Pathway
Intermediate
50 min read
Anatomy of a movement
Six steps to break a movement down: the pattern it follows, the joints it moves, the muscles that produce and those that restrain, and what body proportions change about it.
A movement is rarely well described by its name. "Squat" covers a crouched position, a loaded exercise and a whole family of variants at once. What can be described is what the body does: which joints move, in which direction, and who produces the force.
This pathway follows that breakdown across the four most used patterns, then across two that pose a different problem.
What this pathway lets you understand
By the end, an unfamiliar movement should be classifiable. Three questions are enough: which joints close and open, which muscles cross those joints, and in which direction the load pulls.
It is a reading method, not a catalogue. Variants of one pattern follow by deduction rather than memorisation.
Level, prerequisites and reading time
The Locate and name pathway is a useful but not compulsory prerequisite: it sets up the muscles and joints this one puts to work.
Allow around fifty minutes. Steps 5 and 6 are the densest.
The steps of the pathway
The six steps, in order
0 of 6 steps completed
- 1A symmetrical patternThe squat: phases, joints, how work is shared, and three beliefs about depth and the knee.8 min read
- 2The same movement, shared differentlyThe hip hinge: the same posterior chain, but the knee moves little and the hip does most of the work.8 min read
- 3
- 4When the base narrowsThe lunge introduces a plane the other patterns barely load: sideways control of the pelvis.8 min read
- 5When the load stops movingThe loaded carry: everything becomes holding, and it is the grip that gives out first.7 min read
- 6What makes the movement possibleThe knee, the most loaded joint in this pathway and the least held by its own shape.9 min read
What to take away
The patterns are not told apart by the muscles used — those overlap heavily — but by how work is shared between the joints. The squat splits between hip and knee; the hinge shifts towards the hip; the lunge adds a sideways constraint; the loaded carry removes the movement and keeps only the holding.
Certainty level · Established
How stress is shared between the joints of the lower limb depends on the angle of flexion and on trunk position.
Work on squat biomechanics measures that shift between the patellofemoral joint and the tibiofemoral structures, and reference kinesiology supplies the mechanism. Published values depend on the protocol, the load and the population studied; they describe a trend, not any particular execution.
Neumann DA (2016) · Escamilla RF (2001) · Schoenfeld BJ (2010)
Second point: body proportions change what is reachable, without that reflecting quality of execution. The relative length of the segments and the orientation of the hip socket move the bony limit from person to person. Squat depth is therefore not a transferable criterion.
Certainty level · Probable
The muscles framing the spine take part in transmitting force between the limbs.
The review on core training describes that role and distinguishes endurance from maximal strength. It does not separately measure the trunk's contribution in each movement pattern, and turning it into conduct for a given person goes beyond what it establishes.
McGill SM (2010)
Key point
The thread to keep
Three questions file any movement. Which joints move, and in which direction? Which muscles cross them? Where does the load pull relative to them?
Answering those three is enough to predict who works, without memorising a list of exercises.
Checking what stuck
Check my understanding
What mainly distinguishes the squat from the hip hinge?
How work is shared between hip and knee
The muscles involved, which are different
The load used
Why does the lunge demand something the squat does not?
Control of the pelvis in the frontal plane
More force from the quadriceps
A greater ankle range
In a loaded carry, what usually gives out first?
The grip
The erector spinae
The calves
Choose an answer
Sources
Sources for this pathway
- Neumann DA (2016). Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation, 3rd edition. Elsevier.
- Escamilla RF (2001). Knee biomechanics of the dynamic squat exercise. Medicine and Science in Sports and Exercise.
- Schoenfeld BJ (2010). Squatting kinematics and kinetics and their application to exercise performance. Journal of Strength and Conditioning Research.
- McGill SM (2010). Core training: evidence translating to better performance and injury prevention. Strength and Conditioning Journal.
Read next
- Understanding muscle growthA six-step reading pathway that connects the mechanical signal produced during a set, the protein building that follows, and the volume of work accumulated over a week. A quiz at the end lets you check what you have taken in.Described without a scene
- Vertical pushThe vertical push takes the hand above the head. This page describes its phases, the coordination between the shoulder and the shoulder blade, the prime movers and stabilisers, and the most widespread confusions about overhead movements.With a 3D scene
- The hipA sphere set deep in a socket, locked by three ligaments that tighten in extension. That is what makes standing possible without continuous muscular effort.With a 3D scene
Put it into practice in Shapier
See the squat exercise and its execution
The squat's execution, setup and cues live in Shapier; Body Lab only explains what happens during the movement.
See the squat exercise and its executionBody Lab explains; Shapier lets you act and track.
Available offline
Offline download is available in the mobile app.
Trust and method
Author
equipe-editoriale-shapier
Editorial review
Thanh Chau
Scientific review
Pending
Published on
August 2, 2026
Reviewed on August 2, 2026
Next review due August 2, 2027
Limits of this page
- The descriptions apply to movements with vertical load at controlled speed: a jumping, very fast or strongly asymmetrical movement distributes the loads differently.
- No step judges an execution: the pathway explains what happens, it does not say how to do it or what should be corrected.
- The biomechanical values quoted come from laboratory protocols on small numbers of people, whose transfer to real training remains approximate.
Sources
- Neumann DA (2016). Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation, 3rd edition. Elsevier.
- Escamilla RF (2001). Knee biomechanics of the dynamic squat exercise. Medicine and Science in Sports and Exercise.
- Schoenfeld BJ (2010). Squatting kinematics and kinetics and their application to exercise performance. Journal of Strength and Conditioning Research.
- McGill SM (2010). Core training: evidence translating to better performance and injury prevention. Strength and Conditioning Journal.
Educational content. Body Lab does not diagnose and does not replace professional advice.
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