Glutes

#Function

Gluteus maximus is the largest of the three and does four things: hip extension (driving the hips forward), hip external rotation (rotating the thigh outward), hip abduction (upper fibres, moving the thigh away from the midline), and it assists a posterior pelvic tilt.

Gluteus medius and minimus sit underneath and beside maximus and work primarily as hip abductors and dynamic stabilisers — most active when a joint needs controlling under unilateral or unstable load, not in bilateral, stable lifts.

#Origin and insertion

All three originate broadly across the ilium (plus sacrum and coccyx for maximus). Maximus inserts at the iliotibial tract and the gluteal tuberosity of the femur; medius and minimus insert at the greater trochanter.

#Why the hip thrust and the squat are complements, not alternatives

A squat loads glutes hardest in the bottom, lengthened position — where hip flexion is greatest — and the load falls off as the hip extends toward lockout, because the resistance profile of a squat is heaviest near parallel and lightest at the top.

A hip thrust does close to the opposite: the resistance is heaviest near lockout, at the top of hip extension, where the glutes are shortest and the moment arm from a horizontal bar is largest.

This is the same logic as the quad and hamstring lessons: two exercises training the "same" muscle at genuinely different points on its length-tension curve. A program with only squats is under-training peak-contraction glute force; a program with only hip thrusts is under-training glutes at length. Run both.

#Gluteus medius specifically

Medius is most effectively trained by exercises demanding real single-leg stability — walking lunges, Bulgarian split squats, single-leg RDLs — or by direct hip abduction work (cable or machine). Bilateral, stable exercises like a barbell squat train it only as an incidental stabiliser, not as a prime mover.

#Exercise selection

Source tier: the resistance-profile analysis of squat versus hip thrust is well-established biomechanics (moment-arm geometry is directly measurable, not inferred). The stability-demand basis for medius training follows standard exercise physiology.