When it comes to client assessment: conducting various physical tests to have a better idea of a client’s strengths, weaknesses, compensatory mechanisms, etc, I see three main types of approaches (and variations thereof):

  1. The trainers/coaches who don’t assess anything besides the usual questions about goals, experience, injuries, etc.
  2. Those who do a metric ton of assessments, but don’t really use any of that info to design the program.
  3. Those who assess for what they need to make the best choices when designing their client’s program.

1 and 2 are obviously problematic and out of the two, no.2 is the worst. Sure, it looks professional to do all those strength and mobility tests, but if you don’t modify your decisions when designing the client’s program based on the information gathered you are just a poser.

The coach who doesn’t assess at least has the intellectual honesty not to try to falsely give the impression of being professional and scientific!

Good coaches assess. But only assess to gather information they will use to make better decisions when building the training program.


When you are a personal trainer/coach, the main purpose of conducting an assessment with your client is to make better exercise selections.

Therefore, you are looking to gather information that will help you make the best possible choices.

Let’s look at a few things that can influence what the exercise menu will be for someone.

  1. Body proportions: People with long limbs vs. their torso will require slightly different focuses in their training as their levers will favor certain exercises over others. It can also help you decide the focus of the workouts.

    Someone with long legs will require more quads work and squat assistance, whereas glutes and lower back will get stronger more easily and they won’t require much assistance work to make their deadlift go up. Arm length plays a similar role, and the ratio between the tibia and femur as well as ulna vs the humerus can also have an impact (I will provide full information on that topic later in the article).
  1. Dominant vs. lagging muscle groups: If a muscle is dominant/strong it will require less direct work and a lagging/weak muscle will require more work to correct the imbalance. Since you have a limited capacity to recover and grow from physical training, basically a limited amount of “training money” to invest, you don’t need to spend the same amount of money on every muscle.

    It’s best to invest more on weaker muscles to bring them up to par and invest less on strong muscles. For example, my quads are very dominant compared to my hamstrings and glutes. If I squat, I have no need for any other quadriceps exercise. But I routinely have to use 2 or even 3 direct hamstring exercises for them to develop at the same speed as my quads.
  1. “Red flags”: There are some red flags that can almost rule out certain exercises until you fix the problem. For example, if you have a severe imbalance between the left and right lower body muscles it is ill advised to start heavy squatting and deadlifting.

    Unilateral work like split squats, lunges, step-ups, prowler pushing/pulling, single leg RDL, single leg curl, single leg back extension might be required before you can start loading the squat. Sure, you would still be able to squat with a left-right imbalance but the risk of injuries and accentuating the imbalance is significant. And the stronger you get, the bigger the risk.

    Same thing with the upper body, a big left-right imbalance means that you should focus more on dumbbell than barbell work to avoid developing compensatory mechanisms. Other red flags include a drastic reduction of the range of motion at a joint and an inhibition of a muscle.

For these three, I like to use body proportion testing/anthropometric measures (height, leg length, tibia length, femur length, wingspan, ulna and humerus length), the Klatt test and vertical jump qualitative test and upper body muscle testing for key muscles. More on these in a moment.

This is your bread and butter assessment. It will give you the most information about which exercises to use.

Then you can gather other useful pieces of info by conducting a few more tests (or using the same ones).

  1. Muscle fiber dominance: While you cannot directly measure the ratio of fast twitch fibers you can get an idea via the vertical jump qualitative test as well as the 80% rep test.

    Having an idea about muscle fiber dominance can have an influence on training volume (fast twitch dominant cannot do as much volume and should use slightly lower time under tension for their sets), average training load and rest intervals (the more fast twitch dominant you are, the longer should the rest intervals be).

  2. Efficacy of the stretch reflex: You can use both the vertical jump qualitative test as well as the comparison between a vertical jump and a jump from a static position. The more efficient the stretch reflex is, the more plyometric and explosive work you can include in your training and the more effective the lifting exercises where the target muscle group is stretched under load will be.

    People with a better stretch reflex also tend to have a higher acetylcholine level which means that they can have more frequent variation in their training.
  1. Eccentric/isometric strength vs. concentric strength: To minimize the risk of injuries and give you a greater potential for future strength and size gains, eccentric and isometric strength should be higher compared to concentric strength.

    The greater the difference is, the lower the risk of injuries and the greater the strength gain potential. You can get a good idea of eccentric/isometric strength by looking at the landing of a vertical jump.

Sure, you can test for tons of other things. But with these 6 pieces of information you can design an optimal lifting program for a client.


Here are the tests that I recommend:

The first one is measuring body proportions.

1) First measure height _____
2) Measure leg length from the malleolus to the ASIS (anterior superior illiac spine) _____

3) Measure the tibia length from the malleolus to the bottom of the knee cap _____
4) Calculate femur length (leg length – tibia length = femur length)_____
5) Calculate the ratio of tibia to femur (tibia length x 100 / femur length) _____
6) Calculate the ratio of the leg to total height (leg length x 100 / height) _____
7) Measure wingspan (arms in a cross, from finger tip to finger tip) _____






8) Measure the length of the ulna (from wrist to olecranon/elbow tip) _____
9) Measure the length of the humerus (from the acromion to elbow tip) _____
10) Calculate the ratio between the ulna and humerus (ulna length x 100/ humerus length) ____
11) Find the difference between wingspan and height (wingspan – height) _____


Leg length

Short legs = 40-43% of height
Average legs = 44-47% of height
Long legs = 47-51%+ of height

Tibia/Femur ratio

Short tibia = 75-78% of femur (or less)
Average tibia = 79-84% of femur
Long tibia = 85%+ of femur

Arm length

Short arms = Wingspan less than 1cm longer than height
Average arms = Wingspan 1 to 5cm longer than height
Long arms = Wingspan more than 5cm longer than height

Ulna/Humerus ratio

Short ulna = 75-78% of femur (or less)
Average ulna = 79-84% of femur
Long ulna = 85%+ of femur

The second test is the Klatt test.

