What muscles do hanging knee raises work?

Hanging knee raises work the hip flexors, which lift the thighs, and the rectus abdominis and obliques, which curl and control the pelvis. In an EMG study of abdominal exercises, the hanging knee-up with straps was among the exercises with the highest rectus abdominis and internal oblique activity. The lats, forearms, and shoulders engage isometrically to maintain an active hang.

Why do I only feel hanging knee raises in my hips and not my abs?

If the knees rise but the pelvis stays still, the hip flexors are doing most of the visible work. To feel the abdominals more, curl your pelvis upward into posterior pelvic tilt at the top of the raise, bringing your belt line toward your ribs rather than just raising your knees to 90 degrees.

How do you stop swinging during hanging knee raises?

Maintain an active shoulder hang with depressed scapulae, avoid kicking from your ankles, and pause for a half-second at the bottom of every rep so the next raise starts from a still body.

Are hanging knee raises as effective as hanging leg raises?

They train the same muscles, but the bent knees shorten the lever, so the knee raise is easier and lets you practise the pelvic curl without swinging. The straight-leg version is harder rather than a different exercise. A practical benchmark before progressing is around 15 strict knee raises with a slow lower and no swing.

What should beginners do if grip strength gives out first?

Beginners can use a captain's chair tower where forearms rest on padded supports, or use hanging ab straps. These setups take grip out of the equation so the set ends when your trunk tires, and you can build hanging grip separately with short dead hangs.

Hanging Knee Raise: Form & Muscles Worked

How to Do It

Grip a pull-up bar overhand about shoulder width and hang with straight arms.

Pull the shoulder blades down slightly to set an active hang and stop any swing.

Curl the knees up toward the chest, then tuck the pelvis so the belt line moves toward the ribs.

Lower the legs over two to three seconds until the hips are straight.

Pause briefly at the bottom so the next rep starts from a still body.

Common Mistakes

Swinging or kipping to lift the knees.

Lifting the thighs without curling the pelvis.

Hanging passively with the shoulders shrugged to the ears.

Dropping the legs quickly on the way down.

Hang with active shoulders, curl the knees toward the ribs without swinging, and lower with control. Keep the range controlled, adjust the load when technique changes, and stop or seek qualified advice if an exercise causes persistent pain.

Pelvic Curl Mechanics, Active Hang, and Rectus Abdominis Function

The hanging knee raise is a foundational hanging core exercise for the hip flexors (iliopsoas) and the abdominal wall. The hip flexors lift the thighs, while the rectus abdominis and obliques curl the pelvis and stop the ribs flaring. If you only lift the knees and the pelvis stays still, the abs have less to do; curling the pelvis upward so your belt buckle moves toward your sternum is what makes the rep feel like an ab exercise.

To calibrate your hanging knee raise execution:

Active Shoulder Hang: Grasp the pull-up bar with an overhand grip slightly wider than shoulder-width. Rather than hanging passively with relaxed shoulders, engage your lats and depress your scapulae to create an “active hang” that keeps your body still and makes swinging less likely.
Knee Curl & Pelvic Tuck: Initiate the repetition by bending your knees and curling them up toward your chest. At the midpoint, deliberately tuck your tailbone and curl your pelvis upward, bringing your knees toward your armpits.
Controlled Descent & Dead-Stop Reset: Lower your legs under control over 2 to 3 seconds until your hips are fully extended. Pause for half a second at the bottom of each repetition to completely dissipate any swinging momentum before beginning the next repetition.

Programming & Volume Guidelines

A sensible starting point for hanging core strength and control:

Target Range: 3 to 4 sets of 10 to 15 reps with 1 to 2 repetitions in reserve (RIR).[1]
Tempo: 2 seconds concentric curl, 1-second squeeze at peak pelvic tuck, and 3 seconds eccentric lowering.
Frequency: 2 to 3 times per week, easily slotted into pull days, upper workouts, or core circuits.[1][2]
Progression: Start with knee raises in a captain’s chair station (supported forearms). Progress to free-hanging knee raises, then advance to hanging straight-leg raises or holding a light medicine ball/dumbbell between your feet.

Common Mistakes & Troubleshooting

Kipping & Body Swing: Swinging from the ankles lets momentum do much of the lifting, so the abs do less. Reset to a dead stop at the bottom of every rep.
Lifting Knees Without Pelvic Rotation: Lifting the thighs to 90 degrees while keeping the pelvis flat turns the rep into mostly hip flexor work. Focus on curling the pelvis upward toward your ribs.[1]
Passive Shoulder Sag: Sinking completely into the shoulders makes the body harder to keep still and can feel uncomfortable at the top of the arms. Keep your shoulder blades pulled down throughout the set.
Rushing the Lowering Phase: Letting the legs drop freely skips the lowering half of the rep and sets up a swing. Take two to three seconds to lower.[1]

References

See our exercise methodology for how this evidence is applied and its limits.

Frequently Asked Questions

What muscles do hanging knee raises work?: Hanging knee raises work the hip flexors, which lift the thighs, and the rectus abdominis and obliques, which curl and control the pelvis. In an EMG study of abdominal exercises, the hanging knee-up with straps was among the exercises with the highest rectus abdominis and internal oblique activity. The lats, forearms, and shoulders engage isometrically to maintain an active hang.
Why do I only feel hanging knee raises in my hips and not my abs?: If the knees rise but the pelvis stays still, the hip flexors are doing most of the visible work. To feel the abdominals more, curl your pelvis upward into posterior pelvic tilt at the top of the raise, bringing your belt line toward your ribs rather than just raising your knees to 90 degrees.
How do you stop swinging during hanging knee raises?: Maintain an active shoulder hang with depressed scapulae, avoid kicking from your ankles, and pause for a half-second at the bottom of every rep so the next raise starts from a still body.
Are hanging knee raises as effective as hanging leg raises?: They train the same muscles, but the bent knees shorten the lever, so the knee raise is easier and lets you practise the pelvic curl without swinging. The straight-leg version is harder rather than a different exercise. A practical benchmark before progressing is around 15 strict knee raises with a slow lower and no swing.
What should beginners do if grip strength gives out first?: Beginners can use a captain's chair tower where forearms rest on padded supports, or use hanging ab straps. These setups take grip out of the equation so the set ends when your trunk tires, and you can build hanging grip separately with short dead hangs.