Machine Single-Leg Hip Thrust
What Is the Machine Single-Leg Hip Thrust?
Machine Single-Leg Hip Thrust is a compound exercise that primarily targets the glutes and also engages the hamstrings, the adductor magnus and the hip stabilizers that keep the pelvis level. It is an intermediate-level movement performed on a dedicated hip thrust machine: the upper back rests against a low angled pad, a padded roller sits across the hip crease and is pulled upward against a cable and weight stack, and one foot drives against a fixed platform while the other leg is held in the air.
What the machine contributes is a load that only travels up and down. There is no bar to roll into the hip crease, nothing balanced over a single planted foot, and no free weight that can shift sideways when the working hip starts to tire. Your hands hold the frame for position rather than pinning a weight in place, so the only job left is extending one hip. Loading and unloading is the other half of it: you change the setting, swap legs and start again in a few seconds, which matters more than it sounds on an exercise that has to be done twice every time it appears.
The gluteus maximus does the extending, and the gluteus medius and minimus on the working side spend the whole set keeping the pelvis from dropping or twisting toward the free leg. How much the hamstrings take depends on where the foot sits on the platform. In 21 elite female handball players lifting with a barbell and a bench, hip thrusts finished with a more open knee angle produced higher peak hamstring activation than the same lift with the knee bent to around 90 degrees, 69% of maximum against 50%, and their single-leg hip thrusts, done at that same 90-degree position with half the load, still reached 67%. Planting the foot farther from your hips opens the knee the same way, so bring it back in until the shin finishes close to vertical when you want the glute in charge.
It suits lifters who can already hold the pelvis level through a set of unloaded single-leg reps and want each hip loaded on its own, so a stronger side cannot quietly cover for a weaker one. Above what a dumbbell can be held on the hips, this is the simplest way to keep adding weight to a single-leg thrust, and it asks for none of the bar handling that comes with Barbell Single-Leg Hip Thrust. If holding the pelvis level on one leg is still the hard part, build it first with Glute Bridge, Bodyweight Hip Thrust and Bodyweight Single-Leg Hip Thrust.
In a session it belongs after the main squat or hinge, as accessory glute work for 2 to 4 sets of 8 to 12 reps per side, and it has no competition or testing role. The one thing the machine takes away is fine control of the load. A stack built for two-leg thrusting often steps up in jumps that are too big for one leg, and the back pad is a fixed height rather than a bench you can choose. When the lightest useful setting is still more than one hip can hold level, Dumbbell Single-Leg Hip Thrust fills the gap underneath it, and the same machine with both feet on the platform, Barbell Hip Thrust or Smith Machine Hip Thrust carry the heavier two-leg work above it.
Muscles Worked
- Gluteus Maximus
- Primary
- Biceps Femoris
- High
- Gluteus Medius
- High
- Adductor Magnus
- Medium
- Gluteus Minimus
- Medium
- Semimembranosus
- Medium
- Semitendinosus
- Medium
Instructions
- Set the machine's load lighter than you would use for a two-leg thrust, since one leg has to move all of it.
- Sit on the machine's base with your upper back against the angled back pad, so its top edge crosses you just below the shoulder blades.
- Pull the padded roller down across your hip crease, over the fold where the hips bend, rather than onto your stomach or out on your thighs.
- Plant the working foot flat on the platform roughly in line with that hip, with the heel set so the shin will finish close to vertical at the top.
- Lift the other leg clear of the platform with the hip and knee bent, and hold it there for the whole set.
- Hold the handles beside your hips, tuck your chin and brace your abs so the ribs stay down.
- Drive through the heel and midfoot of the planted foot and extend the hip until your torso and working thigh form a straight line.
- Pause at the top with the pad level across both hips and squeeze the glute, without arching your lower back to push higher.
- Lower under control and stop just short of letting the weights settle back down, then start the next rep.
- After the last rep, put the free foot back on the platform, let the weights down and lift the pad clear before switching sides.
Common Mistakes
Pad parked on the stomach
Pulling the hip pad onto the abdomen or the bony ridge of the pelvis instead of the soft hip crease, which hurts, breaks the brace and moves the load away from the joint it is meant to load.
Letting the pad tilt toward the free leg
Allowing the unsupported side of the pelvis to drop or rotate so one end of the pad finishes lower, which shortens the working glute's range and passes the last of the rep to the lower back.
