Bent Leg Kickback
What Is the Bent Leg Kickback?
Bent Leg Kickback is an isolation exercise that primarily targets the glutes and also engages the hamstrings, the smaller gluteal muscles and the core. It is a beginner-level movement performed on all fours with body weight alone, and it can be loaded with ankle weights or a resistance band once the bodyweight version gets easy.
Keeping the knee bent at about 90 degrees is what sets it apart from the Straight Leg Kickback. The hamstrings cross both the hip and the knee, so bending the knee shortens them and they contribute less to hip extension, leaving a larger share of the work to the gluteus maximus. A dynamometer study of maximal hip extension efforts found the gluteus maximus share of hip extension torque, relative to the hamstrings, was highest with the hip straight and the knee bent to 90 degrees, which is close to the top position of this kickback. The bent knee also shortens the lever, so the leg feels lighter and is easier to control than a straight one.
Because it needs no equipment and little space, it is a common choice for home workouts, for glute activation in a warm-up before heavier leg exercises like squats or deadlifts, and for higher-rep accessory work at the end of a lower-body session. A fine-wire EMG study of common hip exercises in healthy adults found that quadruped hip extension with the knee bent worked both the gluteus medius and the upper gluteus maximus significantly harder than the tensor fasciae latae at the front of the hip, which is why clinicians use it when the goal is to train the glutes specifically.
It suits beginners, people returning to training who need a low-load way to practice hip extension, and lifters who want extra glute volume without loading the spine. Body weight is a light load for a trained lifter, so once 20 controlled reps per side feel easy, add ankle weights or a band, or build heavier hip extension work with the Cable Donkey Kickback, the Glute Bridge and the Barbell Hip Thrust.
Muscles Worked
- Gluteus Maximus
- Primary
- Gluteus Medius
- High
- Biceps Femoris
- Medium
- Erector Spinae
- Minimal
- External Oblique
- Minimal
- Rectus Abdominis
- Minimal
Instructions
- Start on all fours with your hands directly under your shoulders and knees under your hips.
- Keep your back flat, core engaged, and neck neutral.
- Keeping the knee bent at about 90 degrees, lift one knee off the floor.
- Press the sole of that foot toward the ceiling by squeezing your glute until your thigh is roughly in line with your torso.
- Pause and squeeze your glute at the top of the movement without arching your back or turning your hips toward the working side.
- Lower your leg back down with control, stopping just before your knee touches the ground.
- Complete all reps on one side before switching to the other leg.
Common Mistakes
Overarching the lower back
Arching the back shifts tension away from the glutes and can cause back strain.
Kicking too high
Lifting the knee past the point where the thigh lines up with the torso adds movement at the lower back, not more glute work.
Letting the hips rotate
Turning the working hip up toward the ceiling lets the lower back and other hip muscles take over from the glute.
Not keeping the knee bent
Straightening the leg reduces glute isolation and brings the hamstrings more into play.
Swinging the leg
Kicking with momentum and dropping the knee quickly takes tension off the glute, especially on the way down.
Injuries
Bent Leg Kickback is a low risk exercise when performed with proper technique. It uses light loads and keeps the body supported on both hands and one knee, so problems usually come from position and range rather than from the weight.
The most common strain point is the lower back. When the knee is pushed higher than the hip can extend, the extra height comes from the lumbar spine arching and the pelvis tipping forward, which shifts stress onto the lower back instead of the glute. Stop the lift when the thigh is roughly in line with the torso, keep the abs braced and keep the hips square to the floor.
Kneeling on a hard floor can irritate the supporting knee, and the hands-down position loads the wrists. A mat or folded towel under the knees helps, and anyone with wrist discomfort can set up on the forearms instead. If the lower back still arches, shorten the range or start with the Glute Bridge, and add ankle weights or a band only once every rep stays controlled with a flat back.
Stop the set if you feel pinching or pain in the lower back, the front of the hip or the kneeling knee rather than effort in the glute, and have it checked if it persists.
- Primary Focus
- Glutes
- Equipment
- Body weight
- Modality
- Strength
- Difficulty
- Beginner
Alternative Exercises
Other Names for the Bent Leg Kickback
The Bent Leg Kickback is also known as:
- Donkey Kick
- Donkey Kickback
Frequently Asked Questions
- Q: Can I add resistance to this exercise?
Yes, ankle weights or resistance bands can make the exercise more challenging.
- Q: How many reps should I do per side?
Two to three sets of 12 to 20 controlled reps per leg suit most people, since body weight is a light load. Once 20 clean reps feel easy, add ankle weights or a band rather than more reps.
- Q: Should I do bent leg or straight leg kickbacks?
Both train the glutes through hip extension. The bent-knee version keeps more of the work on the glutes because the hamstrings are shortened, and its shorter lever makes it easier to control, while the Straight Leg Kickback gives the hamstrings a bigger role and feels heavier at the same height.
- Q: Can kickbacks alone grow your glutes?
Not for most people on their own. Body weight is a light load, so bodyweight kickbacks work best as activation or extra volume alongside heavier hip extension work such as the Barbell Hip Thrust or Barbell Romanian Deadlift.
- Q: Is this exercise good for beginners?
Yes, it's easy to learn and doesn’t require any equipment to get started.