To execute the Klatt test you stand on one leg on an elevated surface (around 6-8”) with the arms extended in front of you and your hands together.

From that position hop down to the floor. The way you land can tell you which muscles are weak.

The images are from my friend and awesome coach Eric Falstrault at

If the knee caves in it indicates a weak vastus medialis;
If you jump out (side opposite to the landing leg) it indicates weak adductors;
If you jump in (side of the landing leg) it indicates weak abductors;
If you jump forward it is likely weak hamstrings;
If you lean forward it indicates weak glutes;
If the upper body wobbles sideways it indicates a weak core/quadratus lumborum.

Of course, you do the test for both sides and it can reveal which muscles to use corrective exercises with.

My third test is the vertical jump qualitative test. For this one the jump height isn’t important (but you still try to jump as high as possible).

You are looking at the jumping strategy.

This test will give you a clue about muscle fiber dominance, efficiency of the stretch reflex, muscle dominance in the lower body, left-to-right imbalances and eccentric/isometric strength.

IMPORTANT: For the qualitative vertical jump test and the Klatt test, I like to film the attempt to make a more accurate assessment.

If I’m working with athletes, I will use a second vertical jump test. The reflex coefficient test.

In this one, you perform a maximal vertical jump and then a maximal static jump.

In the static jump, you squat down to the normal depth you would use when jumping but pause there for 2-3 seconds to get rid of the stretch reflex and from that position, without any rebounding or swing, jump as high as you can.

Then you calculate the myotatic reflex coefficient:

MRC = Vertical jump – Static jump / 100


The higher the coefficient is, the more the athlete is « reactive »
The lower the coefficient is, the more the athlete is « muscular »

Low coefficient: 0-4%
Average coefficient: 5-10%
High coefficient: + de 10%

The information you get from that is how much plyometric/explosive training an athlete can do in training and what type.

Coefficient 0 – 2.5%: Put a greater emphasis on general strengthening exercises. Low intensity jumps (box jump, hoping, footing drills, low height landing drills, 20-40cm) until you reach 3-5%

Coefficient 3 – 5.5%: You can begin to integrate maximal vertical jumps (reset on every rep), landing drills from higher (50-60cm) with high tension landing. From a lifting perspective you can begin to use the Olympic lifts and explosive squats, until you reach 6-9%

Coefficient 6 – 9.5%: Here you can continue doing maximal vertical jumps but you can also start to use « vertical jump series » (jumping as soon as you land) and low/medium height hurdle jumps. You can introduce depth jumps from a low height (40-60cm). You can also use a small amount of loaded jumps, using 10-15% of your max squat. You can put a greater focus on explosive lifting in your lifting sessions with explosive squats with added chains. Use these methods until you hit 10%.

Coefficient 10% or more:  Here you can use any plyometric drills, high intensity depth jumps (70-80cm), loaded jumps with 20-30% of max squat, jump circuits, broad jumps, « overspeed resisted jump series », squatting with bands, etc.

The other test I use is muscle testing for the upper body. I use the Kendall approach and I assess trap 3, rhomboids, lats and external rotators. These are the muscles that, when weak can decrease performance and increase the risk of injuries the most.

Since muscle testing is a lot about feel I think that it is improper to try to teach them by showing purdypictures. But I recommend that you learn from a specialist how to perform these simple tests.


These fives tests (body proportions, Klatt test, qualitative vertical jump, myotatic coefficient and muscle testing) take less than 20 minutes to do and will give me all the info I need to make the best exercise selection for a client.

– Muscle chain with the greatest mechanical advantage
– Weak/lagging/problematic muscles
– Red flags for the use of some big compound lifts
– Left to right imbalances (more barbell work or dumbbells)
– Efficacy of the stretch reflex

I even gather other information that will help me decide which methods and loading schemes to use.

– The need to focus more or less on eccentric and isometric actions
– Low, high or moderate reps
– Can I use plyometric exercises?

But the assessment doesn’t stop there. In fact, it is ongoing throughout the whole training process. See, if you do a god job coaching you will look at how your client performs during the workout to gather information you can use to adapt the training program or design the next training phase.

The way someone performs the big lifts, the position of the sticking point and what happens to the body when you reach those sticking points gives you lots of clues about how to change the training program or design the rest of the plan.

That’s why I often say that a coach who is good at counting reps is bad at coaching: if you are really paying attention to how your client is doing the exercise, gathering information on every rep (e.g. how is the technique changing when the client builds up fatigue), you simply cannot count reps effectively.

The most important thing with training, regardless of what your goal is, is to correct weaknesses or to solve problems. The more information you accumulate regarding those weak points the better job you can do.

Here are a few tables explaining which are the weak points in a lift depending on the position of the sticking point.

Testing is important and the good coaches do it, but they don’t do it merely to look professional or give the illusion that they are individualizing the program. Testing is first and foremost done to know what the best exercises will be for each individual. Experience, goal and neurotype is mostly useful for determining the best methods, loading schemes and volume. But physical testing is the key to making the best exercise selection possible.


Christian Thibaudeau

Written by Christian Thibaudeau

Christian Thibaudeau has been involved in the business of training for over the last 16 years. During this period, he worked with athletes from 28 different sports. He has been “Head Strength Coach” for the Central Institute for Human Performance (of…