Foot planted too far down the platform
Setting the working foot well away from the hips leaves the knee open at lockout, which hands the extension to the hamstring and is the usual reason a set ends in a cramp.
Finishing with the lower back
Flaring the ribs and arching the lumbar spine to push the hips higher once the glute has run out, instead of stopping where the torso and working thigh form a straight line.
Resting the weights between reps
Lowering until the weights settle back down and bouncing the next rep off them, which drops the tension the glute was holding at the bottom of the range.
Loading it like a two-leg set
Taking the same weight jumps you would take with both feet on the platform because the machine makes loading so easy, which buries the side-to-side gap this exercise was chosen to expose.
Injuries
Machine Single-Leg Hip Thrust is a low risk exercise when performed with proper technique. The load runs on a fixed path, the torso is supported against the pad for the whole rep, and a set that fails simply ends with the weights back down, so none of the bar handling that comes with the free-weight versions applies here.
The lower back is the usual complaint. When the working glute runs out before the hips are level, it is easy to arch the lumbar spine to buy the last few degrees of height, which turns a glute exercise into a low-back exercise. Cramping in the hamstring of the working leg is the second one, and it almost always traces back to a foot planted too far from the hips, which leaves the knee open at the top and the hamstring finishing the rep. The hip pad itself sits on the pelvis, so a pad dragged up onto the abdomen or parked on the bony ridge of the hips can bruise and makes bracing harder, and pinching at the front of the hip at the bottom usually means the hips are being pulled deeper than that hip comfortably flexes.
Most of that is settled before the first rep. Seat the pad in the soft hip crease, brace the abs so the ribs stay stacked over the pelvis, and treat a straight line from shoulder to knee as the end of the rep rather than a checkpoint on the way higher. If the hamstring starts to cramp, walk the heel an inch or two closer and slow the tempo to around two seconds up and two seconds down. Watch the pad rather than the weights: on one leg the free side of the pelvis can rotate or drop without anything else giving it away, and when one end of the pad finishes lower than the other the set is over. The machine's own trap is that loading it is effortless, so a stack built for two-leg thrusting can step up in jumps far too big for a single hip; move up one step at a time and keep the free leg still instead of swinging it to cover the difference.
If the pelvis still tips on one leg, build up with Glute Bridge, Bodyweight Hip Thrust and Bodyweight Single-Leg Hip Thrust first, and use Dumbbell Single-Leg Hip Thrust when the machine's lightest useful setting is more than one hip can control. Stop the set for sharp pain in the lower back, the front of the hip or the groin, for a pelvis that rotates toward the free leg and will not level, and for any pain that does not settle when you change the foot position.
Frequently Asked Questions
- Q: How is this different from doing it with a barbell?
The load runs on a fixed path and stays attached to the machine, so nothing has to be rolled into the hip crease, balanced over one planted foot, or unloaded before you can get out. That is most of the reason to pick it over Barbell Single-Leg Hip Thrust: the same hip extension work with far less to manage, and seconds rather than a minute between sides.
- Q: Where should my foot go on the platform?
In line with the working hip, with the heel set so the shin finishes close to vertical at the top of the rep. A foot planted farther away leaves the knee open and shifts work toward the hamstrings, while one tucked in under the hips pushes it toward the quadriceps.
- Q: The lightest setting is still too heavy for one leg. What now?
Check whether your machine has add-on weights or a half-step selector, since many stacks do. If it does not, drop back to Dumbbell Single-Leg Hip Thrust or Bodyweight Single-Leg Hip Thrust until the first step on the machine is a weight you can hold the pelvis level against.
- Q: What should the free leg be doing?
Hold it in the air with the hip and knee bent for the whole set, as shown here. Swinging it up as the hips rise adds momentum the working glute does not have to produce, and letting the foot rest back on the platform quietly turns the set into a two-leg one.
- Q: How many sets and reps should I do per side?
Two to four sets of 8 to 12 reps per leg fits most glute programs. Start each set with the weaker side and match its rep count on the stronger side, so the gap closes instead of widening.
- Q: Do I still need two-leg hip thrusts?
Yes, if you want to keep building absolute hip extension strength, because two legs will always move more weight than one. Many lifters run a two-leg thrust as the main glute lift and use this one afterwards to make sure each hip earns its own reps.