the list below:
Developing Anti-Extension Core Stability through Posteroanterior and Anteroposterior Forces
Lifters need to develop the anterior core muscles including the abdominals and obliques, but they also need to learn how to perform posterior chain movements without hyperextending their spines, which requires motor control and glute strength.
• Posteroanterior core exercises: front planks, RKC planks, stability ball rollouts, blast strap fallouts, ab wheel rollouts, bodysaws, hollow body holds
• Anteroposterior core exercises: hip thrusts, pendulum quadruped hip extensions, back extensions, reverse hypers with neutral spine
Developing Anti-Lateral Flexion Core Stability through Mediolateral Forces
• Mediolateral core exercises: side planks, lateral sled drags
• Off-set/single limb axial core exercises: single arm lateral raises, single arm lunges and Bulgarian split squats, single leg deadlifts, single arm overhead presses, farmer’s walks, suitcase holds, and waiter’s carries
Developing Anti-Rotation Core Stability through Torsional Forces
• Torsional core exercises: Pallof presses, band anti-rotational holds, chops, lifts, landmines, weighted bird dogs, weighted dead bugs, cable hip rotations, stability ball Russian twist, single arm cable chest flies, one arm cable rotational rows, one arm rows, and single arm dumbbell bench press
Developing Anti-Flexion Core Stability through Axial Forces
• Axial core exercises: squats, deadlifts, and good mornings
Application to Conditioning
Use variety in conditioning. For example, many athletes are great at barbell circuits but do very poorly with band circuits, as they don’t have anteroposterior hip stability, strength, and endurance.
• Bodyweight complexes (good balance of all vectors if done correctly)
• Barbell, dumbbell, and kettlebell complexes (mostly axial)
• JC band and TRX system complexes (mostly anteroposterior)
• Landmine complexes, battlerope and Indian club complexes (great for vector variation and mediolateral/torsional vectors)
Circuits can include each of these implements for vector variety as well.
Application to Activation Work
Force vector consideration can be used to increase the activation for certain muscles or to accentuate the region of force development on initial range or end range contraction (stretch position vs. contracted position). Here are some examples:
• Feet elevated scap push-ups for increased serratus anterior activity (you want a strict anteroposterior vector)
• Face pulls (alter vector from high to low to target different fibers)
• Shoulder elevated glute bridges (hip thrusts) for increased quad and gluteus maximus activity (you want a strict anteroposterior vector up top in the contracted position), feet elevated glute bridges for increased hamstring activity
• X-band and sumo walks – upright for glute med and mediolateral vector focus, crouched with bent knees for more glute max and torsional vector
• Hip flexion – cable column for anteroposterior/stretch position emphasis, standing ankle weight for axial/contracted position emphasis
To most coaches, force vectors are obvious from an upper body standpoint. Vertical pressing will target the shoulders better than horizontal pressing, whereas horizontal pressing will target the pecs better than vertical pressing. Vertical pulling will target the lats, whereas horizontal pulling will likely bring in the mid-scapular retractors to a greater degree. Most coaches understand the difference in muscle activation as it pertains to core exercises as well, as the various spinal flexion, spinal lateral flexion, spinal rotation, and spinal extension (whether dynamic or static) exercises allow us to feel the various muscles working differently. However, many coaches do not possess an adequate understanding of force vectors as it pertains to hip extension. Most mistakenly believe that hip extension is hip extension, that anteroposterior hip extension exercises shouldn’t be loaded up, and that bridging is merely a way to “isolate” prior to “integration” to teach glute activation.
If the direction of the force vector didn’t matter, then we’d prescribe squat motions for glute activation rather than bridging motions. Bridging motions activate more glute than squatting motions at equal loads. For example, a bodyweight bridge might elicit three times as much glute activity as a bodyweight squat, as might a 300 lb glute bridge over a 300 lb squat. Bridging motions strengthen the glutes in a more “hips-extended” position, which is a critical range in sports as that is the precise range at ground contact during a sprint (and the range that yields the highest level of glute activation in a sprint). Don’t be afraid to load up this pattern and go heavy.
Application to Assessment
It’s important to be strong, stable, and ultimately powerful in all directions. Often someone can possess great movement efficiency in one vector and poor movement efficiency in another. This is one of the reasons why many coaches like to say, “Everything is an assessment.” Literally every exercise and activity an athlete performs provides clues as to how strong, mobile, and proficient he or she is in the various movement pattern or vector.
An individual may perform a squat pattern very well but struggle with a bridging pattern. For example, I’ve seen individuals who can squat over 400 lbs but struggle to perform simple bodyweight bridges. These same individuals tend to struggle with proper technique during back extensions and reverse hypers. Their axial proficiency is sound, but their anteroposterior proficiency is not. This might be due to the fact that they have good hip flexion mobility and hip extension strength in flexed positions, but perhaps they have weak end range hip extension strength or poor motor control in the glueus maximus at this range of motion. The converse is true as well; sometimes an athlete possesses incredible strength and technique with anteroposterior hip extension exercises but not so much with axial hip extension exercises.
