Muscle guides
The muscles, one by one
Where each muscle sits, where it starts and attaches, what it moves, and which exercises and stretches work it. Every exercise links to its own guide with a 3D demo and an easier and a harder option.
The anatomy comes from open medical references, and the training and injury notes are graded against the studies each page lists.
Chest and shoulders
Pectoralis major
The pectoralis major and its two heads: what each does, what incline pressing changes, why grip width matters less than you think, and pec tears.
pec minorPectoralis minor
The pectoralis minor sits under the pec major and moves the shoulder blade. What it does, its link to thoracic outlet syndrome, and the stretch that works best.
boxer's muscle · serratusSerratus anterior
The serratus anterior holds your shoulder blade to your ribs and lets you reach overhead. What it does, the push-up plus, and scapular winging.
delts · shoulder muscleDeltoid
The deltoid's three parts and what each does, the raises that target them according to EMG studies, and what the deltoid can and cannot do on its own.
SITS muscles · shoulder cuffRotator cuff
The four rotator cuff muscles: what each does, the exercises that work them, why a tear on a scan is common without pain, and how cuff problems are treated.
Back
Latissimus dorsi
The lats are the widest muscles of the back. What they do, the pull-up and pulldown evidence, and whether a wider grip really builds wider lats.
lat's little helperTeres major
The teres major works as one unit with the lats. Where it is, what it does, why it is not part of the rotator cuff, and the pulls that train it.
trapsTrapezius
The trapezius has three parts that do different jobs. What each does, the exercises that work each one, and what helps neck and shoulder muscle pain.
rhomboid major and minor · muscle between the shoulder bladesRhomboids
The rhomboids squeeze your shoulder blades together. Where they are, what they do, the rows and raises that use them, and pain between the shoulder blades.
lower back muscles · spinal erectorsErector spinae
The erector spinae straighten and steady your spine. Their three columns, what they do, the exercises that work them, and their link to back pain.
deep back muscle · spine stabiliserMultifidus
The multifidus is a deep spine stabiliser that can waste after back pain. What it does, what the research shows, and the exercises that work it.
QL · side lower back muscleQuadratus lumborum
The quadratus lumborum is a deep muscle in the side of the low back. Where it is, what it does, the exercises that load it, and its role in back pain.
Arms
Biceps brachii
The biceps turns your palm up as much as it bends your elbow. Its two heads, what curl grip changes, chin-ups, and biceps tendon problems.
muscle under the bicepsBrachialis
The brachialis lies under the biceps and bends the elbow in every hand position. Where it is, what it does, and the curls that load it.
top of the forearm muscleBrachioradialis
The brachioradialis bends the elbow from the thumb side of the forearm. What it does, what a reverse curl adds, and the nerve problems it can cause.
triceps · back of the armTriceps brachii
The triceps straightens the elbow. Its three heads, why overhead extensions grew it more in a trial, close-grip pressing, and spot reduction.
forearm flexors · grip musclesWrist and finger flexors
The forearm flexors bend the wrist and fingers and power your grip. The muscles, what they do, golfer's elbow (not just golfers) and grip exercises.
forearm extensors · tennis elbow musclesWrist and finger extensors
The forearm extensors lift the wrist and fingers and steady your grip. The muscles, tennis elbow (mostly not from tennis), and the eccentric exercise that helped.
Neck
Levator scapulae
The levator scapulae lifts the shoulder blade and is a common site of neck pain. Where it is, what it does, and how to stretch it without aggravating it.
SCM · front of the neck muscleSternocleidomastoid
The SCM is the rope-like muscle on the side of the neck that turns and tilts the head. What it does, its role in neck pain, and how to stretch and train it.
scalene muscles · side neck musclesScalenes
The scalenes lift your top ribs when you breathe hard and bend the neck sideways. Their three parts, thoracic outlet syndrome, and a gentle stretch.
Core and trunk
Rectus abdominis
The six-pack muscle: what it does, which ab exercises work it hardest, whether upper and lower abs exist, and what ab training does to belly fat.
side abs · external and internal obliquesObliques
The external and internal obliques twist and side-bend the trunk. How they work as a pair, the exercises that load them, and side-strain injuries.
TVA · deep core muscleTransversus abdominis
The transversus abdominis wraps the waist like a corset. What it does, what the evidence says about drawing in before you lift, and how to train it.
breathing muscle · respiratory diaphragmDiaphragm
The diaphragm is your main breathing muscle and part of the core. How it works, its links to posture and the pelvic floor, and belly-breathing practice.
Kegel muscles · pelvic diaphragmPelvic floor muscles
The pelvic floor holds up the pelvic organs and controls leaks. How it works, how to do pelvic floor exercises, and why a tight pelvic floor needs relaxing.
Hips and glutes
Iliopsoas
The psoas and iliacus are your main hip flexors. What they do, the exercises and stretches for them, and whether a tight psoas really causes back pain.
glutes · glute maxGluteus maximus
Where the gluteus maximus is, what it does, and the exercises that work it hardest according to a review of 16 EMG studies, with 3D demos.
glute med · side gluteGluteus medius
The gluteus medius keeps your pelvis level on one leg. Where it is, what it does, the exercises that work it most, and its link to outer hip pain.
glute min · deep gluteGluteus minimus
The smallest and deepest glute: where the gluteus minimus is, how it steadies the hip, the exercises that reach it, and its part in outer hip pain.
deep hip rotator · deep glute musclePiriformis
Where the piriformis sits, how it relates to the sciatic nerve, what piriformis syndrome is (and why it is debated), and stretches for it.
TFL · IT band muscleTensor fasciae latae
The TFL and the IT band: where they are, what they do at the hip and knee, IT band syndrome, and what foam rolling can and cannot change.
Thighs
Adductors
The inner-thigh adductors: each muscle, what they do, why they strain, and the Copenhagen adduction exercise that cut groin problems in football.
tailor's muscleSartorius
The sartorius is the body's longest muscle, crossing the hip and knee. Where it runs, what it does, and the movements and stretches that use it.
quads · front thigh musclesQuadriceps
The four quadriceps muscles: what each does, the exercises used for patellar tendon pain, and why isolating the VMO is not needed for knee pain.
hamstring muscles · back of the thigh musclesHamstrings
The hamstrings: each muscle, what they do in walking and sprinting, why they strain, and what the Nordic curl and leg curl trials found.
Lower legs
Gastrocnemius
The gastrocnemius forms the bulge of the calf. What it does, why straight-knee calf raises build it, and its part in calf strains and Achilles pain.
deep calf muscle · lower calfSoleus
The soleus is the calf's endurance muscle under the gastrocnemius. What it does, what bent-knee calf raises really do, and its link to shin and Achilles pain.
shin muscle · tib anteriorTibialis anterior
The tibialis anterior lifts your foot with every step. Where it is, what it does, tibialis raises, and how it relates to shin splints and foot drop.
posterior tib · arch muscleTibialis posterior
The tibialis posterior holds up the inner arch. Where it runs, what it does in walking, the exercises that target it, and its role in adult flatfoot.
fibularis muscles · peroneal musclesPeroneals
The peroneals steady the ankle against rolling. Where they run, what they do, and the balance training that cut repeat ankle sprains in a trial.
back of the knee musclePopliteus
The popliteus is a small muscle behind the knee that unlocks a straight knee so it can bend. Where it is, what it does, and how it is injured.