Furthermore, I’ve trained female athletes who could squat and deadlift very well, yet struggled with a 20-lb Pallof press (the lightest weight on the cable stack). They possessed sound axial efficiency, but their torsional efficiency was lacking.
During the actual strength and power training portions of the session, you will be provided additional clues as to how strong or powerful an athlete is in a typical vector. If they possess a glaring imbalance in strength between the various vectors, they’re likely leaving some room on the table in terms of athletic prowess. This is especially true for certain sports that rely heavily upon certain vectors for power.
It is quite possible to be strong at the hips and core in one vector but weak in another. Gluteus maximus strength in particular seems to be vector-specific as its role in hip extension, hip hyperextension, hip abduction, hip transverse abduction, hip external rotation, and posterior pelvic tilt may require exercises from each of the axial, anteroposterior, mediolateral, and torsional vectors. Sure, simply developing muscular glutes will go a long way in allowing for multi-directional glute power, but for maximum power in all directions, a multi-vector approach to glute training is likely necessary.
Of course, you always need to consider all possible vector weaknesses and take into account anthropometrical information a well. Does the athlete do poorly on a various moment simply because his or her body isn’t well-suited for the lift, or because it’s a new movement and they haven’t had a chance to learn the form, or are they truly weak in that vector? Sometimes you’ll need to test a couple of different exercises to get an accurate viewpoint.
Popular single leg exercises from various vectors challenge the torsional and mediolateral vectors’ stabilizing mechanisms and involve crucial muscles such as the adductors, gluteus medius and minimus, gluteus maximus, hip external rotators, quadratus lumborum, multifidi, obliques, and erectors, which need to be strengthened and coordinated for proper movement efficiency and power production.
Application to Overall Health
Here are some important considerations for LVT as it pertains to overall health:
• Strong Body – Your body needs to be well adapted to all directions of force for functional strength and work capacity. Too much emphasis in one force vector without enough work on other force vectors will yield sub-optimal results and fail to produce a well-rounded, athletic individual.
• Wolff’s Law of Bone – Bone adapts to become stronger according to the lines of force placed upon it. We want bone to be strong from all directions.
• Davis’ Law of Soft-Tissue – Soft-tissue adapts to become stronger according to the lines of force placed upon it. We want soft-tissue to be strong from all directions.
• Strength/Power – General strength development through the big basic exercises such as squats, deadlifts, bench presses, bent over rows, and military presses will develop an impressive athlete, but the athlete could be ill-prepared from a neuromuscular standpoint for anteroposterior, mediolateral, and torsional activities in sports. Certainly, plyometric, agility, and speed training aid in developing well-rounded power, but a balanced resistance training regimen is highly beneficial as well.
• Fun! – Quite often the best program for an individual is the one with which they’ll be the most consistent. Athletes and lifters have more compliance when they enjoy their routine, and they usually enjoy variety. Vector variety not only provides for a more effective workout; it provides a more fun and enjoyable workout as well.
How to Mimic Load Vectors
Think like MacGyver. He was a crafty individual. Use your knowledge of Biomechanics and all the training tools at your disposal to target the various directional force vectors.
• When using barbells or dumbbells, standing lifts usually target axial vectors, supine lifts usually target anteroposterior load vectors, and prone lifts usually target posteroanterior load vectors.
• When using bands or cables, standing lifts usually target anteroposterior or posteroanterior vectors, while supine lifts usually target axial load vectors.
• Performing unilateral variations of axial lifts tends to increase the mediolateral component (think single arm dumbbell overhead press), while unilateral variations of anteroposterior lifts tend to increase the torsional component (think single arm dumbbell bench press).
• Get creative: change body position, change the angle or line of pull, elevate a part of the body, etc.
I hope this article has given you some food for thought. Anytime you hear someone in the fitness field using planar terminology, smirk at them and say in a snooty voice, “Hmm. Planar terminology. That’s so 2000!” Then teach them force vector terminology. Of course, I’m being facetious as I still use both types of terminology depending on the topic and audience, but I make sure to consider force vectors when designing programs. It should be mentioned that there currently is not much research supporting the inclusion of force vector training. FVT is a theoretical model that would require a great deal of longitudinal research to support it. Axial lifting in the form of squatting and the Olympic lifts have formed the backbone of strength training over the past several decades for good reason – they’re highly effective in developing total body strength. However, they alone will most probably fail to maximize an athlete’s strength, power, and conditioning in all vectors. The better understanding you have of force vectors, the better you’ll be as a lifter, trainer, coach, or rehabilitation specialist.